1
|
Newman TM, Wilson AS, Clear KYJ, Tallant EA, Gallagher PE, Cook KL. Probiotic and Muscadine Grape Extract Interventions Shift the Gut Microbiome and Improve Metabolic Parameters in Female C57BL/6 Mice. Cells 2023; 12:2599. [PMID: 37998334 PMCID: PMC10670540 DOI: 10.3390/cells12222599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/19/2023] [Accepted: 10/27/2023] [Indexed: 11/25/2023] Open
Abstract
Obesity and Western-like diet consumption leads to gut microbiome dysbiosis, which is associated with the development of cardio-metabolic diseases and poor health outcomes. The objective of this study was to reduce Western diet-mediated gut microbial dysbiosis, metabolic dysfunction, and systemic inflammation through the administration of a novel combined intervention strategy (oral probiotic bacteria supplements and muscadine grape extract (MGE)). To do so, adult female C57BL/6 mice were fed a low-fat control or Western-style diet and sub-grouped into diet alone, probiotic intervention, antibiotic treatments, MGE supplementation, a combination of MGE and probiotics, or MGE and antibiotics for 13 weeks. Mouse body weight, visceral adipose tissue (VAT), liver, and mammary glands (MG) were weighed at the end of the study. Fecal 16S rRNA sequencing was performed to determine gut bacterial microbiome populations. Collagen, macrophage, and monocyte chemoattractant protein-1 (MCP-1) in the VAT and MG tissue were examined by immunohistochemistry. Adipocyte diameter was measured in VAT. Immunohistochemistry of intestinal segments was used to examine villi length, muscularis thickness, and goblet cell numbers. We show that dietary interventions in Western diet-fed mice modulated % body weight gain, visceral adiposity, MG weight, gut microbial populations, and inflammation. Intervention strategies in both diets effectively reduced VAT and MG fibrosis, VAT and MG macrophages, adipocyte diameter, and VAT and MG MCP-1. Interventions also improved intestinal health parameters. In conclusion, dietary intervention with MGE and probiotics modulates several microbial, inflammatory, and metabolic factors reducing poor health outcomes associated with Western diet intake.
Collapse
Affiliation(s)
- Tiffany M. Newman
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA;
- Department of Surgery-Hypertension, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; (A.S.W.); (K.Y.J.C.); (E.A.T.); (P.E.G.)
| | - Adam S. Wilson
- Department of Surgery-Hypertension, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; (A.S.W.); (K.Y.J.C.); (E.A.T.); (P.E.G.)
| | - Kenysha Y. J. Clear
- Department of Surgery-Hypertension, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; (A.S.W.); (K.Y.J.C.); (E.A.T.); (P.E.G.)
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - E. Ann Tallant
- Department of Surgery-Hypertension, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; (A.S.W.); (K.Y.J.C.); (E.A.T.); (P.E.G.)
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Patricia E. Gallagher
- Department of Surgery-Hypertension, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; (A.S.W.); (K.Y.J.C.); (E.A.T.); (P.E.G.)
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Katherine L. Cook
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA;
- Department of Surgery-Hypertension, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; (A.S.W.); (K.Y.J.C.); (E.A.T.); (P.E.G.)
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| |
Collapse
|
2
|
Klepin HD, Tooze JA, Bitting RL, Davis B, Pleasant K, Melo AC, Cook K, Soto-Pantoja DR, Tallant EA, Gallagher PE. Study design and methods for the pilot study of muscadine grape extract supplement to improve fatigue among older adult cancer survivors (FOCUS) trial. J Geriatr Oncol 2023; 14:101478. [PMID: 36990930 PMCID: PMC10164712 DOI: 10.1016/j.jgo.2023.101478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 03/07/2023] [Accepted: 03/10/2023] [Indexed: 03/29/2023]
Abstract
INTRODUCTION Fatigue is a prevalent symptom among both cancer survivors and older adults. Negative consequences of fatigue include increased sedentary behavior, decreased physical activity and function, and lower quality of life. Few pharmacologic interventions improve fatigue. Our preclinical and clinical data show promising effects of a muscadine grape extract supplement (MGES) on oxidative stress, mitochondrial bioenergetics, the microbiome, and the symptom of fatigue. This pilot study seeks to translate these observations to cancer survivorship by testing the preliminary effect of MGE supplementation on older adult cancer survivors with self-reported fatigue. MATERIALS AND METHODS We designed a double-blinded placebo-controlled pilot study to evaluate preliminary efficacy of MGE supplementation versus placebo on fatigue among older adult cancer survivors (aged ≥65 years) who report baseline fatigue. Sixty-four participants will be enrolled and randomized 1:1 to twice daily MGES (four tablets twice daily) versus placebo for 12 weeks. The primary outcome is change in Patient-Reported Outcomes Measurement Information System (PROMIS) Fatigue score from baseline to 12 weeks. Secondary outcomes are change in self-reported physical function, physical fitness (6-min walk test), self-reported physical activity, global quality of life (QOL), and the Fried frailty index. Correlative biomarker assays will assess changes in 8-hydroxy-2 deoxyguanosine, peripheral blood mitochondrial function, inflammatory markers, and the gut microbiome. DISCUSSION This pilot study builds on preclinical and clinical observations to estimate effects of MGE supplementation on fatigue, physical function, QOL, and biologic correlates in older adult cancer survivors. Trial registration #: CT.govNCT04495751; IND 152908.
Collapse
Affiliation(s)
- Heidi D Klepin
- Section on Hematology and Oncology, Wake Forest University School of Medicine, Winston Salem, NC, United States of America.
| | - Janet A Tooze
- Division of Public Health Sciences, Wake Forest University School of Medicine, Winston Salem, NC, United States of America
| | - Rhonda L Bitting
- Division of Medical Oncology, Duke University, Durham, NC, United States of America
| | - Brittany Davis
- Department of Surgery/Hypertension, Wake Forest University School of Medicine, Winston Salem, NC, United States of America
| | - Katherine Pleasant
- Department of Surgery/Hypertension, Wake Forest University School of Medicine, Winston Salem, NC, United States of America
| | - Ana Clara Melo
- Department of Surgery/Hypertension, Wake Forest University School of Medicine, Winston Salem, NC, United States of America
| | - Katherine Cook
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC, United States of America
| | - David R Soto-Pantoja
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC, United States of America
| | - E Ann Tallant
- Department of Surgery/Hypertension, Wake Forest University School of Medicine, Winston Salem, NC, United States of America
| | - Patricia E Gallagher
- Department of Surgery/Hypertension, Wake Forest University School of Medicine, Winston Salem, NC, United States of America
| |
Collapse
|
3
|
Patil PD, Melo AC, Westwood BM, Tallant EA, Gallagher PE. A Polyphenol-Rich Extract from Muscadine Grapes Prevents Hypertension-Induced Diastolic Dysfunction and Oxidative Stress. Antioxidants (Basel) 2022; 11:antiox11102026. [PMID: 36290749 PMCID: PMC9598776 DOI: 10.3390/antiox11102026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/06/2022] [Accepted: 10/11/2022] [Indexed: 11/30/2022] Open
Abstract
Muscadine grapes are abundant in dietary polyphenols, but their effect on hypertension-induced cardiac damage is limited. This study assessed whether a muscadine grape skin/seed extract supplement (MGES) prevents hypertension-induced cardiac damage and oxidative stress. Male Sprague Dawley rats were treated for four weeks with drinking water, angiotensin II (Ang II) to induce hypertension, MGES, or both Ang II and MGES. Cardiac function assessed by echocardiography showed that Ang II increased systolic blood pressure while MGES alone or in combination with Ang II had no effect. Ang II increased E/e′, an indicator of left ventricular filling pressure and diastolic dysfunction, by 41% compared to Control and co-treatment with MGES prevented the Ang II-mediated increase, suggesting that the extract attenuated hypertension-induced diastolic function. Ang II infusion increased urinary 8-hydroxy-2′-deoxyguanosine and cardiac 4-hydroxynonenal and malondialdehyde, which were prevented by the extract. The antioxidant enzymes catalase and superoxide dismutase 1 activity and mRNA were increased significantly in animals treated with MGES alone or in combination with Ang II, suggesting that the extract upregulates oxidative stress defense mechanisms in cardiac tissue. Thus, MGES may serve as a medical food to protect the heart from hypertension-induced diastolic dysfunction caused in part by excessive reactive oxygen species production.
Collapse
|
4
|
Rahimi O, Melo AC, Westwood B, Grier RDM, Tallant EA, Gallagher PE. Angiotensin-(1-7) reduces doxorubicin-induced aortic arch dysfunction in male and female juvenile Sprague Dawley rats through pleiotropic mechanisms. Peptides 2022; 152:170784. [PMID: 35288251 DOI: 10.1016/j.peptides.2022.170784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/28/2022]
Abstract
Doxorubicin (Dox), an effective chemotherapeutic, can cause cumulative dose-dependent cardiovascular toxicity, which may manifest as vascular dysfunction leading to long-term end-organ damage. Currently, there are no effective treatments to mitigate Dox-induced vascular damage in cancer patients, particularly pediatric patients. We showed that angiotensin-(1-7) [Ang-(1-7)], an endogenous peptide hormone, mitigated cardiac damage in Dox-treated juvenile rats. In this study assessing aortic stiffness, juvenile male and female rats were administered a clinically equivalent dose of Dox (21-24 mg/kg) over 6 weeks, in the presence and absence of Ang-(1-7) [24 µg/kg/h]. Aortic function was measured using echocardiography. Ang-(1-7) reduced the Dox-mediated increase in pulse wave velocity, a measure of arterial stiffness (males: p < 0.05; females: p < 0.001) as compared in control animals. Dox decreased aortic lumen diameter (p < 0.0001) and increased wall thickness (p < 0.01) in males, which was attenuated by Ang-(1-7). In male but not female aortic arches, Dox increased media hypertrophy (p < 0.05) and reduced elastin content (p < 0.001), which were prevented by Ang-(1-7). Conversely, Dox increased fibrosis (p < 0.0001) in juvenile female rats, which was reduced by Ang-(1-7). Adjunct Ang-(1-7) prevented the Dox-induced increase in total cell and nuclear pERK1/2 in the aortic intima and media of male rats and nuclear pSMAD2 in the intimal and medial regions of the aortic arches of both sexes. These results demonstrate that Ang-(1-7) attenuated Dox-induced aortic dysfunction in both sexes of juvenile rats, albeit through different mechanisms, suggesting that Ang-(1-7) may serve as an effective adjuvant to ameliorate cardiovascular and long-term end-organ damage in pediatric patients produced by anthracyclines.
Collapse
Affiliation(s)
- Omeed Rahimi
- Surgery/Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Ana Clara Melo
- Surgery/Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Brian Westwood
- Surgery/Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Rui D M Grier
- Surgery/Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - E Ann Tallant
- Surgery/Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Patricia E Gallagher
- Surgery/Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA.
| |
Collapse
|
5
|
Abstract
Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that tends to affect young women and has a high propensity to metastasize. No targeted treatments are available for this type of breast cancer due to a lack of estrogen or progesterone receptors or overexpression of human epidermal growth factor receptor type 2 overexpression. Currently, patients have no therapeutic options once standard of care is complete, indicating a need for safe and effective therapies to slow or prevent the progression of TNBC to metastatic disease. Studies showed that isolated polyphenols or polyphenol-rich muscadine grape extracts polyphenols inhibit the proliferation of various cancer cells including breast cancer. A proprietary muscadine grape extract (MGE) was administered to nude mice with human MDA-MB-231 TNBC atumors for 4 weeks to determine the effect of the extract on tumor growth. MGE decreased tumor volume in association with a reduction in the proliferative markers Ki67 and cyclin D1. To determine the molecular mechanisms for the MGE-induced reduction in tumor growth, mouse 4T1, MDA-MB-231, or human BT-549 TNBC cells were treated with MGE, and various signaling pathways were investigated. MGE reduced c-Met, differentially abrogated ERK/MAPK and AKT signaling, and decreased a downstream targets of ERK/MAPK and AKT pathways, cyclin D1. Cyclin D1 reduction was associated with retinoblastoma activation and cell cycle arrest in MDA-MB-231 TNBC cells. MGE-regulated molecular signaling pathways were functionally associated with a dose-dependent reduction in cell proliferation. The pluripotency of MGE and high index of safety and tolerability suggest that the extract may serve as a therapeutic to reduce TNBC progression to metastatic disease.
Collapse
Affiliation(s)
| | | | - E Ann Tallant
- Wake Forest School of Medicine, Winston-Salem, NC, USA
| |
Collapse
|
6
|
Bitting RL, Tooze JA, Isom S, Petty WJ, Grant SC, Desnoyers RJ, Thomas A, Thomas CY, Alistar AT, Golden SL, Pleasant K, Chappell MC, Tallant EA, Gallagher PE, Klepin HD. Phase I Study of Muscadine Grape Extract for Patients With Advanced Cancer. Am J Clin Oncol 2021; 44:239-246. [PMID: 33867481 PMCID: PMC8141001 DOI: 10.1097/coc.0000000000000814] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Preclinical studies with muscadine grape extract (MGE) show antitumor activity and decreased systemic inflammation. This phase I study (NCT02583269) assessed safety and tolerability of a proprietary MGE preparation in patients with advanced solid tumors. METHODS Patients with metastatic or unresectable cancers who were progressing on standard therapies were assigned to MGE in a standard 3+3 design. Five dose levels were tested (320 to 1600 mg total phenolics/d). Safety and maximum-tolerated dose were assessed after 4 weeks. Patients were evaluated for response at 8 weeks and continued on MGE if clinically stable. Secondary outcomes were response, survival, adherence, fatigue, and quality of life (QOL). RESULTS In total, 23 patients (lung, n=7; gastrointestinal, n=7; genitourinary, n=6; other, n=3) received MGE capsules by mouth twice daily. The cohort [median age 72 years, 48% Eastern Cooperative Oncology Group (ECOG) 2] was heavily pretreated. After 4 weeks on MGE, possibly attributable adverse events grade 2 or higher were fatigue (n=1), decreased lymphocyte count (n=1), and constipation (n=2), including 1 dose-limiting toxicity for grade 3 constipation. Maximum-tolerated dose was not reached. No partial responses were observed. Median time on therapy was 8 weeks, with 29% of patients treated beyond 16 weeks and a median overall survival of 7.2 months. QOL and fatigue levels were stable from baseline to 8 weeks. Higher MGE dose was correlated with improvement in self-reported physical well-being QOL at 8 weeks (r=0.6; P=0.04). CONCLUSIONS MGE is safe and well-tolerated in heavily pretreated and older cancer patients. The potential anticancer properties and the effects of MGE on physical well-being and QOL metrics will be evaluated in future studies.
Collapse
Affiliation(s)
- Rhonda L. Bitting
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| | - Janet A. Tooze
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Biostatistics and Data Science, Wake Forest University, Winston-Salem NC
| | - Scott Isom
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Biostatistics and Data Science, Wake Forest University, Winston-Salem NC
| | - W. Jeffrey Petty
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| | - Stefan C. Grant
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| | - Rodwige J. Desnoyers
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| | - Alexandra Thomas
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| | - Christopher Y. Thomas
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| | - Angela T. Alistar
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| | | | | | | | - E. Ann Tallant
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Surgery/Hypertension, Wake Forest University, Winston-Salem NC
| | - Patricia E. Gallagher
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Surgery/Hypertension, Wake Forest University, Winston-Salem NC
| | - Heidi D. Klepin
- Comprehensive Cancer Center of Wake Forest University, Winston-Salem NC
- Departments of Internal Medicine, Wake Forest University, Winston-Salem NC
| |
Collapse
|
7
|
Cruz Diaz N, Duncan AV, Graham W, Westwood B, Gallagher PE, Tallant EA, Chappell MC, Yamaleyeva LM, Diz DI. Abstract P053: Enhanced Exercise Capacity By Muscadine Grape Extract Treatment Is Only Evident In Older Hypertensive Female Rats And Is Independent Of Blood Pressure. Hypertension 2020. [DOI: 10.1161/hyp.76.suppl_1.p053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Physical performance and systolic blood pressure (SBP) during aging in normotensive female Sprague-Dawley (SD) and hypertensive (mRen2)27 transgenic rats were assessed following long-term treatment with a Muscadine Grape Extract (MGE, Piedmont Research and Development Corp). MGE was administered at a dose of 0.2 mg/mL in the drinking water starting at 14 weeks (wks) of age with an endpoint at 70 wks of age (total time of treatment of 56 wks). At 20-, 40- and 70-wks of age, physical performance (exercise capacity in seconds and workload in grams - meters) was determined using a treadmill at a velocity of 17 cm/second with a 5% incline. SBP was determined by tail-cuff plethysmography in trained rats. There were no significant differences in physical performance between SD and (mRen2)27 female rats at any age despite the higher SBP in the (mRen2)27 rats at all ages. Long-term treatment with MGE had no significant effect on physical performance or SBP in SD rats at any age. In contrast, MGE treatment markedly increased exercise capacity (40 wks: 1615 ± 166 vs 4943 ± 442 seconds, p<0.01, n = 4-9; 70 wks: 2520 ± 374 vs 4117 ± 245 seconds, p<0.01, n = 4-8) and workload (40 wks: 4579 ± 490 vs 14730 ± 1353 grams - meters, p<0.01, n = 4-9; 70 wks: 8338 ± 1340 vs 13659 ± 933 grams - meters, p<0.01, n = 4-8) at the later ages in female (mRen2)27 rats, while there was no effect on SBP (20 wks: 167 ± 4 vs 173 ± 4 mm Hg, n = 4-6; 40 wks: 177 ± 8 vs 170 ± 7 mm Hg, n = 6-7; 70 wks:154 ± 6 vs 172 ± 6 mm Hg, n = 5) at any age. These data suggest that MGE treatment is effective in improving physical performance only in hypertensive female rats and may be independent of changes in blood pressure. The benefit of MGE in the older hypertensive female may reflect reductions in vascular stiffness and oxidative stress. Support: Chronic Disease Research Fund, Hypertension & Vascular Research Center
Collapse
|
8
|
Ryalat F, Cruz-Diaz N, Graham W, Gwathmey-Williams T, Gallagher PE, Tallant EA, Yamaleyeva LM, Diz DI. Abstract P045: Sex And Age Specific Circulating Aldosterone Changes In Transgenic Hypertensive (mRen2)27 Rats And Hannover Sprague Dawley (SD) Rats And Its Association With Blood Pressure And Cardiac Function. Hypertension 2020. [DOI: 10.1161/hyp.76.suppl_1.p045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aldosterone plays a significant role in hypertension and target organ damage. Aldosterone antagonists are used in the management of heart failure. However, neither the influence of age nor sex on aldosterone pathophysiology is well understood. We investigated the changes in circulating aldosterone with age and its association with cardiovascular function, using male and female hypertensive renin transgenic (mRen2)27 rats and SD rats at 20 and 50 weeks of age. Both male (22 ± 3 vs. 12 ± 2 ng/dL, n = 9 - 12, p < 0.05) and female (59 ± 10 vs. 23 ± 8 ng/dL, n = 6 - 10, p < 0.05) hypertensive rats had higher serum aldosterone compared with SD rats at 20 weeks of age. At 50 weeks of age, the difference persisted in the hypertensive female rats (63 ± 8 vs. SD: 33 ± 7 ng/dL, n = 6 - 7, p < 0.05), but not in the males. SD male rats have higher systolic blood pressure (SBP) as they age, and consequently develop cardiac diastolic dysfunction associated with higher aldosterone at 50 weeks compared to 20 weeks (28 ± 3 vs. 12 ± 2 ng/dL, n = 7 - 9, p < 0.05). This aging effect on aldosterone was not significant in the other groups. We showed previously that SD males treated with polyphenol rich muscadine grape extract (MGE) have lower aldosterone, less aortic stiffness and better cardiac diastolic function (E/e’) than controls at the older age; the MGE effect was not seen in (mRen2)27 males. Sex differences in aldosterone were not significant in the SD rats at either time point. However, (mRen2)27 female rats had higher aldosterone than (mRen2)27 males at both 20 weeks (59 ± 10 vs. 22 ± 3 ng/dL, n = 10 - 12, p < 0.05) and 50 weeks (63 ± 8 vs. 31 ± 7 ng/dL, n = 6 - 7, p < 0.05), despite the lack of significant differences in SBP. (mRen2)27 female rats preserve cardiac function better than males throughout their life span, while males develop indices of heart failure. Our data suggest that lower aldosterone levels in hypertensive males compared with females do not protect against the higher lifetime burden of elevated SBP and also may reflect different mechanisms controlling circulating aldosterone between sexes. In addition, data suggest a potential therapeutic effect of MGE in the management of age-associated moderate hypertension.
Collapse
Affiliation(s)
| | | | - W Graham
- Wake Forest Univ, Winston Salem, NC
| | | | | | | | | | - D I Diz
- Wake Forest Univ, Winston Salem, NC
| |
Collapse
|
9
|
Rahimi O, Kirby J, Varagic J, Westwood B, Tallant EA, Gallagher PE. Angiotensin-(1–7) reduces doxorubicin-induced cardiac dysfunction in male and female Sprague-Dawley rats through antioxidant mechanisms. Am J Physiol Heart Circ Physiol 2020; 318:H883-H894. [DOI: 10.1152/ajpheart.00224.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Doxorubicin (Dox) is an effective chemotherapeutic for a variety of pediatric malignancies. Unfortunately, Dox administration often results in a cumulative dose-dependent cardiotoxicity that manifests with marked oxidative stress, leading to heart failure. Adjunct therapies are needed to mitigate Dox cardiotoxicity and enhance quality of life in pediatric patients with cancer. Angiotensin-(1–7) [Ang-(1–7)] is an endogenous hormone with cardioprotective properties. This study investigated whether adjunct Ang-(1–7) attenuates cardiotoxicity resulting from exposure to Dox in male and female juvenile rats. Dox significantly reduced body mass, and the addition of Ang-(1–7) had no effect. However, adjunct Ang-(1–7) prevented Dox-mediated diastolic dysfunction, including markers of decreased passive filling as measured by reduced early diastole mitral valve flow velocity peak ( E) ( P < 0.05) and early diastole mitral valve annulus peak velocity ( e′; P < 0.001) and increased E/e′ ( P < 0.001), an echocardiographic measure of diastolic dysfunction. Since Dox treatment increases reactive oxygen species (ROS), the effect of Ang-(1–7) on oxidative by-products and enzymes that generate or reduce ROS was investigated. In hearts of male and female juvenile rats, Dox increased NADPH oxidase 4 ( P < 0.05), a major cardiovascular NADPH oxidase isozyme that generates ROS, as well as 4-hydroxynonenal ( P < 0.001) and malondialdehyde ( P < 0.001), markers of lipid peroxidation; Ang-(1–7) prevented these effects of Dox. Cotreatment with Dox and Ang-(1–7) increased the antioxidant enzymes SOD1 (male: P < 0.05; female: P < 0.01) and catalase ( P < 0.05), which likely contributed to reduced ROS. These results demonstrate that Ang-(1–7) prevents diastolic dysfunction in association with a reduction in ROS, suggesting that the heptapeptide hormone may serve as an effective adjuvant to improve Dox-induced cardiotoxicity. NEW & NOTEWORTHY Ang-(1–7) is a clinically safe peptide hormone with cardioprotective and antineoplastic properties that could be used as an adjuvant therapy to improve cancer treatment and mitigate the long-term cardiotoxicity associated with doxorubicin in pediatric patients with cancer.
Collapse
Affiliation(s)
- Omeed Rahimi
- Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Jay Kirby
- Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Jasmina Varagic
- Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Brian Westwood
- Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - E. Ann Tallant
- Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Patricia E. Gallagher
- Hypertension and Vascular Research, Wake Forest School of Medicine, Winston-Salem, North Carolina
| |
Collapse
|
10
|
Tallant EA, Rahimi O, Varagic J, Westwood BM, Gallagher PE. Abstract P3006: Angiotensin-(1-7) Prevents Doxorubicin-Induced Aortic Dysfunction Through Anti-Fibrotic Mechanisms in Juvenile Male and Female Sprague Dawley Rats. Hypertension 2019. [DOI: 10.1161/hyp.74.suppl_1.p3006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Doxorubicin (Dox) is an effective, anthracycline chemotherapeutic administered for a variety of malignancies, but clinical use of the drug is limited by a cumulative, dose-dependent cardiotoxicity. Thus, adjuvant therapies are needed to mitigate Dox-induced cardiovascular damage in cancer patients, especially in pediatric patients with decades of life ahead. Our group showed that angiotensin-(1-7) [Ang-(1-7)], an endogenous peptide hormone with anti-cancer properties, improved vascular dysfunction in coronary vessels and cremaster muscle microvessels in Ang II-infused rats. In this study, juvenile male and female Sprague Dawley rats (n = 8-10) were administered a clinically equivalent dose of Dox (21-24 mg/kg) over 6 weeks, in the presence or absence of Ang-(1-7) [24 μg/kg/h]. Aortic function was measured using echocardiography. In both sexes, Ang-(1-7) blocked the Dox-mediated increase in pulse wave velocity (PWV), a measure of arterial stiffness (75% in males and 179% in females, p<0.05 and p<0.001). Dox decreased aortic lumen diameter (by 18%, p<0.01) and increased wall thickness at systole (p<0.01) in males, which was attenuated by Ang-(1-7). In male but not female aortas, Dox increased media hypertrophy by 16% (p<0.01) and reduced elastin content by 17% compared to control rats (p<0.001), changes prevented by Ang-(1-7). Conversely, collagen deposition was increased 2.5-fold in the aortic arches of female rats treated with Dox (p<0.001), which was blocked by Ang-(1-7). Dox increased nuclear ERK1/2 by 2-fold in the aortic media of male rats (p<0.01) and Ang-(1-7) significantly attenuated nuclear ERK1/2 localization. In contrast, neither Dox nor Ang-(1-7) changed total or nuclear ERK1/2 in the aortic arches of female rats. Dox increased nuclear pSMAD2 4-fold in males (p<0.05) and 3-fold in females (p<0.05); prophylactic treatment with Ang-(1-7) reduced the Dox-induced increases in nuclear pSMAD2 while the heptapeptide hormone had no effect alone. These results demonstrate that Ang-(1-7) prevented Dox-induced aortic dysfunction in both sexes, albeit through different mechanisms, suggesting that treatment with Ang-(1-7) may serve as an effective adjuvant to improve Dox-induced vascular dysfunction in pediatric patients.
Collapse
|
11
|
Gallagher PE, Patil PD, Varagic J, Westwood BM, Tallant EA. Abstract P3052: A Muscadine Grape Extract Improves Hypertension-Induced Aortic Damage in Conjunction With a Reduction in Fibrosis, Oxidative Stress, and Inflammation. Hypertension 2019. [DOI: 10.1161/hyp.74.suppl_1.p3052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypertension-induced arterial stiffness contributes to both reduced vascular and cardiac function. While the pathophysiology of aortic stiffness is not completely understood, significant vascular remodeling occurs in response to stimuli such as vascular stress and Ang II. The goal of this study was to determine whether a polyphenol-enriched muscadine grape skin and seed extract (MGE) improves Ang II-induced aortic remodeling. Sprague-Dawley rats (male, 8 weeks old) received normal drinking water (Control), 0.2 mg total phenolics/mL in their drinking water (MGE), 24 μg/kg/h of Ang II via osmotic minipump (Ang II), or both Ang II and MGE (Ang II/MGE, pre-treated with MGE for 1 week prior to Ang II treatment). MGE had no effect on systolic blood pressure, measured by tail cuff plethysmography, in normotensive or Ang II-treated rats. Aortic stiffness, determined by echocardiographic pulse wave velocity, was increased 2.5-fold in Ang II-treated animals but was significantly improved by co-administration of MGE. MGE prevented the Ang II-induced increase in aortic media thickness (Control: 95.8 ± 2.1 μm, Ang II: 135.1 ± 3.7 μm, and Ang II/MGE: 118.2 ± 2.9 μm) and lumen diameter (Control: 2.7 ± 0.2, Ang II: 2.1 ± 0.1 mm, and Ang II/MGE: 2.6 ± 0.1 mm). Nuclear phosphorylated ERK (pERK) in aortic medial cells was increased by 131% in Ang II-treated rats compared to Controls (p < 0.05); MGE co-administration prevented this by 83% (p < 0.001). Ang II-induced aortic fibrosis, measured by total collagen and collagen III, was significantly attenuated in hypertensive animals treated with MGE, in association with reduced pSMAD2 and CTGF. 4-HNE, a marker of lipid peroxidation, and subunits of NADPH oxidases--Nox1, Nox2, p-p47phox--were significantly upregulated by Ang II and normalized with MGE. The inflammatory markers IL-6 and NF-κB were also increased in Ang II-treated aortas (8.9- and 12.7-fold, respectively) and attenuated by MGE. This study is the first to demonstrate that Ang II-induced vascular remodeling is prevented by co-administration of MGE. MGE reduced aortic stiffness, in association with a decrease in fibrotic, oxidative stress, and inflammatory signaling, suggesting that MGE supplementation may improve vascular function in hypertensive patients.
Collapse
Affiliation(s)
| | | | | | | | - E A Tallant
- Wake Forest Sch of Medicine, Winston-Salem, NC
| |
Collapse
|
12
|
Ryalat F, Yamaleyeva LM, Cruz-Diaz N, Tallant EA, Gallagher PE, Diz DI. Abstract P155: Chronic Muscadine Grape Extract Intake Improves Diastolic Function Associated With Lower Circulating Aldosterone in Hannover Sprague Dawley Male Rats. Hypertension 2019. [DOI: 10.1161/hyp.74.suppl_1.p155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Muscadine grapes are rich sources of polyphenols, which are natural anti-oxidants linked to cardiovascular health. Circulating aldosterone may contribute to cardiac diastolic dysfunction via pro-oxidant and pro-fibrotic effects. We investigated the effect of chronic treatment with a muscadine grape extract (MGE) on circulating aldosterone and cardiac function in Hannover Sprague Dawley (SD) rats, since we previously showed that male rats develop diastolic dysfunction by 60 weeks of age. MGE (Piedmont Research & Development Corp.) was administered in the drinking water (0.2 mg polyphenolics /mL) starting at 15 weeks of age. Control animals were given regular water. Animals were assessed after 15 and 30 weeks of treatment. At 30 weeks of age, male SD rats have higher systolic blood pressure (SBP, measured by tail-cuff plethysmography: 139 ± 5 vs. 124 ± 2, n = 7-8, p < 0.05), higher E/e’ (measured by Vevo LAZR ultrasound: 12.9 ± 0.7 vs. 10.9 ± 0.2, n = 5-8, p < 0.05), and lower ejection fraction (77 ± 2 vs. 82 ± 1, n = 5-8, p < 0.05) than females at 30 weeks of age. SBP was lower in MGE treated males (126 ± 2 vs. 139 ± 5, n=7-8, p < 0.05) but not in females at 30 weeks of age. At 45 weeks of age, MGE treated male rats had improved (lower) E/e’ ratio than control male rats (E/e’: 10.7 ± 0.6 vs. 13.4 ± 0.4, n = 7, p < 0.05). This effect was accompanied by lower serum aldosterone (15 ± 3 vs. 28 ± 3 ng/dL, n = 7, p < 0.05) at 45 weeks of age. The MGE effects were independent of differences in SBP, ejection fraction, cardiac output or LV mass at this time point in male rats. For the female SD rats, there were no differences in SBP, cardiac systolic or diastolic function comparing values at 30 and 45 weeks of age, and no effect of MGE treatment at either time point. Serum aldosterone was not lower in the female rats at 45 weeks of age relative to control females. Our data demonstrate sex differences in cardiac function in response to chronic MGE consumption in aging rats. The MGE-induced improvement in diastolic cardiac function in males is consistent with lower circulating aldosterone. Our results suggest a protective role for MGE in age-related cardiac dysfunction in males.
Collapse
|
13
|
Mackert J, Gallagher PE, Tallant EA. Abstract 1860: Muscadine grape extract prevents proliferation of trastuzumab-sensitive and -resistant HER2 positive breast cancer cells and has synergistic effects when combined with trastuzumab. Cancer Res 2019. [DOI: 10.1158/1538-7445.am2019-1860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Human epidermal growth factor receptor 2 (HER2) positive breast cancer, characterized by overexpression of the HER2 protein, is an aggressive type of breast cancer comprising ~20% of diagnosed cases. Although targeted HER2 drugs, such as trastuzumab (TRZ), have reduced mortality by about one third, many patients still experience primary or acquired resistance. Grape seed/skin extracts are popular dietary supplements due to their potent antioxidant and anti-inflammatory properties. However, extracts from muscadine grapes are not extensively studied, and information regarding their therapeutic effects on cancer is limited. The objective of this study was to determine whether a muscadine grape skin and seed extract (MGE) inhibits the proliferation of TRZ-sensitive and -resistant HER2 positive breast cancer cells, and determine if combination treatment with MGE and TRZ has synergistic effects. Treatment with increasing concentrations of MGE for 48h significantly inhibited proliferation of TRZ-sensitive SKBR3 and -resistant HCC1954 human HER2 overexpressing breast cancer cells in a time and dose-dependent manner. HER2 heterodimerization and phosphorylation results in activation of the protein kinase B (AKT) pathway, which regulates breast cancer proliferation and cell survival. Treatment with 20 μg/mL MGE for 24h reduced HER2 protein expression by 52% (p≤0.01) in SKBR3 and 60% (p≤0.01) in HCC1954 cells. AKT activation was also reduced by 63% (p≤0.001) and 65% (p≤0.0001) in SKBR3 and HCC1954 cell lines, respectively. Active AKT stabilizes s-phase kinase-associated protein 2 (SKP2), ultimately leading to increased ubiquitination and degradation of cell-cycle inhibitor cyclin-dependent kinase inhibitor 1B (p27) and its transcription factor forkhead box protein 1 (FOXO1). Treatment with 20 μg/mL MGE for 24h increased total FOXO1 and p27 levels by 4-fold (p≤0.01) and 2.5-fold (p≤0.05), respectively, in SKBR3 cells. In addition, FOXO1 was increased 5-fold (p≤0.0001) and p27 4-fold (p≤0.05) in HCC1954 cells. Furthermore, SKP2 protein expression was reduced by 66% (p≤0.01) in SKBR3 and 73% (p≤0.01) in HCC1954 cells. MGE, in combination with TRZ, was synergistic at five different dose combinations (determined using Chou and Talalay method of synergy), and significantly inhibited proliferation to a greater extent than either agent alone in TRZ-sensitive SKBR3 cells. In summary, treatment with MGE reduced proliferation, inhibited components of the AKT pro-proliferation/survival pathway, and had synergistic effects when combined with TRZ in HER2 positive breast cancer cells. Thus, MGE may serve as an effective therapeutic either administered singly or in combination with targeted therapies for the treatment of HER2 positive breast cancer.
Citation Format: Jessica Mackert, Patricia E. Gallagher, E. Ann Tallant. Muscadine grape extract prevents proliferation of trastuzumab-sensitive and -resistant HER2 positive breast cancer cells and has synergistic effects when combined with trastuzumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1860.
Collapse
|
14
|
Ryalat F, Cruz‐Diaz N, Tallant EA, Gallagher PE, Diz D, Yamaleyeva LM. Muscadine Grape Extract Treatment Improves Aortic Pulse Wave Velocity and Superior Mesenteric Artery Pulsatility Index in Hypertensive Transgenic (mRen2)27 Female Rats. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.818.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Fatima Ryalat
- Surgery/Hypertension & Vascular Research and the Cardiovascular Sciences CenterWake Forest UniversitySchool of MedicineWinston‐SalemNC
| | - N Cruz‐Diaz
- Surgery/Hypertension & Vascular Research and the Cardiovascular Sciences CenterWake Forest UniversitySchool of MedicineWinston‐SalemNC
| | - EA Tallant
- Surgery/Hypertension & Vascular Research and the Cardiovascular Sciences CenterWake Forest UniversitySchool of MedicineWinston‐SalemNC
| | - PE Gallagher
- Surgery/Hypertension & Vascular Research and the Cardiovascular Sciences CenterWake Forest UniversitySchool of MedicineWinston‐SalemNC
| | - Di Diz
- Surgery/Hypertension & Vascular Research and the Cardiovascular Sciences CenterWake Forest UniversitySchool of MedicineWinston‐SalemNC
| | - LM Yamaleyeva
- Surgery/Hypertension & Vascular Research and the Cardiovascular Sciences CenterWake Forest UniversitySchool of MedicineWinston‐SalemNC
| |
Collapse
|
15
|
Bitting RL, Tooze JA, Petty WJ, Grant SC, Desnoyers RJ, Thomas A, Thomas CY, Alistar AT, Golden S, Pleasant K, Tallant EA, Gallagher PE, Klepin HD. Phase I study of muscadine grape extract in advanced malignancy. J Clin Oncol 2018. [DOI: 10.1200/jco.2018.36.15_suppl.e14548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Rhonda L. Bitting
- Comprehensive Cancer Center of Wake Forest Baptist Health, Winston Salem, NC
| | - Janet A. Tooze
- Wake Forest University School of Medicine, Winston Salem, NC
| | - William J. Petty
- Comprehensive Cancer Center of Wake Forest Baptist Health, Winston Salem, NC
| | - Stefan C. Grant
- Comprehensive Cancer Center of Wake Forest Baptist Health, Winston Salem, NC
| | | | - Alexandra Thomas
- Comprehensive Cancer Center of Wake Forest Baptist Health, Winston Salem, NC
| | | | | | | | | | - E Ann Tallant
- Wake Forest University School of Medicine, Winston Salem, NC
| | | | - Heidi D. Klepin
- Comprehensive Cancer Center of Wake Forest Baptist Health, Winston Salem, NC
| |
Collapse
|
16
|
Ryalat F, Yamaleyeva LM, Cruz‐Diaz N, Varagic J, Gallagher PE, Tallant EA, Diz DI. Muscadine Grape Extract Improves Arterial Stiffness in Hypertensive (mRen2)27 Female Rats. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.841.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Fatima Ryalat
- Department of Surgery/Hypertension and Vascular Researchand the Cardiovascular Sciences CenterWake Forest University School of MedicineWinston SalemNC
| | - Liliya M. Yamaleyeva
- Department of Surgery/Hypertension and Vascular Researchand the Cardiovascular Sciences CenterWake Forest University School of MedicineWinston SalemNC
| | - Nildris Cruz‐Diaz
- Department of Surgery/Hypertension and Vascular Researchand the Cardiovascular Sciences CenterWake Forest University School of MedicineWinston SalemNC
| | - Jasmina Varagic
- Department of Surgery/Hypertension and Vascular Researchand the Cardiovascular Sciences CenterWake Forest University School of MedicineWinston SalemNC
| | - Patricia E. Gallagher
- Department of Surgery/Hypertension and Vascular Researchand the Cardiovascular Sciences CenterWake Forest University School of MedicineWinston SalemNC
| | - E. Ann Tallant
- Department of Surgery/Hypertension and Vascular Researchand the Cardiovascular Sciences CenterWake Forest University School of MedicineWinston SalemNC
| | - Debra I. Diz
- Department of Surgery/Hypertension and Vascular Researchand the Cardiovascular Sciences CenterWake Forest University School of MedicineWinston SalemNC
| |
Collapse
|
17
|
Patil PD, Westwood BM, Gallagher PE, Tallant EA. Abstract P193: Anti-fibrotic and Anti-oxidant Actions of a Muscadine Grape Extract Supplement on Hypertension-induced Cardiac Damage. Hypertension 2017. [DOI: 10.1161/hyp.70.suppl_1.p193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Approximately 75 million U.S. adults suffer from hypertension, an independent risk factor for pathological cardiac hypertrophy. The current study examines the effects of a muscadine grape extract formulation (MGE; Piedmont Research & Development Corp.) with anti-oxidant, anti-inflammatory, and anti-proliferative properties on hypertension-induced cardiac damage in Sprague-Dawley rats receiving a 4-week Ang II infusion (24 μg/kg/h). We previously showed that MGE in the drinking water had no effect on blood pressure or systolic function in normotensive or hypertensive rats; however, MGE ameliorated the Ang II-induced decrease in diastolic function and increase in cardiomyocyte cross-sectional area. In the current study, MGE supplementation of Ang II-treated rats decreased interstitial cardiac fibrosis, reducing collagen III staining in the myocardium (0.9 ± 0.2% control, 6.8 ± 1.0% Ang II, and 2.8 ± 0.4% Ang II/MGE; p<0.01). MGE alone had no effect on any parameters assessed. The positive correlation between collagen and diastolic function with Ang II compared to control (p<0.01) was significantly abrogated by co-administration of MGE. TGFβ is a critical cytokine that stimulates cardiac fibrosis. The Ang II-mediated increase in cardiac TGFβ mRNA was attenuated by MGE (relative gene expression: 1.0 ± 0.1 control, 2.0 ± 0.4 Ang II, 1.1 ± 0.2 Ang II/MGE; p<0.05) as was downstream pSmad2 protein in cardiomyocytes (% nuclei: 26.1 ± 6 control, 53.8 ± 9.6 Ang II, 27.6 ± 5.5 Ang II/MGE; p<0.05) and cardiac fibroblasts (2.3 ± 1.1 control, 11.7 ± 4.9 Ang II, 2.2 ± 0.5 Ang II/MGE; p<0.05). NADPH oxidase is a primary contributor to cardiac oxidative stress and excess ROS production can lead to activation of pro-fibrotic pathways. MGE significantly reduced the Ang II-induced increase in p22phox mRNA (relative gene expression: 1.0 ± 0.1 control, 1.9 ± 0.1 Ang II, 1.0 ± 0.1 Ang II/MGE; p<0.0001) and protein (relative density: 1.0 ± 0.2 control, 5.4 ± 1.6 Ang II, 2.9 ± 1.0 Ang II/MGE; p<0.05), a subunit required for NADPH oxidase activity. These results indicate that MGE ameliorates cardiac fibrosis by targeting NADPH oxidase and the TGFβ pro-fibrotic pathway, suggesting that MGE supplementation may be an effective, natural therapeutic for hypertension-induced cardiac damage.
Collapse
|
18
|
Tallant EA, Deng G, Chen W, Metheny-Barlow LJ, Gallagher PE. Abstract 1227: Angiotensin-(1-7) reduces triple negative breast cancer brain metastatic growth in association with decreased c-Met signaling. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-1227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Patients with triple negative breast cancer often develop metastatic brain disease and have limited treatment options due to the lack of targeted therapeutics that efficiently cross the blood brain barrier. In the current study, we investigated the effect of angiotensin-(1-7) [Ang-(1-7)], a heptapeptide hormone with anti-proliferative and anti-metastatic activities, on the growth of murine brain tumors using brain trophic BR.5-4T1 cells in a model of metastatic triple negative breast tumor growth. BR.5-4T1 cells (1.25 x 104) were injected into the internal carotid artery of female BALB/c mice; after two days, mice were implanted with osmotic mini-pumps to deliver 24 µg/kg/h Ang-(1-7) and all mice were sacrificed after 20 days of treatment. Ang-(1-7) treatment significantly reduced metastatic tumor number in the brain; an average of 20 metastatic lesions per mouse was observed in the brains of an untreated control cohort while an average of 3 metastatic tumors per mouse was observed in the Ang-(1-7)-treated cohort. Tumor size was also reduced 17-fold by treatment with Ang-(1-7). Ki67, a marker of proliferation, was decreased from 29.1±6.7% to 6.4±2.2% in tumors from mice treated with Ang-(1-7), indicating that the heptapeptide hormone decreased metastatic tumor burden in the brain. Aberrant activation of the c-Met receptor tyrosine kinase signaling pathway facilitates tumor cell invasion and metastasis. Treatment with Ang-(1-7) significantly reduced the percentage of metastatic tumor cells exhibiting phospho-c-Met immunoreactivity, from 20.8±3.4% in tumors from untreated mice to 6.7±2.6% in mice treated with Ang-(1-7). Protein phosphatase 1b (PTB1b), which dephosphorylates and negatively regulates phospho-c-Met, was increased in the tumor cells of mice treated with Ang-(1-7) compared to tumor cells from untreated animals, from 4.1±1.4% in sections of tumors from control mice compared to 8.8±0.9% in sections of tumors from mice treated with Ang-(1-7). These results suggest that Ang-(1-7) increases PTP1b to antagonize c-Met signaling and decrease triple negative breast cancer brain metastasis. In support of a role for c-Met signaling in the regulation of metastatic brain disease in breast cancer patients, analysis of publicly available breast cancer cohort databases demonstrated a significant correlation between low c-Met/high PTP1b expression and improved survival outcome, including an increase in brain metastasis-free survival and distant-metastasis free survival. This is the first report to demonstrate that Ang-(1-7) reduces metastatic triple negative breast cancer localized to the brain in association with increased protein phosphatase PTP1b and decreased phospho-c-Met, suggesting that the heptapeptide hormone may serve as a novel targeted therapy to reduce metastatic brain tumor burden in triple negative breast cancer patients.
Citation Format: E. Ann Tallant, Guorui Deng, Wenhong Chen, Linda J. Metheny-Barlow, Patricia E. Gallagher. Angiotensin-(1-7) reduces triple negative breast cancer brain metastatic growth in association with decreased c-Met signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1227. doi:10.1158/1538-7445.AM2017-1227
Collapse
Affiliation(s)
| | - Guorui Deng
- Wake Forest School of Medicine, Winston-Salem, NC
| | - Wenhong Chen
- Wake Forest School of Medicine, Winston-Salem, NC
| | | | | |
Collapse
|
19
|
Patil P, Gallagher PE, Tallant EA. Abstract P166: The Effect of a Muscadine Grape Extract on Angiotensin II-Induced Hypertension and Cardiac Damage. Hypertension 2016. [DOI: 10.1161/hyp.68.suppl_1.p166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Muscadine grapes, indigenous to the southeastern United States, are a dietary source of polyphenols, such as ellagic acid, quercetin, and resveratrol, which have both anti-inflammatory and antioxidant properties. Preclinical studies show that ground muscadine grape skins and seeds have anti-cancer effects, suggesting that supplementation with a muscadine grape extract (MGE) may serve as a chemotherapeutic or chemopreventive agent. As cancer patients often present with hypertension, diabetes, and other vascular pathologies, it is imperative to determine the effect of a muscadine grape supplement on these underlying comorbidities. The goal of this study was to determine whether MGE administered in the drinking water will exacerbate or improve hypertension and cardiac damage. Sprague-Dawley rats receiving a 4-week infusion of Ang II via subcutaneous osmotic mini-pump (24 μg/kg/h) had a significant increase in systolic blood pressure (123.1 ± 2.3 mm Hg in control vs. 213.1 ± 6.8 mm Hg in Ang II-treated; n=8; p < 0.0001). MGE supplementation had no effect on blood pressure or gross cardiac hypertrophy in either normotensive or hypertensive rats. Additionally, MGE did not alter stroke volume or cardiac output, measured by VEVO ultrasound. However, MGE ameliorated the Ang-II induced decrease in diastolic function, as measured by the E/E’ ratio (19.9 ± 0.8 in control, 28.1 ± 1.1 in Ang II-treated rats, 22.3 ± 2.0 in Ang II/MGE-treated rats; p < 0.05). Co-treatment with MGE also significantly reduced the Ang II-mediated increase in cardiomyocyte cross-sectional area (340.5 ± 12.0 μm
2
in control, 423.2 ± 17.1 μm
2
in Ang II-treated rats, and 342.6 ± 13.2 μm
2
in Ang II/MGE-treated rats, p < 0.01). MGE supplementation of Ang II-treated rats decreased interstitial cardiac fibrosis, measured by Picrosirius red staining (1.0 ± 0.1% in control, 2.0 ± 0.2% in Ang II-treated rats and 1.4 ± 0.1% in Ang II/MGE-treated rats, p < 0.05). These results demonstrate that treatment with MGE does not exacerbate hypertension or hypertension-induced cardiac damage but ameliorates cardiac hypertrophy, suggesting that MGE supplementation has an acceptable safety profile for use as an anti-cancer agent in hypertensive patients and may be used to treat cardiac hypertrophy and damage.
Collapse
Affiliation(s)
- Pooja Patil
- Wake Forest Univ Sch of Medicine, Winston-Salem, NC
| | | | | |
Collapse
|
20
|
Rahimi O, Tallant EA, Gallagher PE. Abstract 023: Angiotensin-(1-7) Reduces Doxorubicin-Induced Cardiac Fibrosis. Hypertension 2016. [DOI: 10.1161/hyp.68.suppl_1.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Doxorubicin (Dox) is a commonly used and effective chemotherapeutic agent for childhood leukemias and sarcomas. However, Dox administration often results in cumulative dose-dependent cardiotoxicity that manifests as cardiomyopathy with marked fibrosis that leads to reduced cardiovascular function and heart failure. Consequently, there is a need for adjunct therapies to reduce Dox-induced cardiotoxicity and enhance long-term quality-of-life in cancer patients, especially in pediatric patients. Angiotensin-(1-7) [Ang-(1-7)] is an endogenous peptide hormone of the renin-angiotensin system with cardioprotective properties; studies by us and others showed that Ang-(1-7) reduces cardiac fibrosis and improves cardiac function in various animal models. In this study, we investigated whether adjunct Ang-(1-7) attenuates cardiotoxicity resulting from an acute (6 week) exposure of juvenile Sprague-Dawley rats (male, n = 8-10) to Dox (22 mg/kg). Dox treatment reduced body mass, cardiac weight and cardiomyocyte size, while Ang-(1-7) co-administration had no effect on these changes. However, co-administration of Ang-(1-7) prevented Dox-mediated increases in cardiac fibrosis (interstitial fibrosis: 1.4 ± 0.1% to 2.5 ± 0.3%; perivascular fibrosis: 15.8 ± 1.4% to 23.2 ± 1.6%; p < 0.01) and coronary vessel hypertrophy (media-to-lumen ratio: 2.4 ± 0.2 to 3.3 ± 0.3; p < 0.05). Administration of Dox significantly increased E/E’ by 47%, a marker of diastolic dysfunction, and pulse wave velocity by 74%, as a measure of arterial stiffness, quantified using a Vevo 2100 small animal ultrasound system; co-administration of Ang-(1-7) prevented the Dox-induced increases in diastolic dysfunction and arterial stiffness. In contrast, Ang-(1-7) had no effect on the Dox-mediated reductions in ventricular diameter, parasternal wall thickness, stroke volume and cardiac output. The anti-fibrotic and anti-hypertrophic effects of Ang-(1-7) may account for the improvement in diastolic and arterial function. Collectively, these results suggest that adjuvant Ang-(1-7) may attenuate cardiac fibrosis and toxicity induced by Dox administration.
Collapse
Affiliation(s)
- Omeed Rahimi
- Wake Forest Univ Sch of Medicine, Winston-Salem, NC
| | | | | |
Collapse
|
21
|
Gallagher PE, Gruber KA, Callahan M, Tallant EA. Abstract 1237: Anti-cancer activity of a stable, orally active angiotensin-(1-7) analog. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, peptide hormone that reduces tumor growth through effects on proliferation, inflammation, angiogenesis, fibrosis and metastasis. Ang-(1-7) mediates biological responses by activating mas, a unique G protein-coupled receptor, thereby providing specific targeted actions when used as a therapeutic agent. Unfortunately, Ang-(1-7) has unfavorable pharmacokinetic properties, resulting in a plasma half-life of about 30 min. In this study, TCAng05, a modified cyclic analog of Ang-(1-7), was compared to the parent compound Ang-(1-7) for efficacy, stability, and oral bioavailability. Ang-(1-7) or TCAng05 was incubated with human A549 lung or MDA-MB-231 breast cancer cells for 6 to 10 days, to assess the effect on tumor cell growth. A single dose of TCAng05 significantly reduced the growth of both MDA-MB-231 and A549 cells, while daily doses of Ang-(1-7) were required due to rapid degradation. Growth inhibition by either compound was blocked by the Ang-(1-7) receptor antagonist D-Ala7-Ang-(1-7) [Dala], showing a receptor-mediated response. Ang-(1-7) was rapidly degraded following incubation in rat plasma with a half-life of about 30 min, while TCAng05 was stable under the same conditions for approximately 50 h. The oral efficacy of TCAng05 to inhibit tumor growth in vivo was assessed by injecting 4T1 cells into the mammary fat pad of BALB/C mice. Once the tumors reached 100 mm3, the mice received daily gavage of TCAng05 at 12 μg/kg/day (low), 60 μg/kg/day (medium) or 300 μg/kg/day (high). Tumors in mice with no treatment continued to grow until sacrifice at day 19, reaching a size of 671.2 ± 127.2 mm3. Oral treatment with TCAng05 at the medium or high dose reduced tumor volume, by 56.8% and 43.6%, respectively, to final tumor volumes of 289.7 ± 64.2 mm3 and 378.3 ± 151.2 mm3. Tumor weight was also reduced by treatment with the medium or high dose of oral TCAng05. TCAng05 had no effect on mouse weight, heart or kidney weight, indicating that oral administration of the Ang-(1-7) analog was well-tolerated. TCAng05 caused a dose-dependent decrease in Ki67 immunoreactivity in tumor tissue sections from mice treated with the analog, suggesting reduced tumor cell proliferation. TCAng05 administration to mice with breast tumors also caused a significant decrease in tumor blood vessel density, as measured by CD34 labeling, suggesting that the analog inhibits angiogenesis to decrease tumor size. Collagen staining with Picrosirius red was markedly decreased in human breast tumor xenografts by oral administration of TCAng05, demonstrating that the analog reduces tumor associated fibrosis. These results indicate that oral administration of TCAng05 to mice with breast tumors reduced tumor size, by decreasing tumor cell proliferation, angiogenesis and fibrosis, as previously observed with the native Ang-(1-7), and suggest that the modified analog may serve as an effective, orally active, targeted chemotherapeutic.
Citation Format: Patricia E. Gallagher, Kenneth A. Gruber, Michael Callahan, E. Ann Tallant. Anti-cancer activity of a stable, orally active angiotensin-(1-7) analog. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1237.
Collapse
Affiliation(s)
| | | | | | - E. Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| |
Collapse
|
22
|
Willey JS, Bracey DN, Gallagher PE, Tallant EA, Wiggins WF, Callahan MF, Smith TL, Emory CL. Angiotensin-(1-7) Attenuates Skeletal Muscle Fibrosis and Stiffening in a Mouse Model of Extremity Sarcoma Radiation Therapy. J Bone Joint Surg Am 2016; 98:48-55. [PMID: 26738903 DOI: 10.2106/jbjs.o.00545] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Radiation-induced fibrosis (RIF) of musculoskeletal tissue is a common complication of radiation therapy for extremity soft-tissue sarcoma, with no standardized strategy for prevention and treatment. Angiotensin-(1-7) (Ang-[1-7]), a well-tolerated endogenous heptapeptide hormone with antitumor and antifibrotic properties, was tested as a radioprotectant for RIF and stiffening of irradiated muscles. METHODS Male CD-1 mice were randomized to one of three treatment groups: control, simulated sarcoma radiation therapy to the gastrocnemius and soleus muscles, or radiation therapy along with continuous Ang-(1-7) delivery initiated three days before radiation therapy. The biologically equivalent dose of radiation (∼100.3 Gy) absorbed by normal musculature during the course of radiation therapy for extremity sarcoma was delivered by means of four dose fractions of 7.3 Gy over two weeks. Fibrosis (n = 5 per group) and mechanical properties (n = 4 to 6 per group) of the muscles were measured at six weeks and four months after radiation therapy, and the intramuscular concentration of the profibrotic cytokines transforming growth factor-beta (TGF-β) and connective tissue growth factor (CTGF) (n = 8 to 10 per group) were measured at six weeks. RESULTS Interstitial (p < 0.01) and perivascular (p < 0.05) fibrosis increased significantly in the muscles treated with radiation therapy alone versus the nonirradiated controls at both six weeks (interstitial, +89%; perivascular, +112%) and four months (interstitial, +154%; perivascular, +88%). The muscles treated with radiation alone also exhibited increased tension (p < 0.01) versus nonirradiated controls at both six weeks (+779%) and four months (+1761%) when placed under 5% strain, and at four months (+1390%; p < 0.001) under 10% strain. At four months, muscle stiffness had increased in the mice treated with radiation therapy alone (+90%; p = 0.002) compared with nonirradiated controls. TGF-β production was also greater in this group at six weeks (+37%; p = 0.06) versus control. Ang-(1-7) administration prevented RIF and stiffening, with no differences observed for any other outcome between those receiving radiation therapy with Ang-(1-7) and the nonirradiated controls. Likewise, Ang-(1-7) mitigated the increase in TGF-β and CTGF concentration from radiation therapy. CONCLUSIONS Ang-(1-7) attenuated RIF, stiffening, and production of profibrotic cytokines that were elevated in mouse skeletal muscles after simulated radiation therapy for extremity sarcoma. CLINICAL RELEVANCE Ang-(1-7) may serve as a potential therapy for the prevention of RIF in patients who require radiation therapy as adjuvant treatment for soft-tissue sarcoma.
Collapse
Affiliation(s)
- Jeffrey S Willey
- Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, North Carolina Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Daniel N Bracey
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Patricia E Gallagher
- Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - E Ann Tallant
- Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Walter F Wiggins
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Michael F Callahan
- Tensive Controls, MU Life Sciences Business Incubator, Columbia, Missouri
| | - Thomas L Smith
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Cynthia L Emory
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, North Carolina Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, North Carolina
| |
Collapse
|
23
|
Gwathmey TM, Tallant EA, Howlett AC, Diz DI. Programs to Recruit and Retain a More Diverse Workforce in Biomedical Sciences Research. J Best Pract Health Prof Divers 2016; 9:1188-1194. [PMID: 28868526 PMCID: PMC5575820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To improve overall healthcare and to reduce health disparities, efforts must focus on increasing the diversity of personnel trained in the biomedical sciences. Here, we describe the development, implementation, and relative outcomes of three pipeline training programs in biomedical sciences research designed to increase workforce diversity institutionally, regionally, and nationally. We report on their effectiveness in improving the recruitment and retention of underrepresented minorities with the long-term goal of remedying health inequities and disparities.
Collapse
Affiliation(s)
- TanYa M. Gwathmey
- Department of Surgery, Hypertension and Vascular Research Center, Winston-Salem, North Carolina
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - E. Ann Tallant
- Department of Surgery, Hypertension and Vascular Research Center, Winston-Salem, North Carolina
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Allyn C. Howlett
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Debra I. Diz
- Department of Surgery, Hypertension and Vascular Research Center, Winston-Salem, North Carolina
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| |
Collapse
|
24
|
Carver KA, Smith TL, Gallagher PE, Tallant EA. Angiotensin-(1-7) prevents angiotensin II-induced fibrosis in cremaster microvessels. Microcirculation 2015; 22:19-27. [PMID: 25079175 DOI: 10.1111/micc.12159] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/29/2014] [Indexed: 01/19/2023]
Abstract
OBJECTIVE The effect of the heptapeptide hormone Ang-(1-7) on microvascular fibrosis in rats with Ang II-induced hypertension was investigated, since vascular fibrosis/remodeling plays a prominent role in hypertension-induced end-organ damage and Ang-(1-7) inhibits vascular growth and fibrosis. METHODS Fibrosis of cremaster microvessels was studied in male Lewis rats infused with Ang II and/or Ang-(1-7). RESULTS Ang II elevated systolic blood pressure by approximately 40 mmHg, while blood pressure was not changed by Ang-(1-7). Ang II increased perivascular fibrosis surrounding 20-50 μm arterioles as well as interstitial fibrosis; coadministration of Ang-(1-7) prevented the increases in fibrosis. The fibrotic factor CTGF and phospho-Smad 2/3, which upregulates CTGF, were increased by Ang II; this effect was prevented by coadministration of Ang-(1-7). Although TGF-β phosphorylates Smad 2/3, TGF-β was no different among treatment groups. In contrast, Ang II increased the MAP kinase phospho-ERK1/2, which also phosphorylates Smad; p-ERK was reduced by Ang-(1-7). Ang-(1-7), in the presence or absence of Ang II, upregulated the MAP kinase phosphatase DUSP1. CONCLUSIONS These results suggest that Ang-(1-7) increases DUSP1 to reduce MAP kinase/Smad/CTGF signaling and decrease fibrosis in resistance arterioles, to attenuate end-organ damage associated with chronic hypertension.
Collapse
Affiliation(s)
- Kyle A Carver
- Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | | | | | | |
Collapse
|
25
|
Deng G, Metheny-Barlow L, Gallagher PE, Tallant EA. Abstract 4981: Angiotensin-(1-7) targets c-Met signaling by up-regulating the phosphatase PTP1b to reduce triple negative breast cancer. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-4981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Triple negative breast cancer (TNBC) is an aggressive form of breast cancer with no known targeted therapies, since the tumors cells lack expression of the estrogen receptor and do not overexpress the HER2/Neu oncoprotein. Our laboratory showed that angiotensin-(1-7) [Ang-(1-7)], an endogenous seven amino acid peptide hormone, specifically activates the G protein-coupled receptor mas to inhibit the growth of lung, breast and prostate cancer cells and tumors. Using the 4T1 syngeneic mouse TNBC model, we examined the molecular signaling involved in the anti-tumor effects of Ang-(1-7). Ang-(1-7) significantly reduced tumor volume when compared to the control group (a 46% reduction by day 18, n = 6-7, p<0.05), with a concomitant decrease in tumor weight (2.0±0.3 g in untreated mice vs. 1.3±0.1 g in treated mice, p<0.05). A significant reduction in the proliferation marker Ki67 was observed in tumors from Ang-(1-7)-treated mice compared to tumors from untreated mice (18.1±3.7 Ki67(+) cells vs 103.9±17.2, p<0.005). Hepatocyte growth factor/scatter factor (HGF/SF) is a potent inducer of cell proliferation and cancer cell invasion by activating the receptor tyrosine kinase (RTK) c-Met and HGF/SF/c-Met signaling is elevated in TNBC. Ang-(1-7) attenuates c-Met RTK activation by HGF [phospho-c-Met(Y1234/1235)] in human MDA-MB-231 and mouse 4T1 TNBC cells by 30.3% (p<0.001) and 32.1% (p<0.005), respectively. The phosphatase PTP1b, a negative regulator of c-Met RTK activation, was significantly up-regulated by 75% in response to Ang-(1-7) treatment in the 4T1 cells (from 0.8±0.1 to 1.4±0.1, p<0.05), suggesting that the heptapeptide hormone increases PTP1b to negatively regulate c-Met signaling. A significant decrease in immunoreactive phospho-c-Met(Y1234/1235) was also observed in 4T1 tumors treated with Ang-(1-7) as compared to untreated tumors (from 47.0 to 19.7% of field, n = 5, p<0.05). The Ang-(1-7)-mediated suppression of HGF/SF-mediated c-Met activation was abrogated by D-alanine7-Ang-(1-7) [D-Ala], a mas receptor antagonist. In agreement with the Ang-(1-7)-mediated reduction of the tumor volume of 4T1 tumors, HGF-induced activation of the MAPKs ERK1 and ERK2 was reduced by the heptapeptide hormone in vitro (by 59.7 and 74.8%, respectively, n = 5). Further, Ang-(1-7) treatment significantly attenuated HGF/SF-stimulated cell invasion through Matrigel (by 53±2, n = 8, p<0.05 compared to HGF/SF stimulation); this effect was abrogated by the mas receptor antagonist D-Ala. Collectively, our data suggest that Ang-(1-7) in part suppresses the progression of triple negative breast tumors by activating the mas receptor to upregulate the phosphatase PTP1b and attenuate HGF/SF-induced c-Met activation, resulting in decreased ERK1/2 signaling, reduced tumor growth and diminished cell invasion, providing support for the use of Ang-(1-7) as a novel therapeutic agent for patients with TNBC.
Citation Format: Guorui Deng, Linda Metheny-Barlow, Patricia E. Gallagher, E. Ann Tallant. Angiotensin-(1-7) targets c-Met signaling by up-regulating the phosphatase PTP1b to reduce triple negative breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4981. doi:10.1158/1538-7445.AM2015-4981
Collapse
Affiliation(s)
- Guorui Deng
- Wake Forest School of Medicine, Winston-Salem, NC
| | | | | | | |
Collapse
|
26
|
Rahimi OA, Castellino SM, Cammock CE, Tallant EA, Gallagher PE. Abstract 4489: Angiotensin-(1-7) prevents fibrosis in doxorubicin-treated rats. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-4489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Anthracyclines such as doxorubicin (Dox) are effective chemotherapeutic agents for multiple malignancies, including childhood leukemias and sarcomas. Despite the efficacy of these agents, anthracyclines can result in cumulative dose-dependent cardiac toxicity that manifests as cardiomyopathy with marked myocardial hypertrophy and fibrosis. This cardiotoxicity culminates in reduced ejection fraction, fractional shortening, and cardiac output, leading to congestive heart failure. Consequently, there is an unmet need for adjunct therapies to temper anthracycline-induced cardiotoxicity and enhance long-term quality of life in patients treated with anthracyclines, especially pediatric cancer patients. Angiotensin-(1-7) [Ang-(1-7)] is an endogenous seven amino acid peptide hormone of the renin-angiotensin system with cardioprotective properties. Studies by us and others showed that Ang-(1-7) improved cardiac function as well as reduced cardiac hypertrophy and fibrosis in various animal models. In this study, we assessed whether adjunct Ang-(1-7) (24 μg/kg/hr) attenuates cardiotoxicity that results from acute (6 week) exposure of 5 week-old Sprague-Dawley rats to Dox, administered weekly at a cumulative dose of 15 mg/kg. Body weight was reduced in rats treated with Dox, in the presence or absence of Ang-(1-7); however, the heart weight/body weight ratio was increased in Dox-treated rats while co-administration with Ang-(1-7) prevented the Dox-mediated increase. Myocyte cross-sectional area was not changed by administration of Dox or Ang-(1-7). Dox administration caused significant increases in cardiac fibrosis (an increase in interstitial fibrosis from 0.9±0.1% to 1.5±0.2%, p<0.001 compared to sham, and perivascular fibrosis from 16.0±1.1% to 23.6±3.0%, p<0.05; n = 3-8), which was prevented by co-administration of Ang-(1-7). Interstitial and perivascular fibrosis in rats treated with Ang-(1-7) or with Dox/Ang-(1-7) was no different than in sham animals. The Dox-mediated increase in cardiac fibrosis and the anti-fibrotic effects of Ang-(1-7) co-administration may account for the changes in heart weight/body weight, since doxorubicin did not alter the size of cardiac myocytes. Cardiac function was assessed using a Vevo 2100 small animal ultrasound system, at baseline and following treatment. Doxorubicin reduced ejection fraction, fractional shortening and cardiac output compared to sham or Ang-(1-7) alone; co-administration of Ang-(1-7) with Dox tended to prevent the Dox-mediated reductions in cardiac contractility. The Dox-mediated increase in fibrosis may contribute to the reduced cardiac contractility and the Ang-(1-7)-mediated reduction in Dox-induced fibrosis may account for the improvement in contractility in rats co-administered Dox and Ang-(1-7). These results suggest that Ang-(1-7) may be effective in preventing Dox-induced cardiac fibrosis and may attenuate acute cardiac toxicity induced by Dox administration.
Citation Format: Omeed A. Rahimi, Sharon M. Castellino, Cheryl E. Cammock, E Ann Tallant, Patricia E. Gallagher. Angiotensin-(1-7) prevents fibrosis in doxorubicin-treated rats. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4489. doi:10.1158/1538-7445.AM2015-4489
Collapse
|
27
|
Porter BE, Moore JE, Miller MS, Tallant EA, Gallagher PE. Abstract 4563: Muscadine grape extract reduces lung carcinogenesis in female mice exposed to 3-methylcholanthrene in utero. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-4563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The developing fetus is highly sensitive to the carcinogenic effects of dietary and environmental carcinogens in cigarette smoke, charbroiled foods and air pollution following transplacental exposure. Oxidative metabolism of toxicants by both maternal and fetal tissue causes DNA damage which can ultimately result in the initiation of childhood cancers. Due to the latency of cancer formation, in utero exposure to carcinogens may even predispose the individual to cancers developing later in life. The goal of this study is to determine whether a proprietary muscadine grape extract (MGE) effectively reduces lung tumor formation in the fetus following transplacental exposure to a polycyclic hydrocarbon. The muscadine grape (Vitis rotundifolia) has a distinct phytochemical composition compared to other grape varieties and limited reports indicate that the extract has potential anti-tumor activity. BALB/c male mice were mated to C57BL/6 female mice to serve as a model for in utero exposure to environmental toxicants. The pregnant mice were treated on the 17th day of gestation by intraperitoneal injection with a 45 mg/kg dose of 3-methylcholanthrene dissolved in olive oil, to induce lung tumors in the fetus. An injection of the olive oil vehicle (0.5 mL/0.35 kg) served as the control. Day 0 was considered as the first day when the vaginal plug was detected. After weaning, cohorts of mice received drinking water alone or water with MGE (approximately 1.0 mg phenolics/25 g mouse) and were sacrificed at 12 months of age. Although all of the mice developed lung tumors, MGE significantly reduced tumor burden in female mice by approximately 48% as compared to the tumor tissue found in control mice drinking regular water (12.4 ± 1.9 g versus 6.5 ± 1.2 g, n = 26-32, p = 0.014). In addition, tumor multiplicity was higher in control mice as compared to MGE-treated animals (6.8 ± 0.4 observed tumors versus 4.2 ± 0.5 observed tumors, n = 26-32, p = 0.0001). Tumor tissue sections from mice administered MGE had a significant decrease in proliferating cell nuclear antigen as compared to tumors from control animals (22.4 ± 1.8 versus 14.2 ± 1.3, p = 0.0009), suggesting that in part MGE reduces tumor burden by decreasing tumor cell proliferation. Lung tumor sections from female mice drinking regular water or MGE were incubated with an antibody to the endothelial cell marker, CD34, and vessels were identified by a combination of morphology and positive CD34 immunoreactivity. MGE significantly reduced blood vessel density in lung tumor tissue as compared to female mice drinking regular water (20.5 ± 2.2 versus 11.3 ± 1.3, p = 0.0012), suggesting that the grape extract inhibits angiogenesis. These results indicate that MGE reduces both tumor proliferation and angiogenesis, leading to a decrease in tumor burden and multiplicity. Thus, MGE may represent a novel nutraceutical for the prevention of lung tumors induced by in utero exposure to environmental toxicants.
Citation Format: Brooke E. Porter, Joseph E. Moore, Mark S. Miller, E. Ann Tallant, Patricia E. Gallagher. Muscadine grape extract reduces lung carcinogenesis in female mice exposed to 3-methylcholanthrene in utero. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4563. doi:10.1158/1538-7445.AM2015-4563
Collapse
Affiliation(s)
| | | | - Mark S. Miller
- 2Division of Cancer Prevention, National Cancer Institute, Bethesda, MD
| | | | | |
Collapse
|
28
|
Gallagher PE, Tallant EA. Abstract 2825: Prevention of breast tumor growth by an extract from the muscadine grape. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-2825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Grape extracts have garnered attention as chemopreventive agents due their anti-proliferative, anti-inflammatory and anti-oxidant properties. The muscadine grape (Vitis rotundifolia) has a distinct phytochemical composition compared to other grape varieties. The current study examines the preventive effects of a proprietary muscadine grape extract (MGE) on breast cancer formation. The proliferation of actively growing human ER+ or triple negative breast cancer cells was significantly reduced by MGE from grape seeds or skins with an associated decrease in phospho-ERK, suggesting that MGE inhibits breast cancer cell proliferation through a reduction in activation of growth-promoting kinases. Female FVB-Tg(MMTV)NKAMul/J transgenic mice with an activated rat Erbb2 oncogene expressed specifically in the mammary gland (c-neu mice) form mammary tumors by 6-8 months of age. c-Neu mice were treated with MGE in the drinking water (approximately 1.0 mg phenolics/25 g mouse) beginning at weaning and were sacrificed at 7½ months of age. No changes were observed in eating or drinking habits or in gross body, heart or kidney weight, suggesting that the MGE was well tolerated. Although all of the mice developed breast tumors, MGE significantly reduce tumor burden compared to the tumor tissue in mice drinking regular water (9.2±1.2 g versus 3.6±1.4 g, p = 0.001, n = 8-10). A group of c-Neu mice were also sacrificed at 4 months of age, once tumors were palpable, to assess tumor multiplicity. Both tumor burden (1.4±.3 g versus 0.3±0.1 g, p = 0.007) and tumor multiplicity (11.8±2.1 versus 5.1±0.9, p = 0.013, n = 6-11) were reduced in mice treated with MGE. Tumor tissue sections from mice administered MGE had a significant decrease in the proliferation marker Ki67 compared to tumors from control animals [310±92 versus 166±70 immunoreactive cells/field, p = 0.002], in agreement with the reduction in proliferation observed in vitro. Tumor sections from c-neu mice were incubated with an antibody to the endothelial cell marker, CD34, and vessels were identified by a combination of morphology and positive CD34 immunoreactivity; MGE significantly reduced blood vessel density in breast tumor tissue compared to tumors from mice drinking regular water [5.7±0.6 versus 3.6±0.9, p = 0.022], suggesting that the grape extract attenuates tumor angiogenesis. Interstitial tumoral fibrosis was quantified in breast tumor tissue sections using picrosirius red, a nonspecific collagen stain. MGE treatment markedly decreased interstitial fibrosis as compared to the tumors from control animals [2.79±0.70% versus 0.14±0.04%, p = 0.0005], indicating that the extract reduces cancer-associated fibrosis in breast tumors. Taken together, these studies suggest that MGE reduces both breast tumor burden and multiplicity, through decreasing proliferation, angiogenesis and fibrosis, suggesting that extracts from muscadine grapes may represent a novel nutraceutical for the prevention of breast cancer.
Citation Format: Patricia E. Gallagher, E. Ann Tallant. Prevention of breast tumor growth by an extract from the muscadine grape. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2825. doi:10.1158/1538-7445.AM2015-2825
Collapse
|
29
|
Tallant EA, Howlett AC, Gallagher PE. Abstract 542: Blockade of Angiotensin-(1-7)-mediated Vascular Remodeling by a CB2 Cannabinoid Receptor Antagonist. Hypertension 2014. [DOI: 10.1161/hyp.64.suppl_1.542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin-(1-7) [Ang-(1-7)] inhibits vascular smooth muscle cell (VSMC) growth and reduces cardiac hypertrophy and vascular remodeling in Ang II-infused hypertensive rats. We previously showed that Ang-(1-7) increased the endocannabinoid 2-AG in VSMCs and that inhibition of VSMC growth by Ang-(1-7) was prevented by blockade of CB2 cannabinoid receptors. VSMCs isolated from mice with ablated CB2 receptors were treated with platelet-derived growth factor to stimulate growth; neither Ang-(1-7) nor the CB2 receptor agonist HU308 reduced VSMC growth (98.7±9.9% and 105.4±13.0% of stimulated growth, respectively, n = 3-6), suggesting that growth inhibition by Ang-(1-7) is mediated through activation of the CB2 receptor. Ang II-infused Sprague-Dawley rats were treated for 28 days with Ang-(1-7), in the presence or absence of the CB2 receptor antagonist SR144528, to determine whether CB2 receptor blockade prevents the Ang-(1-7)-mediated reductions in Ang II-stimulated cardiac hypertrophy and vascular remodeling. Systolic blood pressure was similar in both groups, before or after treatment (115±4.6 mmHg with SR144528 and 115.7±10.2 mmHg with Ang-(1-7)/SR144528 before treatment and 186.7±6.2 mmHg and 182.0±2.1 mmHg after Ang II treatment, respectively, n=4). Ang II increased the mean cross-sectional area of cardiac myocytes which was reduced 55% by Ang-(1-7); CB2 receptor blockade prevented the Ang-(1-7)-mediated reduction in myocyte size. Fibrosis (interstitial and perivascular) and vessel size (M/L) were unchanged by Ang-(1-7) in the presence of SR144528 compared to a 79%, 85% and 90% reduction of the Ang II-mediated increase in interstitial fibrosis, perivascular fibrosis and M/L, respectively, by Ang-(1-7) alone. Brain natriuretic peptide and atrial natriuretic peptide also were unchanged by Ang-(1-7) in the hearts of rats treated with Ang II and SR144528 compared to a 91% and 99% reduction by Ang-(1-7) in Ang II-treated rats. Thus, treatment with a CB2R antagonist blunts the anti-hypertrophic and anti-fibrotic responses to Ang-(1-7) in hypertensive Ang II-treated rats, independent of blood pressure, suggesting that the growth inhibitory properties of Ang-(1-7) involve a novel pathway which includes activation of the CB2 receptor.
Collapse
|
30
|
Tallant EA, Howlett A, Grabenauer M, Thomas BF, Gallagher PE. Abstract 465: The CB2 Cannabinoid Receptor Mediates the Anti-Proliferative Actions of Angiotensin-(1-7) in Vascular Smooth Muscle Cells. Hypertension 2013. [DOI: 10.1161/hyp.62.suppl_1.a465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Therapeutic interventions to reduce vascular proliferation are critical for the effective treatment of hypertension-induced end-organ damage, restenosis and atherosclerosis. We showed that angiotensin-(1-7) [Ang-(1-7)] reduces neointimal formation following vascular injury and inhibits vascular growth, through activation of the AT7 receptor mas and production of arachidonic acid derivatives. Endocannaboids (ECs) derived from membrane phospholipids also inhibit vascular proliferation and reduce growth following vascular injury, by stimulation of the CB2 receptor. The impact of CB2 receptor blockade on the anti-proliferative actions of Ang-(1-7) was investigated to assess a potential interaction between the EC and Ang-(1-7)/mas receptor systems. Rat thoracic aortic vascular smooth muscle cells (VSMCs) were treated with platelet-derived growth factor (PDGF) to stimulate growth and incubated with Ang-(1-7), the AT7 receptor antagonist [D-alanine7]-angiotensin-(1-7) [Dala], the CB2 receptor agonist HU308 and/or the CB2 receptor antagonist AM630. PDGF-stimulated VSMC growth was markedly reduced by Ang-(1-7) (74 ± 6% of control, n = 10, p<0.0001) and this effect was blocked by Dala (116 ± 14% of control, n = 4; n.s.). The Ang-(1-7)-mediated reduction in growth was abolished by the CB2 receptor antagonist AM630 (136 ± 16% of control, n = 4; n.s.); AM630 alone had no effect. In contrast, the CB1 receptor antagonist AM281 did not prevent the inhibitory actions of Ang-(1-7) on VSMC growth. CB2 receptor activation by the agonist HU308 also reduced PDGF-stimulated VSMC proliferation to a similar extent as Ang-(1-7) (67 ± 4% of control, n = 5, p<0.001); Dala did not influence the response to HU308 (50 ± 10% of control, n = 5, p<0.005). Ang-(1-7) significantly increased the endogenous cannabinoid 2-arachidonoylglycerol (2-AG) by 48% in VSMC by 24 h (p<0.05, n = 4). We conclude that the growth inhibitory properties of Ang-(1-7) involve a novel pathway culminating in the downstream formation of 2-AG and subsequent activation of the CB2 receptor in VSMC. Thus, Ang-(1-7) and/or CB2 receptor activation may constitute a new and beneficial therapeutic strategy for the prevention of vascular proliferation that is prevalent in cardiovascular disease.
Collapse
|
31
|
Gallagher PE, Arter AL, Soto-Pantoja DR, Tallant EA. Abstract C66: Angiotensin-(1-7) attenuates triple-negative breast cancer growth and progression through regulation of protein phosphatases. Cancer Res 2013. [DOI: 10.1158/1538-7445.tim2013-c66] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Triple-negative breast cancer is a highly aggressive and invasive tumor type which accounts for 15% of all breast cancers and disproportionately affects pre-menopausal women as well as African-American and Hispanic populations. Triple negative breast tumors show an increased risk for metastasis, due to over-activation of tumor-promoting signaling pathways, including the mitogen-activated protein kinase (MAPK) and PI3 kinase (PI3K)-Akt pathways. The limited available targeted therapies for triple negative breast cancer due to the lack of estrogen and progesterone receptor expression and unamplified human epidermal growth factor receptor 2 (HER2) levels indicate a clear need for novel targeted therapies for patients. Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, seven amino acid peptide hormone of the renin-angiotensin system that activates the G protein-coupled receptor mas. Ang-(1-7) inhibited the growth of MDA-MB-231 human triple negative breast tumors growing in the mammary fat pads of athymic mice. The mean tumor volumes of saline- or Ang-(1-7)-treated mice were similar prior to the initiation of treatment (saline, 113.3±7.0 mm3; Ang-(1-7), 107.6±6.8 mm3). The tumor volume of mice treated with saline increased 4.4-fold over the 28 day treatment period; in contrast, the volume of tumors from mice administered Ang-(1-7) did not increase over the 28-day treatment period compared to tumor volume at the initiation of treatment. Cells in tumors from mice treated with saline showed abundant Ki67 immunoreactivity, while Ki67 immunoreactivity was reduced 51% in tumor cells from mice injected with Ang-(1-7). Ang-(1-7) significantly reduced the phosphorylation of ERK1 and ERK2 in triple negative breast tumors as compared to the phospho-modification of the enzymes in tumors from saline-treated mice, by 95.2% and 81.3%, respectively; no change in non-phosphorylated ERK1 and ERK2 was observed. The dual-specificity phosphatase DUSP1, or MKP-1, is a key phosphatase that regulates the activity of ERK1/ERK2. Ang-(1-7) significantly increased DUSP1 protein and mRNA in tumors of mice injected with Ang-(1-7) as compared to tumors from saline-treated mice. Incubation of human MDA-MB-231 triple negative breast cancer cells with an siRNA to DUSP1 prevented the reduction in ERK activation, demonstrating that the heptapeptide hormone up-regulates DUSP1 to reduce MAP kinase activities. Ang-(1-7) also attenuated PI3 kinase-Akt signaling in human triple negative breast tumors by up-regulating the Akt phosphatase PP2A (protein phosphatase 2A) 5-fold (n=4-5, p<0.05). Incubation of MDA-MB-231 human triple negative breast cancer cells with Ang-(1-7) increased PP2A subunits--both the scaffolding A subunit (a 4-fold increase, n=3-4, p<0.05) and the catalytic C subunit (a 2-fold increase, n=3-4, p<0.05). The heptapeptide hormone also significantly inhibited the growth of 4T1 murine triple negative breast cancer cells (n=3, p<0.05). The reduction in 4T1 cell growth was similarly associated with a 5-fold increase in PP2A-A and a 2-fold increase in PP2A-C (n=3-4, p<0.05 and p<0.01, respectively), with a concomitant 80 to 90% reduction in phospho-Akt at both the serine and threonine residues (n=3-4, p<0.001 and p<0.0001, respectively). Taken together, these results suggest that Ang-(1-7) may serve as a novel, targeted therapy for triple negative breast cancer by regulating protein phosphatases to reduce activation of protein kinase-mediated proliferative signaling cascades.
Citation Format: Patricia E. Gallagher, Alison L. Arter, David R. Soto-Pantoja, E. Ann Tallant. Angiotensin-(1-7) attenuates triple-negative breast cancer growth and progression through regulation of protein phosphatases. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C66.
Collapse
|
32
|
Arter AL, Gallagher PE, Tallant EA. Abstract B34: Angiotensin-(1-7) attenuates the proliferation of cancer-associated fibroblasts in triple negative breast cancer. Cancer Res 2013. [DOI: 10.1158/1538-7445.tim2013-b34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The interaction between cancer cells and the surrounding microenvironment transforms the stroma into an abnormal phenotype, altering normal function, tissue architecture, cellular morphology, and extracellular matrix-cell interactions that directly contribute to formation of neoplasia. About 80% of reactive stroma associated with breast carcinoma is comprised of activated myofibroblasts or cancer-associated fibroblasts which secrete extracellular matrix proteins resulting in the desmoplasia that is associated with advanced breast tumor progression. Cancer-associated fibroblasts, transformed by cytokines such as transforming growth factor-β (TGF-β), secrete tumor promoting growth factors and extracellular matrix components, to promote tumor initiation, growth, and metastases. Inhibition of cancer-associated fibroblast proliferation and function may be an effective therapeutic strategy, since these cells play a vital role in carcinogenesis. Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, seven amino acid peptide hormone of the renin-angiotensin system with anti-proliferative and anti-fibrotic properties. We showed that Ang-(1-7) inhibited the growth of MDA-MB-231 human triple negative breast tumors growing in the mammary fat pads of athymic mice with a concomitant 3-fold decrease in interstitial tumor fibrosis (n=9-11, p<0.0001). Cancer-associated fibroblasts were isolated from orthotopic breast tumors, to assess the effect of Ang-(1-7) on fibroblast proliferation. The isolated tumoral fibroblasts stained positive for fibronectin, vimentin, collagen I, and β-smooth muscle actin, confirming that the isolated cells were activated myofibroblasts. Ang-(1-7) significantly reduced the growth of cancer-associated fibroblasts isolated from orthotopic triple negative breast tumors (n=4-5, p<0.05). The decrease in cancer-associated fibroblast proliferation was accompanied by attenuation of the activation of the growth-promoting mitogen-activated protein kinases (MAPK) ERK1 and ERK2 (n=3, p<0.001) as quantified by Western blot hybridization. In contrast, incubation of the heptapeptide hormone resulted in a 2.5-fold increase in the MAPK phosphatase DUSP1 (dual specificity phosphatase 1) in cancer-associated fibroblasts (n=3, p<0.05). These studies suggest that Ang-(1-7) promotes the dephosphorylation of MAPK by up-regulating DUSP1 to reduce this proliferative signaling pathway in cancer-associated fibroblasts and prevent tumor growth. TGF-β is a potent stimulator of fibroblast activation and plays an important role in promoting fibrosis, including activation of the MAP kinase pathway to stimulate fibroblast proliferation. TGF-β activates tumor-promoting cancer-associated fibroblasts by phosphorylation of Smad2/3 which translocates to the nucleus to induce pro-fibrotic gene expression. Stimulation of the Smad signaling pathway by TGF-β results in extracellular matrix protein synthesis and deposition as well as its own production, creating an autocrine cycle of fibroblast activation and extracellular matrix deposition. TGF-β was quantified by Western blot hybridization in protein homogenates from myofibroblasts isolated from orthotopic breast tumors. TGF-β stimulation of cancer-associated fibroblasts significantly increased phospho-Smad2/3 which was reduced approximately 60% by treatment with Ang-(1-7) (n=3, p<0.001), indicating that the heptapeptide inhibits both the growth of stromal fibroblasts as well as the signaling pathways that participate in extracellular matrix protein production. These findings suggest that Ang-(1-7) may serve as a first-in-class chemotherapeutic agent for triple negative breast cancer in part through a reduction in the proliferation and function of cancer-associated fibroblasts in the tumor microenvironment.
Citation Format: Alison L. Arter, Patricia E. Gallagher, E. Ann Tallant. Angiotensin-(1-7) attenuates the proliferation of cancer-associated fibroblasts in triple negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B34.
Collapse
|
33
|
Krishnan B, Smith TL, Dubey P, Zapadka ME, Torti FM, Willingham MC, Tallant EA, Gallagher PE. Angiotensin-(1-7) attenuates metastatic prostate cancer and reduces osteoclastogenesis. Prostate 2013; 73:71-82. [PMID: 22644942 PMCID: PMC3842188 DOI: 10.1002/pros.22542] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 05/03/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, heptapeptide hormone with anti-proliferative and anti-angiogenic properties. The primary objective of this study was to determine whether Ang-(1-7) effectively reduces prostate cancer metastasis in mice. METHODS Human PC3 prostate cancer cells were injected into the aortic arch via the carotid artery of SCID mice pre-treated with Ang-(1-7) or injected into the tibia of athymic mice, administered Ang-(1-7) for 5 weeks beginning 2 weeks post-injection. Tumor growth and volume were determined by bioluminescent and magnetic resonance imaging. The presence of tumors was confirmed by hematoxylin and eosin staining; TRAP histochemistry was used to identify osteolytic lesions. The effect of Ang-(1-7) on osteoclastogenesis was assessed in differentiated bone marrow cells. RESULTS Pre-treatment with Ang-(1-7) prevented metastatic tumor formation following intra-aortic injection of PC3 cells, while 83% of untreated mice developed tumors in metastatic sites. Circulating VEGF was significantly higher in control mice compared to mice administered Ang-(1-7). A 5-week regimen of the heptapeptide hormone attenuated intra-tibial tumor growth; Ang-(1-7) was significantly higher in the tibia of treated mice than in control animals. Osteoclastogenesis was reduced by 50% in bone marrow cells differentiated in the presence of Ang-(1-7), suggesting that the heptapeptide hormone prevents the formation of osteolytic lesions to reduce tumor survival in the bone microenvironment. CONCLUSIONS These findings suggest that Ang-(1-7) may serve as an anti-angiogenic and anti-metastatic agent for advanced prostate cancer. By extension, the heptapeptide hormone may provide effective therapy for bone metastasis produced from primary tumors of the lung and breast.
Collapse
Affiliation(s)
- Bhavani Krishnan
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
- Molecular Genetics & Genomics Program, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - Thomas L. Smith
- Department of Orthopedic Surgery, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - Purnima Dubey
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - Michael. E. Zapadka
- Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - Frank M. Torti
- Department of Cancer Biology Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - Mark C. Willingham
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - E. Ann Tallant
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
- Molecular Genetics & Genomics Program, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - Patricia E. Gallagher
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| |
Collapse
|
34
|
Krishnan B, Torti FM, Gallagher PE, Tallant EA. Angiotensin-(1-7) reduces proliferation and angiogenesis of human prostate cancer xenografts with a decrease in angiogenic factors and an increase in sFlt-1. Prostate 2013; 73:60-70. [PMID: 22644934 DOI: 10.1002/pros.22540] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/20/2012] [Indexed: 12/27/2022]
Abstract
BACKGROUND Prostate cancer is the most frequently diagnosed malignancy and the second-leading cause of cancer death in men. The purpose of this study was to determine the anti-proliferative and anti-angiogenic efficacy of angiotensin-(1-7) [Ang-(1-7)], an endogenous peptide hormone, in human prostate cancer xenografts. METHODS Human LNCaP prostate cancer cells were injected into the flank of athymic mice and tumors were treated with Ang-(1-7) for 54 days. Tumor growth and angiogenesis were determined by immunohistochemistry and western blot hybridization. RESULTS Ang-(1-7) markedly reduced the volume and wet weight of LNCaP xenograft tumors. Histological analysis of tumor sections from saline-treated mice showed increased Ki67 immunoreactivity and enhanced phosphorylation of the MAP kinases ERK1/2 compared to tumors from Ang-(1-7)-treated mice, suggesting that the heptapeptide reduces cell proliferation. Intratumoral vessel density was decreased in Ang-(1-7)-treated mice with an associated reduction in vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), suggesting that the heptapeptide attenuates vascularization by reducing angiogenic factors. Ang-(1-7) administration markedly increased the soluble fraction of VEGF receptor 1 (sFlt-1), with a concomitant reduction in VEGF receptors 1 and 2. sFlt-1 serves as a decoy receptor that traps VEGF and PlGF, making the ligands unavailable to membrane-bound VEGF receptors and preventing activation of pro-angiogenic signaling. CONCLUSIONS The decrease in PlGF and VEGF coupled with the increase in sFlt-1 suggests that Ang-(1-7) may serve as a novel anti-angiogenic therapy for prostate cancer. Further, the pleiotropic mechanisms of action by Ang-(1-7) may limit angiogenic resistance that occurs with VEGF inhibitors or receptor blockers.
Collapse
Affiliation(s)
- Bhavani Krishnan
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | | | | | | |
Collapse
|
35
|
Tallant EA, Carver KA, Gallagher PE. Abstract 512: Angiotensin-(1-7) Attenuates PDGF-dependent Migration of Vascular Smooth Muscle Cells. Hypertension 2012. [DOI: 10.1161/hyp.60.suppl_1.a512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Over one million percutaneous coronary intervention (PCI) procedures are performed each year and restenosis, the narrowing of the vessel lumen due to vascular damage, occurs in more than 40% of these patients. Previous studies by our laboratory demonstrated that infusion of angiotensin-(1-7) [Ang-(1-7)], an anti-proliferative peptide hormone of the renin-angiotensin system, attenuated neointimal formation after vascular injury which was associated with reduced vascular smooth muscle cell (VSMC) proliferation. However, prevention of restenosis after PCI requires inhibition of both VSMC proliferation and migration. In this study, the effect of Ang-(1-7) on VSMC migration was investigated to determine whether a decrease in VSMC migration also represents a component of the heptapeptide-induced reduction in neointimal formation. Platelet-derived growth factor (PDGF), a potent stimulus for VSMC migration, increased chemotaxis in a modified Boyden’s chamber; PDGF stimulated chemotaxis 228% over random migration and pre-treatment with Ang-(1-7) reduced the PDGF-mediated migration to 132% over random movement, a reduction of 42.1% (n=6, p<0.05). PDGF also stimulated directional migration in a wounding assay, by 600% over random migration; pre-treatment with Ang-(1-7) reduced directional migration in response to PDGF to 317% of random migration, a 40.4% decrease (n=5, p>0.01). The reduction in PDGF-mediated migration by Ang-(1-7) was associated with a significant decrease in the phosphorylation of tyrosine 1009 on the PDGF beta receptor as well as the src homology 2 phosphatase-2 (SHP-2) and the tyrosine kinase Src, two enzymes which are positive mediators of PDGF-induced migration. Pre-treatment with Ang-(1-7) attenuated the PDGF-dependent increase in the phosphoY1009-PDGF receptor by 60%, phosphoY580-SHP-2 by 56% and phosphoY416-Src by 45% (n=5, p<0.05). These data demonstrate that Ang-(1-7) inhibits VSMC migration to attenuate neointimal formation, which may result from a reduction in the phosphorylation of the PDGF receptor or attenuation of the cellular events resulting from receptor activation. Further, these results suggest that Ang-(1-7) may be administered as a targeted therapeutic to prevent vascular restenosis.
Collapse
|
36
|
Carver KA, Smith TL, Gallagher PE, Tallant EA. Abstract 530: Vascular Remodeling by Angiotensin Peptide Hormones Alters Reactivity of the Microcirculation. Hypertension 2012. [DOI: 10.1161/hyp.60.suppl_1.a530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endothelial dysfunction associated with hypertension leads to end-organ damage through impairment in tissue perfusion. Angiotensin II (Ang II) causes vascular remodeling and fibrotic stiffening and attenuates endothelial-dependent vasorelaxation. However, the heptapeptide hormone angiotensin-(1-7) [Ang-(1-7)] reduces the structural effects of Ang II and acutely vasodilates vessels
ex vivo
. Lewis rats were chronically treated with either Ang II, Ang-(1-7), or both angiotensin peptides to examine the effect of the peptide hormones on microvascular remodeling and reactivity of cremaster muscle arterioles
in vivo
. Cremaster arterioles (50 microns in diameter) were visualized by intravital microscopy to measure vascular reactivity. Ang II elevated systolic blood pressure by 43 mmHg, an effect that was not changed by co-administration of Ang-(1-7); Ang-(1-7) alone had no effect. Ang II increased the media to lumen ratio (by 82% compared to Sham, n=7, p<0.01) and perivascular fibrosis (by 133% compared to Sham, n=7, p<0.001), while co-treatment with Ang-(1-7) attenuated the Ang II-enhanced remodeling and fibrosis to values no different than Sham or Ang-(1-7) alone. Phenylephrine (PE) elicited vasoconstriction in Sham rats, reducing vessel diameter by 21%, and this effect was not altered in rats treated with Ang II. Although PE-constricted arterioles from Sham rats vasodilated in response to acetylcholine (Ach, a 31.4% increase in diameter), vessels from Ang II-treated rats had a blunted response to Ach (a 9% increase). These results suggest that the Ang II-mediated microvascular remodeling altered microvascular vasodilation. In contrast, arterioles from rats treated with Ang-(1-7) or the combination of Ang-(1-7) and Ang II did not constrict in response to PE or endothelin. However, acute administration of the nitric oxide synthase inhibitor L-NAME to Ang-(1-7)-treated rats restored the vasoconstrictive response to PE, indicating that Ang-(1-7) increases endogenous nitric oxide to maximally dilate microvascular arterioles and prevent constriction. These results suggest Ang-(1-7) may serve as an effective adjuvant therapy to attenuate end-organ damage by increasing blood flow and tissue perfusion caused by hypertension.
Collapse
|
37
|
Nautiyal M, Katakam PVG, Busija DW, Gallagher PE, Tallant EA, Chappell MC, Diz DI. Differences in oxidative stress status and expression of MKP-1 in dorsal medulla of transgenic rats with altered brain renin-angiotensin system. Am J Physiol Regul Integr Comp Physiol 2012; 303:R799-806. [PMID: 22914751 DOI: 10.1152/ajpregu.00566.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
ANG II-stimulated production of reactive oxygen species (ROS) through NADPH oxidase is suggested to activate MAPK pathways, which are implicated in neurally mediated pressor effects of ANG II. Emerging evidence suggests that ANG-(1-7) up regulates MAPK phosphatases to reduce MAPK signaling and attenuate actions of ANG II. Whether angiotensin peptides participate in long-term regulation of these systems in the brain is not known. Therefore, we determined tissue and mitochondrial ROS, as well as expression and activity of MAPK phosphatase-1 (MKP-1) in brain dorsal medullary tissue of hypertensive transgenic (mRen2)27 rats exhibiting higher ANG II/ANG-(1-7) tone or hypotensive transgenic rats with targeted decreased glial expression of angiotensinogen, ASrAOGEN (AS) exhibiting lower ANG II/ANG-(1-7) tone compared with normotensive Sprague-Dawley (SD) rats that serve as the control strain. Transgenic (mRen2)27 rats showed higher medullary tissue NADPH oxidase activity and dihydroethidium fluorescence in isolated mitochondria vs. SD or AS rats. Mitochondrial uncoupling protein 2 was lower in AS and unchanged in (mRen2)27 compared with SD rats. MKP-1 mRNA and protein expression were higher in AS and unchanged in (mRen2)27 compared with SD rats. AS rats also had lower phosphorylated ERK1/2 and JNK consistent with higher MKP-1 activity. Thus, an altered brain renin-angiotensin system influences oxidative stress status and regulates MKP-1 expression. However, there is a dissociation between these effects and the hemodynamic profiles. Higher ROS was associated with hypertension in (mRen2)27 and normal MKP-1, whereas the higher MKP-1 was associated with hypotension in AS, where ROS was normal relative to SD rats.
Collapse
Affiliation(s)
- Manisha Nautiyal
- The Hypertension and Vascular Research Center, Wake Forest Univ. School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1032, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Garcia-Espinosa MA, Lesser GJ, Debinski W, Tallant EA, Gallagher PE. Abstract 1938: Angiotensin-(1-7), a peptide hormone with therapeutic potential for the treatment of glioblastomas. Cancer Res 2012. [DOI: 10.1158/1538-7445.am2012-1938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Glioblastoma multiforme (GBM), the most common primary malignant brain tumor in adults, is characterized by aggressive proliferation throughout the brain parenchyma and enhanced angiogenesis. Despite multimodality treatment, GBM therapy is only palliative with a median patient survival of less than 10 to 12 months after diagnosis, indicating a need for novel agents with therapeutic potential. Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, seven amino acid peptide hormone with anti-proliferative and anti-angiogenic properties which provides targeted therapy by activating mas, a unique G protein-coupled receptor. In this study, Ang-(1-7) effectively reduced the growth of human GBM in an orthotopic mouse model. Athymic mice with brain tumors resulting from injection of human G48a GBM cells, isolated from a grade 4 astrocytoma, were treated for 28 days with 24 μg/kg/h Ang-(1-7), delivered by osmotic mini-pump. The G48 GBM cells formed an aggressive and invasive phenotype, with outgrowths extending into the brain parenchyma. Ang-(1-7) administration markedly reduced the average tumor burden (a 75% reduction in tumor mass) as compared to untreated control mice (9.4 ± 1.6 x1010 vs 2.4 ± 1.3 x1010 p/sec/cm2/sr, p < 0.022). Histological analysis of brain tissue sections from untreated mice showed a significantly higher percent of Ki67 positive immunoreactivity in tumors as compared to tumor tissue from Ang-(1-7)-treated animals, suggesting that the heptapeptide hormone reduces cell proliferation. In support, proliferation of G48a cultured cells which express the mas receptor was reduced approximately 50% following incubation with 100 nM Ang-(1-7) for five days. Ang-(1-7) treatment also resulted in a marked decrease in MAP kinase ERK1/ERK2 phosphorylation with a concomitant 2-fold increase in the MAP kinase phosphatase DUSP1, suggesting that the heptapeptide hormone negatively regulates GBM cell growth in part by attenuating ERK1/ERK2 activation. Intratumoral vessel density in GBMs from mice administered Ang-(1-7) was attenuated more than 50% as compared to tumors from control animals. VEGF mRNA and protein were decreased over time with a maximal reduction at 8 h in G48a cells following treatment with 100 nM Ang-(1-7). Conversely, the soluble VEGF receptor sFlt-1 was significantly increased in cells incubated with the heptapeptide hormone. sFlt-1, produced by alternative mRNA splicing of Flt-1, is secreted into the circulation and serves as an endogenous trap that sequesters VEGF family ligands, making the angiogenic factors unavailable to the cell-bound VEGF receptors and preventing the downstream activation of pro-angiogenic signaling pathways. Taken together, these studies suggest that Ang-(1-7) inhibits the growth of aggressive, invasive GMBs by pleiotrophic mechanisms and may serve as a first-in-class, targeted, anti-proliferative, anti-angiogenic chemotherapeutic agent for GBM.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1938. doi:1538-7445.AM2012-1938
Collapse
|
39
|
McCollum LT, Gallagher PE, Tallant EA. Angiotensin-(1-7) abrogates mitogen-stimulated proliferation of cardiac fibroblasts. Peptides 2012; 34:380-8. [PMID: 22326709 PMCID: PMC3326596 DOI: 10.1016/j.peptides.2012.01.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 01/24/2012] [Accepted: 01/24/2012] [Indexed: 12/16/2022]
Abstract
Previous studies showed that angiotensin-(1-7) [Ang-(1-7)] attenuates cardiac remodeling by reducing both interstitial and perivascular fibrosis. Although a high affinity binding site for Ang-(1-7) was identified on cardiac fibroblasts, the molecular mechanisms activated by the heptapeptide hormone were not identified. We isolated cardiac fibroblasts from neonatal rat hearts to investigate signaling pathways activated by Ang-(1-7) that participate in fibroblast proliferation. Ang-(1-7) reduced (3)H-thymidine, -leucine and -proline incorporation into cardiac fibroblasts stimulated with serum or the mitogen endothelin-1 (ET-1), demonstrating that the heptapeptide hormone decreases DNA, protein and collagen synthesis. The reduction in DNA synthesis by Ang-(1-7) was blocked by the AT((1-7)) receptor antagonist [d-Ala(7)]-Ang-(1-7), showing specificity of the response. Treatment of cardiac fibroblasts with Ang-(1-7) reduced the Ang II- or ET-1-stimulated increase in phospho-ERK1 and -ERK2. In contrast, Ang-(1-7) increased dual-specificity phosphatase DUSP1 immunoreactivity and mRNA, suggesting that the heptapeptide hormone increases DUSP1 to reduce MAP kinase phosphorylation and activity. Incubation of cardiac fibroblasts with ET-1 increased cyclooxygenase 2 (COX-2) and prostaglandin synthase (PGES) mRNAs, while Ang-(1-7) blocked the increase in both enzymes, suggesting that the heptapeptide hormone alters the concentration and the balance between the proliferative and anti-proliferative prostaglandins. Collectively, these results indicate that Ang-(1-7) participates in maintaining cardiac homeostasis by reducing proliferation and collagen production by cardiac fibroblasts in association with up-regulation of DUSP1 to reduce MAP kinase activities and attenuation of the synthesis of mitogenic prostaglandins. Increased Ang-(1-7) or agents that enhance production of the heptapeptide hormone may prevent abnormal fibrosis that occurs during cardiac pathologies.
Collapse
Affiliation(s)
- LaTronya T McCollum
- The Hypertension and Vascular Research Center, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1032, USA
| | | | | |
Collapse
|
40
|
McCollum LT, Gallagher PE, Ann Tallant E. Angiotensin-(1-7) attenuates angiotensin II-induced cardiac remodeling associated with upregulation of dual-specificity phosphatase 1. Am J Physiol Heart Circ Physiol 2011; 302:H801-10. [PMID: 22140049 DOI: 10.1152/ajpheart.00908.2011] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic hypertension induces cardiac remodeling, including left ventricular hypertrophy and fibrosis, through a combination of both hemodynamic and humoral factors. In previous studies, we showed that the heptapeptide ANG-(1-7) prevented mitogen-stimulated growth of cardiac myocytes in vitro, through a reduction in the activity of the MAPKs ERK1 and ERK2. In this study, saline- or ANG II-infused rats were treated with ANG-(1-7) to determine whether the heptapeptide reduces myocyte hypertrophy in vivo and to identify the signaling pathways involved in the process. ANG II infusion into normotensive rats elevated systolic blood pressure >50 mmHg, in association with increased myocyte cross-sectional area, ventricular atrial natriuretic peptide mRNA, and ventricular brain natriuretric peptide mRNA. Although infusion with ANG-(1-7) had no effect on the ANG II-stimulated elevation in blood pressure, the heptapeptide hormone significantly reduced the ANG II-mediated increase in myocyte cross-sectional area, interstitial fibrosis, and natriuretic peptide mRNAs. ANG II increased phospho-ERK1 and phospho-ERK2, whereas cotreatment with ANG-(1-7) reduced the phosphorylation of both MAPKs. Neither ANG II nor ANG-(1-7) altered the ERK1/2 MAPK kinase MEK1/2. However, ANG-(1-7) infusion, with or without ANG II, increased the MAPK phosphatase dual-specificity phosphatase (DUSP)-1; in contrast, treatment with ANG II had no effect on DUSP-1, suggesting that ANG-(1-7) upregulates DUSP-1 to reduce ANG II-stimulated ERK activation. These results indicate that ANG-(1-7) attenuates cardiac remodeling associated with a chronic elevation in blood pressure and upregulation of a MAPK phosphatase and may be cardioprotective in patients with hypertension.
Collapse
Affiliation(s)
- Latronya T McCollum
- The Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, NC 27157-1032, USA
| | | | | |
Collapse
|
41
|
Tallant EA, Holmes CH, Gallagher PE. Abstract 4220: Inhibition of cancer cell growth by muscadine grape seed and grape skin extracts. Cancer Res 2011. [DOI: 10.1158/1538-7445.am2011-4220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The muscadine grape (Vitis rotundifolia) is native to the Southeastern United States and muscadine grape seed products are marketed as dietary supplements, based upon their antioxidant properties. Extracts from muscadine grapes contain a number of antioxidants, including resveratrol and ellagic acid; however, the natural antioxidants found in grape seed extracts are predominantly procyanidins, while the grape skin extracts contain more anthocyanins. We investigated the effect of muscadine grape seed extracts (MSE) and muscadine grape skin extracts (MSKE) on the growth of human lung, colon, prostrate, skin, brain and breast cancers as well as human leukemias. Cells were incubated with increasing concentrations (from 0.5 to 50 μg/mL) of aqueous extracts of either MSE or MSKE and the total number of cells was quantified after 7 days. Both the MSE and MSKE inhibited the growth of A549 and SK-LU-1 human lung adenocarcinoma cancer cells (81.8% inhibition at the highest concentration) and HT29 and HCT116 human colon cancer cells (80.5% inhibition at the highest dose). Similarly, extracts from both muscadine grape seeds and skins inhibited the growth of LNCaP and PC3 human prostate cancer cells. The growth of U87 and U373 human glioblastoma cells and RPMI 7951 and SKMEL28 human skin cancer cells was dose-dependently reduced by treatment with the MSE or MSKE. Human leukemia cells were also incubated with increasing concentrations of the extracts; the growth of THP-1 human acute monocytic leukemia cells, HL-60 human acute promyelocytic cells, and K562 human chronic myelogenous leukemia cells was reduced by both muscadine grape extracts (average of 74.2% inhibition at the highest dose). Both the MSE and MSKE inhibited the growth of estrogen receptor-dependent ZR-75-1, HER2 over-expressing SKBR3, and triple negative MDA-MB-231 human breast cancer cells. The inhibition of growth by either extract was highest in the triple negative breast cancer cells (92.6% inhibition at the highest concentration). The reduction in human breast cancer cell growth was accompanied by a significant decrease in the phosphorylation and activation of the mitogen-activated protein kinases ERK1 and ERK2; MAP kinase activities were reduced 91% by MSE and 80% by MSKE in ZR-75-1 estrogen receptor-dependent breast cancer cells and 73% by MSE and 66% by MSKE in MDA-MB-231 triple negative breast cancer cells. There were no significant differences between the effects of the grape seed extract compared to the grape skin extract with any of the cell lines. These results demonstrate that extracts from muscadine grape seeds and muscadine grape skins inhibit the growth of human lung, colon, prostate, breast, skin, brain and leukemia cells in vitro, suggesting that further studies are warranted to investigate their potential use in the prevention or treatment of cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4220. doi:10.1158/1538-7445.AM2011-4220
Collapse
Affiliation(s)
- E. Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | | | | |
Collapse
|
42
|
Arter AL, Cook KL, Soto-Pantoja DL, Gallagher PE, Tallant EA. Abstract 3274: Molecular mechanisms for the angiotensin-(1-7)-mediated reduction in triple negative breast cancer. Cancer Res 2011. [DOI: 10.1158/1538-7445.am2011-3274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Breast cancer is the most common type of cancer in women and the second leading cause of death, with approximately 40,000 deaths each year. Triple negative breast cancer, which accounts for 10-15% of all breast cancers, disproportionately affects younger women as well as women of African-American and Hispanic descent. Triple negative breast cancer cells do not express estrogen or progesterone receptors nor over-express human epidermal growth factor receptor 2 (HER2) and thus do not respond to targeted therapies, limiting treatment options to cytotoxic drugs. Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, seven amino acid peptide hormone of the renin-angiotensin system which inhibits cell growth by activation of the unique G protein-coupled receptor mas. We showed that Ang-(1-7) significantly reduced the in vivo growth of human triple negative MDA-MB-231 breast tumors in an orthotopic model, with a significant decrease in both tumor volume and wet weight compared with saline controls. The heptapeptide inhibited cell proliferation, reducing Ki67 immunoreactivity and activity of the mitogen-activated protein kinases ERK1 and ERK2 in triple negative breast tumors. Ang-(1-7) also reduced the phosphorylation of Akt (protein kinase B), which is phosphorylated by phosphoinositide-dependent kinases in response to receptor-mediated activation of phosphatidylinositol-3-kinase (PI3 kinase), to stimulate cell proliferation and increase cell survival. The heptapeptide reduced Ser473 phospho-Akt in MDA-MB-231 cells by 65%, with a maximal effect at 4 h, in agreement with a 51% reduction in phospho-Ser473 in MDA-MB-231 tumors in mice treated with Ang-(1-7). Phospho-Thr308 Akt was also reduced approximately 45% by treatment of MDA-MB-231 cells with Ang-(1-7), with a maximal effect after 4 h (n = 3-4, p < 0.05). Since full activation of Akt requires phosphorylation on both serine and threonine residues, these results suggest that Ang-(1-7) significantly reduces Akt activation to inhibit cell growth. Treatment of mice with Ang-(1-7) significantly decreased vessel density in MDA-MB-231 tumors (by 70%), in association with a reduction in the pro-angiogenic factors vascular endothelial growth factor (VEGF, by 72%) and placental growth factor (PlGF, by 58%) [n = 5, p < 0.05]. The heptapeptide caused a concomitant increase in the anti-angiogenic factor sFlt-1, the soluble portion of the VEGF receptor, in triple negative breast cancer cells. Treatment of MDA-MB-231 cells with Ang-(1-7) increased sFlt-1 approximately 7.6-fold, with a maximal effect after 4 h (n = 3-5, p < 0.05). Since sFlt-1 binds VEGF and PlGF but lacks the tyrosine kinase domain, it reduces circulating levels of VEGF and PlGF to attenuate tumor angiogenesis. These results suggest that Ang-(1-7) inhibits tumor cell proliferation and survival as well as angiogenesis and may be a first-in-class targeted treatment for triple negative breast cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3274. doi:10.1158/1538-7445.AM2011-3274
Collapse
Affiliation(s)
- Alison L. Arter
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | | | | | | | - E. Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| |
Collapse
|
43
|
Krishnan B, Smith TL, Dubey P, Zapadka ME, Torti FM, Tallant EA, Gallagher PE. Abstract 550: Angiotensin-(1-7) inhibits prostate cancer angiogenesis and metastasis to bone. Cancer Res 2011. [DOI: 10.1158/1538-7445.am2011-550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Prostate cancer is the most frequently diagnosed malignancy and the second-leading cause of cancer death in men. We previously showed that angiotensin-(1-7) [Ang-(1-7)], a seven amino acid peptide hormone, significantly inhibited the growth of human lung cancer cells and tumors, with an associated reduction in angiogenesis. Since previous epidemiological studies suggest that administration of anti-hypertensive drugs which increase Ang-(1-7) reduces the risk of sex-specific cancers, we investigated the effects of the heptapeptide on prostate cancer. Ang-(1-7) markedly reduced human LNCaP prostate tumor xenograft size by 72% in association with a decrease in Ki67 and CD34, markers of tumor proliferation and angiogenesis, respectively. Ang-(1-7) significantly decreased both vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) with a concomitant 12-fold increase in the soluble fraction of VEGF receptor 1 (sFlt-1); sFlt-1 is a decoy receptor that traps PlGF and VEGF, rendering the ligands unavailable to membrane-associated VEGF receptors. Ang-(1-7) also inhibits metastasis of prostate cancer to bone, which is the primary cause of mortality in prostate cancer patients. Human prostate cancer cells were injected into the circulation of SCID mice pretreated with Ang-(1-7), to determine the effect of the heptapeptide on the migration of cells to the metastatic environment. Six weeks following the injection of stably transfected luciferase tagged PC3 (PC3Luc) cells, 5 of the 6 untreated mice developed metastatic bone tumors, measured by bioluminescence and MRI imaging; in contrast, no detectable tumors were observed in mice administered Ang-(1-7). Circulating VEGF was significantly higher in untreated mice compared to mice treated with the heptapeptide. Ang-(1-7) also significantly reduced metastatic tumor formation in athymic mice injected with PC3Luc cells in the tibia as determined by bioluminescence, MRI imaging and immunohistochemistry. Osteolytic lesions as assessed by tartrate resistant acid phosphatase (TRAP) staining were observed surrounding the tibial tumors in control animals. A 50% reduction in osteoclastogenesis was observed when bone marrow cells were differentiated with RANK ligand and colony-stimulating factor in the presence of Ang-(1-7) [from 78.6 ± 8.0 TRAP+-multinucleated cells/field to 33.6 ± 4], suggesting that Ang-(1-7) hinders tumor survival in the bone microenvironment and prevents the formation of osteolytic lesions. Since VEGF is known to facilitate tumor growth and osteolytic disease by enhancing osteoclast survival, the inhibition of VEGF coupled with the reduction in osteoclastogenesis may mediate the inhibition of metastatic skeletal tumor formation. These results suggest that Ang-(1-7) may serve as an anti-proliferative, anti-angiogenic, and anti-metastatic agent for the treatment of prostate cancer that targets the tumor microenvironment.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 550. doi:10.1158/1538-7445.AM2011-550
Collapse
Affiliation(s)
| | - Thomas L. Smith
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | - Purnima Dubey
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | | | - Frank M. Torti
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | - E. Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | | |
Collapse
|
44
|
Gallagher PE, Maglic D, Krishnan B, Castellino SM, Tallant EA. Abstract 5349: Angiotensin-(1-7) inhibits the growth of human pediatric rhabdomyosarcoma in a mouse xenograft model. Cancer Res 2011. [DOI: 10.1158/1538-7445.am2011-5349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Pediatric sarcomas are rare tumors encompassing a diversity of histology and can arise in almost any part of the body. Despite overall advances in pediatric cancer treatment, outcomes in sarcomas have improved little in the past 2 decades. Based on the rarity of these tumors and the growing body of knowledge on late effects of conventional therapies in pediatric cancer survivors, it is imperative to develop new targeted agents for the treatment of these childhood diseases. In published studies, we showed that angiotensin-(1-7) [Ang-(1-7)], an endogenous seven amino acid peptide hormone, inhibited the proliferation of human lung cancer cells through activation of a unique AT(1-7) receptor and significantly reduced the size of human A549 lung tumor xenografts, in association with a decrease in the density of blood vessels and pro-angiogenic factors. These studies are in agreement with our Phase I clinical trial in which adult patients displaying clinical benefit had reduced circulating levels of the angiogenic factor PlGF; two of the four patients showing a clinical response to Ang-(1-7) had a primary sarcoma. The purpose of this study was to determine whether Ang-(1-7) may serve as a targeted chemotherapeutic agent for the treatment of pediatric sarcoma. Ang-(1-7) significantly inhibited the growth of A673 cells, a pediatric rhabdomyosarcoma cell line which expresses the AT(1-7) receptor mas. More importantly, the heptapeptide significantly reduced the proliferation of human A673 tumor xenograft growth in vivo. A673 rhabdomyosarcoma cells were injected into the flank of athymic male mice; the tumors grew to approximately 100 mm3 followed by infusion of saline or 24 µg/kg/h Ang-(1-7) for 18 days. The average volume of the tumors from mice treated with the heptapeptide was approximately 6-fold less than the size of the tumors from control animals (4770.6 ± 860.4 mm3 versus 664.8 ± 190.9 mm3; n = 6, p < 0.001). In addition, Ang-(1-7) administration markedly reduced tumor weight, from 7.2 ± 1.5 g in the saline-treated mice to 2.2 ± 0.8 g in Ang-(1-7)-treated mice (n = 6, p < 0.02). The decrease in tumor growth from Ang-(1-7)-medicated mice was associated with an approximate 50% reduction in immunoreactive Ki67, suggesting that the heptapeptide reduces tumor cell proliferation. Tumors from mice treated with Ang-(1-7) also showed a marked decrease in vessel density as assessed by CD34 immunoreactivity and morphology (7.6 ± 0.9 to 3.6 ± 0.6 vessels/per field, p < 0.001), demonstrating that the observed reduction in tumor growth was due, in part, to inhibition of angiogenesis. These studies suggest that the heptapeptide has both anti-proliferative and anti-angiogenic properties and that Ang-(1-7) may be a new, first-in-class compound for the treatment of pediatric sarcoma targeting a specific AT(1-7) receptor mas.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5349. doi:10.1158/1538-7445.AM2011-5349
Collapse
Affiliation(s)
| | - Dino Maglic
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | | | | | - E. Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| |
Collapse
|
45
|
Diz DI, Arnold AC, Nautiyal M, Isa K, Shaltout HA, Tallant EA. Angiotensin peptides and central autonomic regulation. Curr Opin Pharmacol 2011; 11:131-7. [PMID: 21367658 DOI: 10.1016/j.coph.2011.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 02/08/2011] [Indexed: 10/18/2022]
Abstract
Aging, hypertension, and fetal-programmed cardiovascular disease are associated with a functional deficiency of angiotensin (Ang)-(1-7) in the brain dorsomedial medulla. The resulting unrestrained activity of Ang II in brainstem regions negatively impacts resting mean arterial pressure, sympathovagal balance, and baroreflex sensitivity for control of heart rate. The differential effects of Ang II and Ang-(1-7) may be related to the cellular sources of these peptides as well as different precursor pathways. Long-term alterations of the brain renin-angiotensin system may influence signaling pathways including phosphoinositol-3-kinase and mitogen-activated protein kinase and their downstream mediators, and as a consequence may influence metabolic function. Differential regulation of signaling pathways in aging and hypertension by Ang II versus Ang-(1-7) may contribute to the autonomic dysfunction accompanying these states.
Collapse
Affiliation(s)
- Debra I Diz
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
| | | | | | | | | | | |
Collapse
|
46
|
Abstract
Angiotensin-(1-7) [Ang-(1-7)] is an endogenous 7-amino acid peptide hormone of the renin-angiotensin system that has antiproliferative properties. In this study, Ang-(1-7) inhibited the growth of cancer-associated fibroblasts (CAF) and reduced fibrosis in the tumor microenvironment. A marked decrease in tumor volume and weight was observed in orthotopic human breast tumors positive for the estrogen receptor (BT-474 or ZR-75-1) and HER2 (BT-474) following Ang-(1-7) administration to athymic mice. Ang-(1-7) concomitantly reduced interstitial fibrosis in association with a significant decrease in collagen I deposition, along with a similar reduction in perivascular fibrosis. In CAFs isolated from orthotopic breast tumors, the heptapeptide markedly attenuated in vitro growth as well as reduced fibronectin, transforming growth factor-β (TGF-β), and extracellular signal-regulated kinase 1/2 kinase activity. An associated increase in the mitogen-activated protein kinase (MAPK) phosphatase DUSP1 following treatment with Ang-(1-7) suggested a potential mechanism by which the heptapeptide reduced MAPK signaling. Consistent with these in vitro observations, immunohistochemical analysis of Ang-(1-7)-treated orthotopic breast tumors revealed reduced TGF-β and increased DUSP1. Together, our findings indicate that Ang-(1-7) targets the tumor microenvironment to inhibit CAF growth and tumor fibrosis.
Collapse
Affiliation(s)
- Katherine L Cook
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
| | | | | | | |
Collapse
|
47
|
Tallant EA, Ferrario CM, Gallagher PE. Cardioprotective role for angiotensin-(1-7) and angiotensin converting enzyme 2 in the heart. Future Cardiol 2010; 2:335-42. [PMID: 19804091 DOI: 10.2217/14796678.2.3.335] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Angiotensin-(1-7), a biologically active peptide of the renin-angiotensin system, is cardioprotective following ischemia/reperfusion and reduces cardiac hypertrophy. A recently discovered homolog of angiotensin converting enzyme (ACE), ACE2, is present in the heart and synthesizes angiotensin-(1-7) from angiotensin II. Cardiac ACE2 is elevated following inhibition of Ang II subtype 1 (AT(1)) receptors or blockade of angiotensin II production, suggesting that angiotensin-(1-7) plays a role in the beneficial effects of AT(1) receptor antagonists and ACE inhibitors in the heart. An increase in ACE2 activity and the production of angiotensin-(1-7) may thus represent a novel therapy for heart failure following myocardial infarction.
Collapse
Affiliation(s)
- E Ann Tallant
- The Hypertension and Vascular Disease Center, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1032, USA.
| | | | | |
Collapse
|
48
|
Krishnan B, Gallagher PE, Tallant EA. Abstract 1299: Angiotensin-(1-7) inhibits angiogenesis in human prostate cancer xenografts through an increase in soluble vascular endothelial growth factor receptor 1 (sFLT1). Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-1299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Prostate cancer is the most frequently diagnosed malignancy and the second-leading cause of cancer death in men. We showed that angiotensin-(1-7) [Ang-(1-7)], a seven amino acid peptide hormone of the renin-angiotensin system, significantly inhibited the proliferation of human lung cancer cells and attenuated the growth of non-small cell adenocarcinoma tumors in a xenograft model, with an associated reduction in angiogenesis. Since previous epidemiological studies suggest that treatment with anti-hypertensive drugs which increase Ang-(1-7) reduces the risk of sex-specific cancers, we investigated the effects of the heptapeptide on prostate cancer. Ang-(1-7) significantly reduced the growth of both androgen-responsive LNCaP human prostate cancer cells and PC3 cells derived from a bone metastasis of a patient with prostate cancer. Athymic mice with xenograft LNCaP human prostate tumors were treated with Ang-(1-7) for 54 days. Treatment with the heptapeptide resulted in an 84.5% reduction in tumor volume and a 72% decrease in tumor weight. The reduction in tumor size was associated with a 78% decrease in Ki67 immunoreactivity, suggesting that Ang-(1-7) inhibits tumor cell proliferation. Treatment with the heptapeptide also caused a 50% decrease in the density of tumor vessels, identified by morphology using an antibody to CD34 to label endothelial cells, suggesting that Ang-(1-7) reduces angiogenesis. The reduction in angiogenesis by heptapeptide administration was associated with a decrease in the mRNA and protein of vascular endothelial growth factor (VEGF) (a 48% reduction in protein and an 82% reduction in mRNA) and placental growth factor (PlGF) (a 72% reduction in both protein and mRNA), key factors involved in angiogenesis. Incubation of LnCaP cells with 100 nM Ang-(1-7) for 24 h also caused a significant reduction in the secretion of both VEGF (64%) and PlGF (71%). The decrease in PlGF and VEGF correlated with a 12-fold increase in the soluble fraction of VEGF receptor 1 (sFLT1) [from 0.12 ± 0.06 relative density units in tumors from saline-treated mice compared to 1.41 ± 0.30 relative density units in tumors from Ang-(1-7)-treated mice, n = 5, p < 0.001]. sFLT1 is a decoy receptor that traps PlGF and VEGF, making the ligands unavailable to membrane-associated VEGF receptors and blocking activation of key angiogenic signaling pathway. While anti-angiogenic therapies targeting VEGF revolutionized cancer treatment, tumors develop resistance to these agents and patients have an increased risk of developing metastases, which may result from production of alternate pro-angiogenic factors, such as PlGF. Since treatment with Ang-(1-7) reduces both VEGF and PlGF and concomitantly increases sFLT1 to attenuate angiogenic signaling, the heptapeptide may represent a novel anti-angiogenic therapeutic in the treatment of prostate cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1299.
Collapse
Affiliation(s)
| | | | - E Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| |
Collapse
|
49
|
Calipari ES, Tallant EA, Lesser G, Debinski W, Gallagher PE. Abstract 3575: Angiotensin-(1-7) and temozolomide provide combinatorial inhibition of glioblastoma cell growth. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-3575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Glioblastoma multiforme (GBM), an anaplastic, highly cellular, poorly differentiated tumor, is the predominant malignant brain tumor diagnosed in adults. Standard treatment for glioblastoma consists of surgical resection and radiation with the possible addition of chemotherapy. For example, temozolomide, an orally active imidazotetrazinone pro-drug that exerts its anti-neoplastic effect by interfering with DNA replication, proved to be efficacious in patients with glioblastoma. Even with aggressive therapy, the average survival rate for most patients is less than one year. This poor prognosis suggests a need for novel approaches for the treatment of glioblastoma. Angiotensin-(1-7) [Ang-(1-7)], an endogenous, seven amino acid peptide targeting the mas receptor, significantly reduced the serum-stimulated growth of human G48a glioblastoma cells isolated from a primary, high-grade astrocytoma. Incubation of the glioblastoma cells for 4 days with 100 nM Ang-(1-7) or 10 μM temozolomide caused a greater than 40% reduction in cell growth. More importantly, an additive inhibition (72.0% decrease) of glioblastoma cell growth was obtained by co-incubation of Ang-(1-7) and temozolomide. The combinatorial effect of the two drugs suggests differing mechanisms of action. Treatment of human G48a cells with 100 nM Ang-(1-7) reduced phosphorylation of the mitogen-activated protein kinases, extracellular signal-regulated kinase (ERK)1 and ERK2, by 66.8% and 45.5% (n = 3), respectively, indicating that the anti-proliferative effects may occur, at least in part, through inhibition of the ERK signal transduction pathway. The decrease in ERK activation was associated with a 4.8 ± 1.3-fold increase in the dual-specificity phosphatase DUSP1/MKP-1 (n = 4; p<0.05). This suggests that the heptapeptide regulates DUSP1 to reduce ERK1/ERK2 auto-phosphorylation and activation and inhibit glioblastoma cell growth. Ang-(1-7) treatment also caused a time-dependent decrease in both vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) mRNAs with maximal attenuation at 8 and 16 h, respectively (VEGF - 1.0 ± 0.1 vs. 0.58 ± 0.14; p<0.05; n=5; PlGF - 1.0 ± 0.1 vs. 0.62 ± 0.12; p<0.05; n=5). This reduction correlates with results from our recently completed Phase I clinical trial demonstrating a decrease in plasma PlGF in four patients who exhibited stable disease for greater than 3 months following treatment with Ang-(1-7). Taken together, these data suggest that Ang-(1-7) may serve as a first-in-class, targeted, anti-angiogenic chemotherapeutic agent for glioblastoma. Since Ang-(1-7) exerts its anti-proliferative effects through activation of the G protein-coupled receptor mas, representing a unique mechanism of action distinct from other cell growth modulators, the heptapeptide could be administered singly or with other chemotherapeutic agents to provide synergistic effects.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3575.
Collapse
Affiliation(s)
| | - E Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | - Glenn Lesser
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | | | | |
Collapse
|
50
|
Cook KL, Tallant EA, Gallagher PE. Abstract 2273: Angiotensin-(1-7) reduces angiogenesis and fibrosis in orthotopic breast cancer. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-2273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Angiotensin-(1-7) [Ang-(1-7)] is an endogenous seven-amino acid peptide hormone of the renin-angiotensin system with anti-proliferative properties. We previously showed that Ang-(1-7) significantly inhibited the growth of non-small cell lung adenocarcinoma in a xenograft mouse model in association with a reduction in angiogenesis. In a recently completed Phase I clinical trial conducted in the Wake Forest University Comprehensive Cancer Center, we reported that Ang-(1-7) significantly reduced the pro-angiogenic factor placental growth factor (PlGF) in four patients who had stable disease for greater than 3 months, suggesting that Ang-(1-7) is a novel anti-angiogenic drug for the treatment of cancer. In this study, BT-474 human epidermal growth factor receptor 2 (HER2) over-expressed, estrogen receptor (ER) positive breast cancer cells or ZR-75-1 ER positive breast cancer cells were injected into mammary fat pads of athymic mice and treated with Ang-(1-7), to determine the effect of the drug on breast cancer. After the tumors grew to 100-200 mm3, mice were treated with either saline or 24 µg/kg/h Ang-(1-7) for 18 days. Treatment with Ang-(1-7) reduced tumor volume (68.2% in BT-474 tumors and 77.0% in ZR-75-1 tumors) and tumor weight (38.9% in BT-474 tumors and 50% in ZR-75-1 tumors), indicating that the heptapeptide inhibits breast tumor growth. Vessel density was also decreased 50% by the heptapeptide, demonstrating that Ang-(1-7) reduced angiogenesis in breast tumors. Tumoral fibrosis, measured by picrosirius red collagen staining, was attenuated in Ang-(1-7)-treated breast tumors. The heptapeptide reduced interstitial fibrosis from 4.91 ± 0.96%/field to 1.2 ± 0.2 in BT474 tumors and from 23.3 ± 2.4%/field to 8.3 ± 0.8 in ZR-75-1 tumors, in association with a 66% reduction in collagen I deposition. Treatment with Ang-(1-7) also reduced perivascular fibrosis in BT-474 tumors, from 49.3 ± 3.2% fibrosis/vessel to 13.4 ± 2.2% fibrosis/vessel. Ang-(1-7) markedly attenuated the in vitro growth of fibroblasts isolated from orthotopic breast tumors. Treatment of tumoral fibroblasts with Ang-(1-7) reduced fibronectin protein by 40%, in association with a 50% decrease in transforming growth factor-β (TGF-β). Ang-(1-7) also caused a 2-fold increase in the mitogen-activated protein (MAP) kinase phosphatase DUSP1, with an associated 50% decrease in MAP kinase ERK1 and ERK2 activities, suggesting that the heptapeptide increases DUSP1 to reduce MAP kinase signaling. This is the first report that Ang-(1-7) targets the tumor microenvironment, by inhibiting the growth of tumor-associated fibroblasts to reduce fibrosis. Collectively, these results suggest that Ang-(1-7) may serve as a first-in-class chemotherapeutic agent for breast cancer, targeting the tumor microenvironment through a reduction in angiogenesis and a decrease in tumor fibrosis.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2273.
Collapse
Affiliation(s)
| | - E. Ann Tallant
- 1Wake Forest University School of Medicine, Winston-Salem, NC
| | | |
Collapse
|