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Gaumond SI, Abdin R, Costoya J, Schally AV, Jimenez JJ. Exploring the role of GHRH antagonist MIA-602 in overcoming Doxorubicin-resistance in acute myeloid leukemia. Oncotarget 2024; 15:248-254. [PMID: 38588464 PMCID: PMC11001269 DOI: 10.18632/oncotarget.28579] [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] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
Acute myeloid leukemia (AML) is characterized by the rapid proliferation of mutagenic hematopoietic progenitors in the bone marrow. Conventional therapies include chemotherapy and bone marrow stem cell transplantation; however, they are often associated with poor prognosis. Notably, growth hormone-releasing hormone (GHRH) receptor antagonist MIA-602 has been shown to impede the growth of various human cancer cell lines, including AML. This investigation examined the impact of MIA-602 as monotherapy and in combination with Doxorubicin on three Doxorubicin-resistant AML cell lines, KG-1A, U-937, and K-562. The in vitro results revealed a significant reduction in cell viability for all treated wild-type cells. Doxorubicin-resistant clones were similarly susceptible to MIA-602 as the wild-type counterpart. Our in vivo experiment of xenografted nude mice with Doxorubicin-resistant K-562 revealed a reduction in tumor volume with MIA-602 treatment compared to control. Our study demonstrates that these three AML cell lines, and their Doxorubicin-resistant clones, are susceptible to GHRH antagonist MIA-602.
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Affiliation(s)
- Simonetta I Gaumond
- Dr. Philip Frost Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Rama Abdin
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Joel Costoya
- Dr. Philip Frost Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | | | - Joaquin J Jimenez
- Dr. Philip Frost Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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Rodrigues-Dos-Santos K, Soares GM, Guimarães DSPSF, Araújo TR, Vettorazzi JF, Zangerolamo L, Marconato-Júnior E, Cai R, Sha W, Schally AV, Boschero AC, Barbosa HCL. Effects of growth hormone-releasing hormone agonistic analog MR-409 on insulin-secreting cells under cyclopiazonic acid-induced endoplasmic reticulum stress. Mol Cell Endocrinol 2021; 535:111379. [PMID: 34252492 DOI: 10.1016/j.mce.2021.111379] [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: 03/16/2021] [Revised: 06/11/2021] [Accepted: 06/29/2021] [Indexed: 11/18/2022]
Abstract
The endoplasmic reticulum (ER) stress is one of the mechanisms related to decreased insulin secretion and beta cell death, contributing to the progress of type 2 diabetes mellitus (T2D). Thus, investigating agents that can influence this process would help prevent the development of T2D. Recently, the growth-hormone-releasing hormone (GHRH) action has been demonstrated in INS-1E cells, in which it increases cell proliferation and insulin secretion. As the effects of GHRH and its agonists have not been fully elucidated in the beta cell, we proposed to investigate them by evaluating the role of the GHRH agonist, MR-409, in cells under ER stress. Our results show that the agonist was unable to ameliorate or prevent ER stress. However, cells exposed to the agonist showed less oxidative stress and greater survival even under ER stress. The mechanisms by which GHRH agonist, MR-409, leads to these outcomes require further investigation.
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Affiliation(s)
- Karina Rodrigues-Dos-Santos
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
| | - Gabriela M Soares
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
| | - Dimitrius S P S F Guimarães
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
| | - Thiago R Araújo
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
| | - Jean F Vettorazzi
- Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil; Educational Union of Cascavel, UNIVEL, Cascavel, Parana, Brazil
| | - Lucas Zangerolamo
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
| | - Emilio Marconato-Júnior
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
| | - Renzhi Cai
- Veterans Affairs Medical Center, 1201 NW 16th Street, Research Service (151), Room 2A103C, Miami, FL, 33125, United States; Departments of Pathology and Medicine, Divisions of Hematology/Oncology and Endocrinology, Miller School of Medicine, University of Miami, 1600 NW 10th Avenue #1140, Miami, FL, 33136, United States
| | - Wei Sha
- Veterans Affairs Medical Center, 1201 NW 16th Street, Research Service (151), Room 2A103C, Miami, FL, 33125, United States; Departments of Pathology and Medicine, Divisions of Hematology/Oncology and Endocrinology, Miller School of Medicine, University of Miami, 1600 NW 10th Avenue #1140, Miami, FL, 33136, United States
| | - Andrew V Schally
- Veterans Affairs Medical Center, 1201 NW 16th Street, Research Service (151), Room 2A103C, Miami, FL, 33125, United States; Departments of Pathology and Medicine, Divisions of Hematology/Oncology and Endocrinology, Miller School of Medicine, University of Miami, 1600 NW 10th Avenue #1140, Miami, FL, 33136, United States.
| | - Antônio C Boschero
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
| | - Helena C L Barbosa
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, P.O. Box 6109, CEP: 13083-865, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil.
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Recinella L, Chiavaroli A, Orlando G, Ferrante C, Gesmundo I, Granata R, Cai R, Sha W, Schally AV, Brunetti L, Leone S. Growth hormone-releasing hormone antagonistic analog MIA-690 stimulates food intake in mice. Peptides 2021; 142:170582. [PMID: 34051291 DOI: 10.1016/j.peptides.2021.170582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 01/14/2021] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 12/26/2022]
Abstract
In addition to its metabolic and endocrine effects, growth hormone-releasing hormone (GHRH) was found to modulate feeding behavior in mammals. However, the role of recently synthetized GHRH antagonist MIA-690 and MR-409, a GHRH agonist, on feeding regulation remains to be evaluated. We investigated the effects of chronic subcutaneous administration of MIA-690 and MR-409 on feeding behavior and energy metabolism, in mice. Compared to vehicle, MIA-690 increased food intake and body weight, while MR-409 had no effect. Both analogs did not modify locomotor activity, as well as subcutaneous, visceral and brown adipose tissue (BAT) mass. A significant increase of hypothalamic agouti-related peptide (AgRP) gene expression and norepinephrine (NE) levels, along with a reduction of serotonin (5-HT) levels were found after MIA-690 treatment. MIA-690 was also found able to decrease gene expression of leptin in visceral adipose tissue. By contrast, MR-409 had no effect on the investigated markers. Concluding, chronic peripheral administration of MIA-690 could play an orexigenic role, paralleled by an increase in body weight. The stimulation of feeding could be mediated, albeit partially, by elevation of AgRP gene expression and NE levels and decreased 5-HT levels in the hypothalamus, along with reduced leptin gene expression, in the visceral adipose tissue.
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Affiliation(s)
- Lucia Recinella
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy.
| | | | - Giustino Orlando
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy.
| | - Claudio Ferrante
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy.
| | - Iacopo Gesmundo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin and Città Della Salute e Della Scienza Hospital, Turin, 10126, Italy.
| | - Riccarda Granata
- Division of Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Turin and Città Della Salute e Della Scienza Hospital, Turin, 10126, Italy.
| | - Renzhi Cai
- Veterans Affairs Medical Center, Miami, FL, 33125, United States; Division of Endocrinology, Diabetes and Metabolism, and Division of Medical/Oncology, Department of Medicine, and Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL33136 and Sylvester Comprehensive Cancer Center, Miami, FL, 33136, United States.
| | - Wei Sha
- Veterans Affairs Medical Center, Miami, FL, 33125, United States; Division of Endocrinology, Diabetes and Metabolism, and Division of Medical/Oncology, Department of Medicine, and Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL33136 and Sylvester Comprehensive Cancer Center, Miami, FL, 33136, United States.
| | - Andrew V Schally
- Veterans Affairs Medical Center, Miami, FL, 33125, United States; Division of Endocrinology, Diabetes and Metabolism, and Division of Medical/Oncology, Department of Medicine, and Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL33136 and Sylvester Comprehensive Cancer Center, Miami, FL, 33136, United States.
| | - Luigi Brunetti
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy.
| | - Sheila Leone
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy.
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4
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Cen LP, Ng TK, Liang JJ, Xu C, Zhuang X, Liu YF, Chen SL, Xu Y, Yang Q, Yuan XL, Qin YJ, Chan SO, Chen H, Zhang M, Schally AV, Pang CP. Agonist of growth hormone-releasing hormone enhances retinal ganglion cell protection induced by macrophages after optic nerve injury. Proc Natl Acad Sci U S A 2021; 118:e1920834118. [PMID: 34244423 PMCID: PMC8285901 DOI: 10.1073/pnas.1920834118] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Optic neuropathies are leading causes of irreversible visual impairment and blindness, currently affecting more than 100 million people worldwide. Glaucoma is a group of optic neuropathies attributed to progressive degeneration of retinal ganglion cells (RGCs). We have previously demonstrated an increase in survival of RGCs by the activation of macrophages, whereas the inhibition of macrophages was involved in the alleviation on endotoxin-induced inflammation by antagonist of growth hormone-releasing hormone (GHRH). Herein, we hypothesized that GHRH receptor (GHRH-R) signaling could be involved in the survival of RGCs mediated by inflammation. We found the expression of GHRH-R in RGCs of adult rat retina. After optic nerve crush, subcutaneous application of GHRH agonist MR-409 or antagonist MIA-602 promoted the survival of RGCs. Both the GHRH agonist and antagonist increased the phosphorylation of Akt in the retina, but only agonist MR-409 promoted microglia activation in the retina. The antagonist MIA-602 reduced significantly the expression of inflammation-related genes Il1b, Il6, and Tnf Moreover, agonist MR-409 further enhanced the promotion of RGC survival by lens injury or zymosan-induced macrophage activation, whereas antagonist MIA-602 attenuated the enhancement in RGC survival. Our findings reveal the protective effect of agonistic analogs of GHRH on RGCs in rats after optic nerve injury and its additive effect to macrophage activation, indicating a therapeutic potential of GHRH agonists for the protection of RGCs against optic neuropathies especially in glaucoma.
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Affiliation(s)
- Ling-Ping Cen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
- Shantou University Medical College, 515041 Shantou, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Jia-Jian Liang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Ciyan Xu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Xi Zhuang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Yu-Fen Liu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
- Shantou University Medical College, 515041 Shantou, China
| | - Shao-Lang Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Yanxuan Xu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Qichen Yang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Xiang-Ling Yuan
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
- Shantou University Medical College, 515041 Shantou, China
| | - Yong Jie Qin
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital and Guangdong Academy of Medical Sciences, 510080 Guangzhou, China
| | - Sun On Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Haoyu Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Mingzhi Zhang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China
| | - Andrew V Schally
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136;
- Division of Medical Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Division of Endocrinology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136
- Cancer Institute, Veterans Affairs Medical Center, Miami, FL 33125
| | - Chi Pui Pang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, 515041 Shantou, China;
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
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Abstract
Growth hormone-releasing hormone is a hypothalamic neuropeptide, which regulates the secretion of growth hormone by the anterior pituitary gland. Recent evidence suggest that it exerts growth factor activities in a diverse variety of in vivo and in vitro experimental malignancies, which are counteracted by growth hormone-releasing hormone antagonists. Those peptides support lung endothelial barrier integrity by suppressing major inflammatory pathways and by inducing the endothelial defender P53. The present effort provides information regarding the effects of growth hormone-releasing hormone in the regulation of P53 and the unfolded protein response. Furthermore, it suggests the possible application of growth hormone-releasing hormone antagonists towards the management of acute lung injury, including the lethal acute respiratory distress syndrome.
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Affiliation(s)
- Nektarios Barabutis
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA 71201, USA
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Barabutis N, Akhter MS, Uddin MA, Kubra KT, Schally AV. GHRH Antagonists Protect Against Hydrogen Peroxide-Induced Breakdown of Brain Microvascular Endothelium Integrity. Horm Metab Res 2020; 52:336-339. [PMID: 32403147 DOI: 10.1055/a-1149-9347] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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] [Indexed: 10/24/2022]
Abstract
Growth hormone releasing hormone is a hypothalamic neuropeptide, which regulates the release of growth hormone from the anterior pituitary gland. Growth hormone releasing hormone antagonists are anticancer agents, associated with strong anti-inflammatory activities. In the present study, we investigated the effects of the GHRH antagonist MIA-602 in the integrity of the brain microvascular endothelium in vitro. Our observations suggest that MIA-602 protects against the H2O2-induced breakdown of the brain endothelium and enhances its integrity by inducing P53, deactivating cofilin, and suppressing the RhoA inflammatory pathway. Thus, GHRH antagonists may offer an exciting possibility for the treatment of pathologies related to the blood brain barrier dysfunction, including the Parkinson's and Alzheimer's diseases.
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Affiliation(s)
- Nektarios Barabutis
- School of Basic Pharmaceutical and Toxicological Sciences, University of Louisiana Monroe, Monroe, LA, USA
| | - Mohammad S Akhter
- School of Basic Pharmaceutical and Toxicological Sciences, University of Louisiana Monroe, Monroe, LA, USA
| | - Mohammad A Uddin
- School of Basic Pharmaceutical and Toxicological Sciences, University of Louisiana Monroe, Monroe, LA, USA
| | - Khadeja-Tul Kubra
- School of Basic Pharmaceutical and Toxicological Sciences, University of Louisiana Monroe, Monroe, LA, USA
| | - Andrew V Schally
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, University of Miami, Miami, FL, USA
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Zhang C, Cai R, Lazerson A, Delcroix G, Wangpaichitr M, Mirsaeidi M, Griswold AJ, Schally AV, Jackson RM. Growth Hormone-Releasing Hormone Receptor Antagonist Modulates Lung Inflammation and Fibrosis due to Bleomycin. Lung 2019; 197:541-549. [PMID: 31392398 PMCID: PMC6778540 DOI: 10.1007/s00408-019-00257-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/29/2019] [Indexed: 12/30/2022]
Abstract
PURPOSE Growth hormone-releasing hormone (GHRH) is a 44-amino acid peptide that regulates growth hormone (GH) secretion. We hypothesized that a GHRH receptor (GHRH-R) antagonist, MIA-602, would inhibit bleomycin-induced lung inflammation and/or fibrosis in C57Bl/6J mice. METHODS We tested whether MIA-602 (5 μg or vehicle given subcutaneously [SC] on days 1-21) would decrease lung inflammation (at day 14) and/or fibrosis (at day 28) in mice treated with intraperitoneal (IP) bleomycin (0.8 units on days 1, 3, 7, 10, 14, and 21). Bleomycin resulted in inflammation and fibrosis around airways and vessels evident histologically at days 14 and 28. RESULTS Inflammation (histopathologic scores assessed blindly) was visibly less evident in mice treated with MIA-602 for 14 days. After 28 days, lung hydroxyproline (HP) content increased significantly in mice treated with vehicle; in contrast, lung HP did not increase significantly compared to naïve controls in mice treated with GHRH-R antagonist. GHRH-R antagonist increased basal and maximal oxygen consumption of cultured lung fibroblasts. Multiple genes related to chemotaxis, IL-1, chemokines, regulation of inflammation, and extracellular signal-regulated kinases (ERK) were upregulated in lungs of mice treated with bleomycin and MIA-602. MIA-602 also prominently suppressed multiple genes related to the cellular immune response including those for T-cell differentiation, receptor signaling, activation, and cytokine production. CONCLUSIONS MIA-602 reduced lung inflammation and fibrosis due to bleomycin. Multiple genes related to immune response and T-cell functions were downregulated, supporting the view that MIA-602 can modulate the cellular immune response to bleomycin lung injury.
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Affiliation(s)
| | - Renzhi Cai
- Research Service, Miami VAHS, Miami, FL, 33125, USA
| | - Aaron Lazerson
- Department of Comparative Pathology, University of Miami, Miami, FL, 33101, USA
| | | | | | - Mehdi Mirsaeidi
- Research Service, Miami VAHS, Miami, FL, 33125, USA
- Department of Medicine, University of Miami, Miami, FL, 33101, USA
| | - Anthony J Griswold
- Dr. John T. MacDonald Foundation Department of Human Genetics, University of Miami, Miami, FL, 33101, USA
| | - Andrew V Schally
- Research Service, Miami VAHS, Miami, FL, 33125, USA
- Department of Medicine, University of Miami, Miami, FL, 33101, USA
- Department of Pathology and Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, FL, 33101, USA
| | - Robert M Jackson
- Research Service, Miami VAHS, Miami, FL, 33125, USA.
- Department of Medicine, University of Miami, Miami, FL, 33101, USA.
- Research Service, Miami VAHS, 1201 NW 16th Street, Miami, FL, 33125, USA.
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8
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Muñoz-Moreno L, Schally AV, Prieto JC, Carmena MJ, Bajo AM. Growth hormone-releasing hormone receptor antagonists modify molecular machinery in the progression of prostate cancer. Prostate 2018; 78:915-926. [PMID: 29748961 DOI: 10.1002/pros.23648] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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: 01/28/2018] [Accepted: 04/12/2018] [Indexed: 01/31/2023]
Abstract
BACKGROUND Therapeutic strategies should be designed to transform aggressive prostate cancer phenotypes to a chronic situation. To evaluate the effects of the new growth hormone-releasing hormone receptor (GHRH-R) antagonists: MIA-602, MIA-606, and MIA-690 on processes associated with cancer progression as cell proliferation, adhesion, migration, and angiogenesis. METHODS We used three human prostate cell lines (RWPE-1, LNCaP, and PC3). We analyzed several molecules such as E-cadherin, β-catenin, Bcl2, Bax, p53, MMP2, MMP9, PCNA, and VEGF and signaling mechanisms that are involved on effects exerted by GHRH-R antagonists. RESULTS GHRH-R antagonists decreased cell viability and provoked a reduction in proliferation in LNCaP and PC3 cells. Moreover, GHRH-R antagonists caused a time-dependent increase of cell adhesion in all three cell lines and retarded the wound closure with the highest value with MIA-690 in PC3 cells. GHRH-R antagonists also provoked a large number of cells in SubG0 phase revealing an increase in apoptotic cells in PC3 cell line. CONCLUSIONS Taken all together, GHRH-R antagonists of the MIAMI series appear to be inhibitors of tumor progression in prostate cancer and should be considered for use in future therapeutic strategies on this malignancy.
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Affiliation(s)
- Laura Muñoz-Moreno
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
| | - Andrew V Schally
- Veterans Affairs Medical Center, Miami, Florida
- Departments of Pathology and Medicine, Divisions of Hematology/Oncology, Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Juan C Prieto
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
| | - M José Carmena
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
| | - Ana M Bajo
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
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9
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Gan J, Ke X, Jiang J, Dong H, Yao Z, Lin Y, Lin W, Wu X, Yan S, Zhuang Y, Chu WK, Cai R, Zhang X, Cheung HS, Block NL, Pang CP, Schally AV, Zhang H. Growth hormone-releasing hormone receptor antagonists inhibit human gastric cancer through downregulation of PAK1-STAT3/NF-κB signaling. Proc Natl Acad Sci U S A 2016; 113:14745-14750. [PMID: 27930339 PMCID: PMC5187693 DOI: 10.1073/pnas.1618582114] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Gastric cancer (GC) ranks as the fourth most frequent in incidence and second in mortality among all cancers worldwide. The development of effective treatment approaches is an urgent requirement. Growth hormone-releasing hormone (GHRH) and GHRH receptor (GHRH-R) have been found to be present in a variety of tumoral tissues and cell lines. Therefore the inhibition of GHRH-R was proposed as a promising approach for the treatment of these cancers. However, little is known about GHRH-R and the relevant therapy in human GC. By survival analyses of multiple cohorts of GC patients, we identified that increased GHRH-R in tumor specimens correlates with poor survival and is an independent predictor of patient prognosis. We next showed that MIA-602, a highly potent GHRH-R antagonist, effectively inhibited GC growth in cultured cells. Further, this inhibitory effect was verified in multiple models of human GC cell lines xenografted into nude mice. Mechanistically, GHRH-R antagonists target GHRH-R and down-regulate the p21-activated kinase 1 (PAK1)-mediated signal transducer and activator of transcription 3 (STAT3)/nuclear factor-κB (NF-κB) inflammatory pathway. Overall, our studies establish GHRH-R as a potential molecular target in human GC and suggest treatment with GHRH-R antagonist as a promising therapeutic intervention for this cancer.
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Affiliation(s)
- Jinfeng Gan
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Xiurong Ke
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Jiali Jiang
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Hongmei Dong
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Zhimeng Yao
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Yusheng Lin
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Wan Lin
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Xiao Wu
- Tumor Tissue Bank, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
| | - Shumei Yan
- Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Yixuan Zhuang
- Tumor Tissue Bank, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
| | - Wai Kit Chu
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Renzhi Cai
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL 33125
- South Florida Veterans Affairs Foundation for Research and Education, Miami, FL 33125
- Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Division of Endocrinology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Xianyang Zhang
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL 33125
- South Florida Veterans Affairs Foundation for Research and Education, Miami, FL 33125
- Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Division of Endocrinology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Herman S Cheung
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL 33125
- South Florida Veterans Affairs Foundation for Research and Education, Miami, FL 33125
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146
| | - Norman L Block
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Chi Pui Pang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Joint Shantou International Eye Center, Shantou University and The Chinese University of Hong Kong, Shantou 515041, China
| | - Andrew V Schally
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL 33125;
- South Florida Veterans Affairs Foundation for Research and Education, Miami, FL 33125
- Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Division of Endocrinology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Hao Zhang
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China;
- Tumor Tissue Bank, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Department of Biotherapy, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
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Chu WK, Law KS, Chan SO, Yam JCS, Chen LJ, Zhang H, Cheung HS, Block NL, Schally AV, Pang CP. Antagonists of growth hormone-releasing hormone receptor induce apoptosis specifically in retinoblastoma cells. Proc Natl Acad Sci U S A 2016; 113:14396-14401. [PMID: 27911838 PMCID: PMC5167144 DOI: 10.1073/pnas.1617427113] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Retinoblastoma (RB) is the most common intraocular cancer in children worldwide. Current treatments mainly involve combinations of chemotherapies, cryotherapies, and laser-based therapies. Severe or late-stage disease may require enucleation or lead to fatality. Recently, RB has been shown to arise from cone precursor cells, which have high MDM2 levels to suppress p53-mediated apoptosis. This finding leads to the hypothesis that restoring apoptosis mechanisms in RBs could specifically kill the cancer cells without affecting other retinal cells. We have previously reported involvement of an extrapituitary signaling pathway of the growth hormone-releasing hormone (GHRH) in the retina. Here we show that the GHRH receptor (GHRH-R) is highly expressed in RB cells but not in other retinal cells. We induced specific apoptosis with two different GHRH-R antagonists, MIA-602 and MIA-690. Importantly, these GHRH-R antagonists do not trigger apoptosis in other retinal cells such as retinal pigmented epithelial cells. We delineated the gene expression profiles regulated by GHRH-R antagonists and found that cell proliferation genes and apoptotic genes are down- and up-regulated, respectively. Our results reveal the involvement of GHRH-R in survival and proliferation of RB and demonstrate that GHRH-R antagonists can specifically kill the RB cells.
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Affiliation(s)
- Wai Kit Chu
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Ka Sin Law
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Sun On Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Jason Cheuk Sing Yam
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Li Jia Chen
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Hao Zhang
- Cancer Research Center, Shantou University Medical College, Shantou 515041, Guangdong, China
- Department of Biotherapy, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Tumor Tissue Bank, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
| | - Herman S Cheung
- Department of Biomedical Engineering, University of Miami, Miami, FL 33146
| | - Norman L Block
- Department of Biomedical Engineering, University of Miami, Miami, FL 33146
- Department of Pathology, University of Miami Medical School, Miami, FL 33136
| | - Andrew V Schally
- Department of Pathology, University of Miami Medical School, Miami, FL 33136;
- Veterans Affairs Medical Center, Miami, FL 33125
- Department of Medicine, Divisions of Hematology and Oncology and Endocrinology, University of Miami School of Medicine, Miami, FL 33136
- Sylvester Comprehensive Cancer Center, University of Miami School of Medicine, Miami, FL 33136
| | - Chi Pui Pang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong;
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11
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Szalontay L, Schally AV, Popovics P, Vidaurre I, Krishan A, Zarandi M, Cai RZ, Klukovits A, Block NL, Rick FG. Novel GHRH antagonists suppress the growth of human malignant melanoma by restoring nuclear p27 function. Cell Cycle 2014; 13:2790-7. [PMID: 25486366 PMCID: PMC4615138 DOI: 10.4161/15384101.2015.945879] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/13/2014] [Accepted: 06/16/2014] [Indexed: 01/21/2023] Open
Abstract
Malignant melanoma is the deadliest form of skin cancer; the treatment of advanced and recurrent forms remains a challenge. It has recently been reported that growth hormone-releasing hormone (GHRH) receptor is involved in the pathogenesis of melanoma. Therefore, we investigated the effects of our new GHRH antagonists on a human melanoma cancer cell line. Antiproliferative effects of GHRH antagonists, MIA-602, MIA-606 and MIA-690, on the human melanoma cell line, A-375, were studied in vitro using the MTS assay. The effect of MIA-690 (5 μg/day 28 d) was further evaluated in vivo in nude mice bearing xenografts of A-375. Subcellular localization of p27 was detected with Western blot and immunofluorescent staining. MIA-690 inhibited the proliferation of A-375 cells in a dose-dependent manner (33% at 10 μM, and 19.2% at 5 μM, P < 0 .05 vs. control), and suppressed the growth of xenografted tumors by 70.45% (P < 0.05). Flow cytometric analysis of cell cycle effects following the administration of MIA-690 revealed a decrease in the number of cells in G2/M phase (from 19.7% to 12.9%, P < 0.001). Additionally, Western blot and immunofluorescent studies showed that exposure of A-375 cells to MIA-690 triggered the nuclear accumulation of p27. MIA-690 inhibited tumor growth in vitro and in vivo, and increased the translocation of p27 into the nucleus thus inhibiting progression of the cell cycle. Our findings indicate that patients with malignant melanoma could benefit from treatment regimens, which combine existing chemotherapy agents and novel GHRH-antagonists.
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Key Words
- ANOVA, one-way analysis of variance
- Abu, a-aminobutyric acid
- Ac, acetyl
- Ada, 12-aminododecanoyl
- Agm, agmatine
- Amc, 8-aminocaprylyl
- Cpa, parachlorophenylalanine
- FBS, fetal bovine serum
- Fpa5, pentafluoro-phenylalanine
- GH, growth hormone
- GHRH, growth hormone-releasing hormone
- GHRH-R, growth hormone-releasing hormone receptor
- Har, homoarginine
- IGF-I, insulin-like growth factor I
- MTS, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfonphenyl)-2H-tetrazolium
- Nle, norleucine
- Orn, ornithine
- Ph, phenyl
- PhAc, phenylacetyl
- SVs, splice variants
- TBS, tris-buffered saline
- Tyr(Me), O-methyltyrosine
- growth hormone-releasing hormone antagonist
- hGHRH, human growth hormone-releasing hormone
- mTOR, mammalian target of rapamycin
- melanoma
- p27
- pGHRH-R, pituitary type GHRH-receptor
- targeted therapy
- xenografted mouse model
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Affiliation(s)
- Luca Szalontay
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
| | - Andrew V Schally
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
- Divisions of Hematology/Oncology; University of Miami; Miller School of Medicine; Miami, FL USA
- Department of Endocrinology; University of Miami; Miller School of Medicine; Miami, FL USA
- Sylvester Comprehensive Cancer Center; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Petra Popovics
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Cardiovascular Diseases; Department of Medicine; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Irving Vidaurre
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
| | - Awtar Krishan
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Marta Zarandi
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Ren-Zhi Cai
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Anna Klukovits
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Norman L Block
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
- Divisions of Hematology/Oncology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Ferenc G Rick
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Urology; Herbert Wertheim College of Medicine; Florida International University; Miami, FL, USA
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12
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Rick FG, Schally AV, Block NL, Abi-Chaker A, Krishan A, Szalontay L. Mechanisms of synergism between antagonists of growth hormone-releasing hormone and antagonists of luteinizing hormone-releasing hormone in shrinking experimental benign prostatic hyperplasia. Prostate 2013; 73:873-83. [PMID: 23280565 DOI: 10.1002/pros.22633] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [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: 09/28/2012] [Accepted: 12/03/2012] [Indexed: 12/30/2022]
Abstract
BACKGROUND Benign prostatic hyperplasia (BPH) affects aging men. Combined therapy with antagonists of growth hormone-releasing hormone (GHRH) and of luteinizing hormone-releasing hormone (LHRH or GnRH) induces prostate shrinkage in rat models. We investigated the mechanisms of action of this combination on cell cycle traverse and expression of prostatic genes. METHODS Effects of GHRH antagonist, JMR-132 (40 µg/day), the LHRH antagonist, cetrorelix (0.625 mg/kg), and their combination were evaluated on testosterone-induced benign prostatic hyperplasia in male Wistar rats. Influence of JMR-132, cetrorelix, and their combinations on cell viability was assessed by MTS assay in BPH-1 human prostate epithelial cells and WPMY-1 normal prostate stromal cells. Cell cycle was analyzed by laser flow cytometry. Real-time PCR arrays were performed. RESULTS The combination of antagonists caused marked shrinkage of rat prostate (29.5%). In vitro, JMR-132 plus cetrorelix (both 5µM) produced synergistic (57.4%) inhibition of growth of BPH-1 cells, but a lesser inhibition (46%) of WPMY-1 cells. Co-treatment of with JMR-132 plus cetrorelix induced a significant increase of BPH-1 cells blocked in S-phase plus cells with lower G0 /G1 and G2 /M DNA content. Significant changes in expression of >40 gene transcripts related to growth factors, inflammatory cytokines, and signal transduction were identified. CONCLUSIONS GHRH antagonist and LHRH antagonist combination potentiates rat prostate weight reduction and synergistically inhibits of growth of BPH-1 leading to cell cycle arrest in S-phase. These effects were lesser in normal stromal prostate cell line, WPMY-1. Our findings suggest that GHRH antagonists could be useful for BPH therapy, possibly in combination with LHRH antagonists.
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Affiliation(s)
- Ferenc G Rick
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida 33125, USA.
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13
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Ziegler CG, Ullrich M, Schally AV, Bergmann R, Pietzsch J, Gebauer L, Gondek K, Qin N, Pacak K, Ehrhart-Bornstein M, Eisenhofer G, Bornstein SR. Anti-tumor effects of peptide analogs targeting neuropeptide hormone receptors on mouse pheochromocytoma cells. Mol Cell Endocrinol 2013; 371:189-94. [PMID: 23267837 PMCID: PMC3690370 DOI: 10.1016/j.mce.2012.12.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 12/12/2012] [Accepted: 12/14/2012] [Indexed: 01/31/2023]
Abstract
Pheochromocytoma is a rare but potentially lethal chromaffin cell tumor with currently no effective treatment. Peptide hormone receptors are frequently overexpressed on endocrine tumor cells and can be specifically targeted by various anti-tumor peptide analogs. The present study carried out on mouse pheochromocytoma cells (MPCs) and a more aggressive mouse tumor tissue-derived (MTT) cell line revealed that these cells are characterized by pronounced expression of the somatostatin receptor 2 (sst2), growth hormone-releasing hormone (GHRH) receptor and the luteinizing hormone-releasing hormone (LHRH) receptor. We further demonstrated significant anti-tumor effects mediated by cytotoxic somatostatin analogs, AN-162 and AN-238, by LHRH antagonist, Cetrorelix, by the cytotoxic LHRH analog, AN-152, and by recently developed GHRH antagonist, MIA-602, on MPC and for AN-152 and MIA-602 on MTT cells. Studies of novel anti-tumor compounds on these mouse cell lines serve as an important basis for mouse models of metastatic pheochromocytoma, which we are currently establishing.
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MESH Headings
- 2-Hydroxyphenethylamine/analogs & derivatives
- 2-Hydroxyphenethylamine/pharmacology
- Adrenal Gland Neoplasms/drug therapy
- Aniline Compounds/pharmacology
- Animals
- Apoptosis/drug effects
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Doxorubicin/analogs & derivatives
- Doxorubicin/pharmacology
- Gonadotropin-Releasing Hormone/analogs & derivatives
- Gonadotropin-Releasing Hormone/antagonists & inhibitors
- Gonadotropin-Releasing Hormone/pharmacology
- Growth Hormone-Releasing Hormone/antagonists & inhibitors
- Mice
- Pheochromocytoma/drug therapy
- Pyrroles/pharmacology
- Receptors, LHRH/biosynthesis
- Receptors, LHRH/drug effects
- Receptors, LHRH/metabolism
- Receptors, Neuropeptide/biosynthesis
- Receptors, Neuropeptide/drug effects
- Receptors, Neuropeptide/metabolism
- Receptors, Pituitary Hormone-Regulating Hormone/biosynthesis
- Receptors, Pituitary Hormone-Regulating Hormone/drug effects
- Receptors, Pituitary Hormone-Regulating Hormone/metabolism
- Receptors, Somatostatin/biosynthesis
- Receptors, Somatostatin/drug effects
- Receptors, Somatostatin/metabolism
- Sermorelin/analogs & derivatives
- Sermorelin/pharmacology
- Somatostatin/analogs & derivatives
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Affiliation(s)
- C G Ziegler
- University Hospital Carl Gustav Carus, Department of Medicine III, Dresden, Germany.
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14
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Siejka A, Barabutis N, Schally AV. GHRH antagonist inhibits focal adhesion kinase (FAK) and decreases expression of vascular endothelial growth factor (VEGF) in human lung cancer cells in vitro. Peptides 2012; 37:63-8. [PMID: 22819774 DOI: 10.1016/j.peptides.2012.07.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [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: 06/24/2012] [Revised: 07/10/2012] [Accepted: 07/10/2012] [Indexed: 12/27/2022]
Abstract
Lung cancers which show increased vascularization and high microvessel density are considered highly metastatic and with poor prognosis. Growth hormone releasing hormone (GHRH) antagonists are anticancer agents without adverse events in lung cancer tumor models. In the present study we investigated the in vitro effect of GHRH antagonist, MZ-5-156, on focal adhesion kinase (FAK) activity, on the expression of MMP-2 and MMP-9 metalloproteinases, as well as on vascular endothelial growth factor (VEGF) levels in A549 non-small cell lung (NSCLC) cancer cells and H727 bronchial carcinoid cells. We demonstrate for the first time that GHRH antagonist, MZ-5-156, inhibits FAK signaling in lung cancer cells and decreases the expression of additional factors involved in angiogenesis and invasion. In contrast, GHRH itself counteracted these effects. Our study contributes to the further understanding of the processes which govern the mechanism of action of GHRH and its antagonists in cancers.
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Affiliation(s)
- Agnieszka Siejka
- Veterans Affairs Medical Center Education, Miami, FL 33125, USA.
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15
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Stangelberger A, Schally AV, Rick FG, Varga JL, Baker B, Zarandi M, Halmos G. Inhibitory effects of antagonists of growth hormone releasing hormone on experimental prostate cancers are associated with upregulation of wild-type p53 and decrease in p21 and mutant p53 proteins. Prostate 2012; 72:555-65. [PMID: 21796649 DOI: 10.1002/pros.21458] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [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: 05/19/2011] [Accepted: 06/22/2011] [Indexed: 01/18/2023]
Abstract
BACKGROUND The tumor suppressor gene p53 is implicated in cell cycle control and apoptosis. Antagonists of growth hormone-releasing hormone (GHRH) have been shown to inhibit human experimental prostate cancers. METHODS We investigated the involvement of p53 apoptotic pathways in this effect. Nude mice bearing xenografted PC-3, DU-145, and MDA-PCa-2b human prostate cancer lines were treated with a new potent GHRH antagonist MZ-J-7-138. To determine whether tumor inhibition by MZ-J-7-138 involves apoptotic mechanisms such as p53 and p21, we evaluated by Western Blot the expression of mutant mt-p53 in PC-3 and DU-145 and of wild type (wt-p53) in MDA-PCa-2b prostate cancers as well as p21. RESULTS MZ-J-7-138 significantly inhibited the growth of PC-3, DU-145, and MDA-PCa-2b xenografts in nude mice. Androgen deprivation with the LHRH antagonist Cetrorelix enhanced the anti-proliferative effect of GHRH antagonist MZ-J-7-138 on MDA-PCa-2b tumors. The expression of mutant (mt-p53) and p21 protein in PC-3 and DU-145 tumors was significantly decreased by treatment with MZ-J-7-138, whereas wild type wt-p53 expression in MDA-PCA-2b tumors was up regulated by treatment with Cetrorelix. All three models investigated expressed specific, high affinity GHRH receptors. CONCLUSIONS Our findings indicate that the anti-proliferative effects of GHRH antagonist MZ-J-7-138 and LHRH antagonist Cetrorelix on prostate cancers involve p53 and p21 signaling.
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16
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Szalontay L, Benveniste RJ, Schally AV, Vidaurre I, Nadji M, Zarandi M, Block NL, Kovacs M. Inhibitory effects of GHRH antagonists on human GH-secreting adenoma tissue. Neuroendocrinology 2012; 96:81-8. [PMID: 22377963 DOI: 10.1159/000335989] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [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: 05/17/2011] [Accepted: 12/06/2011] [Indexed: 11/19/2022]
Abstract
Experimental data indicate that antagonists of growth hormone-releasing hormone (GHRH) could be used clinically in disorders characterized by excessive GHRH/growth hormone (GH) secretion, but direct evidence for the effectiveness of GHRH antagonists on human pituitary tissue is still lacking. In this study, we investigated the inhibitory effect of our GHRH antagonists MZ-4-71 and JV-1-36 and the somatostatin (SST) analog RC-160 on superfused pituitary cells obtained from a human GH-secreting adenoma. Using Western blot analysis and immunohistochemistry, we demonstrated profuse expression of the GHRH receptor and its major splice variant SV1 and an increase in the expression of Gsa protein in the adenoma tissue. Exposure of the tumor cells to exogenous pulses of GHRH induced definite GH responses, causing a 3- to 5-fold elevation of the basal GH level. The antagonists MZ-4-71 and JV-1-36 did not alter basal GH secretion, indicating that the adenoma cells did not secrete GHRH in an autocrine manner. However, both antagonists prevented the stimulatory effect of exogenous GHRH. Similarly to the GHRH antagonists, neither SST-14 nor the SST analog RC-160 had an effect on the basal GH secretion of the tumor cells, but both peptides inhibited the stimulatory effect of exogenous GHRH, with RC-160 being more potent than SST. Our study provides direct evidence for the effectiveness of potent GHRH antagonists such as MZ-4-71 and JV-1-36 on human pituitary GH-secreting adenoma tissue and strongly suggests that these drugs could be used for therapy of GHRH-associated forms of acromegaly, particularly for those patients in whom surgery fails or is not an option.
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Affiliation(s)
- Luca Szalontay
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, FL 33125, USA
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17
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Abstract
The aim of the current study is to investigate the effects of growth hormone releasing hormone (GHRH) antagonist on acetaminophen (APAP)-induced acute liver injury in mice. Healthy C57/B6L mice were orally treated with 200 mg/kg APAP with or without a 30-min pre-treatment with 300 µg/kg GHRH antagonist MZ-5-156. After 12 hours, serum, plasma, and liver samples from each mouse were collected for analyses. Our results showed that twelve-hour treatment with APAP caused obvious liver injury, elevated serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, increased oxidative stress, reduced expressions of antioxidant enzymes, accumulated expression of pro-inflammatory cytokines, and increased circulating levels of growth hormone (GH) and insulin-like growth factor-I (IGF-I). Pre-treatment with MZ-5-156 aggravated liver injury, further increased serum ALT and AST levels, exacerbated oxidative stress and inflammation induced by APAP. Treatment of MZ-5-156 also blocked the phosphorylation form and total form of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5). Treatment of GHRH super-agonist JI-38 immediately after MZ-5-156 treatment partly reversed the liver injury caused by APAP and MZ-5-156. In conclusion, GHRH plays essential protective role in APAP-induced acute liver injury in vivo. The protective properties of GHRH are partially through GH/IGF-I axis and JAK/STAT pathway.
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Affiliation(s)
- Tao Wang
- First affiliated hospital, Xinxiang Medical University, Henan, China
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18
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Papadia A, Schally AV, Halmos G, Varga JL, Seitz S, Buchholz S, Rick F, Zarandi M, Bellyei S, Treszl A, Szalontay L, Lucci JA. Growth hormone-releasing hormone antagonists inhibit growth of human ovarian cancer. Horm Metab Res 2011; 43:816-20. [PMID: 22009378 DOI: 10.1055/s-0031-1287766] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [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] [Indexed: 01/24/2023]
Abstract
Epithelial ovarian carcinoma is the leading cause of cancer-related deaths among women with gynecologic malignancies. Antagonists of the growth hormone-releasing hormone (GHRH) have been shown to inhibit growth of various cancers through endocrine, autocrine, and paracrine mechanisms. In this study, we have investigated the effects of GHRH antagonists (GHRHa) in ES-2 human clear cell ovarian cancer and in UCI-107 human serous ovarian cancer in vitro and in vivo. We evaluated the expression of mRNA for GHRH receptor, the binding to GHRH receptors, in specimens of ES-2 ovarian cancer. We evaluated also the in vitro effects of GHRHa on ES-2 cells and the in vivo effect of 2 different GHRHa on ES-2 and UCI-107 tumors. Nude mice bearing xenografts on ES-2 and UCI-107 ovarian cancer were treated with JMR-132 and MZ-J-7-118, respectively. Tumor growth was compared to control. ES-2 cells expressed mRNA for the functional splice variant SV1 of the GHRH receptor. JMR-132 inhibited cell proliferation in vitro by 42% and 18% at 10 and 1 μM concentration, respectively. Specific high affinity receptors for GHRH were detected in ES-2 cancer samples. In vivo daily subcutaneous injections of GHRHa significantly reduced tumor growth compared to a control group in both animal models. Our results indicate that GHRHa such as JMR-132 and MZ-J-7-118 can inhibit the growth of human ovarian cancer. The efficacy of GHRHa in ovarian cancer should be assessed in clinical trials.
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Affiliation(s)
- A Papadia
- University of Miami, Department of Obstetrics and Gynecology, Miami, FL, USA.
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Wu HM, Schally AV, Cheng JC, Zarandi M, Varga J, Leung PCK. Growth hormone-releasing hormone antagonist induces apoptosis of human endometrial cancer cells through PKCδ-mediated activation of p53/p21. Cancer Lett 2010; 298:16-25. [PMID: 20630651 DOI: 10.1016/j.canlet.2010.05.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 05/31/2010] [Indexed: 11/19/2022]
Abstract
The growth hormone-releasing hormone (GHRH) antagonists have been shown to inhibit growth of human cancer cells, but the underlying molecular mechanisms and their actions have not been fully investigated. In this study, we first showed that GHRH-R splice variant 1 (SV1) was expressed in two human endometrial cancer cell lines, Ishikawa and ECC-1. By using MTT assay, immunoblotting for cleaved caspase-3 and TUNEL assays, we found that cell growth inhibition and apoptosis were induced in GHRH antagonist, JMR-132-treated cells by activating PKCδ and could be inhibited by treatment with PKC inhibitor, GF109203X. In addition, activation and protein expression of p53 as well as the expression of its downstream effector, p21, were increased by JMR-132 treatment. Moreover, JMR-132-induced p53 and p21 expression were diminished by treatment with PKC inhibitor. Knockdown of endogenous p53 and p21 by siRNAs abolished the JMR-132-induced cell growth inhibition and apoptosis. This study demonstrates a novel mechanism in which GHRH antagonist-induced cell growth inhibition and apoptosis through PKCδ-mediated activation of p53/p21 in human endometrial cancer cells. These findings may suggest the feasibility of GHRH antagonists as a therapeutic approach for human cancer.
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Affiliation(s)
- Hsien-Ming Wu
- Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, British Columbia, Canada V6H3V5
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Siejka A, Schally AV, Block NL, Barabutis N. Antagonists of growth hormone-releasing hormone inhibit the proliferation of human benign prostatic hyperplasia cells. Prostate 2010; 70:1087-93. [PMID: 20232355 DOI: 10.1002/pros.21142] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [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] [Indexed: 12/31/2022]
Abstract
BACKGROUND Growth hormone-releasing hormone (GHRH), besides stimulating the secretion of GH from the pituitary gland, acts as an autocrine/paracrine growth factor in many cancers. Antagonists of GHRH inhibit growth of experimental human tumors, but their effects on benign prostatic hyperplasia (BPH) have not been studied. MATERIALS AND METHODS We evaluated the effects of GHRH and GHRH antagonists JMR-132, MZ-5-156, MIA-601, and MIA-479 on the proliferation rate of human BPH-1 cells. We also measured by Western blot the influence of GHRH and GHRH antagonist JMR-132 on the expression of the PCNA and the activation of ERK1/2 and JAK/STAT3. RESULTS BPH-1 cells express GHRH and GHRH-receptor proteins. The proliferation rate of BPH-1 cells is increased by GHRH and inhibited by all the GHRH antagonists, the latest analogs MIA-601 and MIA-479 being the most potent. The stimulatory effect of GHRH is nullified by GHRH antagonists. GHRH strongly activates and GHRH antagonists significantly suppress the expression of the PCNA and the phosphorylation of ERK1/2 and JAK2/STAT3 pathways in these cells. Treatment with JAK2 inhibitor (AG490) decreases the proliferation rate of BPH-1 cells, and AG490 does nullify the effect of GHRH. CONCLUSION This study demonstrates for the first time that GHRH can act as a growth factor in BPH-1 cells and that GHRH antagonists can reverse its stimulatory effect. New observations are provided on the mechanism of action of GHRH antagonists in BPH. Our findings support the merit of further work on the development of GHRH antagonists for therapy of BPH.
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Affiliation(s)
- Agnieszka Siejka
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida
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21
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Guo J, Schally AV, Zarandi M, Varga J, Leung PCK. Antiproliferative effect of growth hormone-releasing hormone (GHRH) antagonist on ovarian cancer cells through the EGFR-Akt pathway. Reprod Biol Endocrinol 2010; 8:54. [PMID: 20509930 PMCID: PMC2891788 DOI: 10.1186/1477-7827-8-54] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 05/28/2010] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Antagonists of growth hormone-releasing hormone (GHRH) are being developed for the treatment of various human cancers. METHODS MTT assay was used to test the proliferation of SKOV3 and CaOV3. The splice variant expression of GHRH receptors was examined by RT-PCR. The expression of protein in signal pathway was examined by Western blotting. siRNA was used to block the effect of EGFR. RESULTS In this study, we investigated the effects of a new GHRH antagonist JMR-132, in ovarian cancer cell lines SKOV3 and CaOV3 expressing splice variant (SV)1 of GHRH receptors. MTT assay showed that JMR-132 had strong antiproliferative effects on SKOV3 and CaOV3 cells in both a time-dependent and dose-dependent fashion. JMR-132 also induced the activation and increased cleaved caspase3 in a time- and dose-dependent manner in both cell lines. In addition, JMR-132 treatments decreased significantly the epidermal growth factor receptor (EGFR) level and the phosphorylation of Akt (p-Akt), suggesting that JMR-132 inhibits the EGFR-Akt pathway in ovarian cancer cells. More importantly, treatment of SKOV3 and CaOV3 cells with 100 nM JMR-132 attenuated proliferation and the antiapoptotic effect induced by EGF in both cell lines. After the knockdown of the expression of EGFR by siRNA, the antiproliferative effect of JMR-132 was abolished in SKOV3 and CaOV3 cells. CONCLUSIONS The present study demonstrates that the inhibitory effect of the GHRH antagonist JMR-132 on proliferation is due, in part, to an interference with the EGFR-Akt pathway in ovarian cancer cells.
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Affiliation(s)
- Jian Guo
- Department of Obstetrics & Gynaecology, Child and Family Research Institute, UBC, Vancouver, Canada
- School of Preclinical Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Andrew V Schally
- Veterans Affairs Medical Center and Departments of Pathology and Medicine, Division of Hematology/Oncology, University of Miami Miller School of Medicine, Miami, FL 33125, USA
| | - Marta Zarandi
- Veterans Affairs Medical Center and Departments of Pathology and Medicine, Division of Hematology/Oncology, University of Miami Miller School of Medicine, Miami, FL 33125, USA
| | - Jozsef Varga
- Veterans Affairs Medical Center and Departments of Pathology and Medicine, Division of Hematology/Oncology, University of Miami Miller School of Medicine, Miami, FL 33125, USA
| | - Peter CK Leung
- Department of Obstetrics & Gynaecology, Child and Family Research Institute, UBC, Vancouver, Canada
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22
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Abstract
Hypothalamic GHRH controls the release of GH from the pituitary gland and also acts as a growth factor in a variety of cancers. The mitogenetic activity of GHRH is exerted through the binding to the pituitary type receptor (pGHRH-R) and its splice variants, mainly SV1. The intracellular signaling pathways that are activated upon the binding of GHRH to the SV1 receptor have not been elucidated. HeLa cervical cancer cells do not express GHRH or GHRH receptors (GHRHRs) and thus do not respond to GHRH or GHRH antagonists. In order to elucidate the mechanism of action of SV1 receptor, we transfected HeLa cells with plasmids for pcDNA3-GHRHR or pcDNA3-SV1. The transfected cells responded to both GHRH (1-29)NH(2) and GHRH antagonist MZ-5-156, as shown by an increase or decrease respectively in the proliferation rate in vitro and the expression of proliferative cell nuclear antigen. We also demonstrated that when the cells transfected with SV1 plasmid are stimulated with GHRH (1-29)NH(2), SV1 receptor activates the mitogen-activated protein kinases pathway (MAPKs), as shown previously for the cells that express pGHRH-R. Our results show, for the first time, the activation of the MAPKs cascade by the SV1 receptor. Since SV1 receptor is found in various tumors and mediates the responses to GHRH and synthetic antagonists, our findings shed light on the mechanism of action of SV1 receptor in cancer cells.
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Affiliation(s)
- Nektarios Barabutis
- Research Service (151), Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, 1201 Northwest 16th Street, Miami, Florida 33125, USA.
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23
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Heinrich E, Schally AV, Buchholz S, Rick FG, Halmos G, Mile M, Groot K, Hohla F, Zarandi M, Varga JL. Dose-dependent growth inhibition in vivo of PC-3 prostate cancer with a reduction in tumoral growth factors after therapy with GHRH antagonist MZ-J-7-138. Prostate 2008; 68:1763-72. [PMID: 18729085 DOI: 10.1002/pros.20843] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [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] [Indexed: 01/22/2023]
Abstract
BACKGROUND Antagonists of growth hormone-releasing hormone (GHRH) inhibit the growth of various cancers and affect tumoral growth factors. METHODS We investigated the effect of a new GHRH antagonist MZ-J-7-138 at doses of 1.25, 2.5, 5 and 10 microg/day s.c. on the growth of PC-3 human androgen independent prostate cancers xenografted s.c. into nude mice. Binding assays were used to investigate GHRH receptors. The levels of IGF-II and VEGF in tumors were measured by radioimmunoassays. RESULTS Treatment with 2.5, 5, and 10 microg/day MZ-J-7-138 caused a significant dose-dependent growth reduction of PC-3 tumors. The greatest inhibition of 78% was obtained with 10 microg/day. The suppression of IGF-II protein levels in tumors was seen at all doses of MZ-J-7-138, but only 10 microg dose induced a significant inhibition. MZ-J-7-138 also reduced VEGF protein levels, the inhibition being significant at doses of 5 and 10 microg. Specific high affinity binding sites for GHRH were found on PC-3 tumors using (125)I-labeled GHRH antagonist JV-1-42. MZ-J-7-138 displaced radiolabeled JV-1-42 with an IC(50) of 0.32 nM indicating its high affinity to GHRH receptors. Real-time PCR analyses detected splice variant 1 (SV1) of GHRH receptor (GHRH-R) as well as pituitary type of GHRH-R and GHRH ligand. CONCLUSION Our results demonstrate the efficacy of GHRH antagonist MZ-J-7-138 in suppressing growth of PC-3 prostate cancer at doses lower than previous antagonists. The reduction of levels of growth factors such as VEGF and IGF-II in tumors by GHRH antagonist was correlated with the suppression of tumor growth.
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Affiliation(s)
- Elmar Heinrich
- Veterans Affairs Medical Center, Tulane University School of Medicine, New Orleans, Louisiana, USA
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24
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Seitz S, Hohla F, Schally AV, Moder A, Engel JB, Horn F, Varga J, Zarandi M, Ortmann O, Köster F, Buchholz S. Inhibition of estrogen receptor positive and negative breast cancer cell lines with a growth hormone-releasing hormone antagonist. Oncol Rep 2008; 20:1289-1294. [PMID: 18949435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
GHRH antagonists have been shown to inhibit growth of various human cancer cell lines xenografted into nude mice including estrogen receptor negative human breast cancers. Previous observations also suggest that GHRH locally produced in diverse neoplasms including breast cancer might directly affect proliferation of tumor cells. In the present study we demonstrate that a novel highly potent GHRH antagonist JMR-132 strongly inhibits the proliferation of both estrogen receptor negative SKBR 3 and estrogen receptor positive ZR 75 human breast cancer cell lines in vitro. The proliferation in vitro of ZR 75 and SKBR 3 was increased after direct stimulation with GHRH(1-29)NH2. The GHRH antagonist JMR-132 had a significant antiproliferative activity in the absence of GHRH and nullified the proliferative effect of GHRH in these cell lines. SKBR 3 and ZR 75 expressed the GHRH ligand as well as the pituitary type of GHRH-receptor, which likely appears to mediate the antiproliferative mechanisms in these cell lines. These in vitro results suggest that JMR-132 is a potent inhibitor of breast cancer growth, independent of the estrogen receptor status. Further investigations on the combination treatment with endocrine agents affecting the estrogen pathway and GRHR antagonists are needed in order to improve the treatment of breast cancer.
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Affiliation(s)
- Stephan Seitz
- Veterans Affairs Medical Center Miami, FL 33125, USA
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25
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Volakaki AA, Lafkas D, Kassi E, Schally AV, Papavassiliou AG, Kiaris H. Essential role of p21/waf1 in the mediation of the anti-proliferative effects of GHRH antagonist JMR-132. J Mol Endocrinol 2008; 41:389-92. [PMID: 18765563 DOI: 10.1677/jme-08-0106] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [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] [Indexed: 11/27/2022]
Abstract
GHRH, besides its neuroendocrine action in controlling the release of GH from the pituitary, stimulates the growth of various cancers in vivo and in vitro by direct mechanism(s). However, the molecular mechanism that mediates these proliferative effects of GHRH in extrapituitary tissues remains poorly characterized. In the present study, we investigated whether the tumor suppressor p21/waf1 is involved in the mediation of the proliferative effects of GHRH in A549 human lung cancer epithelial cells. Exposure of A549 cells to the GHRH antagonist JMR-132 caused a significant inhibition in the rate of cell proliferation. In A549 cells, GHRH suppressed while JMR-132 increased the levels of p21 expression in a dose-dependent manner. This suggests that GHRH could regulate p21 levels. We then evaluated whether p21 is required in A549 cells for the regulation of cell proliferation by GHRH. To this end, we knocked-down p21 expression in A549 cells by siRNA and assessed the effects of antagonist JMR-132 on cell proliferation. We found that the loss of p21 expression abolished the anti-proliferative effects of JMR-132. Suppression of p21 expression by siRNA in human HT29 colon cancer cells and non-transformed mouse osteoblasts KS483 also blocked the anti-proliferative effects of JMR-132 suggesting that the regulation of cell proliferation by GHRH is p21 dependent. These results shed light on the molecular mechanism of action of GHRH antagonists in tumor tissues and suggest that the antineoplastic activity of GHRH antagonists could be considered for the treatment of cancers expressing p21.
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Affiliation(s)
- Aspasia-Athina Volakaki
- Department of Biological Chemistry, University of Athens Medical School, 11527 Athens, Greece
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26
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Zhao L, Yano T, Osuga Y, Nakagawa S, Oishi H, Wada-Hiraike O, Tang X, Yano N, Kugu K, Schally AV, Taketani Y. Cellular mechanisms of growth inhibition of human endometrial cancer cell line by an antagonist of growth hormone-releasing hormone. Int J Oncol 2008; 32:593-601. [PMID: 18292936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
The expression of growth hormone-releasing hormone (GHRH) and its receptors has been demonstrated in peripheral tissues as well as CNS. Recently, the functional splice variant SV1 of GHRH receptor was identified in various human cancers and cancer cell lines. Although antineoplastic activity of GHRH antagonists has been clearly demonstrated, the mechanism of action is incompletely understood. The objective of this study was the investigation of direct anti-proliferative effect of GHRH antagonist MZ-5-156 on HEC-1A human endometrial cancer cell line and the elucidation of underlying mechanisms. RT-PCR revealed the expression of mRNA for GHRH and SV1 of GHRH receptor in HEC-1A cells. MZ-5-156, at concentrations between 10(-7) and 10(-5) M, had a dose-dependent antiproliferative effect on HEC-1A cells, as determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, (MTS) assay. Hoechst 33342 staining and flow cytometric analysis indicated that MZ-5-156, at 10(-6) M, induced apoptosis in HEC-1A cells after 48 h of treatment. Western blot analysis of apoptosis-related proteins demonstrated that treatment with MZ-5-156 (10(-6) M) for 48 h significantly increased the protein levels of Fas, phospho-p53 (Ser46), p53AIP1 (p53-regulated Apoptosis-Inducing Protein 1), and caspase-8, -9, and -3, and decreased the protein level of Bcl-2. These results demonstrate that MZ-5-156 can directly inhibit the proliferation of human endometrial cancer cells, which express mRNA for GHRH and SV1 of GHRH receptor, presumably through the induction of p53-dependent apoptosis coupled with the up-regulation of Fas, phospho-p53 (Ser46), p53AIP1, and caspase-8, -9, and -3, and the down-regulation of Bcl-2.
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MESH Headings
- Adenocarcinoma, Papillary/genetics
- Adenocarcinoma, Papillary/pathology
- Aged
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- Apoptosis/genetics
- Caspases/genetics
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Drug Evaluation, Preclinical
- Endometrial Neoplasms/genetics
- Endometrial Neoplasms/pathology
- Female
- Gene Expression Regulation, Neoplastic
- Genes, bcl-2
- Genes, p53
- Growth Hormone-Releasing Hormone/antagonists & inhibitors
- Growth Hormone-Releasing Hormone/genetics
- Humans
- RNA, Messenger/metabolism
- Receptors, Neuropeptide/genetics
- Receptors, Neuropeptide/metabolism
- Receptors, Pituitary Hormone-Regulating Hormone/genetics
- Receptors, Pituitary Hormone-Regulating Hormone/metabolism
- Sermorelin/analogs & derivatives
- Sermorelin/pharmacology
- Signal Transduction/drug effects
- Signal Transduction/genetics
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Affiliation(s)
- Lin Zhao
- Department of Obstetrics and Gynecology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
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27
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Keller G, Schally AV, Groot K, Toller GL, Havt A, Köster F, Armatis P, Halmos G, Zarandi M, Varga JL, Engel JB. Effective treatment of experimental human non-Hodgkin's lymphomas with antagonists of growth hormone-releasing hormone. Proc Natl Acad Sci U S A 2005; 102:10628-33. [PMID: 16027368 PMCID: PMC1180787 DOI: 10.1073/pnas.0504102102] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Antagonists of growth hormone-releasing hormone (GHRH) were shown to inhibit the growth of various cancers. We investigated the antitumor activity and the mechanism of action of GHRH antagonists in human non-Hodgkin's lymphomas (NHL). Nude mice bearing xenografts of RL and HT human NHL were treated with GHRH antagonists MZ-5-156 and MZ-J-7-138 at a dose of 40 microg twice daily. The concentrations of serum IGF-1 and GHRH, bFGF, and VEGF in tumor tissue were measured by radioimmunoassays. Expression of GHRH and splice variant 1 of the GHRH receptor in both cell lines was examined by RT-PCR. The effects of MZ-5-156, MZ-J-7-138 and GHRH on cell proliferation were evaluated in vitro. Treatment with MZ-5-156 and MZ-J-7-138 significantly (P < 0.05) inhibited the growth of RL and HT tumors by 59.9-73.9%. High-affinity binding sites for GHRH and mRNA for GHRH and splice variant-1 of the GHRH receptors were found on RL and HT tumors. RL and HT cells contained GHRH peptide, and their growth in vitro was significantly inhibited by both antagonists. IGF-I levels in serum of mice were significantly decreased by antagonist MZ-5-156. Therapy with GHRH antagonists also significantly reduced tumoral bFGF, whereas VEGF levels were not suppressed. Our findings suggest that GHRH antagonists inhibit the growth of RL and HT lymphomas by direct effects mediated by tumoral receptors for GHRH. GHRH antagonists could offer a new therapeutic modality for the management of advanced NHL.
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Affiliation(s)
- Gunhild Keller
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, and Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
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28
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Jessup SK, Malow BA, Symons KV, Barkan AL. Blockade of endogenous growth hormone-releasing hormone receptors dissociates nocturnal growth hormone secretion and slow-wave sleep. Eur J Endocrinol 2004; 151:561-6. [PMID: 15538933 DOI: 10.1530/eje.0.1510561] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES A temporal association between non-rapid eye movement (NREM) sleep stages 3 and 4 and nocturnal augmentation of GH release was found long ago, yet the precise mechanism for this association has not been identified. It has been shown, however that pulsatile GHRH administration increases both slow-wave sleep (SWS) and GH. Based on these data, a role for GHRH as an inducer of SWS was proposed. To test this hypothesis, we have performed the corollary experiment whereby the action of endogenous GHRH has been antagonized. DESIGN Healthy men (20-33 years old) had an infusion of GHRH antagonist ((N-Ac-Tyr(1), D-Arg(2)) GHRH-29 (NH(2))) or saline for a 12-h period, between 2100 and 0900 h. An i.v. bolus of GHRH was given at 0700 h and GH samples were drawn from 0700 to 0900 h to document the efficacy of GH suppression by the GHRH antagonist. METHODS A limited montage sleep study was recorded from 2300 to 0700 h during each admission. Plasma GH concentrations were analyzed by the use of a sensitive chemiluminometric assay. RESULTS Effectiveness of the GHRH antagonist was validated in all subjects by demonstrating 93+/-1.8% (P=0.012) suppression of GH response to a GHRH bolus. Polysomnography demonstrated that the percentage of SWS was not different when saline and GHRH antagonist nights were compared (P=0.607); other quantifiable sleep parameters were also unchanged. CONCLUSIONS We conclude that endogenous GHRH is indispensable for the nocturnal augmentation of GH secretion, but that it is unlikely to participate in the genesis of SWS.
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Affiliation(s)
- Stacy K Jessup
- Department of Internal Medicine, Division of Endocrinology and Metabolism, University of Michigan Medical Center, Ann Arbor, Michigan, USA
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29
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Abstract
A series of analogues of hGH-RH-(1-29)-NH2 designed to have metabolic stability has been synthesized. Standard Boc-SPPS was employed, modified to permit the guanidinylation of amino side-chains after chain assembly but before release from the resin. [Dat1, Har(11, 12, 20, 21, 29), Ala15, Nle27, Asp28]-, [Dat1, Har(11, 20, 29), Orn12, Ala15, Nle27, Asp28]-, and [Dat1, Gap(11,12, 21, 29), Ala15, Har20, Nle27, Asp28]-hGH-RH-(1-29)-NH2 were completely resistant to trypsin and about 50 times as potent as hGH-RH-(1-29)-NH2 itself when injected subcutaneously in rats. These peptides are candidates for clinical application in the therapy of GH deficiency.
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Affiliation(s)
- Jan Izdebski
- Peptide Laboratory, Department of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland.
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30
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D'Antonio M, Louveau I, Esposito P, Bertolino M, Canali S. Pharmacodynamic evaluation of a PEGylated analogue of human growth hormone releasing factor in rats and pigs. Growth Horm IGF Res 2004; 14:226-234. [PMID: 15125884 DOI: 10.1016/j.ghir.2003.12.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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: 02/18/2003] [Revised: 12/24/2003] [Accepted: 12/29/2003] [Indexed: 11/23/2022]
Abstract
The aim of this study was to assess the in vivo efficacy of monoPEGylated GRF(1-29)NH(2) having one PEG(5000) chains attached to either lysine 12 or 21 as compared to the GRF(1-29)NH(2) in rats and pigs. This analogue termed GRF-1PEG(5000) was tested after a single intravenous administration in rats and after a single intravenous or subcutaneous injection in pigs. After 1 h administration, GH concentrations returned to values close to controls in the group of rats injected with GRF(1-29)NH(2). In animals injected with the same dose of GRF-1PEG(5000), the AUC values corresponding to the whole period 0.5-48 h and particularly to the 0.5-8 h period were higher than in the placebo or in the GRF(1-29)NH(2) groups. Interestingly, two additional peaks were observed at about 6 and 8 h following administration. An increase in the response of the endogenous GH peaks was also observed in pigs administered GRF-1PEG(5000) by intravenous route. When GRF-1PEG(5000) was administered subcutaneously to pigs, a significant increase, as compared to placebo and GRF(1-29)NH(2,) in both GH and IGF-I levels was observed. This new analogue might find therapeutic application in paediatric growth hormone deficiency or in aging.
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Affiliation(s)
- M D'Antonio
- Industria Farmaceutica Serono SpA, Drug Delivery Systems, Via Ribes 5, I-10010 Colleretto Giacosa, Turin, Italy. mauro.d'
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31
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Siejka A, Ławnicka H, Komorowski J, Stepień T, Krupiński R, Stepień H. Effect of growth hormone-releasing hormone (GHRH) and GHRH antagonist (MZ-4-71) on interferon-gamma secretion from human peripheral blood mononuclear cells in vitro. Neuropeptides 2004; 38:35-9. [PMID: 15003714 DOI: 10.1016/j.npep.2003.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [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: 10/18/2003] [Accepted: 12/13/2003] [Indexed: 10/26/2022]
Abstract
Numerous reports indicate close interactions between the neuroendocrine and the immune systems. Hypothalamic neuropeptide, growth hormone-releasing hormone (GHRH) stimulates growth hormone (GH) secretion from the anterior pituitary gland, but recently some immunomodulatory properties of this peptide have also been demonstrated. In the present studies we evaluated the effect of human synthetic GHRH(1-44)NH(2) and GHRH antagonist (MZ-4-71) on interferon (IFN)-gamma secretion from human peripheral blood mononuclear cells (PBMC). GHRH(1-44)NH(2) at 10(-10), 10(-8) and 10(-6) M concentrations significantly (p < 0.05) increased the IFN-gamma level in supernatants of cultured cells, as compared with the controls. GHRH antagonist (MZ-4-71) at 10(-10), 10(-8) and 10(-6) M concentrations diminished the IFN-gamma level in supernatants in a dose-dependent manner, but statistically significant differences were observed only at 10(-8) M and 10(-6) M (p < 0.05 vs controls). Our results demonstrate that GHRH and GHRH antagonist MZ-4-71 can modulate IFN-gamma secretion in vitro by human peripheral blood mononuclear cells.
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Affiliation(s)
- A Siejka
- Department of Experimental Endocrinology and Hormone Diagnostics, Institute of Endocrinology, Medical University of Łódź, Sterling 3, Łódź 91-425, Poland
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32
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Byrnes ME. Reversed-phase high-performance liquid chromatography. A semipreparative methodology. Methods Mol Biol 2003; 36:37-52. [PMID: 7535163 DOI: 10.1385/0-89603-274-4:37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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33
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Abstract
Synthetically produced GRF1-29 (Sermorelin) has an amino acid composition identical to the N-terminal 29 amino acids sequence of the natural hypothalamic GHRH1-44 (Figure 1). It maintains bioactivity in vitro and is almost equally effective in eliciting secretion of endogenous growth hormone in vivo. The main drawbacks associated with the pharmaceutical use of hGRF1-29 relate to its short half-life in plasma, about 10-20 min in humans, which is caused mostly by renal ultrafiltration and enzymatic degradation at the N terminus. PEGylation has been considered as one valid approach to obtain more stable forms of the peptide, with a longer in vivo half-life and ultimately with increased pharmacodynamic response along the somatotropic axis (endogenous GH, IGF-1 levels). Different PEGylated GRF conjugates were obtained and their bioactivity was tested in vitro and in vivo by monitoring endogenous growth hormone (GH) serum levels after intravenous (i.v.) injection in rats, and intravenous and subcutaneous (s.c.) injection in pigs. It was found that GRF-PEG conjugates are able to bind and activate the human GRF receptor, although with different potency. The effect of PEG molecular weight, number of PEG chains bound and position of PEGylation site on GRF activity were investigated. Mono-PEGylated isomers with a PEG5000 polymer chain linked to Lys 12 or Lys 21 residues, showed high biological activity in vitro, which is similar to that of hGRF1-29, and a higher pharmacodynamic response as compared to unmodified GRF molecule.
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Affiliation(s)
- P Esposito
- Industria Farmaceutica Serono, Drug Delivery Systems, Via Ribes 5, BioIndustry Park del Canavese, 10010 Colleretto Giacosa (TO), Italy.
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Siejka A, Ławnicka H, Komorowski J, Schally AV, Stepień T, Krupiński R, Stepień H. GH-RH antagonist (MZ-4-71) inhibits VEGF secretion and proliferation of murine endothelial cells. Life Sci 2003; 72:2473-9. [PMID: 12650855 DOI: 10.1016/s0024-3205(03)00164-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Angiogenesis plays a key role in solid tumor formation, invasiveness and metastasis. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is necessary in the process of neovascularisation. Antagonists of growth hormone-releasing hormone (GH-RH) have been shown to suppress both in vivo and in vitro growth and metastasis of many human cancer cell lines. The mechanisms that mediate the antitumorigenic actions of these antagonists involve direct and indirect pathways, but are not completely elucidated. We have examined the effect of GH-RH antagonist MZ-4-71 on proliferation activity and VEGF release from cultured murine endothelial cells HECa10 in vitro. MZ-4-71 at 10(-8) to 10(-6) M concentrations inhibited the proliferative activity of cultured cells and suppressed the release of VEGF into supernatants of 72 h endothelial cell cultures. To our knowledge this is the first study reporting antiangiogenic properties of GH-RH antagonists.
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Affiliation(s)
- A Siejka
- Institute of Endocrinology, Medical University of Łódź, 91-425, Sterlinga 3, Łódź, Poland
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Bagnasco M, Tulipano G, Melis MR, Argiolas A, Cocchi D, Muller EE. Endogenous ghrelin is an orexigenic peptide acting in the arcuate nucleus in response to fasting. Regul Pept 2003; 111:161-7. [PMID: 12609764 DOI: 10.1016/s0167-0115(02)00283-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Ghrelin, a circulating growth-hormone releasing peptide derived from stomach, stimulates food intake through neuropeptide Y (NPY) neurons of the arcuate nucleus in the hypothalamus (ARC). We examined the effect of ghrelin microinjected into the ARC and the influence of intracerebroventricular (i.c.v.) pretreatment with a GHRH or NPY receptor antagonist on ghrelin-induced food intake in free-feeding male rats. Ghrelin (0.1-1 microg) stimulated food intake in a dose-dependent manner, and this effect was reduced by 55-60% by the Y(5) NPY receptor antagonist (10 microg i.c.v.), but not by the GHRH receptor antagonist MZ-4-71 (10 microg i.c.v.). We also evaluated the effects of passive ghrelin immunoneutralization by the microinjection of anti-ghrelin immunoglobulins (IgGs) intracerebroventricularly or directly into the ARC on food intake in free-feeding and fasted male rats. i.c.v. administration of anti-ghrelin IgGs decreased cumulative food intake over 24 h, whereas microinfusion of anti-ghrelin IgGs into the ARC induced only a short-lived (2 and 6 h) effect. Collectively, these data would indicate that centrally derived ghrelin has a major role in the control of food intake in rats and, in this context, blood-born ghrelin would be effective only in relation to its ability to reach the ARC, which is devoid of blood-brain barrier.
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Affiliation(s)
- Michela Bagnasco
- Department of Pharmacology, Chemotherapy and Medical Toxicology, University of Milan, Via Vanvitelli, 32-20129 Milan, Italy
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36
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Chatzistamou I, Schally AV, Varga JL, Groot K, Armatis P, Busto R, Halmos G. Antagonists of growth hormone-releasing hormone and somatostatin analog RC-160 inhibit the growth of the OV-1063 human epithelial ovarian cancer cell line xenografted into nude mice. J Clin Endocrinol Metab 2001; 86:2144-52. [PMID: 11344219 DOI: 10.1210/jcem.86.5.7487] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [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] [Indexed: 12/31/2022]
Abstract
The effects of antagonists of GHRH and the somatostatin analog RC-160 on the growth of OV-1063 human epithelial ovarian cancer cells xenografted into nude mice were investigated. Treatment with 20 microg/day of the GHRH antagonist JV-1-36 or MZ-5-156 and 60 microg/day of the somatostatin analog RC-160 for 25 days decreased tumor volume by 70.9% (P < 0.01), 58.3% (P < 0.05), and 60.6% (P < 0.01), respectively, vs. the control value. The levels of GH in serum were decreased in all of the treated groups, but only RC-160 significantly reduced serum insulin-like growth factor I (IGF-I). The levels of messenger ribonucleic acid (mRNA) for IGF-I and -II and for their receptors in OV-1063 tumors were investigated by multiplex RT-PCR. No expression of mRNA for IGF-I was detected, but treatment with JV-1-136 caused a 51.8% decrease (P < 0.05) in the level of mRNA for IGF-II in tumors. Exposure of OV-1063 cells cultured in vitro to GHRH, IGF-I, or IGF-II significantly (P < 0.05) stimulated cell growth, but 10(-5) mol/L JV-1-36 nearly completely inhibited (P < 0.001) OV-1063 cell proliferation. OV-1063 tumors expressed mRNA for GHRH receptors and showed the presence of binding sites for GHRH. Our results indicate that antagonistic analogs of GHRH and the somatostatin analog RC-160 inhibit the growth of epithelial ovarian cancers. The effects of RC-160 seem to be exerted more on the pituitary GH-hepatic IGF-I axis, whereas GHRH antagonists appear to reduce IGF-II production and interfere with the autocrine regulatory pathway. The antitumorigenic action of GHRH antagonists appears to be mediated by GHRH receptors found in OV-1063 tumors.
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Affiliation(s)
- I Chatzistamou
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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Torsello A, Locatelli V, Melis MR, Succu S, Spano MS, Deghenghi R, Müller EE, Argiolas A. Differential orexigenic effects of hexarelin and its analogs in the rat hypothalamus: indication for multiple growth hormone secretagogue receptor subtypes. Neuroendocrinology 2000; 72:327-32. [PMID: 11146415 DOI: 10.1159/000054601] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [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] [Indexed: 11/19/2022]
Abstract
We have previously reported that hexarelin and some of its analogs, including EP 50885, stimulated GH secretion and feeding after systemic administration in the rat, whereas EP 40904 selectively stimulated food intake and EP 40737 only GH release. The precise mechanism of growth hormone-releasing peptides (GHRPs) actions is still unclear, but the integrity of the arcuate nucleus of the hypothalamus (ARC) appears crucial for their endocrine effects. To better characterize the site(s) and mechanisms(s) of the orexigenic action of GHRPs, we have investigated their effects after infusion into the arcuate, paraventricular, ventromedial and medial preoptic areas of the hypothalamus. Food intake was measured for 60 min following injection of the test compound (2 microg/rat). Hexarelin, EP 40904 and EP 50885 had significant orexigenic effects after injection into the ARC. A specific NPY antagonist significantly inhibited the effect of hexarelin, whereas a GHRH antagonist was ineffective. In the paraventricular nucleus, only EP 50885 stimulated feeding, whereas all peptides were ineffective in the ventromedial nucleus and medial preoptic area. Taken altogether, these results demonstrate that GHRPs are endowed with site-specific orexigenic actions and that endogenous NPY, but not GHRH, mediates these effects. The additional orexigenic action of EP 50885 in the paraventricular nucleus suggests the existence of a GHRP receptor subtype different from the already cloned one.
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Affiliation(s)
- A Torsello
- Department of Experimental and Environmental Medicine and Biotechnologies, University of Milano-Bicocca, Italy.
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38
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Plonowski A, Schally AV, Varga JL, Rekasi Z, Hebert F, Halmos G, Groot K. Potentiation of the inhibitory effect of growth hormone-releasing hormone antagonists on PC-3 human prostate cancer by bombesin antagonists indicative of interference with both IGF and EGF pathways. Prostate 2000; 44:172-80. [PMID: 10881027 DOI: 10.1002/1097-0045(20000701)44:2<172::aid-pros10>3.0.co;2-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [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] [Indexed: 11/09/2022]
Abstract
BACKGROUND In view of the involvement of various neuropeptides and growth factors in the progression of androgen-independent prostate cancer, we investigated the effects of antagonists of growth hormone-releasing hormone (GHRH) alone or in combination with an antagonist of bombesin/gastrin-releasing peptide (BN/GRP) on PC-3 human prostate cancers. METHODS Nude mice implanted with PC-3 tumors received GHRH antagonists MZ-5-156 or JV-1-38, each at 20 microgram/day s.c. In experiment 2, treatment consisted of daily injections of JV-1-38 (20 microgram), BN/GRP antagonist RC-3940-II (10 microgram), or a combination of JV-1-38 and RC-3940-II. Serum IGF-I levels, expression of mRNA for IGF-II, and characteristics of BN/GRP and EGF receptors in tumor tissue were investigated. RESULTS JV-1-38 induced a greater inhibition of tumor growth and suppression of IGF-II mRNA than MZ-5-156, both compounds causing a similar decrease in serum IGF-I. In experiment 2, JV-1-38 and RC-3940-II produced a comparable reduction in tumor volume (65% and 61%, respectively), but a combination of both antagonists augmented tumor inhibition to 75%. Combined treatment with JV-1-38 and RC-3940-II also led to a greater suppression of IGF-II mRNA (92%), as compared with JV-1-38 (72%) or RC-3940-II (77%). Serum IGF-I concentration was lowered only in mice treated with JV-1-38, while the downregulation of BN/GRP and EGF receptors was specific for groups receiving RC-3940-II. CONCLUSIONS The inhibitory effects of GHRH antagonists on PC-3 human androgen-independent prostate cancer can be potentiated by concomitant use of BN/GRP antagonists. The combination of both types of analogs apparently interferes with both IGF and bombesin/EGF pathways, and might be clinically useful for the management of androgen-independent prostate cancer.
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Affiliation(s)
- A Plonowski
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, New Orleans, Louisiana, USA
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39
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Liu DM, Cuevas J, Adams DJ. VIP and PACAP potentiation of nicotinic ACh-evoked currents in rat parasympathetic neurons is mediated by G-protein activation. Eur J Neurosci 2000; 12:2243-51. [PMID: 10947803 DOI: 10.1046/j.1460-9568.2000.00116.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effects of vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP27 and PACAP38) on isolated parasympathetic neurons of rat intracardiac and submandibular ganglia were examined under voltage clamp using whole-cell patch-clamp recording techniques. VIP and PACAP (</= 10 nM) selectively and reversibly increased the affinity of nicotinic acetylcholine receptor channels (nAChRs) for their agonists resulting in a potentiation of acetylcholine (ACh)-evoked whole-cell currents at low agonist concentrations. VIP-induced potentiation was observed with either ACh or nicotine as the cholinergic agonist. The VIP- but not the PACAP-induced potentiation of ACh-evoked currents was inhibited by [Ac-Tyr1, D-Phe2]-GRF 1-29, amide (100 nM), a selective antagonist of VPAC1 and VPAC2 receptors; whereas the PACAP38- but not the VIP-induced potentiation was inhibited by 100 nM PACAP6-38, a PAC1 and VPAC2 receptor antagonist. The signal transduction pathway mediating VIP- and PACAP-induced potentiation of nicotinic ACh-evoked currents involves a pertussis toxin (PTX)-sensitive G-protein. Intracellular application of 200 microM GTPgammaS or GDPbetaS inhibited VIP-induced potentiation of ACh-evoked whole-cell currents. GTPgammaS alone potentiated ACh- and nicotine-evoked currents and the magnitude of these currents was not further increased by VIP or PACAP. The G-protein subtype modulating the neuronal nAChRs was examined by intracellular dialysis with antibodies directed against alphao, alphai-1,2, alphai-3 or beta G-protein subunits. Only the anti-Galphao and anti-Gbeta antibodies significantly inhibited the effect of VIP and PACAP on ACh-evoked currents. The potentiation of ACh-evoked currents by VIP and PACAP may be mediated by a membrane-delimited signal transduction cascade involving the PTX-sensitive Go protein.
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Affiliation(s)
- D M Liu
- Department of Physiology and Pharmacology, University of Queensland, Brisbane, Australia
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40
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Szepeshazi K, Schally AV, Groot K, Armatis P, Halmos G, Herbert F, Szende B, Varga JL, Zarandi M. Antagonists of growth hormone-releasing hormone (GH-RH) inhibit IGF-II production and growth of HT-29 human colon cancers. Br J Cancer 2000; 82:1724-31. [PMID: 10817510 PMCID: PMC2374518 DOI: 10.1054/bjoc.2000.1223] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Insulin-like growth factors (IGFs) I and II are implicated in progression of various tumours including colorectal carcinomas. To interfere with the production of IGFs, we treated male nude mice bearing xenografts of HT-29 human colon cancer with various potent growth hormone-releasing hormone (GH-RH) antagonists. Twice daily injections of antagonist MZ-4-71, 10 microg intraperitoneally or 5 microg subcutaneously (s.c.) resulted in a significant 43-45% inhibition of tumour growth. Longer acting GH-RH antagonists, MZ-5-156 and JV-1-36 given once daily at doses of 20 microg s.c. produced a 43-58% decrease in volume and weight of cancers. Histological analyses of HT-29 cancers demonstrated that both a decreased cell proliferation and an increased apoptosis contributed to tumour inhibition. GH-RH antagonists did not change serum IGF-I or IGF-II levels, but significantly decreased IGF-II concentration and reduced mRNA expression for IGF-II in tumours. In vitro studies showed that HT-29 cells produced and secreted IGF-II into the medium, and addition of MZ-5-156 dose-dependently decreased IGF-II production by about 40% as well as proliferation of HT-29 cells. Our studies demonstrate that GH-RH antagonists inhibit growth of HT-29 human colon cancers in vivo and in vitro. The effect of GH-RH antagonists may be mediated through a reduced production and secretion of IGF-II by cancer cells.
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Affiliation(s)
- K Szepeshazi
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, New Orleans, Louisiana 70112-1262, USA
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41
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Abstract
Antagonists of growth hormone-releasing hormone(GH-RH)inhibit the growth of various cancers by mechanisms that involve the suppression of the insulin-like growth factor (IGF)-I and/or IGF-II. In view of the importance of the IGF system in glioma tumorigenesis, the effects of GH-RH antagonists MZ-5-156 and JV-1-36 were investigated in nude mice bearing subcutaneous and orthotopic xenografts of U-87MG human glioblastomas. After 4 weeks of therapy with MZ-5-156 or JV-1 -36 at the dose of 20 microg/day per animal, the final volume of subcutaneous U-87MG tumors was significantly (P < .01) decreased by 84% and 76%, respectively, as compared with controls. Treatment with GH-RH antagonists also reduced tumor weight and the levels of mRNA for IGF receptor type I (IGFR-I). A reduction in the mRNA levels for IGF-II was found in tumors of mice treated with MZ-5-156. Treatment with MZ-5-156 or JV-1 -36 also extended the survival of nude mice implanted orthotopically with U-87MG glioblastomas by 81% (P < .005) and 18%, respectively, as compared with the controls. Exposure in vitro to GH-RH antagonists MZ-5-156 or JV-1 -36 at 1 microM concentration for 24 hours decreased the tumorigenicity of U-87MG cells in nude mice by 10% to 30% and extended the latency period for the development of subcutaneous palpable tumors by 31% to 56%, as compared with the controls. Exposure of U-87MG cells to GH-RH antagonists in vitro also resulted in a time-dependent increase in the mRNA levels of IGFR-II or a decrease in the mRNA levels of IGFR-I. mRNA for GH-RH was detected in U-87MG cells and xenografts implying that GH-RH may play a role in the pathogenesis of this tumor. Our results suggest that GH-RH antagonists MZ-5-156 and JV-1-36 inhibit the growth of U-87MG human glioblastoma by mechanisms that involve the suppression of IGF system. Antagonistic analogs of GH-RH merit further development for the treatment of malignant glioblastoma.
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Affiliation(s)
- H Kiaris
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112-1262, USA
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42
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Kahán Z, Varga JL, Schally AV, Rékási Z, Armatis P, Chatzistamou L, Czömpöly T, Halmos G. Antagonists of growth hormone-releasing hormone arrest the growth of MDA-MB-468 estrogen-independent human breast cancers in nude mice. Breast Cancer Res Treat 2000; 60:71-9. [PMID: 10845811 DOI: 10.1023/a:1006363230990] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Since antagonists of growth hormone-releasing hormone (GH-RH) inhibit proliferation of various tumors, in this study we investigated the effects of GH-RH antagonists MZ-5-156 or JV-1-36 on growth of estrogen-independent MDA-MB-468 human breast cancers xenografted into nude mice. Both GH-RH antagonists administered at a dose of 20 microg/day induced regression of some and growth-arrest of other tumors, while control tumors continued to grow. After 5 weeks of therapy with MZ-5-156 or JV-1-36, final volume and weight of MDA-MB-468 tumors were significantly decreased (all p values < 0.001) and serum IGF-I levels as well as tumor IGF-I mRNA expression were reduced as compared with controls. High affinity binding sites for IGF-I were detected by the ligand binding method. Gene expression of human IGF-I receptors, as measured by the RT-PCR, was not significantly different in control and treated MDA-MB-468 tumors. In cell culture, IGF-I did not stimulate, GH-RH slightly stimulated, while MZ-5-156 and JV-1-36 inhibited proliferation of MDA-MB-468 cells known to possess defective insulin and IGF-I receptor signaling. The expression of mRNA for human GH-RH was found in five of 8 tumors treated with GH-RH antagonists, and in one of the five control tumors. These results suggest that GH-RH antagonists inhibit MDA-MB-468 breast cancers possibly through mechanisms involving interference with locally produced GH-RH.
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MESH Headings
- Animals
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- DNA Primers
- Disease Models, Animal
- Female
- Gene Expression Regulation, Neoplastic
- Growth Hormone-Releasing Hormone/analogs & derivatives
- Growth Hormone-Releasing Hormone/antagonists & inhibitors
- Growth Hormone-Releasing Hormone/genetics
- Growth Hormone-Releasing Hormone/pharmacology
- Growth Hormone-Releasing Hormone/therapeutic use
- Humans
- Insulin-Like Growth Factor I/genetics
- Insulin-Like Growth Factor I/metabolism
- Insulin-Like Growth Factor II/genetics
- Insulin-Like Growth Factor II/metabolism
- Mice
- Mice, Nude
- RNA, Messenger/genetics
- Radioimmunoassay
- Receptor, IGF Type 1/genetics
- Receptor, IGF Type 1/metabolism
- Receptors, Neuropeptide/genetics
- Receptors, Neuropeptide/metabolism
- Receptors, Pituitary Hormone-Regulating Hormone/genetics
- Receptors, Pituitary Hormone-Regulating Hormone/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sermorelin/analogs & derivatives
- Sermorelin/pharmacology
- Sermorelin/therapeutic use
- Transplantation, Heterologous
- Tumor Cells, Cultured/drug effects
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Affiliation(s)
- Z Kahán
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center New Orleans, Louisiana 70112-1262, USA
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43
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Szepeshazi K, Schally AV, Groot K, Armatis P, Hebert F, Halmos G. Antagonists of growth hormone-releasing hormone (GH-RH) inhibit in vivo proliferation of experimental pancreatic cancers and decrease IGF-II levels in tumours. Eur J Cancer 2000; 36:128-36. [PMID: 10741306 DOI: 10.1016/s0959-8049(99)00230-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Insulin-like growth factors (IGF-I and IGF-II) are implicated in the pathogenesis of pancreatic carcinoma. Antagonists of growth hormone-releasing hormone (GH-RH) suppress the GH-RH-GH-IGF-I axis and also act directly on tumours to reduce production of IGF-I or II. The aim of this study was to investigate the effects of two potent GH-RH antagonists in two experimental models of pancreatic cancer. Syrian golden hamsters with nitrosamine-induced pancreatic tumours were treated with 10 micrograms/day of GH-RH antagonist MZ-4-71 for 60 days. The therapy reduced the number of tumorous animals, decreased the weight of tumorous pancreata by 55%, and lowered AgNOR numbers in tumour cells. In two other experiments, GH-RH antagonists MZ-4-71 and MZ-5-156 significantly inhibited growth of SW-1990 human pancreatic cancers xenografted into nude mice, as shown by a reduction in tumour volume and tumour weights, and a decrease in AgNORs in cancer cells. IGF-I levels in serum and in pancreatic cancer tissue remained unchanged after therapy, suggesting that an effect on IGF-I is not involved in tumour inhibition. In contrast, IGF-II concentrations in tumours were significantly reduced by 50-60% after treatment with the GH-RH antagonists as compared with controls. In vitro studies showed that the concentration of IGF-II in the culture medium was increased after seeding of SW-1990 cells, indicating that this pancreatic cancer cell line produced and released IGF-II. This finding was also supported by the expression of IGF-II mRNA in the SW-1990 cells. Addition of 3 x 10(-6) M of GH-RH antagonist MZ-5-156 to the reduced-serum medium decreased cell proliferation, IGF-II mRNA expression in the cells and IGF-II concentration in the medium. Our findings indicate that inhibitory effects of GH-RH antagonists on the growth of experimental pancreatic cancers, may result from a decrease in the production and concentration of IGF-II in the tumours.
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Affiliation(s)
- K Szepeshazi
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, New Orleans, LA 70146, USA
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44
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Abstract
It is well known that psoriasis, an immunogenetic cutaneous disorder whose major pathogenic findings are epidermal hyperplasia and T-cell infiltration, is aggravated by psychological stresses. Although the exact mechanism is not yet clarified, antidromic secretion of neuropeptides by cutaneous nerve fibers is thought to be involved. In this study, we examined the effect and mechanism of vasoactive intestinal polypeptide (VIP), one of the major neuropeptides, on the proliferation of HaCaT cell which is a spontaneous, immortalized, human keratinocyte cell line. Twenty-four and 48 h after its addition, 1 pM to 100 nM of VIP increased the number of cells cultured with/without serum. We indirectly verified VIP(1)R on the surface of HaCaT cell based on the proliferative ability of various VIP families such as VIP, PACAP and secretin, and increased PKA level 30 min after stimulation. However, because H-89, a PKA inhibitor, did not inhibit the proliferative potential of VIP, its mitogenicity is not medicated through VIP(1)R. One nM VIP produced the TGF-alpha protein which is a strong mitogen of keratinocytes and increased in the psoriatic lesion 2.25 times more compared with the control. Genistein, a tyrosine kinase inhibitor, abrogated the mitogenic activity of VIP. Like VIP, VIP fragments, VIP(1-12) and VIP(10-28) also acted as a mitogen for HaCaT cells through the same mechanism. Collectively, our studies clearly show that VIP and its fragments stimulate keratinocyte growth, not through increased cAMP level, but through increased TGF-alpha protein production.
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Affiliation(s)
- K J Sung
- Division of Dermatology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea
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45
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Csernus VJ, Schally AV, Kiaris H, Armatis P. Inhibition of growth, production of insulin-like growth factor-II (IGF-II), and expression of IGF-II mRNA of human cancer cell lines by antagonistic analogs of growth hormone-releasing hormone in vitro. Proc Natl Acad Sci U S A 1999; 96:3098-103. [PMID: 10077643 PMCID: PMC15901 DOI: 10.1073/pnas.96.6.3098] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Antagonistic analogs of growth hormone-releasing hormone (GHRH) suppress growth of various tumors in vivo. This effect is exerted in part through inhibition of the GHRH-GH-insulin-like growth factor (IGF)-I axis. Nevertheless, because autocrine/paracrine control of proliferation by IGF-II also is a major factor in many tumors, the interference with this growth-stimulating pathway would offer another approach to tumor control. We thus investigated whether GHRH antagonists MZ-4-71 and MZ-5-156 also act on the tumor cells directly by blocking the production of IGF-II. An increase in the IGF-II concentration in the media during culture was found in 13 of 26 human cancer cell lines tested. Reverse transcription-PCR studies on 8 of these cell lines showed that they also expressed IGF-II mRNA. Antagonists of GHRH significantly inhibited the rate of proliferation of mammary (MDA-MB-468 and ZR-75-1), prostatic (PC-3 and DU-145), and pancreatic (MiaPaCa-2, SW-1990, and Capan-2) cancer cell lines as shown by colorimetric and [3H]thymidine incorporation tests and reduced the expression of IGF-II mRNA in the cells and the concentration of IGF-II secreted into the culture medium. Growth and IGF-II production of lung (H-23 and H-69) and ovarian (OV-1063) cancer cells that express mRNA for IGF-II and excrete large quantities of IGF-II also was marginally suppressed by the antagonists. These findings suggest that antagonistic analogs of GHRH can inhibit growth of certain tumors not only by inhibiting the GHRH-GH-IGF-I axis, but also by reducing the IGF-II production and by interfering with the autocrine regulatory pathway.
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Affiliation(s)
- V J Csernus
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, New Orleans, LA 70112-1262, USA
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46
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Kiaris H, Schally AV. Decrease in telomerase activity in U-87MG human glioblastomas after treatment with an antagonist of growth hormone-releasing hormone. Proc Natl Acad Sci U S A 1999; 96:226-31. [PMID: 9874800 PMCID: PMC15121 DOI: 10.1073/pnas.96.1.226] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Antagonists of growth hormone-releasing hormone (GH-RH) inhibit the growth of various tumors through mechanisms that involve the suppression of the insulin-like growth factor I and/or insulin-like growth factor II levels or secretion. In the present study, we tested the hypothesis that the tumor inhibition is associated with a decrease in telomerase activity because telomerase is considered obligatory for continued tumor growth. Nude mice bearing xenografts of U-87MG human glioblastomas were treated with GH-RH antagonist MZ-5-156. Telomerase activity was assessed by the telomerase repeat amplification protocol. Treatment with MZ-5-156 reduced levels of telomerase activity as compared with controls. When U-87 glioblastomas, H-69 small cell lung carcinomas, H-23 non-small cell lung carcinomas, and MDA-MB-468 breast carcinoma cells were cultured in vitro, addition of 3 microM MZ-5-156 also inhibited telomerase activity. Reverse transcription-PCR analysis revealed that in U-87MG glioblastomas, the expression of the hTRT gene encoding for the telomerase catalytic subunit was significantly decreased by MZ-5-156, whereas the levels of mRNA for hTR and TP1, which encode for the telomerase RNA and telomerase-associated protein, respectively, were unaffected. The repression of the telomerase activity was not accompanied by a significant decrease of mRNA level for the c-myc protooncogene that regulates telomerase. Our findings suggest that tumor inhibition induced by the GH-RH antagonists in U-87MG glioblastomas is associated with the down-regulation of the hTRT gene, resulting in a decrease in telomerase activity. Further studies are needed to establish whether GH-RH antagonists produce telomerase inhibition in other tumors.
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Affiliation(s)
- H Kiaris
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, New Orleans, LA 70112-1262, USA
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Abstract
Antagonistic analogs of growth hormone-releasing hormone (GHRH) inhibit growth of various human cancers both in vivo and in vitro. GHRH, vasoactive intestinal peptide (VIP), and pituitary adenylate cyclase-activating peptide stimulate cyclic AMP (cAMP) release from various human cancer cell lines in vitro. Thus, in the present study, we investigated the effects of antagonistic analogs of GHRH on the GHRH- and VIP-induced cAMP release from cultured human cancer cells in a superfusion system. Various human cancer cell lines were exposed to human GHRH(1-29)NH2 (2-20 nM) or VIP (0.1-5 nM) repeatedly for 12 min or continuously for 96 min. GHRH antagonist MZ-5-156 at 100 to 200 nM concentration inhibited the GHRH- or VIP-induced cAMP release from mammary (MDA-MB-468), prostatic (PC-3), and pancreatic (SW-1990 and CAPAN-2) cancer cells. These results show that antagonistic analogs of GHRH suppress the stimulatory effects of GHRH and VIP on the cAMP production of various cancer cells. Because cAMP is a potent second messenger controlling many intracellular functions, including the stimulation of cell growth, an inhibition of autocrine/paracrine action of GHRH by the GHRH antagonists may provide the basis for the development of new methods for cancer treatment.
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Affiliation(s)
- V Csernus
- Endocrine, Polypeptide and Cancer Institute, VA Medical Center, New Orleans, Louisiana 70112-1262, USA
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48
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Wester TJ, Fiorotto ML, Klindt J, Burrin DG. Feeding colostrum increases circulating insulin-like growth factor I in newborn pigs independent of endogenous growth hormone secretion. J Anim Sci 1998; 76:3003-9. [PMID: 9928604 DOI: 10.2527/1998.76123003x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our objective was to examine the influence of feeding and endogenous GH secretion on circulating IGF-I in colostrum-deprived newborn pigs fed colostrum (n = 4), formula (control, n = 4), or water (n = 4). In another four formula-fed pigs, GH was ablated (GRF-A) with two intravenous injections of a GH releasing-factor antagonist (N-Ac-Tyr1,D-Arg2)-GRF(1-29)-NH2. Blood was serially sampled in all pigs to measure plasma IGF-I and GH profiles. Feeding increased plasma IGF-I concentration two- to fourfold and decreased GH secretion. Despite a more than 80% decrease in the plasma GH in GRF-A pigs, the circulating IGF-I concentration was similar to that in control pigs. In colostrum-fed pigs, plasma IGF-I was higher than that in control pigs, despite equal nutrient intake and lower circulating GH. There were no differences in plasma IGF binding protein (IGFBP)-3 levels among the treatment groups. However, the relative abundance of plasma IGFBP-4 was lower, and that of IGFBP-1 higher, in unfed pigs than in any of the three fed groups. The plasma insulin concentration was not different among fed pigs, but it was lower in unfed pigs. Our results indicate that the circulating IGF-I concentration is more dependent on nutrient intake than on GH in newborn pigs, despite relatively high GH concentrations. However, because the nutrient content in the formula was designed to match that of colostrum, a factor other than nutrient intake and GH was responsible for the maximal increase in circulating IGF-I concentration observed in colostrum-fed pigs.
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Affiliation(s)
- T J Wester
- Children's Nutrition Research Center, ARS, USDA, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
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Lamharzi N, Schally AV, Koppán M, Groot K. Growth hormone-releasing hormone antagonist MZ-5-156 inhibits growth of DU-145 human androgen-independent prostate carcinoma in nude mice and suppresses the levels and mRNA expression of insulin-like growth factor II in tumors. Proc Natl Acad Sci U S A 1998; 95:8864-8. [PMID: 9671770 PMCID: PMC21168 DOI: 10.1073/pnas.95.15.8864] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Insulin-like growth factors I and II (IGF-I and -II) are potent mitogens for various cancers, including carcinoma of the prostate. In several experimental cancers, treatment with antagonists of growth hormone-releasing hormone (GH-RH) produces a reduction in IGF-I and -II, concomitant to inhibition of tumor growth. To investigate the mechanisms involved, we treated male nude mice bearing xenografts of DU-145 human androgen-independent prostate cancer for 8 weeks with potent GH-RH antagonist MZ-5-156 at a dose of 20 microg/animal s.c. twice a day. Tumor growth, serum and tumor levels of IGF-I and -II, and the mRNA expression of IGF-I and -II in tumors were evaluated. After 8 weeks of therapy, final volume and weight of DU-145 tumors in mice treated with MZ-5-156 were significantly (P < 0.01) decreased compared with controls, and serum IGF-I showed a significant reduction. Treatment of nude mice bearing DU-145 xenografts with MZ-5-156 also significantly (P < 0.01) diminished by 77% the levels of IGF-II in tumor tissue compared with controls, but did not affect the concentration of IGF-I. Reverse transcription-PCR analyses revealed a high expression of IGF-II mRNA in DU-145 tumors. Treatment with GH-RH antagonist MZ-5-156 decreased the expression of IGF-II mRNA by 58% (P < 0.01) as compared with controls. Our work suggests that GH-RH antagonist MZ-5-156 may inhibit the growth of DU-145 human androgen-independent prostate cancers through a reduction in the production and mRNA expression of IGF-II by the tumor tissue. These findings extend our observations on the mechanism of action of GH-RH antagonists and may explain how GH-RH antagonists inhibit tumor growth.
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Affiliation(s)
- N Lamharzi
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, New Orleans, LA 70146, USA
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50
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Pandya N, DeMott-Friberg R, Bowers CY, Barkan AL, Jaffe CA. Growth hormone (GH)-releasing peptide-6 requires endogenous hypothalamic GH-releasing hormone for maximal GH stimulation. J Clin Endocrinol Metab 1998; 83:1186-9. [PMID: 9543138 DOI: 10.1210/jcem.83.4.4711] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
GH-releasing peptide-6 (GHRP-6) is a potent GH secretagogue that releases GH by uncertain mechanisms. To assess whether GHRH is required for GH release by GHRP-6 in humans, we used the specific antagonist to GHRH (N-Ac-Tyr1,D-Arg2)GHRH(1-29)NH2 (GHRH Ant). We have previously shown that GHRH-Ant (400 microg/kg) blocked the GH response to 0.33 and 3.3 microg/kg boluses of GHRH by 95% and 81%, respectively. Nine healthy men between the ages of 20 and 30 yr were studied on two occasions. They received either saline or GHRH-Ant (400 microg/kg, i.v.) at 0840 h, followed by GHRP-6 (1 microg/kg, i.v. bolus) at 0900 h. Blood was sampled every 10 min from 0800-1100 h. GH responses were measured as the maximal increase over the baseline GH concentration and as the area under the curve. GHRH-Ant eliminated most of the GH response to GHRP-6 [maximal increase over the baseline GH concentration, 33.8 +/- 4.8 vs. 6.2 +/- 1.8 microg/L (mean +/- SEM; P < 0.0001); area under the curve, 1701 +/- 278 vs. 376 +/- 113 microg/min x L (P < 0.001)]. These data show that endogenous GHRH is necessary for most of the GH response to GHRP-6 in humans.
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Affiliation(s)
- N Pandya
- Department of Internal Medicine, University of Michigan and Ann Arbor Veterans Affairs Medical Center, 48109-0354, USA
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