1
|
Budamagunta V, Kumar A, Rani A, Manohar Sindhu S, Yang Y, Zhou D, Foster TC. Senolytic treatment alleviates doxorubicin-induced chemobrain. Aging Cell 2024; 23:e14037. [PMID: 38225896 PMCID: PMC10861213 DOI: 10.1111/acel.14037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/21/2023] [Accepted: 10/23/2023] [Indexed: 01/17/2024] Open
Abstract
Doxorubicin (Dox), a widely used treatment for cancer, can result in chemotherapy-induced cognitive impairments (chemobrain). Chemobrain is associated with inflammation and oxidative stress similar to aging. As such, Dox treatment has also been used as a model of aging. However, it is unclear if Dox induces brain changes similar to that observed during aging since Dox does not readily enter the brain. Rather, the mechanism for chemobrain likely involves the induction of peripheral cellular senescence and the release of senescence-associated secretory phenotype (SASP) factors and these SASP factors can enter the brain to disrupt cognition. We examined the effect of Dox on peripheral and brain markers of aging and cognition. In addition, we employed the senolytic, ABT-263, which also has limited access to the brain. The results indicate that plasma SASP factors enter the brain, activating microglia, increasing oxidative stress, and altering gene transcription. In turn, the synaptic function required for memory was reduced in response to altered redox signaling. ABT-263 prevented or limited most of the Dox-induced effects. The results emphasize a link between cognitive decline and the release of SASP factors from peripheral senescent cells and indicate some differences as well as similarities between advanced age and Dox treatment.
Collapse
Affiliation(s)
- Vivekananda Budamagunta
- Department of Neuroscience, McKnight Brain InstituteUniversity of FloridaGainesvilleFloridaUSA
- Genetics and Genomics Graduate Program, Genetics InstituteUniversity of FloridaGainesvilleFloridaUSA
- Department of Pharmacodynamics, College of PharmacyUniversity of FloridaGainesvilleFloridaUSA
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain InstituteUniversity of FloridaGainesvilleFloridaUSA
| | - Asha Rani
- Department of Neuroscience, McKnight Brain InstituteUniversity of FloridaGainesvilleFloridaUSA
| | - Sahana Manohar Sindhu
- Genetics and Genomics Graduate Program, Genetics InstituteUniversity of FloridaGainesvilleFloridaUSA
| | - Yang Yang
- Department of Pharmacodynamics, College of PharmacyUniversity of FloridaGainesvilleFloridaUSA
| | - Daohong Zhou
- Department of Pharmacodynamics, College of PharmacyUniversity of FloridaGainesvilleFloridaUSA
- Department of Biochemistry and Structural BiologyUniversity of Texas Health Science Center at San AntonioSan AntonioTexasUSA
| | - Thomas C. Foster
- Department of Neuroscience, McKnight Brain InstituteUniversity of FloridaGainesvilleFloridaUSA
- Genetics and Genomics Graduate Program, Genetics InstituteUniversity of FloridaGainesvilleFloridaUSA
| |
Collapse
|
2
|
Mehdipour M, Mehdipour T, Skinner CM, Wong N, Liu C, Chen CC, Jeon OH, Zuo Y, Conboy MJ, Conboy IM. Plasma dilution improves cognition and attenuates neuroinflammation in old mice. GeroScience 2020; 43:1-18. [PMID: 33191466 PMCID: PMC8050203 DOI: 10.1007/s11357-020-00297-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/01/2020] [Indexed: 02/06/2023] Open
Abstract
Our recent study has established that young blood factors are not causal, nor necessary, for the systemic rejuvenation of mammalian tissues. Instead, a procedure referred to as neutral blood exchange (NBE) that resets signaling milieu to a pro-regenerative state through dilution of old plasma, enhanced the health and repair of the muscle and liver, and promoted better hippocampal neurogenesis in 2-year-old mice (Mehdipour et al., Aging 12:8790–8819, 2020). Here we expand the rejuvenative phenotypes of NBE, focusing on the brain. Namely, our results demonstrate that old mice perform much better in novel object and novel texture (whisker discrimination) tests after a single NBE, which is accompanied by reduced neuroinflammation (less-activated CD68+ microglia). Evidence against attenuation/dilution of peripheral senescence-associated secretory phenotype (SASP) as the main mechanism behind NBE was that the senolytic ABT 263 had limited effects on neuroinflammation and did not enhance hippocampal neurogenesis in the old mice. Interestingly, peripherally acting ABT 263 and NBE both diminished SA-βGal signal in the old brain, demonstrating that peripheral senescence propagates to the brain, but NBE was more robustly rejuvenative than ABT 263, suggesting that rejuvenation was not simply by reducing senescence. Explaining the mechanism of the positive effects of NBE on the brain, our comparative proteomics analysis demonstrated that dilution of old blood plasma yields an increase in the determinants of brain maintenance and repair in mice and in people. These findings confirm the paradigm of rejuvenation through dilution of age-elevated systemic factors and extrapolate it to brain health and function.
Collapse
Affiliation(s)
- Melod Mehdipour
- Department of Bioengineering and QB3, UC Berkeley, Berkeley, CA, USA
| | - Taha Mehdipour
- Department of Bioengineering and QB3, UC Berkeley, Berkeley, CA, USA
| | - Colin M Skinner
- Department of Bioengineering and QB3, UC Berkeley, Berkeley, CA, USA
| | - Nathan Wong
- Department of Bioengineering and QB3, UC Berkeley, Berkeley, CA, USA
| | - Chao Liu
- Department of Bioengineering and QB3, UC Berkeley, Berkeley, CA, USA
| | - Chia-Chien Chen
- Department of Molecular and Cellular Biology and QB3, UCSC, Santa Cruz, CA, USA
| | - Ok Hee Jeon
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, USA.,Department of Biomedical Sciences, Korea University College of Medicine, Seoul, Republic of Korea
| | - Yi Zuo
- Department of Molecular and Cellular Biology and QB3, UCSC, Santa Cruz, CA, USA
| | - Michael J Conboy
- Department of Bioengineering and QB3, UC Berkeley, Berkeley, CA, USA
| | - Irina M Conboy
- Department of Bioengineering and QB3, UC Berkeley, Berkeley, CA, USA.
| |
Collapse
|
3
|
Lever JR, Fergason-Cantrell EA. Allosteric modulation of sigma receptors by BH3 mimetics ABT-737, ABT-263 (Navitoclax) and ABT-199 (Venetoclax). Pharmacol Res 2019; 142:87-100. [PMID: 30721730 DOI: 10.1016/j.phrs.2019.01.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/12/2018] [Accepted: 01/21/2019] [Indexed: 11/21/2022]
Abstract
ABT-737, ABT-263 (Navitoclax) and ABT-199 (Venetoclax) are under intensive preclinical and clinical investigation as treatments for hematologic and other malignancies. These small molecules mimic pro-death B-cell lymphoma-2 (Bcl-2) Homology 3 (BH3) domain-only proteins. They also bear a structural resemblance to certain sigma (σ) receptor ligands. Moreover, the Bcl-2 and σ receptor protein families are both located primarily at the endoplasmic reticulum, mediate cell death and survival through protein-protein interactions, and physically associate. Accordingly, we examined the ability of the ABT series of BH3 mimetics to interact with σ receptors using radioligand-binding techniques. Negative allosteric modulation of [3H](+)-pentazocine, an agonist, binding to σ1 receptors in guinea pig brain membranes was observed for ABT-737, ABT-263 and ABT-199. Findings included reduction of specific binding to distinct plateaus in concentration-dependent fashion, significant slowing of radioligand dissociation kinetics, and decreases in radioligand affinity with no or modest changes in maximal receptor densities. Using a ternary complex model, dissociation constants (KX) for modulator binding to the σ1 receptor ranged from 1 to 2.5 μM, while negative cooperativity factors (α), representing the changes in affinity of ligand and modulator when bound as a ternary complex with the receptor, ranged from 0.15 to 0.42. These observations were extended and reinforced by studies using intact small cell (NCI-H69) and non-small cell (NCI-H23) lung cancer cells, and by using an antagonist σ1 receptor radioligand, E-N-1-(3'-[125I]iodoallyl)-N'-4-(3″,4″-dimethoxyphenethyl)piperazine, in mouse brain membranes. By contrast, exploratory studies indicate marked enhancement of the σ2 receptor binding of [3H]1,3-di-(o-tolyl)guanidine/(+)-pentazocine in NCI-H23 cells and guinea pig brain membranes. These findings raise intriguing questions regarding mechanism and potential functional outcomes.
Collapse
Affiliation(s)
- John R Lever
- Department of Radiology, University of Missouri, Columbia, MO 65211, USA; Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.
| | - Emily A Fergason-Cantrell
- Department of Radiology, University of Missouri, Columbia, MO 65211, USA; Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA
| |
Collapse
|
4
|
Ketchem CJ, Kucera C, Barve A, Beverly LJ. The Antiarrhythmic Drug, Amiodarone, Decreases AKT Activity and Sensitizes Human Acute Myeloid Leukemia Cells to Apoptosis by ABT-263. Am J Med Sci 2018; 355:488-496. [PMID: 29753379 DOI: 10.1016/j.amjms.2018.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/22/2018] [Accepted: 01/22/2018] [Indexed: 01/12/2023]
Abstract
BACKGROUND Successful treatment of leukemia requires new medications to combat drug resistance, but the development of novel therapies is an arduous and risky endeavor. Repurposing currently approved drugs or those already in clinical development to treat other indications is a more practical approach. Moreover, combinatorial therapeutics are often more efficacious than single agent therapeutics because the former can simultaneously target multiple pathways that mitigate tumor aggressiveness and induce cancer cell death. MATERIAL AND METHODS In this study, we combined the class III antiarrhythmic agent amiodarone and the BH3 mimetic ABT-263 based on data from a prior drug screen to assess the degree of apoptotic induction in 2 human leukemia cell lines. RESULTS The combination yielded statistically significant increases in apoptosis in both cell lines by downregulating AKT activity and increasing cleaved caspase-3. CONCLUSIONS Overall, our findings suggest that combining K+ channel blockers with prosurvival Bcl-2 family inhibitors is a promising therapeutic approach in treating leukemia.
Collapse
Affiliation(s)
- Corey J Ketchem
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky
| | - Cory Kucera
- Department of Physiology, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky
| | - Aditya Barve
- Department of Pharmacology and Toxicology, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky
| | - Levi J Beverly
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky; Department of Physiology, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky; Department of Pharmacology and Toxicology, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky
| |
Collapse
|
5
|
Srinivas NR. Pharmacokinetic Interaction of Rifampicin with Oral Versus Intravenous Anticancer Drugs: Challenges, Dilemmas and Paradoxical Effects Due to Multiple Mechanisms. Drugs R D 2017; 16:141-8. [PMID: 27098526 PMCID: PMC4875928 DOI: 10.1007/s40268-016-0133-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
Since many drugs are cytochrome P450 (CYP)-3A4 substrates, it has become common practice to assess drug-drug interaction (DDI) potential with a CYP3A4 inhibitor (ketoconazole) or inducer (rifampicin) in early drug development. Such an evaluation is relevant to anticancer drugs with metabolism governed by CYP3A4. DDIs with rifampicin are complex, involving other physiological mechanisms that may impact overall pharmacokinetics. Our objective was to study and delineate such mechanisms for oral versus intravenous anticancer drugs. We hypothesized that DDIs between anticancer drugs and rifampicin were primarily driven by CYP3A4 induction. This hypothesis was proven for the oral anticancer drugs; however, in some cases, other intrinsic mechanisms such as P-glycoprotein (Pgp)/UDP glucuronosyl transferase (UGT) induction and transporter inhibition may have played an important role alongside the induced CYP3A4 enzymes. The hypothesis that CYP3A4 induction would decrease drug exposure appeared paradoxical for intravenous romidepsin and-to a somewhat lesser extent-for cabazitaxel. In light of this dilemma in the interpretation of the pharmacokinetic data with rifampicin, several questions require further consideration. Given the complexity and paradoxical effects arising with DDIs with rifampicin, the continued preference for rifampicin as CYP3A4 inducer needs immediate re-appraisal.
Collapse
Affiliation(s)
- Nuggehally R Srinivas
- Suramus Bio, Drug Development, 29th Main, 10th Cross, JP Nagar I Phase, Bangalore, 560078, Karnataka, India.
| |
Collapse
|
6
|
CD44 promotes chemoresistance in T-ALL by increased drug efflux. Exp Hematol 2016; 44:166-71.e17. [DOI: 10.1016/j.exphem.2015.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 11/28/2015] [Accepted: 12/01/2015] [Indexed: 11/20/2022]
|
7
|
Theile D, Allendorf D, Köhler BC, Jassowicz A, Weiss J. Obatoclax as a perpetrator in drug-drug interactions and its efficacy in multidrug resistance cell lines. ACTA ACUST UNITED AC 2015; 67:1575-84. [PMID: 26255619 DOI: 10.1111/jphp.12455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 05/17/2015] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Obatoclax is a pan-Bcl-2 inhibitor with promising efficacy, especially when combined with other antineoplastic agents. Pharmacokinetic drug-drug interactions can occur systemically and at the level of the tumour cell. Thus, this study scrutinised the interaction potential of obatoclax in vitro. METHODS Obatoclax was screened for P-gp inhibition by calcein assay, for breast cancer resistance protein (BCRP) inhibition by pheophorbide A assay and for inhibition of cytochrome P450 isoenzymes (CYPs) by commercial kits. Induction of mRNA of drug-metabolising enzymes and drug transporters was quantified in LS180 cells via real-time polymerase chain reaction and involvement of nuclear receptors was assessed by reporter gene assays. Proliferation assays were used to assess whether obatoclax retains its efficacy in cell lines overexpressing BCRP, P-glycoprotein (P-gp) or multidrug resistance-associated protein 2 (MRP2). KEY FINDINGS Obatoclax induced the mRNA expression of several genes (e.g. CYP1A1, CYP1A2 and ABCG2 (five to seven-fold) through activation of the aryl hydrocarbon receptor in the nanomolar range. Obatoclax inhibits P-gp, BCRP and some CYPs at concentrations exceeding plasma levels. P-gp, MPR2 or BCRP overexpression did not influence the efficacy of obatoclax. CONCLUSIONS Obatoclax retains its efficacy in cells overexpressing P-gp, MRP2 or BCRP and might act as a perpetrator drug in interactions with drugs, for example being substrates of CYP1A2 or BCRP.
Collapse
Affiliation(s)
- Dirk Theile
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - David Allendorf
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Bruno Christian Köhler
- National Centre for Tumour Diseases, Department of Medical Oncology, Internal Medicine VI, University of Heidelberg, Heidelberg, Germany
| | - Adam Jassowicz
- National Centre for Tumour Diseases, Department of Medical Oncology, Internal Medicine VI, University of Heidelberg, Heidelberg, Germany
| | - Johanna Weiss
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| |
Collapse
|
8
|
Yang J, Pradhan RS, Rosen LS, Graham AM, Holen KD, Xiong H. Effect of rifampin on the pharmacokinetics, safety and tolerability of navitoclax (ABT-263), a dual inhibitor of Bcl-2 and Bcl-XL
, in patients with cancer. J Clin Pharm Ther 2014; 39:680-4. [DOI: 10.1111/jcpt.12193] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 06/30/2014] [Indexed: 11/30/2022]
Affiliation(s)
- J. Yang
- AbbVie Inc.; North Chicago IL USA
| | | | - L. S. Rosen
- UCLA Santa Monica Hematology-Oncology; Santa Monica CA USA
| | | | | | - H. Xiong
- AbbVie Inc.; North Chicago IL USA
| |
Collapse
|
9
|
Overcoming multiple drug resistance mechanisms in medulloblastoma. Acta Neuropathol Commun 2014; 2:57. [PMID: 24887326 PMCID: PMC4229867 DOI: 10.1186/2051-5960-2-57] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 12/18/2022] Open
Abstract
INTRODUCTION Medulloblastoma (MB) is the most common malignant paediatric brain tumour. Recurrence and progression of disease occurs in 15-20% of standard risk and 30-40% of high risk patients. We analysed whether circumvention of chemoresistance pathways (drug export, DNA repair and apoptotic inhibition) can restore chemotherapeutic efficacy in a panel of MB cell lines. RESULTS We demonstrate, by immunohistochemistry in patient tissue microarrays, that ABCB1 is expressed in 43% of tumours and is significantly associated with high-risk. We show that ABCB1, O6-methylguanine-DNA-methyltransferase (MGMT) and BCL2 family members are differentially expressed (by quantitative reverse transcription polymerase chain reaction, Western blotting and flow cytometry) in MB cell lines. Based on these findings, each pathway was then inhibited or circumvented and cell survival assessed using clonogenic assays. Inhibition of ABCB1 using vardenafil or verapamil resulted in a significant increase in sensitivity to etoposide in ABCB1-expressing MB cell lines. Sensitivity to temozolomide (TMZ) was MGMT-dependent, but two novel imidazotetrazine derivatives (N-3 sulfoxide and N-3 propargyl TMZ analogues) demonstrated ≥7 fold and ≥3 fold more potent cytotoxicity respectively compared to TMZ in MGMT-expressing MB cell lines. Activity of the BAD mimetic ABT-737 was BCL2A1 and ABCB1 dependent, whereas the pan-BCL2 inhibitor obatoclax was effective as a single cytotoxic agent irrespective of MCL1, BCL2, BCL2A1, or ABCB1 expression. CONCLUSIONS ABCB1 is associated with high-risk MB; hence, inhibition of ABCB1 by vardenafil may represent a valid approach in these patients. Imidazotetrazine analogues of TMZ and the BH3 mimetic obatoclax are promising clinical candidates in drug resistant MB tumours expressing MGMT and BCL2 anti-apoptotic members respectively.
Collapse
|
10
|
A phase 1 study of the BCL2-targeted deoxyribonucleic acid inhibitor (DNAi) PNT2258 in patients with advanced solid tumors. Cancer Chemother Pharmacol 2013; 73:363-71. [PMID: 24297683 PMCID: PMC3909249 DOI: 10.1007/s00280-013-2361-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 11/13/2013] [Indexed: 11/04/2022]
Abstract
Purpose Maximum tolerated dose, safety, pharmacokinetics, and pharmacodynamics were assessed in this phase 1 study of PNT2258, a BCL-2-targeted liposomal formulation of a 24-base DNA oligonucleotide called PNT100. Methods Patients with malignant solid tumors were assigned sequentially to one of ten dose-escalation cohorts of PNT2258 at 1, 2, 4, 8, 16, 32, 64, 85, 113, and 150 mg/m2 administered intravenously on days 1 through 5 of each 21-day cycle. Pharmacokinetics were determined on days 1 and 5 of the first cycle. Lymphocyte and platelets concentrations were measured for evidence of BCL2-targeted effect. CT scans were used to identify radiologic evidence of anti-tumor effect. Results Twenty-two subjects received PNT2258, and the maximum tolerated dose for PNT2258 was not reached. Doses at or above 32 mg/m2 resulted in exposure to PNT2258 above the exposure level required for anti-tumor activity in preclinical xenograft testing of 22,377 ng h/ml (PK analysis 2012). Fatigue was the most commonly reported adverse event. Dose-limiting toxicity, manifesting as a transient increase in aspartate aminotransferase, occurred at 150 mg/m2, the highest dose tested. Four subjects, two each with diagnosis of non-small-cell lung cancer and sarcoma, treated at doses of 64 mg/m2 or higher, remained on study for 5–8 cycles. Conclusions PNT2258 was safe and well tolerated at the doses tested up to 150 mg/m2. Exposure to PNT2258 resulted in clinically manageable decreases in lymphocyte and platelet concentrations.
Collapse
|
11
|
A multi-system approach assessing the interaction of anticonvulsants with P-gp. PLoS One 2013; 8:e64854. [PMID: 23741405 PMCID: PMC3669347 DOI: 10.1371/journal.pone.0064854] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/19/2013] [Indexed: 12/27/2022] Open
Abstract
30% of epilepsy patients receiving antiepileptic drugs (AEDs) are not fully controlled by therapy. The drug transporter hypothesis for refractory epilepsy proposes that P-gp is over expressed at the epileptic focus with a role of P-gp in extruding AEDs from the brain. However, there is controversy regarding whether all AEDs are substrates for this transporter. Our aim was to investigate transport of phenytoin, lamotrigine and carbamazepine by using seven in-vitro transport models. Uptake assays in CEM/VBL cell lines, oocytes expressing human P-gp and an immortalised human brain endothelial cell line (hCMEC/D3) were carried out. Concentration equilibrium transport assays were performed in Caco-2, MDCKII ±P-gp and LLC-PK1±P-gp in the absence or presence of tariquidar, an inhibitor of P-gp. Finally, primary porcine brain endothelial cells were used to determine the apparent permeability (Papp) of the three AEDs in the absence or presence of P-gp inhibitors. We detected weak transport of phenytoin in two of the transport systems (MDCK and LLC-PK1 cells transfected with human P-gp) but not in the remaining five. No P-gp interaction was observed for lamotrigine or carbamazepine in any of the seven validated in-vitro transport models. Neither lamotrigine nor carbamazepine was a substrate for P-gp in any of the model systems tested. Our data suggest that P-gp is unlikely to contribute to the pathogenesis of refractory epilepsy through transport of carbamazepine or lamotrigine.
Collapse
|
12
|
Kim HR, Heo YM, Jeong KI, Kim YM, Jang HL, Lee KY, Yeo CY, Kim SH, Lee HK, Kim SR, Kim EG, Choi JK. FGF-2 inhibits TNF-α mediated apoptosis through upregulation of Bcl2-A1 and Bcl-xL in ATDC5 cells. BMB Rep 2012; 45:287-92. [PMID: 22617452 DOI: 10.5483/bmbrep.2012.45.5.287] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
FGF-2 is involved in cell survival, proliferation, apoptosis, and angiogenesis in a wide variety of cells. FRGRs, PI3K and MAP kinases are well known mediators of FGF signaling. Despite its known roles during many developmental processes, including osteogenesis, there are few known targets of FGF-2. In the present study, we identified Bcl2-A1 and Bcl-xL as two prominent targets involved in promoting cell survival. Pretreatment of ATDC5 cells with FGF-2 increased cell survival, while siRNAs specific for Bcl2-A1 and Bcl-xL compromised the anti- apoptotic effect of FGF-2, sensitized the cells to apoptosis triggered by TNF-α. Chemical inhibition of FGFR, NFkB, and PI3K activity by PD173074, pyrrolidine dithiocarbamate, and LY294002 respectively abrogated the FGF-2-mediated induction of Bcl2-A1 and Bcl-xL expression. Taken together, our data demonstrate that a subset of Bcl2 family proteins are the targets of FGF-2 signaling that promotes the survival of ATDC5 cells.
Collapse
Affiliation(s)
- Hey-Ryun Kim
- Division of Biochemistry, College of Medicine, Chungbuk National University, Cheongju 361-763, Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
van Oosterwijk JG, Herpers B, Meijer D, Briaire-de Bruijn IH, Cleton-Jansen AM, Gelderblom H, van de Water B, Bovée JVMG. Restoration of chemosensitivity for doxorubicin and cisplatin in chondrosarcoma in vitro: BCL-2 family members cause chemoresistance. Ann Oncol 2011; 23:1617-26. [PMID: 22112972 DOI: 10.1093/annonc/mdr512] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Chondrosarcomas are malignant cartilage-forming tumors notorious for their resistance to conventional chemo- and radiotherapy. Postulated explanations describe the inaccessibility due to abundant hyaline cartilaginous matrix, presence of multidrug resistance (MDR) pumps, and expression of anti-apoptotic BCL-2 family members. MATERIALS AND METHODS We studied the sensitivity of chondrosarcoma cell lines (SW1353, CH2879, JJ012, OUMS27) and two primary cultures for doxorubicin and cisplatin. We examined the role of extracellular matrix using three-dimensional (3D) pellet models and MDR pump activity using fluorescence-activated cell sorter analysis. The role of BCL-2 family members was investigated using the BH3 mimetic ABT-737. RESULTS Chondrosarcoma cells showed highest resistance to cisplatin. 3D cell pellets, morphologically strongly resembling chondrosarcoma in vivo, confirmed nuclear incorporation of doxorubicin. MDR pump activity was heterogeneous among cultures. Chondrosarcoma cells responded to ABT-737 and combination with doxorubicin led to complete loss of cell viability and apoptosis with cytochrome C release. CONCLUSIONS Despite MDR pump activity and abundance of hyaline cartilaginous matrix, doxorubicin is able to accumulate in the cell nuclei. By repairing the apoptotic machinery, we were able to sensitize chondrosarcoma cells to doxorubicin and cisplatin, indicating an important role for BCL-2 family members in chemoresistance and a promising new treatment strategy for inoperable chondrosarcoma.
Collapse
Affiliation(s)
- J G van Oosterwijk
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Because each cancer is a heterogeneous mix of cancer cells at different stages of development, we are faced with trying to treat many different diseased cells all at once. An authentic approach is to build a genomic and proteomic profile of a patient, identify the target oncogenes, and prescribe the combination of targeted drugs tailored for that patient. However, there are many practical problems with this personalized medicine approach: (i) cancers often generate treatment-resistant phenotypes, (ii) the treatment could be enormously expensive, and (iii) most of the targeted drugs have not been developed yet. We propose a different approach: therapies that combine 2-deoxyglucose (2DG) with Bcl-2 antagonist such as ABT-263/737 (ABT). Proapoptotic protein Bak is normally sequestered by Mcl-1 and Bcl-xL. Only when Bak is released from both Mcl-1 and Bcl-xL can it induce apoptosis. 2DG can prime highly glycolytic cells by dissociating Bak-Mcl-1 complex. Some brain cells and most cancer cells are primed by 2DG. ABT can bind to Bcl-xL, dissociating Bak-Bcl-xL complex, freeing Bak and inducing apoptosis. Because ABT cannot cross blood-brain barrier, the only cells exposed to both agents are highly glycolytic cancer cells located outside the brain. Because ABT directly triggers apoptosis at the step very near the terminal point of apoptosis, 2DG-ABT combination therapies are applicable to many types of cancer at all stages of development, with little side effect.
Collapse
|