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Hetschko H, Voss V, Seifert V, Prehn JHM, Kögel D. Upregulation of DR5 by proteasome inhibitors potently sensitizes glioma cells to TRAIL-induced apoptosis. FEBS J 2008; 275:1925-36. [PMID: 18341587 DOI: 10.1111/j.1742-4658.2008.06351.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study was undertaken to explore the potential of new therapeutic approaches designed to reactivate cell death pathways in apoptosis-refractory gliomas and to characterize the underlying molecular mechanisms of this reactivation. Here we investigated the sensitivity of a panel of glioma cell lines (U87, U251, U343, U373, MZ-54, and MZ-18) to apoptosis induced by the death receptor ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), TRAIL in combination with gamma irradiation, and TRAIL in combination with proteasome inhibitors (MG132 and epoxomicin). Analysis of these six glioma cell lines revealed drastic differences in their sensitivity to these treatments, with two of the six cell lines revealing no significant induction of cell death in response to TRAIL alone. Interestingly, the proteasome inhibitors MG132 and epoxomicin were capable of potentiating TRAIL-induced apoptosis in TRAIL-sensitive U87 and U251 cells and of reactivating apoptosis in TRAIL-resistant U343 and U373 cells. In contrast, gamma irradiation had no synergistic effects with TRAIL in the two TRAIL-resistant cell lines. RNA interference against death receptor 5 (DR5) revealed that reactivation of TRAIL-induced apoptosis by proteasome inhibitors depended on enhanced transcription and surface expression of DR5. Transient knockdown of the transcription factor GADD153/C/EBP homologous protein and application of the synthetic c-Jun N-terminal kinase inhibitor SP600125 indicated that enhanced DR5 expression occurred independently of GADD153/C/EBP homologous protein, but required activation of the c-Jun N-terminal kinase/c-Jun signaling pathway. Novel therapeutic approaches using TRAIL or agonistic TRAIL receptor antibodies in combination with proteasome inhibitors may represent a promising approach to reactivate apoptosis in therapy-resistant high-grade gliomas.
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Affiliation(s)
- Holger Hetschko
- Department of Neurosurgery, Centre for Neurology and Neurosurgery, Johann Wolfgang Goethe University Clinics, Theodor-Stern-Kai 7, Frankfurt/Main, Germany
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202
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203
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Sorolla A, Yeramian A, Dolcet X, Pérez de Santos AM, Llobet D, Schoenenberger JA, Casanova JM, Soria X, Egido R, Llombart A, Vilella R, Matias-Guiu X, Marti RM. Effect of proteasome inhibitors on proliferation and apoptosis of human cutaneous melanoma-derived cell lines. Br J Dermatol 2008; 158:496-504. [PMID: 18205878 DOI: 10.1111/j.1365-2133.2007.08390.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cutaneous malignant melanoma is an aggressive type of skin cancer which causes disproportionate mortality in young and middle-aged adults. Once disseminated, melanoma can be considered an incurable disease, highly resistant to standard antineoplastic treatment, such as chemotherapy or radiation therapy. The proteasome represents a novel target for cancer therapy that can potentially be used in melanoma. OBJECTIVES To assess the effect of four structurally different proteasome inhibitors on human cutaneous melanoma-derived cell lines. METHODS Sixteen human cutaneous melanoma-derived cell lines which are original were obtained from patients who were treated by two of the authors. Cells were cultured, exposed to proteasome inhibitors (bortezomib, ALLN, MG-132 and epoxomicin) and then assayed for cell cycle and cell death analyses. RESULTS Proteasome inhibitors inhibited the in vitro growth of melanoma cells, and this effect was due to a reduction in cell proliferation rate and an induction of both caspase-dependent and caspase-independent cell death. Moreover, release of apoptosis-inducing factor was observed in the presence of the broad-specificity caspase inhibitor BAF (Boc-D-fmk). In addition, the four different proteasome inhibitors induced caspase 2 processing. CONCLUSIONS This study provides information regarding the in vitro effects of proteasome inhibitors on melanoma cell lines, and the molecular mechanisms involved. It also gives support to the future use of such inhibitors in the treatment of patients with melanoma, either administered alone or in combination with other drugs.
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Affiliation(s)
- A Sorolla
- Department of Dermatology, and Laboratory of Research, Hospital Universitair Arnau de Vilanova, Universitat de Lleida, 25198 Lleida, Spain
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204
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Noxa/Mcl-1 balance regulates susceptibility of cells to camptothecin-induced apoptosis. Neoplasia 2007; 9:871-81. [PMID: 17971907 DOI: 10.1593/neo.07589] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 08/26/2007] [Accepted: 08/27/2007] [Indexed: 12/21/2022] Open
Abstract
Although camptothecin (CPT) has been reported to induce apoptosis in various cancer cells, the molecular details of this regulation remain largely unknown. In this study, we demonstrate that BH3-only protein Noxa is upregulated during CPT-induced apoptosis, which is independent of p53. In addition, we show that phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is responsible for Noxa's induction. Luciferase assay and cAMP response element binding protein (CREB) knockdown experiments further demonstrate that CREB is involved in the transcriptional upregulation of Noxa. Moreover, blocking Noxa expression using specific small interfering ribonucleic acid (siRNA) significantly reduces the apoptosis in response to CPT, indicating that Noxa is an essential mediator for CPT-induced apoptosis. Interestingly, antiapoptotic Mcl-1 was also upregulated through PI3K/Akt signaling pathway upon CPT treatment. Using immunoprecipitation assay, Noxa was found to interact with Mcl-1 in the presence or absence of CPT. Knockdown of Mcl-1 expression by short hairpin ribonucleic acid (shRNA) was shown to potentiate CPT-induced apoptosis. Consistently, ectopic overexpression of Mcl-1 rescued cells from apoptosis induced by CPT. Cells coexpressing Noxa and Mcl-1 at different ratio correlates well with the extent of apoptosis, suggesting that the balance between Noxa and Mcl-1 may determine the susceptibility of HeLa cells to CPT-induced apoptosis.
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205
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Bortezomib blocks Bax degradation in malignant B cells during treatment with TRAIL. Blood 2007; 111:2797-805. [PMID: 18160669 DOI: 10.1182/blood-2007-08-110445] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Proapoptotic Bcl-2 family member Bax is a crucial protein in the induction of apoptosis, and its activation is required for this process. Here we report that Bax is a short-lived protein in malignant B cells and Bax protein levels decreased rapidly when protein synthesis was blocked. Malignant B cells were relatively resistant to tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-induced apoptosis, and this correlated with low basal Bax protein levels. Furthermore, during treatment with TRAIL, the resistant cell lines showed prominent Bax degradation activity. This degradation activity was localized to mitochondrial Bax and could be prevented by truncated Bid, a BH3-only protein; in contrast, cytosolic Bax was relatively stable. The proteasome inhibitor bortezomib is a potent drug in inducing apoptosis in vitro in malignant B-cell lines and primary chronic lymphocytic leukemic (CLL) cells. In CLL cells, bortezomib induced Bax accumulation, translocation to mitochondria, conformational change, and oligomerization. Accumulation and stabilization of Bax protein by bortezomib-sensitized malignant B cells to TRAIL-induced apoptosis. This study reveals that Bax instability confers resistance to TRAIL, which can be reversed by Bax stabilization with a proteasome inhibitor.
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206
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Eberle J, Kurbanov BM, Hossini AM, Trefzer U, Fecker LF. Overcoming apoptosis deficiency of melanoma-hope for new therapeutic approaches. Drug Resist Updat 2007; 10:218-34. [PMID: 18054518 DOI: 10.1016/j.drup.2007.09.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 09/02/2007] [Accepted: 09/07/2007] [Indexed: 11/16/2022]
Abstract
The increased incidence of malignant melanoma in the last decades, its high mortality and pronounced therapy resistance pose an enormous challenge. Important therapeutic targets for melanoma are the induction of apoptosis and suppression of survival pathways. Preclinical studies have demonstrated the efficacy of pro-apoptotic Bcl-2 proteins and of death receptor ligands to trigger apoptosis in melanoma cells. In the clinical setting, BH3 domain mimics and death receptor agonists are therefore considered as promising, specific novel treatments to add to the conventional pro-apoptotic strategies such as chemo- or radiotherapy. However, constitutively activated survival pathways, in particular the mitogen-activated protein kinases, protein kinase B/Akt and nuclear factor (NF)-kappaB, all may work in concert to prevent effective therapy. Thus, selective biologicals developed with the aim to inhibit pro-survival signaling are currently tested in melanoma. For highly therapy-resistant tumors such as melanoma, development of novel drug combinations will be essential, and combinations of survival inhibitors and pro-apoptotic mediators appear most promising. The challenge of the near future will be to make a rational choice of the multiple possible combinations and protocols. This review gives a critical overview of proteins involved in melanoma chemoresistance, which are targets for current drug development leading to the best choice for future trials.
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Affiliation(s)
- Jürgen Eberle
- Charité-Universitätsmedizin Berlin, Department of Dermatology and Allergy, Skin Cancer Center Charité, Charité Campus Mitte, Charitéplatz 1, 10117 Berlin, Germany.
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207
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Tumor cell-selective regulation of NOXA by c-MYC in response to proteasome inhibition. Proc Natl Acad Sci U S A 2007; 104:19488-93. [PMID: 18042711 DOI: 10.1073/pnas.0708380104] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The proteasome controls a plethora of survival factors in all mammalian cells analyzed to date. Therefore, it is puzzling that proteasome inhibitors such as bortezomib can display a preferential toxicity toward malignant cells. In fact, proteasome inhibitors have the salient feature of promoting a dramatic induction of the proapoptotic protein NOXA in a tumor cell-restricted manner. However, the molecular determinants that control this specific regulation of NOXA are unknown. Here, we show that the induction of NOXA by bortezomib is directly dependent on the oncogene c-MYC. This requirement for c-MYC was found in a variety of tumor cell types, in marked contrast with dispensable roles of p53, HIF-1alpha, and E2F-1 (classical proteasomal targets that can regulate NOXA mRNA under stress). Conserved MYC-binding sites identified at the NOXA promoter were validated by ChIP and reporter assays. Down-regulation of the endogenous levels of c-MYC abrogated the induction of NOXA in proteasome-defective tumor cells. Conversely, forced expression of c-MYC enabled normal cells to accumulate NOXA and subsequently activate cell death programs in response to proteasome blockage. c-MYC is itself a proteasomal target whose levels or function are invariably up-regulated during tumor progression. Our data provide an unexpected function of c-MYC in the control of the apoptotic machinery, and reveal a long sought-after oncogenic event conferring sensitivity to proteasome inhibition.
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208
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Small molecule obatoclax (GX15-070) antagonizes MCL-1 and overcomes MCL-1-mediated resistance to apoptosis. Proc Natl Acad Sci U S A 2007; 104:19512-7. [PMID: 18040043 DOI: 10.1073/pnas.0709443104] [Citation(s) in RCA: 517] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Elevated expression of members of the BCL-2 pro-survival family of proteins can confer resistance to apoptosis in cancer cells. Small molecule obatoclax (GX15-070), which is predicted to occupy a hydrophobic pocket within the BH3 binding groove of BCL-2, antagonizes these members and induces apoptosis, dependent on BAX and BAK. Reconstitution in yeast confirmed that obatoclax acts on the pathway and overcomes BCL-2-, BCL-XL-, BCL-w-, and MCL-1-mediated resistance to BAX or BAK. The compound potently interfered with the direct interaction between MCL-1 and BAK in intact mitochondrial outer membrane and inhibited the association between MCL-1 and BAK in intact cells. MCL-1 has been shown to confer resistance to the BCL-2/BCL-XL/BCL-w-selective antagonist ABT-737 and to the proteasome inhibitor bortezomib. In both cases, this resistance was overcome by obatoclax. These findings support a rational clinical development opportunity for the compound in cancer indications or treatments where MCL-1 contributes to resistance to cell killing.
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209
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Abstract
Bortezomib (Velcade, PS341) was licensed in 2003 as a first-in-class 20S proteasome inhibitor indicated for treatment of multiple myeloma, and is currently being evaluated clinically in a range of solid tumours. The mechanisms underlying its cancer cell toxicity are complex. A growing body of evidence suggests proteasome inhibition-dependent regulation of the BCL-2 family is a critical requirement. In particular, the stabilization of BH3-only proteins BIK, NOXA and BIM, appear to be essential for effecting BAX- and BAK-dependent cell death. These mechanisms are reviewed and the implications for favourable novel drug interactions are highlighted.
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Affiliation(s)
- D A Fennell
- Thoracic Oncology Research Group, Centre for Cancer Research and Cell Biology, Queen's University Belfast, Northern Ireland, UK.
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210
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Inoue S, Riley J, Gant TW, Dyer MJS, Cohen GM. Apoptosis induced by histone deacetylase inhibitors in leukemic cells is mediated by Bim and Noxa. Leukemia 2007; 21:1773-82. [PMID: 17525724 DOI: 10.1038/sj.leu.2404760] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Several histone deacetylase inhibitors (HDACi), which have recently entered early clinical trials, exert their anticancer activity in part through the induction of apoptosis although the precise mechanism of this induction is not known. Induction of apoptosis by structurally diverse HDACi in primary cells from patients with chronic lymphocytic leukemia (CLL) and different leukemic cell lines was mediated by the Bcl-2 regulated intrinsic pathway and demonstrated a requirement for de novo protein synthesis. A marked time-dependent induction of the pro-apoptotic BH3-only proteins, Bim, Noxa and Bmf was observed, which preceded the induction of apoptosis. A key role for both Bim and Noxa was proposed in HDACi-mediated apoptosis based on our findings that siRNA for Bim and Noxa but not Bmf largely prevented the HDACi-induced loss in mitochondrial membrane potential, caspase processing and phosphatidylserine externalization. Noxa, induced by HDACi, in CLL cells and tumor cell lines, bound extensively to Mcl-1, a major anti-apoptotic Bcl-2 family member present in CLL cells. Our data strongly suggests that HDACi induce apoptosis primarily through inactivation of anti-apoptotic Bcl-2 family members by increases in Bim and Noxa and highlights these increases as a potential clinical target for CLL/lymphoma therapy.
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MESH Headings
- Adaptor Proteins, Signal Transducing/antagonists & inhibitors
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Apoptosis/drug effects
- Apoptosis Regulatory Proteins/antagonists & inhibitors
- Apoptosis Regulatory Proteins/genetics
- Apoptosis Regulatory Proteins/metabolism
- Bcl-2-Like Protein 11
- Blotting, Western
- Cell Line
- Cell Nucleus/metabolism
- Enzyme Inhibitors/pharmacology
- Histone Deacetylase Inhibitors
- Humans
- Immunoprecipitation
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Myeloid Cell Leukemia Sequence 1 Protein
- Neoplasm Proteins/metabolism
- Proto-Oncogene Proteins/antagonists & inhibitors
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors
- Proto-Oncogene Proteins c-bcl-2/genetics
- Proto-Oncogene Proteins c-bcl-2/metabolism
- RNA Interference
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reactive Oxygen Species/metabolism
- Transcriptional Activation
- Tumor Cells, Cultured
- Tumor Suppressor Protein p53/metabolism
- bcl-2 Homologous Antagonist-Killer Protein/antagonists & inhibitors
- bcl-2 Homologous Antagonist-Killer Protein/genetics
- bcl-2 Homologous Antagonist-Killer Protein/metabolism
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Affiliation(s)
- S Inoue
- MRC Toxicology Unit, Hodgkin Building, University of Leicester, Leicester, UK
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211
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Hamner JB, Dickson PV, Sims TL, Zhou J, Spence Y, Ng CY, Davidoff AM. Bortezomib inhibits angiogenesis and reduces tumor burden in a murine model of neuroblastoma. Surgery 2007; 142:185-91. [PMID: 17689684 DOI: 10.1016/j.surg.2007.04.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 04/05/2007] [Accepted: 04/07/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Bortezomib is a proteasome inhibitor with pleiotropic antitumor activity. Here we investigate the antiangiogenic and antitumor efficacy of bortezomib against neuroblastoma both in vitro and in a murine model of localized and disseminated disease. METHODS In vitro activity of bortezomib was assessed by evaluating its effect on cell proliferation and cell cycle status. Localized tumor burden was followed with caliper measurements and total-body bioluminescence in mice with disseminated disease. The antiangiogenic activity was evaluated with immunohistochemistry and human vascular endothelial growth factor (VEGF) enzyme-linked immunosorbent assay on tumor protein extracts. RESULTS Bortezomib treatment resulted in dose and time-dependent decreases in cell proliferation and resulted in cell cycle arrest. In vivo, bortezomib restricted tumor growth in a model of localized disease and decreased bioluminescence in mice with disseminated disease. That decreased bioluminescence reflected decreased tumor burden was confirmed at necropsy by assessing disease in specific organs. In addition, treatment resulted in a decrease in intratumoral vessel counts and reduced tumor VEGF expression. CONCLUSION Bortezomib shows significant activity against neuroblastoma in vitro, and it inhibits tumor growth and angiogenesis in vivo. These results suggest that clinical studies of bortezomib are warranted for the treatment of this difficult disease.
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Affiliation(s)
- John B Hamner
- Department of Surgery, St. Jude Children's Research Hospital, Memphis, Tenn, USA
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212
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Podar K, Gouill SL, Zhang J, Opferman JT, Zorn E, Tai YT, Hideshima T, Amiot M, Chauhan D, Harousseau JL, Anderson KC. A pivotal role for Mcl-1 in Bortezomib-induced apoptosis. Oncogene 2007; 27:721-31. [PMID: 17653083 DOI: 10.1038/sj.onc.1210679] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bortezomib is a proteasome inhibitor for the treatment of relapsed/refractory multiple myeloma (MM). Mechanisms of resistance to Bortezomib are undefined. Myeloid cell leukemia-1 (Mcl-1) is an antiapoptotic protein, which protects tumor cells against spontaneous and chemotherapy-induced apoptosis. In MM, specific downregulation of Mcl-1 induces apoptosis. Here, we examined the role of Mcl-1 in Bortezomib- and doxorubicin-induced apoptosis. We demonstrate that Bortezomib, but not doxorubicin, triggers caspase-dependent generation of a 28 kDa Mcl-1-fragment, in several MM cell lines, including MM.1S cells. Conversely, transient transfection of MM.1S cells with a previously reported 28 kDa Mcl-1(128-350) fragment, but not with the Mcl-1(1-127) fragment, induces apoptosis. Therefore, both downregulation of full-length antiapoptotic Mcl-1, as well as Bortezomib-induced generation of Mcl-1(128-350) cleaved protein, contribute to MM cell apoptosis. To verify further these findings, we next compared effects triggered by Bortezomib, doxorubicin and melphalan in Mcl-1(wt/wt) and Mcl-1(Delta/null) murine embryonic fibroblasts (MEFs). Our results show that Bortezomib, but not doxorubicin or melphalan, triggers Mcl-1 cleavage in Mcl-1(wt/wt), but not Mcl-1(Delta/null) MEFs and induces sub-G(1) phase cells; caspase-3 and -9, and PARP cleavage as well as morphological signs of apoptosis. Taken together, these results support an important role of Mcl-1 and a Mcl-1 fragment in Bortezomib-induced cell death in general, and in MM in particular. To prevent relapse of MM in patients treated with Bortezomib, we therefore recommend the combination of Bortezomib with agents that induce MM cell death independent of Mcl-1.
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Affiliation(s)
- K Podar
- Department of Medical Oncology, Jerome Lipper Multiple Myeloma Center, Harvard Medical School, Dana-Farber Cancer Institute, Boston, MA 022115, USA.
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213
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Yang C, Kaushal V, Shah SV, Kaushal GP. Mcl-1 is downregulated in cisplatin-induced apoptosis, and proteasome inhibitors restore Mcl-1 and promote survival in renal tubular epithelial cells. Am J Physiol Renal Physiol 2007; 292:F1710-7. [PMID: 17311906 DOI: 10.1152/ajprenal.00505.2006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mcl-1 is an antiapoptotic member of the Bcl-2 family that plays an important role in cell survival. We demonstrate that proteasome-dependent regulation of Mcl-1 plays a critical role in renal tubular epithelial cell injury from cisplatin. Protein levels of Mcl-1 rapidly declined in a time-dependent manner following cisplatin treatment of LLC-PK1cells. However, mRNA levels of Mcl-1 were not altered following cisplatin treatment. Expression of other antiapoptotic members of the Bcl-2 family such as Bcl-2 and BclxL was not affected by cisplatin treatment. Cisplatin-induced loss of Mcl-1 occurs at the same time as the mitochondrial release of cytochrome c, activation of caspase-3, and initiation of apoptosis. Treatment of cells with cycloheximide, a protein synthesis inhibitor, revealed rapid turnover of Mcl-1. In addition, treatment with cycloheximide in the presence or absence of cisplatin demonstrated that cisplatin-induced loss of Mcl-1 results from posttranslational degradation rather than transcriptional inhibition. Overexpression of Mcl-1 protected cells from cisplatin-induced caspase-3 activation and apoptosis. Preincubating cells with the proteasome inhibitor MG-132 or lactacystin not only restored cisplatin-induced loss of Mcl-1 but also resulted in an accumulation of Mcl-1 that exceeded basal levels; however, Bcl-2 and BclxL levels did not change in response to MG-132 or lactacystin. The proteasome inhibitors effectively blocked cisplatin-induced mitochondrial release of cytochrome c, caspase-3 activation, and apoptosis. These studies suggest that proteasome regulation of Mcl-1 is crucial in the cisplatin-induced apoptosis via the mitochondrial apoptotic pathway and that Mcl-1 is an important therapeutic target in cisplatin injury to renal tubular epithelial cells.
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Affiliation(s)
- Cheng Yang
- Department of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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214
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Gomez-Bougie P, Wuillème-Toumi S, Ménoret E, Trichet V, Robillard N, Philippe M, Bataille R, Amiot M. Noxa Up-regulation and Mcl-1 Cleavage Are Associated to Apoptosis Induction by Bortezomib in Multiple Myeloma. Cancer Res 2007; 67:5418-24. [PMID: 17545623 DOI: 10.1158/0008-5472.can-06-4322] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Targeting the ubiquitin-proteasome pathway has emerged as a potent anticancer strategy. Bortezomib, a specific proteasome inhibitor, has been approved for the treatment of relapsed or refractory multiple myeloma. Multiple myeloma cell survival is highly dependent on Mcl-1 antiapoptotic molecules. In a recent study, proteasome inhibitors induced Mcl-1 accumulation that slowed down their proapoptotic effects. Consequently, we investigated the role of Bcl-2 family members in bortezomib-induced apoptosis. We found that bortezomib induced apoptosis in five of seven human myeloma cell lines (HMCL). Bortezomib-induced apoptosis was associated with Mcl-1 cleavage regardless of Mcl-1L accumulation. Furthermore, RNA interference mediated Mcl-1 decrease and sensitized RPMI-8226 HMCL to bortezomib, highlighting the contribution of Mcl-1 in bortezomib-induced apoptosis. Interestingly, an important induction of Noxa was found in all sensitive HMCL both at protein and mRNA level. Concomitant to Mcl-1 cleavage and Noxa induction, we also found caspase-3, caspase-8, and caspase-9 activation. Under bortezomib treatment, Mcl-1L/Noxa complexes were highly increased, Mcl-1/Bak complexes were disrupted, and there was an accumulation of free Noxa. Finally, we observed a dissociation of Mcl-1/Bim complexes that may be due to a displacement of Bim induced by Noxa. Thus, in myeloma cells, the mechanistic basis for bortezomib sensitivity can be explained mainly by the model in which the sensitizer Noxa can displace Bim, a BH3-only activator, from Mcl-1, thus leading to Bax/Bak activation.
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215
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Wolter KG, Verhaegen M, Fernández Y, Nikolovska-Coleska Z, Riblett M, de la Vega CM, Wang S, Soengas MS. Therapeutic window for melanoma treatment provided by selective effects of the proteasome on Bcl-2 proteins. Cell Death Differ 2007; 14:1605-16. [PMID: 17541428 DOI: 10.1038/sj.cdd.4402163] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Melanoma cells depend on sustained proteasomal function for survival. However, bortezomib, the first proteasome inhibitor in clinical use, is not sufficient to improve the poor prognosis of metastatic melanoma patients. Since the proteasome is also expressed in all normal cell compartments, it is unclear how to enhance the efficacy of bortezomib without exacerbating secondary toxicities. Here, we present pharmacological and genetic analyses of mechanisms of resistance to proteasome inhibition. We focused on Bcl-2, Bcl-x(L) and Mcl-1 as main antiapoptotic factors associated with melanoma progression. Despite an efficient blockage of the proteasome, bortezomib could not counteract the intrinsically high levels of Bcl-2 and Bcl-x(L) in melanoma cells. Moreover, Mcl-1 was only downregulated at late time points after treatment. Based on these results, a combination treatment including (-)-gossypol, an inhibitor of Mcl-1/Bcl-2/Bcl-x(L), was designed and proven effective in vivo. Using a specific RNA interference approach, the survival of bortezomib-treated melanoma cells was found to rely primarily on Mcl-1, and to a lesser extent on Bcl-x(L) (but not on Bcl-2). Importantly, neither Mcl-1 nor Bcl-x(L) inactivation affected the viability of normal melanocytes. This hierarchical requirement of Bcl-2 family members for the maintenance of normal and malignant cells offers a therapeutic window to overcome melanoma chemoresistance in a tumor cell-selective manner.
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Affiliation(s)
- K G Wolter
- Department of Dermatology, University of Michigan, Comprehensive Cancer Center, Ann Arbor, MI 48109, USA
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216
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Abstract
Impaired apoptosis is both critical in cancer development and a major barrier to effective treatment. In response to diverse intracellular damage signals, including those evoked by cancer therapy, the cell's decision to undergo apoptosis is determined by interactions between three factions of the Bcl-2 protein family. The damage signals are transduced by the diverse 'BH3-only' proteins, distinguished by the BH3 domain used to engage their pro-survival relatives: Bcl-2, Bcl-x(L), Bcl-w, Mcl-1 and A1. This interaction ablates pro-survival function and allows activation of Bax and Bak, which commit the cell to apoptosis by permeabilizing the outer membrane of the mitochondrion. Certain BH3-only proteins (e.g. Bim, Puma) can engage all the pro-survival proteins, but others (e.g. Bad, Noxa) engage only subsets. Activation of Bax and Bak appears to require that the BH3-only proteins engage the multiple pro-survival proteins guarding Bax and Bak, rather than binding to the latter. The balance between the pro-survival proteins and their BH3 ligands regulates tissue homeostasis, and either overexpression of a pro-survival family member or loss of a proapoptotic relative can be oncogenic. Better understanding of the Bcl-2 family is clarifying its role in cancer development, revealing how conventional therapy works and stimulating the search for "BH3 mimetics" as a novel class of anticancer drugs.
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Affiliation(s)
- J M Adams
- Department of Molecular Genetics of Cancer, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia.
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217
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Abstract
Every cell in the human body has most of the components of the apoptotic apparatus and is thus principally equipped to die by apoptosis. Situations of increased or decreased apoptosis contribute to many forms of human disease, making this pathway an attractive target of therapeutic intervention. The past few years have seen an enormous refinement in the understanding how apoptosis works on a molecular level and the role of mitochondria as a central element in apoptotic signal transduction has become obvious. Here, the authors consider the events that are critical in this mitochondrial pathway, in particular at mitochondria but also upstream and downstream. The authors' opinion is presented on the merits and feasibility of approaches that aim at treating disease by interfering with the mitochondrial apoptotic pathway.
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Affiliation(s)
- Georg Häcker
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstr. 30, D-81675 Munich, Germany.
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218
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Han J, Goldstein LA, Hou W, Rabinowich H. Functional linkage between NOXA and Bim in mitochondrial apoptotic events. J Biol Chem 2007; 282:16223-31. [PMID: 17374615 DOI: 10.1074/jbc.m611186200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
NOXA is a BH3-only protein whose expression is induced by certain p53-depenent or independent apoptotic stimuli. Both NOXA and Bim are avid binders of Mcl-1, but a functional linkage between these BH3-only proteins has not yet been reported. In this study, we demonstrate that Mcl-1 binding of endogenously induced NOXA interferes with the ability of Mcl-1 to efficiently sequester endogenous Bim, as Bim is displaced from its complex with Mcl-1. Induced NOXA significantly enhances the UV sensitivity of cells, and the ensuing mitochondrial depolarization is entirely abrogated by Bim knockdown. These results demonstrate a Mcl-1-mediated cross-talk between endogenous NOXA and Bim that occurs upstream of the Bak/Bax-dependent execution of UV-induced mitochondrial depolarization. The current findings demonstrate that the mitochondrial response to an induced expression of NOXA is executed by endogenous Bim and suggest a plausible mechanism for the observed NOXA-Bim linkage.
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Affiliation(s)
- Jie Han
- Department of Pathology, University of Pittsburgh School of Medicine, PA 15213, USA
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219
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Miller CP, Ban K, Dujka ME, McConkey DJ, Munsell M, Palladino M, Chandra J. NPI-0052, a novel proteasome inhibitor, induces caspase-8 and ROS-dependent apoptosis alone and in combination with HDAC inhibitors in leukemia cells. Blood 2007; 110:267-77. [PMID: 17356134 PMCID: PMC1896116 DOI: 10.1182/blood-2006-03-013128] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The proteasome has been successfully targeted for the treatment of multiple myeloma and mantle cell lymphoma; however, in other hematologic malignancies, bortezomib has been less effective as a single agent. Here, we describe effects of NPI-0052, a novel proteasome inhibitor, in leukemia model systems. In cell lines, NPI-0052 inhibits all 3 proteolytic activities associated with the proteasome: chymotrypsin-, trypsin-, and caspase-like. NPI-0052 also induces DNA fragmentation in leukemia lines and in mononuclear cells from a Ph + acute lymphoblastic leukemia (ALL) patient. Caspase-3 activation by NPI-0052 was seen in wild-type Jurkat cells, but was significantly lessened in Fas-associated death domain (FADD)-deficient or caspase-8-deficient counterparts. NPI-0052-induced apoptosis was further probed using caspase-8 inhibitors, which were more protective than caspase-9 inhibitors. N-acetyl cysteine (NAC) also conferred protection against NPI-0052-induced apoptosis, indicating a role for oxidative stress by NPI-0052. In support of the drug's in vitro activities, biweekly treatment with NPI-0052 lessened total white blood cell (WBC) burden over 35 days in leukemic mice. Interestingly, combining NPI-0052 with either MS-275 or valproic acid (VPA) induced greater levels of cell death than the combination of bortezomib with these histone deacetylase inhibitors (HDACi). These effects of NPI-0052, alone and in combination with HDACi, warrant further testing to determine the compound's clinical efficacy in leukemia.
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Affiliation(s)
- Claudia P Miller
- Department of Pediatrics Research, University of Texas, M. D. Anderson Cancer Center, Houston, TX 77030, USA
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220
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Cavaletti G, Gilardini A, Canta A, Rigamonti L, Rodriguez-Menendez V, Ceresa C, Marmiroli P, Bossi M, Oggioni N, D'Incalci M, De Coster R. Bortezomib-induced peripheral neurotoxicity: A neurophysiological and pathological study in the rat. Exp Neurol 2007; 204:317-25. [PMID: 17214983 DOI: 10.1016/j.expneurol.2006.11.010] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 11/06/2006] [Accepted: 11/17/2006] [Indexed: 11/16/2022]
Abstract
Bortezomib is a new proteasome inhibitor with a high antitumor activity, but also with a potentially severe peripheral neurotoxicity. To establish a preclinical model and to characterize the changes induced on the peripheral nerves, dorsal root ganglia (DRG) and spinal cord, bortezomib was administered to Wistar rats (0.08, 0.15, 0.20, 0.30 mg/kg/day twice [2q7d] or three times [3q7d] weekly for a total of 4 weeks). At baseline, on days 14, 21 and 28 after the beginning the treatment period and during a 4-week follow-up period sensory nerve conduction velocity (SNCV) was determined in the tail of each animal. Sciatic nerve, DRG and spinal cord specimens were processed for light and electron microscope observations and morphometry. At the maximum tolerated dose bortezomib induced a significant reduction in SNCV, with a complete recovery at the end of the follow-up period. Sciatic nerve examination and morphometric determinations demonstrated mild to moderate pathological changes, involving predominantly the Schwann cells and myelin, although axonal degeneration was also observed. Bortezomib-induced changes were also observed in DRG and they were represented by satellite cell intracytoplasmatic vacuolization due to mitochondrial and endoplasmic reticulum damage, closely resembling the changes observed in sciatic nerve Schwann cells. Only rarely did the cytoplasm of DRG neurons has a dark appearance and clear vacuoles occurring in the cytoplasm. Spinal cord was morphologically normal. This model is relevant to the neuropathy induced by bortezomib in the treatment of human malignancies and it could be useful in increasing our knowledge regarding the mechanisms underlying bortezomib neurotoxicity.
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Affiliation(s)
- Guido Cavaletti
- Department of Neurosciences and Biomedical Technologies, University of Milan Bicocca, Monza, Italy.
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221
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Govindarajan B, Sligh JE, Vincent BJ, Li M, Canter JA, Nickoloff BJ, Rodenburg RJ, Smeitink JA, Oberley L, Zhang Y, Slingerland J, Arnold RS, Lambeth JD, Cohen C, Hilenski L, Griendling K, Martínez-Diez M, Cuezva JM, Arbiser JL. Overexpression of Akt converts radial growth melanoma to vertical growth melanoma. J Clin Invest 2007; 117:719-29. [PMID: 17318262 PMCID: PMC1797605 DOI: 10.1172/jci30102] [Citation(s) in RCA: 221] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Accepted: 12/12/2006] [Indexed: 12/17/2022] Open
Abstract
Melanoma is the cancer with the highest increase in incidence, and transformation of radial growth to vertical growth (i.e., noninvasive to invasive) melanoma is required for invasive disease and metastasis. We have previously shown that p42/p44 MAP kinase is activated in radial growth melanoma, suggesting that further signaling events are required for vertical growth melanoma. The molecular events that accompany this transformation are not well understood. Akt, a signaling molecule downstream of PI3K, was introduced into the radial growth WM35 melanoma in order to test whether Akt overexpression is sufficient to accomplish this transformation. Overexpression of Akt led to upregulation of VEGF, increased production of superoxide ROS, and the switch to a more pronounced glycolytic metabolism. Subcutaneous implantation of WM35 cells overexpressing Akt led to rapidly growing tumors in vivo, while vector control cells did not form tumors. We demonstrated that Akt was associated with malignant transformation of melanoma through at least 2 mechanisms. First, Akt may stabilize cells with extensive mitochondrial DNA mutation, which can generate ROS. Second, Akt can induce expression of the ROS-generating enzyme NOX4. Akt thus serves as a molecular switch that increases angiogenesis and the generation of superoxide, fostering more aggressive tumor behavior. Targeting Akt and ROS may be of therapeutic importance in treatment of advanced melanoma.
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Affiliation(s)
- Baskaran Govindarajan
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - James E. Sligh
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Bethaney J. Vincent
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Meiling Li
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jeffrey A. Canter
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Brian J. Nickoloff
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Richard J. Rodenburg
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jan A. Smeitink
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Larry Oberley
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Yuping Zhang
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Joyce Slingerland
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rebecca S. Arnold
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - J. David Lambeth
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Cynthia Cohen
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Lu Hilenski
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Kathy Griendling
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Martínez-Diez
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - José M. Cuezva
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jack L. Arbiser
- Department of Dermatology, Emory University School of Medicine, and Atlanta Veterans Administration Medical Center, Atlanta, Georgia, USA.
Division of Dermatology and Center for Human Genetics Research, Vanderbilt University Medical Center and VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
Cardinal Bernardin Cancer Center, Loyola University Health System, Chicago, Illinois, USA.
Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, USA.
Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA.
Department of Pathology and Laboratory Medicine and
Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
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222
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Abstract
Irrespective of the morphological features of end-stage cell death (that may be apoptotic, necrotic, autophagic, or mitotic), mitochondrial membrane permeabilization (MMP) is frequently the decisive event that delimits the frontier between survival and death. Thus mitochondrial membranes constitute the battleground on which opposing signals combat to seal the cell's fate. Local players that determine the propensity to MMP include the pro- and antiapoptotic members of the Bcl-2 family, proteins from the mitochondrialpermeability transition pore complex, as well as a plethora of interacting partners including mitochondrial lipids. Intermediate metabolites, redox processes, sphingolipids, ion gradients, transcription factors, as well as kinases and phosphatases link lethal and vital signals emanating from distinct subcellular compartments to mitochondria. Thus mitochondria integrate a variety of proapoptotic signals. Once MMP has been induced, it causes the release of catabolic hydrolases and activators of such enzymes (including those of caspases) from mitochondria. These catabolic enzymes as well as the cessation of the bioenergetic and redox functions of mitochondria finally lead to cell death, meaning that mitochondria coordinate the late stage of cellular demise. Pathological cell death induced by ischemia/reperfusion, intoxication with xenobiotics, neurodegenerative diseases, or viral infection also relies on MMP as a critical event. The inhibition of MMP constitutes an important strategy for the pharmaceutical prevention of unwarranted cell death. Conversely, induction of MMP in tumor cells constitutes the goal of anticancer chemotherapy.
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Affiliation(s)
- Guido Kroemer
- Institut Gustave Roussy, Institut National de la Santé et de la Recherche Médicale Unit "Apoptosis, Cancer and Immunity," Université de Paris-Sud XI, Villejuif, France
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223
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Abstract
Apoptosis, or programmed cell death, is essential for normal development and homeostasis. Insufficient apoptosis may contribute to the pathogenesis of malignancy and acute and chronic inflammation. Apoptosis may be induced by the death receptor or the mitochondrial pathways. Myeloid cell leukemia (Mcl)-1 is a member of the Bcl-2 family that contributes to the control of mitochondrial integrity, which is critical for maintaining cell viability. Mcl-1 has been shown to be essential for the development and survival of a variety of cell types. This review characterizes the role of Mcl-1 in the regulation of apoptosis and the promotion of disease, and defines novel strategies that have been identified to target this molecule.
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Affiliation(s)
- Arthur M Mandelin
- Division of Rheumatology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
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224
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Huang CL, Yokomise H, Miyatake A. Clinical significance of the p53 pathway and associated gene therapy in non-small cell lung cancers. Future Oncol 2007; 3:83-93. [PMID: 17280505 DOI: 10.2217/14796694.3.1.83] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Many molecules, including several regulators and various target genes, are involved in the biological functions of p53, thus making the p53 pathway rather complicated. However, recent clinical studies have demonstrated that most human cancers have an abnormality in some of the molecules associated with the p53 pathway. Most non-small cell lung cancers (NSCLCs) have either mutations of p53, a reduced p14 alternate reading frame expression, a reduced herpesvirus-associated ubiquitin-specific protease expression or a reduced p33 inhibitor of growth gene1b expression. As a result, the balance of expression of p53 target genes, such as p21, Bax and PUMA, regulates the biological behavior and determines the fate of tumor cells. To date, many studies on cancer gene therapy using these molecules associated with the p53 pathway have been performed to develop new strategies for treating NSCLC patients. Thus, the establishment of a comprehensive and simple evaluation protocol for the p53 pathway is required for clinical use.
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Affiliation(s)
- Cheng-long Huang
- Second Department of Surgery, Faculty of Medicine, Kagawa University, 1750-1, Mikicho, Kita-gun, Kagawa 761-0793, Japan.
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225
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Hur J, Bell DW, Dean KL, Coser KR, Hilario PC, Okimoto RA, Tobey EM, Smith SL, Isselbacher KJ, Shioda T. Regulation of expression of BIK proapoptotic protein in human breast cancer cells: p53-dependent induction of BIK mRNA by fulvestrant and proteasomal degradation of BIK protein. Cancer Res 2006; 66:10153-61. [PMID: 17047080 DOI: 10.1158/0008-5472.can-05-3696] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Induction of mRNA for BIK proapoptotic protein by doxorubicin or gamma-irradiation requires the DNA-binding transcription factor activity of p53. In MCF7 cells, pure antiestrogen fulvestrant also induces BIK mRNA and apoptosis. Here, we provide evidence that, in contrast to doxorubicin or gamma-irradiation, fulvestrant induction of BIK mRNA is not a direct effect of the transcriptional activity of p53, although p53 is necessary for this induction. It is known that p53 up-regulated modulator of apoptosis (PUMA) mRNA is induced directly by the transcriptional activity of p53. Whereas gamma-irradiation induced both BIK and PUMA mRNA, only BIK mRNA was induced by fulvestrant. Whereas both fulvestrant and doxorubicin induced BIK mRNA, only doxorubicin enhanced the DNA-binding activity of p53 and induced PUMA mRNA. Small interfering RNA (siRNA) suppression of p53 expression as well as overexpression of dominant-negative p53 effectively inhibited the fulvestrant induction of BIK mRNA, protein, and apoptosis. Transcriptional activity of a 2-kb BIK promoter, which contained an incomplete p53-binding sequence, was not affected by fulvestrant when tested by reporter assay. Fulvestrant neither affected the stability of the BIK mRNA transcripts. Interestingly, other human breast cancer cells, such as ZR75-1, constitutively expressed BIK mRNA even without fulvestrant. In these cells, however, BIK protein seemed to be rapidly degraded by proteasome, and siRNA suppression of BIK in ZR75-1 cells inhibited apoptosis induced by MG132 proteasome inhibitor. These results suggest that expression of BIK in human breast cancer cells is regulated at the mRNA level by a mechanism involving a nontranscriptional activity of p53 and by proteasomal degradation of BIK protein.
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MESH Headings
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents, Hormonal/pharmacology
- Apoptosis Regulatory Proteins/biosynthesis
- Apoptosis Regulatory Proteins/genetics
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Cell Line, Tumor
- Doxorubicin/pharmacology
- Estradiol/analogs & derivatives
- Estradiol/pharmacology
- Fulvestrant
- Gamma Rays
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Expression Regulation, Neoplastic/radiation effects
- Humans
- Leupeptins/pharmacology
- Membrane Proteins/biosynthesis
- Membrane Proteins/genetics
- Mitochondrial Proteins
- Promoter Regions, Genetic
- Proteasome Endopeptidase Complex/metabolism
- Proteasome Inhibitors
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptors, Estrogen/biosynthesis
- Transcription, Genetic/drug effects
- Transcription, Genetic/radiation effects
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
- Tumor Suppressor Protein p53/physiology
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Affiliation(s)
- Jingyung Hur
- Department of Tumor Biology, Massachusetts General Hospital Center for Cancer Research, Charlestown, Massachusetts 02129, USA
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226
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Abstract
All bone surfaces are periodically remodeled by the coupled and balanced action of osteoclasts and osteoblasts, of which the activities are regulated by a variety of cytokines and growth factors. Patients with cancer metastatic to the skeleton often develop osteolytic bone lesions, in which the actions of osteoclasts and osteoblasts remain coupled, but become imbalanced in sites adjacent to the tumor. The result is net bone loss. Many cancers secrete osteoclast-stimulating cytokines, which increase bone resorption by osteoclasts. In turn, factors released from the bone matrix during osteolysis can stimulate tumor growth. In this so-called "vicious cycle," there are multiple sites that are targets for new bone-directed therapies. A variety of new agents for the treatment and prevention of osteolytic bone metastasis are currently being developed. These include new agents that inhibit osteoclast differentiation, bone adhesion, and osteoclast function. These new strategies have evolved from a better understanding of the interaction between tumor cells and cells in the bone marrow microenvironment. There is great promise that these new bone-targeted therapies can decrease the frequent skeletal-related events that greatly diminish quality of life of patients with bone metastases.
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Affiliation(s)
- Allan Lipton
- Department of Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033-0850, USA.
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227
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Benito A, Gutierrez O, Pipaon C, Real PJ, Gachon F, Ritchie AE, Fernandez-Luna JL. A novel role for proline- and acid-rich basic region leucine zipper (PAR bZIP) proteins in the transcriptional regulation of a BH3-only proapoptotic gene. J Biol Chem 2006; 281:38351-7. [PMID: 17057225 DOI: 10.1074/jbc.m607004200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Proline- and acid-rich (PAR) basic region leucine zipper (bZIP) proteins thyrotroph embryonic factor (TEF), D-site-binding protein (DBP), and hepatic leukemia factor have been involved in neurotransmitter homeostasis and amino acid metabolism. Here we demonstrate a novel role for these proteins in the transcriptional control of a BH3-only gene. PAR bZIP proteins are able to transactivate the promoter of bcl-gS. This promoter is particularly responsive to TEF activation and is silenced by NFIL3, a repressor that shares the consensus binding site with PAR bZIP proteins. Consistently, transfection of TEF induces the expression of endogenous bcl-gS in cancer cells, and this induction is independent of p53. A naturally occurring variant of DBP (tDBP), lacking the transactivation domain, has been identified and shown to impede the formation of active TEF dimers in a competitive manner and to reduce the TEF-dependent induction of bcl-gS. Of note, treatment of cancer cells with etoposide induces TEF activation and promotes the expression of bcl-gS. Furthermore, blockade of bcl-gS or TEF expression by a small interfering RNA strategy or transfection with tDBP significantly reduces the etoposide-mediated apoptotic cell death. These findings represent the first described role for PAR bZIP proteins in the regulation of a gene involved in the execution of apoptosis.
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Affiliation(s)
- Adalberto Benito
- Unidad de Genetica Molecular, Hospital Universitario Marques de Valdecilla, Servicio Cantabro de Salud, 39008 Santander, Spain
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228
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Smit LA, Hallaert DYH, Spijker R, de Goeij B, Jaspers A, Kater AP, van Oers MHJ, van Noesel CJM, Eldering E. Differential Noxa/Mcl-1 balance in peripheral versus lymph node chronic lymphocytic leukemia cells correlates with survival capacity. Blood 2006; 109:1660-8. [PMID: 17038534 DOI: 10.1182/blood-2006-05-021683] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The gradual accumulation of chronic lymphocytic leukemia (B-CLL) cells is presumed to derive from proliferation centers in lymph nodes and bone marrow. To what extent these cells possess the purported antiapoptotic phenotype of peripheral B-CLL cells is unknown. Recently, we have described that, in B-CLL samples from peripheral blood, aberrant apoptosis gene expression was not limited to protective changes but also included increased levels of proapoptotic BH3-only member Noxa. Here, we compare apoptosis gene profiles from peripheral blood B-CLL (n = 15) with lymph node B-CLL (> 90% CD5+/CD19+/CD23+ lymphocytes with Ki67+ centers; n = 9). Apart from expected differences in Survivin and Bcl-xL, a prominent distinction with peripheral B-CLL cells was the decreased averaged level of Noxa in lymph nodes. Mcl-1 protein expression showed a reverse trend. Noxa expression could be reduced also in vitro by CD40 stimulation of peripheral blood B-CLL. Direct manipulation of Noxa protein levels was achieved by proteasome inhibition in B-CLL and via RNAi in model cell lines. In each instance, cell viability was directly linked with Noxa levels. These data indicate that suppression of Noxa in the lymph node environment contributes to the persistence of B-CLL at these sites and suggest that therapeutic targeting of Noxa might be beneficial.
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Affiliation(s)
- Laura A Smit
- Department of Pathology, Academic Medical Center, Amsterdam, The Netherlands
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229
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Qin JZ, Xin H, Sitailo LA, Denning MF, Nickoloff BJ. Enhanced Killing of Melanoma Cells by Simultaneously Targeting Mcl-1 and NOXA. Cancer Res 2006; 66:9636-45. [PMID: 17018621 DOI: 10.1158/0008-5472.can-06-0747] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
By deciphering the dysregulation of apoptosis in melanoma cells, new treatment approaches exploiting aberrant control mechanisms regulating cell death can be envisioned. Among the Bcl-2 family, a BH3-only member, NOXA, functions in a specific mitochondrial-based cell death pathway when melanoma cells are exposed to a proteasome inhibitor (e.g., bortezomib). Some therapeutic agents, such as bortezomib, not only induce proapoptotic Bcl-2 family members and active conformational changes in Bak and Bax but also are associated with undesirable effects, including accumulation of antiapoptotic proteins, such as Mcl-1. To enhance the bortezomib-mediated killing of melanoma cells, the apoptotic pathway involving NOXA was further investigated, leading to identification of an important target (i.e., the labile Bcl-2 homologue Mcl-1 but not other survival proteins). To reduce Mcl-1 levels, melanoma cells were pretreated with several different agents, including Mcl-1 small interfering RNA (siRNA), UV light, or the purine nucleoside analogue fludarabine. By simultaneously triggering production of NOXA (using bortezomib) as well as reducing Mcl-1 levels (using siRNA, UV light, or fludarabine), significantly enhanced killing of melanoma cells was achieved. These results show binding interactions between distinct Bcl-2 family members, such as NOXA and Mcl-1, in melanoma cells, paving the way for novel and rational therapeutic combination strategies, which target guardians of the proapoptotic Bak- and Bax-mediated pathways, against this highly aggressive and often fatal malignancy.
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Affiliation(s)
- Jian-Zhong Qin
- Department of Pathology, Loyola University Medical Center, Maywood, IL 60153, USA
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230
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Real PJ, Sanz C, Gutierrez O, Pipaon C, Zubiaga AM, Fernandez-Luna JL. Transcriptional activation of the proapoptotic bik gene by E2F proteins in cancer cells. FEBS Lett 2006; 580:5905-9. [PMID: 17027756 DOI: 10.1016/j.febslet.2006.08.088] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 08/04/2006] [Accepted: 08/07/2006] [Indexed: 11/24/2022]
Abstract
BH3-only proteins are required for execution of apoptotic cell death. We have found that one of these proteins, Bik, is strongly induced in cancer cells treated with chemotherapeutic agents. Furthermore, we showed that chemotherapy-induced expression of bik is independent of p53. Consistent with its pro-apoptotic activity, blockade of bik expression reduces the adriamycin-mediated apoptotic cell death. We also found that the bik gene is transcriptionally activated by E2F proteins. Consistently, adriamycin induces the E2F-bik pathway. In addition, E2Fs transactivate bik by a p53-independent mechanism. Thus, our data indicate that transcriptional regulation of bik contributes to the efficient apoptotic response to chemotherapeutic agents.
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Affiliation(s)
- Pedro J Real
- Unidad de Genetica Molecular, Hospital Universitario Marques de Valdecilla, Av. Valdecilla s/n, 39008 Santander, Spain
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231
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Chauhan D, Velankar M, Brahmandam M, Hideshima T, Podar K, Richardson P, Schlossman R, Ghobrial I, Raje N, Munshi N, Anderson KC. A novel Bcl-2/Bcl-X(L)/Bcl-w inhibitor ABT-737 as therapy in multiple myeloma. Oncogene 2006; 26:2374-80. [PMID: 17016430 DOI: 10.1038/sj.onc.1210028] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Bcl-2 or Bcl-X(L) confers resistance to chemotherapy in multiple myeloma (MM). Here we characterized the effects of ABT-737, a potent small-molecule inhibitor of antiapoptotic proteins Bcl-2, Bcl-X(L) and Bcl-w with markedly higher affinity than previously reported compounds, on human MM cells. ABT-737 induces apoptosis in MM cells, including those resistant to conventional therapy. Examination of purified patient MM cells demonstrated similar results, without significant toxicity against normal peripheral blood mononuclear cells and MM bone marrow stromal cells. Importantly, ABT-737 decreases the viability of bortezomib-, dexamethasone-(Dex) and thalidomide-refractory patient MM cells. Additionally, ABT-737 abrogates MM cell growth triggered by interleukin-6 or insulin-like growth factor-1. Mechanistic studies show that ABT-737-induced apoptosis is associated with activation of caspase-8, caspase-9 and caspase-3, followed by poly(ADP-ribose) polymerase cleavage. Combining ABT-737 with proteasome inhibitor bortezomib, melphalan or dexamethasone induces additive anti-MM activity. Taken together, our study provides the rationale for clinical protocols evaluating ABT-737, alone and together with botezomib, mephalan or dexamethasone, to enhance MM cell killing, overcome drug resistance conferred by Bcl-2 and improve patient outcome in MM.
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Affiliation(s)
- D Chauhan
- The Jerome Lipper Multiple Myeloma Center, Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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232
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Mitsiades CS, McMillin D, Kotoula V, Poulaki V, McMullan C, Negri J, Fanourakis G, Tseleni-Balafouta S, Ain KB, Mitsiades N. Antitumor effects of the proteasome inhibitor bortezomib in medullary and anaplastic thyroid carcinoma cells in vitro. J Clin Endocrinol Metab 2006; 91:4013-21. [PMID: 16849420 DOI: 10.1210/jc.2005-2472] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT The ubiquitin-proteasome pathway is a major pathway for degradation of intracellular proteins. Proteasome inhibitors constitute a novel class of antitumor agents with preclinical and clinical evidence of activity against hematological malignancies and solid tumors. The proteasome inhibitor bortezomib (PS-341, Velcade) has been approved by the Food and Drug Administration for the treatment of multiple myeloma and is being studied intensely in several other malignancies. Its mechanism of action is complex but appears to include the inhibition of inhibitory-kappaB degradation, which leads to inactivation of the transcriptional factor nuclear factor-kappaB (NF-kappaB). NF-kappaB has been implicated in the pathophysiology of the most aggressive forms of thyroid carcinoma, i.e. medullary and anaplastic. OBJECTIVE AND METHODS We evaluated the effect of bortezomib on a panel of thyroid carcinoma cell lines, originating from papillary, follicular, anaplastic, and medullary carcinomas. RESULTS Bortezomib induced apoptosis in medullary and anaplastic cell lines with IC(50) values well within the range of clinically achievable concentrations and much lower than respective IC(50) values for other solid malignancies. Bortezomib inhibited NF-kappaB activity; increased p53, p21, and jun expression; and induced caspase-dependent apoptosis. Sensitivity of thyroid carcinoma cells to bortezomib was partially decreased by overexpression of Bcl-2 or treatment with IGF-I, whereas the combination of bortezomib with chemotherapy (doxorubicin) was synergistic. CONCLUSIONS These data provide both insights into the molecular mechanisms of antitumor activity of proteasome inhibitors and the rationale for future clinical trials of bortezomib, alone or in combination with conventional chemotherapy, to improve patient outcome in medullary and anaplastic thyroid carcinomas.
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Affiliation(s)
- Constantine S Mitsiades
- Department of Medical Oncology, Dana Farber Cancer Institute, Mayer Building, Room M555, 44 Binney Street, Boston, MA 02115, USA.
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233
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Seo YW, Park SY, Yun CW, Kim TH. Differential Efflux of Mitochondrial Endonuclease G by hNoxa and tBid. BMB Rep 2006; 39:556-9. [PMID: 17002876 DOI: 10.5483/bmbrep.2006.39.5.556] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bcl-2 family of proteins regulates mitochondrial functions during cell death by modulating the efflux of death-promoting proteins such as cytochrome c and endonuclease G. Upon the binding of death ligands to their receptors, caspase-8 cleaves Bid, a BH3-only protein, into tBid that causes the mitochondrial damages resulting in the release of cytochrome c and endonuclease G. Also, another BH3-only protein, hNoxa, has been shown to induce the efflux of cytochrome c from the mitochondria. Whether the efflux proteins from the mitochondria in response to tBid or hNoxa are the same or different, however, has not been addressed. We have demonstrated that endonuclease G activities are not detectable among the proteins released from isolated mitochondria by hNoxa but are detectable in that by tBid. These results suggest that the efflux of proteins from the mitochondria are differentially modulated by tBid and hNoxa.
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Affiliation(s)
- Young Woo Seo
- Department of Biochemistry and Molecular Biology, Chosun University School of Medicine, Dong-Gu, Gwangju, 501-759, Korea
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234
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Concannon CG, Koehler BF, Reimertz C, Murphy BM, Bonner C, Thurow N, Ward MW, Villunger A, Strasser A, Kögel D, Prehn JHM. Apoptosis induced by proteasome inhibition in cancer cells: predominant role of the p53/PUMA pathway. Oncogene 2006; 26:1681-92. [PMID: 16983338 DOI: 10.1038/sj.onc.1209974] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The proteasome has emerged as a novel target for antineoplastic treatment of hematological malignancies and solid tumors, including those of the central nervous system. To identify cell death pathways activated in response to inhibition of the proteasome system in cancer cells, we treated human SH-SY5Y neuroblastoma cells with the selective proteasome inhibitor (PI) epoxomicin (Epoxo). Prolonged exposure to Epoxo was associated with increased levels of poly-ubiquitinylated proteins and p53, release of cytochrome c from the mitochondria, and activation of caspases. Analysis of global gene expression using high-density oligonucleotide microarrays revealed that Epoxo triggered transcriptional activation of the two Bcl-2-homology domain-3-only (BH3-only) genes p53 upregulated modulator of apoptosis (PUMA) and Bim. Subsequent studies in PUMA- and Bim-deficient cells indicated that Epoxo-induced caspase activation and apoptosis was predominantly PUMA-dependent. Further characterization of the transcriptional response to Epoxo in HCT116 human colon cancer cells demonstrated that PUMA induction was p53-dependent; with deficiency in either p53 or PUMA significantly protected HCT116 cells against Epoxo-induced apoptosis. Our data suggest that p53 activation and the transcriptional induction of its target gene PUMA play an important role in the sensitivity of cancer cells to apoptosis induced by proteasome inhibition, and imply that antineoplastic therapies with PIs might be especially useful in cancers with functional p53.
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Affiliation(s)
- C G Concannon
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
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235
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Aleo E, Henderson CJ, Fontanini A, Solazzo B, Brancolini C. Identification of New Compounds That Trigger Apoptosome-Independent Caspase Activation and Apoptosis. Cancer Res 2006; 66:9235-44. [PMID: 16982768 DOI: 10.1158/0008-5472.can-06-0702] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Identification of alternative pathways of caspase activation is an important step to develop new antitumor treatments. We report here the result of a screening with a small chemical library, the Developmental Therapeutics Program-National Cancer Institute "challenge set," on cells expressing mutated caspase-9. We have identified two molecules capable of activating an apoptosome-independent apoptotic pathway. These compounds, named F6 and G5, target the ubiquitin-proteasome system by inhibiting the ubiquitin isopeptidases. We have shown that F6 and G5 induce a rather unique apoptotic pathway, which includes a Bcl-2-dependent but apoptosome-independent mitochondrial pathway with up-regulation of the BH3-only protein Noxa, stabilization of the inhibitor of apoptosis antagonist Smac, but also the involvement of the death receptor pathway. Noxa plays an important role in the induction of mitochondrial fragmentation and caspase activation, whereas the death receptor pathway becomes critical in the absence of a functional apoptosome. This study suggests that screening of chemical libraries on cancer cells with defined mutations in apoptotic key elements can lead to the identification of compounds that are useful to characterize alternative pathways of caspase activation.
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Affiliation(s)
- Emanuela Aleo
- Dipartimento di Scienze e Tecnologie Biomediche, Sezione di Biologia and MATI Center of Excellence, Universita' di Udine, Udine, Italy
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236
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Mestre-Escorihuela C, Rubio-Moscardo F, Richter JA, Siebert R, Climent J, Fresquet V, Beltran E, Agirre X, Marugan I, Marín M, Rosenwald A, Sugimoto KJ, Wheat LM, Karran EL, García JF, Sanchez L, Prosper F, Staudt LM, Pinkel D, Dyer MJS, Martinez-Climent JA. Homozygous deletions localize novel tumor suppressor genes in B-cell lymphomas. Blood 2006; 109:271-80. [PMID: 16960149 DOI: 10.1182/blood-2006-06-026500] [Citation(s) in RCA: 191] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Abstract
Integrative genomic and gene-expression analyses have identified amplified oncogenes in B-cell non-Hodgkin lymphoma (B-NHL), but the capability of such technologies to localize tumor suppressor genes within homozygous deletions remains unexplored. Array-based comparative genomic hybridization (CGH) and gene-expression microarray analysis of 48 cell lines derived from patients with different B-NHLs delineated 20 homozygous deletions at 7 chromosome areas, all of which contained tumor suppressor gene targets. Further investigation revealed that only a fraction of primary biopsies presented inactivation of these genes by point mutation or intragenic deletion, but instead some of them were frequently silenced by epigenetic mechanisms. Notably, the pattern of genetic and epigenetic inactivation differed among B-NHL subtypes. Thus, the P53-inducible PIG7/LITAF was silenced by homozygous deletion in primary mediastinal B-cell lymphoma and by promoter hypermethylation in germinal center lymphoma, the proapoptotic BIM gene presented homozygous deletion in mantle cell lymphoma and promoter hypermethylation in Burkitt lymphoma, the proapoptotic BH3-only NOXA was mutated and preferentially silenced in diffuse large B-cell lymphoma, and INK4c/P18 was silenced by biallelic mutation in mantle-cell lymphoma. Our microarray strategy has identified novel candidate tumor suppressor genes inactivated by genetic and epigenetic mechanisms that substantially vary among the B-NHL subtypes.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Apoptosis/genetics
- Apoptosis Regulatory Proteins/genetics
- Bcl-2-Like Protein 11
- Biopsy
- Carrier Proteins/genetics
- Cell Line, Tumor
- Chromosome Mapping
- Chromosomes, Human/genetics
- Chromosomes, Human/ultrastructure
- Cyclin-Dependent Kinase Inhibitor p18/genetics
- DNA Methylation
- DNA Mutational Analysis
- DNA, Neoplasm/genetics
- Epigenesis, Genetic
- Gene Dosage
- Gene Expression Regulation, Neoplastic
- Gene Silencing
- Genes, Tumor Suppressor
- Homeodomain Proteins/genetics
- Homozygote
- Humans
- Lymphoma, B-Cell/classification
- Lymphoma, B-Cell/genetics
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/pathology
- Membrane Proteins/genetics
- Nuclear Proteins/genetics
- Nucleic Acid Hybridization
- Oligonucleotide Array Sequence Analysis
- Point Mutation
- Promoter Regions, Genetic/genetics
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins c-bcl-2/genetics
- RNA-Binding Proteins
- Sequence Deletion
- Sorting Nexins
- Transcription Factors/genetics
- Vesicular Transport Proteins/genetics
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Affiliation(s)
- Cinta Mestre-Escorihuela
- Center for Applied Medical Research (CIMA), University of Navarra, Avda Pio XII, 55, Pamplona 31008, Spain.
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237
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Bauer A, Villunger A, Labi V, Fischer SF, Strasser A, Wagner H, Schmid RM, Häcker G. The NF-kappaB regulator Bcl-3 and the BH3-only proteins Bim and Puma control the death of activated T cells. Proc Natl Acad Sci U S A 2006; 103:10979-84. [PMID: 16832056 PMCID: PMC1544160 DOI: 10.1073/pnas.0603625103] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Apoptosis of activated T cells is critical for the termination of immune responses. Here we show that adjuvant-stimulated dendritic cells secrete cytokines that prime activated T cells for survival and analyze the roles of the NF-kappaB regulator Bcl-3 and the proapoptotic Bcl-2 family members Bim and Puma. Bcl-3 overexpression increased survival, and activated bcl-3-/- T cells died abnormally rapidly. Cytokines from adjuvant-stimulated dendritic cells induced Bcl-3, but survival through cytokine priming was Bcl-3-independent. Apoptosis inhibition by Bcl-3 involved blockade of Bim activation, because Bim was overactivated in Bcl-3-deficient cells, and Bcl-3 failed to increase survival of bim-/- T cells. However, adjuvants increased survival also in Bim-deficient T cells. This Bim-independent death pathway is at least in part regulated by Puma, as shown by analysis of puma-/- and noxa-/- T cells. IL-1, IL-7, and IL-15 primed T cells for survival even in the absence of Bim or Puma. Our data define interrelations and a Bim-independent pathway to activated T cell death.
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Affiliation(s)
- Anette Bauer
- *Institute for Medical Microbiology, Technical University Munich, Trogerstrasse 9, D-81675 Munich, Germany
| | - Andreas Villunger
- Division of Developmental Immunology, Biocenter, Innsbruck Medical University, Fritz-Pregl-Strasse 3, A-6020 Innsbruck, Austria
| | - Verena Labi
- Division of Developmental Immunology, Biocenter, Innsbruck Medical University, Fritz-Pregl-Strasse 3, A-6020 Innsbruck, Austria
| | - Silke F. Fischer
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville VIC 3050, Australia; and
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville VIC 3050, Australia; and
| | - Hermann Wagner
- *Institute for Medical Microbiology, Technical University Munich, Trogerstrasse 9, D-81675 Munich, Germany
| | - Roland M. Schmid
- Department of Internal Medicine II, Technical University Munich, Ismaningerstrasse 22, D-81675 Munich, Germany
| | - Georg Häcker
- *Institute for Medical Microbiology, Technical University Munich, Trogerstrasse 9, D-81675 Munich, Germany
- To whom correspondence should be addressed. E-mail:
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238
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Cretney E, Shanker A, Yagita H, Smyth MJ, Sayers TJ. TNF-related apoptosis-inducing ligand as a therapeutic agent in autoimmunity and cancer. Immunol Cell Biol 2006; 84:87-98. [PMID: 16405656 DOI: 10.1111/j.1440-1711.2005.01413.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Recombinant, soluble TNF-related apoptosis-inducing ligand (TRAIL) is currently being developed as a promising natural immune molecule for trial in cancer patients because it selectively induces apoptosis in transformed or stressed cells but not in most normal cells. In cancer patients, phase 1 and 2 clinical trials using agonistic mAbs that engage the human TRAIL receptors DR4 and DR5 have also provided encouraging results. It is now evident that TRAIL suppresses autoimmune disease in various experimental animal models, suggesting that the therapeutic value of recombinant TRAIL and agonistic DR4 and DR5 mAbs might also extend to the suppression of autoimmune disease. This review provides an insight into our current understanding of the role(s) of TRAIL in disease, with a specific focus on cancer and autoimmunity. We also emphasize biological agents and drugs that sensitize tumour cells to TRAIL-mediated apoptosis and discuss the potential molecular basis for their sensitization.
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Affiliation(s)
- Erika Cretney
- Cancer Immunology Program, Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
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239
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Abstract
The discovery of B-cell lymphoma-2 (BCL-2) over 20 years ago revealed a new paradigm in cancer biology: the development and persistence of cancer can be driven by molecular roadblocks along the natural pathway to cell death. The subsequent identification of an expansive family of BCL-2 proteins provoked an intensive investigation of the interplay among these critical regulators of cell death. What emerged was a compelling tale of guardians and executioners, each participating in a molecular choreography that dictates cell fate. Ten years into the BCL-2 era, structural details defined how certain BCL-2 family proteins interact, and molecular targeting of the BCL-2 family has since become a pharmacological quest. Although many facets of BCL-2 family death signaling remain a mechanistic mystery, small molecules and peptides that effectively target BCL-2 are eliminating the roadblock to cell death, raising hopes for a medical breakthrough in cancer and other diseases of deregulated apoptosis.
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Affiliation(s)
- L D Walensky
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
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240
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Dolcet X, Llobet D, Encinas M, Pallares J, Cabero A, Schoenenberger JA, Comella JX, Matias-Guiu X. Proteasome inhibitors induce death but activate NF-kappaB on endometrial carcinoma cell lines and primary culture explants. J Biol Chem 2006; 281:22118-22130. [PMID: 16735506 DOI: 10.1074/jbc.m601350200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Proteasome inhibitors are currently used as chemotherapeutic drugs because of their ability to block NF-kappaB, a transcription factor constitutively activated in many different types of human cancer. In the present study, we demonstrate that proteasome inhibitors induce cell death in endometrial carcinoma cell lines and primary explants but, instead of blocking NF-kappaB, they increase its transcriptional activity. Proteasome inhibitors induce phosphorylation of IKK alpha/beta, phosphorylation and degradation of IkappaB alpha, and phosphorylation of the p65 NF-kappaB subunit on serine 536. Proteasome inhibitor-induced NF-kappaB activity can be blocked by a non-degradable form of IkappaB alpha or dominant negative forms of either IKK alpha or IKK beta. Lentiviral delivery of shRNAs to either IKK alpha or IKK beta cause blockade of NF-kappaB transcriptional activity and inhibit phosphorylation of p65 on serine 536, but has no effect on IkappaB alpha degradation. These results suggest a role for p65 phosphorylation in proteasome inhibitor-induced NF-kappaB activation. Accordingly, siRNA knockdown of p65 inhibits proteasome inhibitor-induced NF-kappaB transcriptional activity. Our results demonstrate that proteasome inhibitors, including bortezomib, induce cell death on endometrial carcinoma cells and primary explants. However, they activate NF-kappaB instead of blocking its transcriptional potential. Therefore, the concept that proteasome inhibitors are blockers of NF-kappaB activation should be carefully examined in particular cell types.
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Affiliation(s)
- Xavier Dolcet
- Department of Pathology and Molecular Genetics, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain.
| | - David Llobet
- Department of Pathology and Molecular Genetics, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain
| | - Mario Encinas
- Cell Signalling and Apoptosis Group, Laboratori de Recerca de l'Hospital, Universitari Arnau de Vilanova, Departament de Ciencies Mèdiques Bàsiques i Cirurgia, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain
| | - Judit Pallares
- Department of Pathology and Molecular Genetics, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain
| | - Albert Cabero
- Department of Gynecology, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain
| | - Joan Antoni Schoenenberger
- Department of Pharmacy, Hospital Universitari Arnau de Vilanova, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain
| | - Joan X Comella
- Cell Signalling and Apoptosis Group, Laboratori de Recerca de l'Hospital, Universitari Arnau de Vilanova, Departament de Ciencies Mèdiques Bàsiques i Cirurgia, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain
| | - Xavier Matias-Guiu
- Department of Pathology and Molecular Genetics, Universitat de Lleida, IRBLLEIDA, 25198 Lleida Spain
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241
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Labi V, Erlacher M, Kiessling S, Villunger A. BH3-only proteins in cell death initiation, malignant disease and anticancer therapy. Cell Death Differ 2006; 13:1325-38. [PMID: 16645634 DOI: 10.1038/sj.cdd.4401940] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Induction of apoptosis in tumour cells, either by direct activation of the death receptor pathway using agonistic antibodies or recombinant ligands, or direct triggering of the Bcl-2-regulated intrinsic apoptosis pathway by small molecule drugs, carries high hopes to overcome the shortcomings of current anticancer therapies. The latter therapy concept builds on a more detailed understanding of how Bcl-2-like molecules maintain mitochondrial integrity and how BH3-only proteins and Bax/Bak-like molecules can undermine it. Means to unleash the apoptotic potential of BH3-only proteins in tumour cells, or bypass the need for BH3-only proteins by blocking possible interactions of Bcl-2-like prosurvival molecules with Bax and/or Bak allowing their direct activation, constitute interesting options for the design of novel anticancer therapies.
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Affiliation(s)
- V Labi
- Division of Experimental Pathophysiology and Immunology, Biocenter, Innsbruck Medical University, Austria
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242
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Olivier S, Close P, Castermans E, de Leval L, Tabruyn S, Chariot A, Malaise M, Merville MP, Bours V, Franchimont N. Raloxifene-Induced Myeloma Cell Apoptosis: A Study of Nuclear Factor-κB Inhibition and Gene Expression Signature. Mol Pharmacol 2006; 69:1615-23. [PMID: 16497877 DOI: 10.1124/mol.105.020479] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Because multiple myeloma remains associated with a poor prognosis, novel drugs targeting specific signaling pathways are needed. The efficacy of selective estrogen receptor modulators for the treatment of multiple myeloma is not well documented. In the present report, we studied the antitumor activity of raloxifene, a selective estrogen receptor modulator, on multiple myeloma cell lines. Raloxifene effects were assessed by tetrazolium salt reduction assay, cell cycle analysis, and Western blotting. Mobility shift assay, immunoprecipitation, chromatin immunoprecipitation assay, and gene expression profiling were performed to characterize the mechanisms of raloxifene-induced activity. Indeed, raloxifene, as well as tamoxifen, decreased JJN-3 and U266 myeloma cell viability and induced caspase-dependent apoptosis. Raloxifene and tamoxifen also increased the cytotoxic response to vincristine and arsenic trioxide. Moreover, raloxifene inhibited constitutive nuclear factor-kappaB (NF-kappaB) activity in myeloma cells by removing p65 from its binding sites through estrogen receptor alpha interaction with p65. It is noteworthy that microarray analysis showed that raloxifene treatment decreased the expression of known NF-kappaB-regulated genes involved in myeloma cell survival and myeloma-induced bone lesions (e.g., c-myc, mip-1alpha, hgf, pac1,...) and induced the expression of a subset of genes regulating cellular cycle (e.g., p21, gadd34, cyclin G2,...). In conclusion, raloxifene induces myeloma cell cycle arrest and apoptosis partly through NF-kappaB-dependent mechanisms. These findings also provide a transcriptional profile of raloxifene treatment on multiple myeloma cells, offering the framework for future studies of selective estrogen receptor modulators therapy in multiple myeloma.
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Affiliation(s)
- Sabine Olivier
- Department of Rheumatology, Center for Biomedical Integrative Genoproteomics, University of Liège, Centre Hospitalier Universitaire Sart-Tilman, Belgium
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243
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Demarchi F, Brancolini C. Altering protein turnover in tumor cells: New opportunities for anti-cancer therapies. Drug Resist Updat 2005; 8:359-68. [PMID: 16406769 DOI: 10.1016/j.drup.2005.12.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Accepted: 12/09/2005] [Indexed: 11/20/2022]
Abstract
The promising effects of the proteasome inhibitor bortezomib (Velcade, PS-341) in the treatment of certain types of cancer have fired up the interest on this multicatalytic proteolytic machinery. A number of recent reviews thoroughly describe various aspects of the ubiquitin-proteasome system and its importance in the control of cell growth and tumorigenesis. Here, we will focus on recent data unveiling a link between the proteasome and some elements of the apoptotic machinery including Bcl-2 members, caspases, IAPs and IAP antagonists. Perturbing their turnover significantly contributes to the apoptotic response and the anti-neoplastic activity of proteasome inhibitors.
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Affiliation(s)
- Francesca Demarchi
- LNICB, Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie, Pardiciano 99, 34100 Trieste, Italy
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244
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Fernández Y, Miller TP, Denoyelle C, Esteban JA, Tang WH, Bengston AL, Soengas MS. Chemical blockage of the proteasome inhibitory function of bortezomib: impact on tumor cell death. J Biol Chem 2005; 281:1107-18. [PMID: 16278210 DOI: 10.1074/jbc.m511607200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proteasome inhibitor bortezomib is emerging as a potent anti-cancer agent. Still, recent clinical trials have revealed a significant secondary toxicity of bortezomib. Consequently, there is much interest in dissecting the mechanism of action of this compound to rationally improve its therapeutic index. The cytotoxic effect of bortezomib is frequently characterized by interfering with downstream events derived from the accumulation of proteasomal targets. Here we identify the first chemical agent able to act upstream of the proteasome to prevent cell killing by bortezomib. Specifically, we show that the polyhydroxyl compound Tiron can function as a competitive inhibitor of bortezomib. This effect of Tiron was surprising, since it is a classical radical spin trap and was expected to scavenge reactive oxygen species produced as a consequence of bortezomib action. The inhibitory effect of Tiron against bortezomib was selective, since it was not shared by other antioxidants, such as vitamin E, MnTBAP, L-N-acetyl-cysteine, and FK-506. Comparative analyses with nonboronated proteasome inhibitors (i.e. MG132) revealed a specificity of Tiron for bortezomib. We exploited this novel feature of Tiron to define the "point of no return" of proteasome inhibition in melanoma cells and to block cell death in a three-dimensional model of human skin. Cells from T-cell lymphoma, breast carcinoma, and non-small cell lung cancer were also responsive to Tiron, suggesting a broad impact of this agent as a bortezomib blocker. These results may have important implications for the analysis of bortezomib in vivo and for the design of drug mixtures containing proteasome inhibitors.
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Affiliation(s)
- Yolanda Fernández
- Comprehensive Cancer Center and the Department of Dermatology, University of Michigan, Ann Arbor, 48109, USA
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245
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Willis SN, Adams JM. Life in the balance: how BH3-only proteins induce apoptosis. Curr Opin Cell Biol 2005; 17:617-25. [PMID: 16243507 PMCID: PMC2930980 DOI: 10.1016/j.ceb.2005.10.001] [Citation(s) in RCA: 599] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Accepted: 10/03/2005] [Indexed: 01/12/2023]
Abstract
BH3-only members of the Bcl-2 intracellular protein family, which include Bim, Bmf, Bik, Bad, Bid, Puma, Noxa and Hrk, mediate many developmentally programmed and induced cytotoxic signals. They have key roles in development, tissue homeostasis, immunity and tumor suppression, and compounds mimicking them are promising anti-cancer agents. Their activity is normally constrained by transcriptional and/or diverse post-transcriptional controls. When activated, these death ligands engage pro-survival Bcl-2-like proteins via the BH3 domain, inactivating their function. Bim and Puma bind all the pro-survival proteins, whereas others, such as Noxa and Bad, engage distinct subsets and exhibit complementary killing. Hence, multiple pro-survival proteins must be inactivated to unleash Bax and Bak, which drive apoptosis. Whether certain BH3-only proteins also directly activate Bax/Bak remains controversial.
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Affiliation(s)
- Simon N Willis
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville 3050, Victoria, Australia
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246
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Wondrak GT, Jacobson MK, Jacobson EL. Antimelanoma activity of apoptogenic carbonyl scavengers. J Pharmacol Exp Ther 2005; 316:805-14. [PMID: 16210394 DOI: 10.1124/jpet.105.094953] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Therapeutic induction of apoptosis is an important goal of anticancer drug design. Cellular carbonyl stress mediated by endogenous reactive carbonyl species (RCS) such as glyoxal and methylglyoxal (MG) affects proliferative signaling and metastasis of human tumor cells. Recent research suggests that RCS produced constitutively during increased tumor cell glycolysis may be antiapoptotic survival factors and thus represent a novel molecular target for anticancer intervention. Here, we demonstrate the tumor cell-specific apoptogenicity of carbonyl scavengers, which act by covalently trapping RCS, against human (A375, G361, and LOX) and murine (B16) melanoma cell lines. A structure-activity relationship study identified nucleophilic carbonyl scavenger pharmacophores as the functional determinants of apoptogenic antimelanoma activity of structurally diverse agents such as 3,3-dimethyl-D-cysteine and aminoguanidine. Previous work has demonstrated that covalent adduction of protein-arginine residues in the mitochondrial permeability transition (MPT) pore and heat shock protein 27 by intracellular MG produced in tumor cell glycolysis inhibits mitochondrial apoptosis and enhances cancer cell survival. Indeed, in various melanoma cell lines, carbonyl scavenger-induced apoptosis was antagonized by pretreatment with the membrane-permeable RCS phenylglyoxal (PG). Carbonyl scavenger-induced apoptosis was associated with early loss of mitochondrial transmembrane potential, and cyclosporin A antagonized the effects of carbonyl scavengers, suggesting a causative role of MPT pore opening in carbonyl scavenger apoptogenicity. Consistent with RCS inhibition of mitochondrial apoptosis in melanoma cells, staurosporine-induced apoptosis also was suppressed by PG pretreatment. Our results suggest that carbonyl scavengers acting as direct molecular antagonists of RCS are promising apoptogenic prototype agents for antimelanoma drug design.
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Affiliation(s)
- Georg T Wondrak
- Department of Pharmacology and Toxicology, College of Pharmacy, Arizona Cancer Center, University of Arizona, Tucson, USA.
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247
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Shore GC, Viallet J. Modulating the Bcl-2 Family of Apoptosis Suppressors for Potential Therapeutic Benefit in Cancer. Hematology 2005:226-30. [PMID: 16304385 DOI: 10.1182/asheducation-2005.1.226] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Members of the BCL-2 family of proteins regulate and execute many cell intrinsic apoptosis pathways, including those arising from dysregulated expression of cellular oncogenes. Since pro-survival members of the family are often strongly elevated in diverse cancers, with the potential to confer resistance to both endogenous cell death stimuli and many cancer treatments, there has been intense interest to develop strategies to therapeutically modulate their activity. Although encouraging genetic and pharmacological preclinical proof of concept has been obtained, the challenge for clinical development will be to devise strategies that address the fact that multiple pro-survival members are typically up-regulated in a given cancer and the family operates primarily through protein-protein interactions. Moreover, since several current therapies themselves are known to stimulate the levels of one or more family members, there will be additional challenges (and opportunities) in exploiting this target in the clinic. In this review, we describe the rationale for targeting the BCL-2 family of apoptosis suppressors in cancer and the progress that has been made in modulating the family by small molecule antagonists.
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