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Lee WJ, Hsiao M, Chang JL, Yang SF, Tseng TH, Cheng CW, Chow JM, Lin KH, Lin YW, Liu CC, Lee LM, Chien MH. Quercetin induces mitochondrial-derived apoptosis via reactive oxygen species-mediated ERK activation in HL-60 leukemia cells and xenograft. Arch Toxicol 2014; 89:1103-17. [PMID: 25138434 DOI: 10.1007/s00204-014-1300-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 06/17/2014] [Indexed: 02/04/2023]
Abstract
Quercetin is a plant-derived bioflavonoid that was recently shown to have multiple anticancer activities in various solid tumors. Here, novel molecular mechanisms through which quercetin exerts its anticancer effects in acute myeloid leukemia (AML) cells were investigated. Results from Western blot and flow cytometric assays revealed that quercetin significantly induced caspase-8, caspase-9, and caspase-3 activation, poly ADP-ribose polymerase (PARP) cleavage, and mitochondrial membrane depolarization in HL-60 AML cells. The induction of PARP cleavage by quercetin was also observed in other AML cell lines: THP-1, MV4-11, and U937. Moreover, treatment of HL-60 cells with quercetin induced sustained activation of extracellular signal-regulated kinase (ERK), and inhibition of ERK by an ERK inhibitor significantly abolished quercetin-induced cell apoptosis. MitoSOX red and 2',7'-dichlorofluorescin fluorescence, respectively, showed that mitochondrial superoxide and intracellular peroxide levels were higher in quercetin-treated HL-60 cells compared with the control group. Moreover, both N-acetylcysteine and the superoxide dismutase mimetic, MnTBAP, reversed quercetin-induced intracellular reactive oxygen species production, ERK activation, and subsequent cell death. The in vivo xenograft mice experiments revealed that quercetin significantly reduced tumor growth through inducing intratumoral oxidative stress while activating the ERK pathway and subsequent cell apoptosis in mice with HL-60 tumor xenografts. In conclusions, our results indicated that quercetin induced cell death of HL-60 cells in vitro and in vivo through induction of intracellular oxidative stress following activation of an ERK-mediated apoptosis pathway.
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Affiliation(s)
- Wei-Jiunn Lee
- Department of Urology, Wan Fang Hospital, Taipei Medical University, 111 Hsing Long Road, Section 3, Taipei, 116, Taiwan
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2
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Hyland PL, Lin SW, Hu N, Zhang H, Wang L, Su H, Wang C, Ding T, Tang ZZ, Fan JH, Qiao YL, Xiong X, Wheeler W, Giffen C, Yu K, Yuenger J, Burdett L, Wang Z, Chanock SJ, Tucker MA, Dawsey SM, Freedman ND, Goldstein AM, Abnet CC, Taylor PR. Genetic variants in fas signaling pathway genes and risk of gastric cancer. Int J Cancer 2013; 134:822-31. [PMID: 23921907 DOI: 10.1002/ijc.28415] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Accepted: 07/16/2013] [Indexed: 01/03/2023]
Abstract
Populations in north central China are at high risk for gastric cancers (GC), and altered FAS-mediated cell signaling and/or apoptosis may contribute to this risk. We examined the association of 554 single nucleotide polymorphisms (SNPs) in 53 Fas signaling-related genes using a pathway-based approach in 1758 GC cases (1126 gastric cardia adenocarcinomas (GCA) and 632 gastric noncardia adenocarcinomas (GNCA)), and 2111 controls from a genome-wide association study (GWAS) of GC in ethnic Chinese. SNP associations with risk of overall GC, GCA and GNCA were evaluated using unconditional logistic regressions controlling for age, sex and study. Gene- and pathway-based associations were tested using the adaptive rank-truncated product (ARTP) method. Statistical significance was evaluated empirically by permutation. Significant pathway-based associations were observed for Fas signaling with risk of overall GC (p = 5.5E-04) and GCA (p = 6.3E-03), but not GNCA (p= 8.1E-02). Among examined genes in the Fas signaling pathway, MAP2K4, FAF1, MAPK8, CASP10, CASP8, CFLAR, MAP2K1, CAP8AP2, PAK2 and IKBKB were associated with risk of GC (nominal p < 0.05), and FAF1 and MAPK8 were significantly associated with risk of both GCA and GNCA (nominal p< 0.05). Our examination of genetic variation in the Fas signaling pathway is consistent with an association of altered Fas signaling and/or apoptosis with risk of GC. As one of the first attempts to investigate a pathway-level association, our results suggest that these genes and the Fas signaling pathway warrant further evaluation in relation to GC risk in other populations.
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Affiliation(s)
- Paula L Hyland
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD, USA; Cancer Prevention Fellowship Program, Division of Cancer Prevention, NCI, NIH, Bethesda, MD, USA
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3
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Fisetin induces apoptosis in human cervical cancer HeLa cells through ERK1/2-mediated activation of caspase-8-/caspase-3-dependent pathway. Arch Toxicol 2011; 86:263-73. [DOI: 10.1007/s00204-011-0754-6] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 09/14/2011] [Indexed: 10/17/2022]
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4
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Smith AG, Lim W, Pearen M, Muscat GEO, Sturm RA. Regulation of NR4A nuclear receptor expression by oncogenic BRAF in melanoma cells. Pigment Cell Melanoma Res 2011; 24:551-63. [PMID: 21362156 DOI: 10.1111/j.1755-148x.2011.00843.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Activating mutations in the MAPK pathway effectors, NRAS or BRAF, are detected in over 70% of melanomas. Accordingly, the identification of downstream targets of constitutive MAPK signalling in melanoma represents a major goal in understanding the genesis of this disease. We report here the regulation of members of the NR4A family of nuclear receptors by the BRAF-MEK-ERK cascade in melanoma cells. Expression profiling of melanoma cells in which both the NR4A1 and NR4A2 family members have been down-regulated by siRNA revealed alterations in genes associated with proliferation, survival and invasiveness of tumour cells. Notably, the up-regulation of Wnt/β-catenin pathway antagonists, DACT1 and CITED1, following NR4A1/2 ablation suggests a possible link between NR4A and β-catenin activity in melanoma cells. Taken together, these data suggest that dysregulation of NR4A nuclear receptors expression and function by the MAPK pathway may contribute to melanoma tumourigenicity.
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Affiliation(s)
- Aaron G Smith
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
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Abstract
Proper regulation of T cell death is of vital importance for the function of the immune system. Positive and negative selection of developing T cells in the thymus ensures the survival of only those T cells that can recognize peptides presented by self-MHC molecules and at the same time not respond to self-antigens, and thus, T cell death within the thymus is instrumental in shaping the mature T cell repertoire. The death of activated peripheral T cells is crucial for processes such as down-modulation of immune responses after clearance of infectious agents, peripheral tolerance, and maintenance of immune-privileged sites. These processes are largely proceeding due to the enhanced susceptibility of activated T cells to spontaneous, activation-, and Fas-induced apoptosis. The active metabolite of the immune regulator vitamin A, retinoic acid, has been reported to influence various types of apoptotic processes in both thymocytes and activated peripheral T cells. This chapter gives an overview of, and discusses the reported effects of vitamin A on spontaneous and activation-induced cell death of thymocytes and mature T cells, as well as on Fas-induced T cell death.
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Wei G, Wang M, Carr BI. Sorafenib combined vitamin K induces apoptosis in human pancreatic cancer cell lines through RAF/MEK/ERK and c-Jun NH2-terminal kinase pathways. J Cell Physiol 2010; 224:112-9. [PMID: 20301194 DOI: 10.1002/jcp.22099] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Apoptosis has been shown to be induced by many agents, including the clinically useful Sorafenib and K vitamins (VKs). Since few agents have activity against pancreas cancer cell growth, we evaluated the role of naturally occurring K vitamins and Sorafenib both independently and together on the growth in culture of pancreas adenocarcinoma cell lines, including PL-5, PANC-1, and MIA PaCa-2. We found that when a K vitamin was combined with Sorafenib, the dose of Sorafenib required for growth inhibition was substantially reduced. Furthermore, growth could be inhibited at doses of each VK plus Sorafenib in combination that were ineffective when used alone. This effect was seen using vitamins K1, K2, and K5. The combination of VK1 plus Sorafenib-induced apoptosis, as determined by both FACS and TUNEL staining. Phospho-ERK and Bcl-2 levels were decreased, but not levels of other bcl-2 family members. Cleavage of caspases 3 and 8, PARP and Bid were all induced by this combination. Vitamin K1 plus Sorafenib combination also resulted in elevated levels of activated c-Jun N-terminal kinase (JNK) and its substrates c-Jun and FasL. JNK inhibition partly antagonized the induction of apoptosis. Thus, combination VK1 plus Sorafenib strongly induced growth inhibition and apoptosis in pancreas cancer cells, involving both inhibition of the RAF/MEK/ERK pathway as well as activation of the JNK, c-Jun and FasL apoptotic pathway. Since both agents are available for human use, the combination is attractive for evaluation against pancreas cancer growth in vivo.
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Affiliation(s)
- Gang Wei
- Department of Medical Oncology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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7
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Nabissi M, Morelli MB, Amantini C, Farfariello V, Ricci-Vitiani L, Caprodossi S, Arcella A, Santoni M, Giangaspero F, De Maria R, Santoni G. TRPV2 channel negatively controls glioma cell proliferation and resistance to Fas-induced apoptosis in ERK-dependent manner. Carcinogenesis 2010; 31:794-803. [DOI: 10.1093/carcin/bgq019] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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8
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Sekulic A, Haluska P, Miller AJ, Genebriera De Lamo J, Ejadi S, Pulido JS, Salomao DR, Thorland EC, Vile RG, Swanson DL, Pockaj BA, Laman SD, Pittelkow MR, Markovic SN. Malignant melanoma in the 21st century: the emerging molecular landscape. Mayo Clin Proc 2008; 83:825-46. [PMID: 18613999 PMCID: PMC2739389 DOI: 10.4065/83.7.825] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Malignant melanoma presents a substantial clinical challenge. Current diagnostic methods are limited in their ability to diagnose early disease and accurately predict individual risk of disease progression and outcome. The lack of adequate approaches to properly define disease subgroups precludes rational treatment design and selection. Better tools are urgently needed to provide more accurate and personalized melanoma patient management. Recent progress in the understanding of the molecular aberrations that underlie melanoma oncogenesis will likely advance the diagnosis, prognosis, and treatment of melanoma. The emerging pattern of molecular complexity in melanoma tumors mirrors the clinical diversity of the disease and highlights the notion that melanoma, like other cancers, is not a single disease but a heterogeneous group of disorders that arise from complex molecular changes. Understanding of molecular aberrations involving important cellular processes, such as cellular signaling networks, cell cycle regulation, and cell death, will be essential for better diagnosis, accurate assessment of prognosis, and rational design of effective therapeutics. Defining an individual patient's unique tumor characteristics may lead to personalized prediction of outcomes and selection of therapy. We review the emerging molecular landscape of melanoma and its implications for better management of patients with melanoma.
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Abstract
PURPOSE OF REVIEW As understanding of molecular and genetic processes in cancer evolves, so does appreciation of tumor heterogeneity. Tumor profiling has expanded knowledge of relevant pathways, and their interplay. Similar to the revolution in breast cancer with the discovery and successful therapeutic targeting of HER2/neu, the melanoma field is rapidly evolving. The MAPK pathway is dysregulated in most melanomas. Several therapeutic agents directed against this pathway are in development. This review summarizes current understanding of the MAPK pathway in melanoma biology and therapeutic strategies. RECENT FINDINGS Recent data support the concept of distinct groups of molecular and genetic abnormalities in melanomas, related to type of sun exposure and body site. MAPK abnormalities, specifically BRAF or NRAS mutations, are most prevalent. The efficacy of sorafenib, a multitargeted kinase inhibitor, in melanoma is still under evaluation. While ineffective as a single agent, efficacy in combination with chemotherapy or targeted agents is being assessed. More specific inhibitors of BRAF, or other MAPK members, may prove more effective. SUMMARY Tumor profiling has led to exciting advances. The MAPK pathway is one of several potentially targetable pathways in melanoma. Ultimately, combinatorial therapeutics against relevant disrupted pathways in specific tumors likely will prove most successful.
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Yiang GT, Yu YL, Hu SC, Chen MHC, Wang JJ, Wei CW. PKC and MEK pathways inhibit caspase-9/-3-mediated cytotoxicity in differentiated cells. FEBS Lett 2008; 582:881-5. [PMID: 18282472 DOI: 10.1016/j.febslet.2008.02.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 01/31/2008] [Accepted: 02/06/2008] [Indexed: 10/22/2022]
Abstract
Many studies have indicated that differentiated cells inhibit drug-induced cytotoxicity but undifferentiated cells do not, though the mechanisms are unclear. Currently, HL-60 cells are induced to differentiate into macrophage-like cells with Phorbol-12-myristate-13-acetate (TPA) treatment (TPA-differentiated cells). Our study shows that caspase-9/-3-mediated cytotoxicity can be induced in undifferentiated HL-60 cells but not in TPA-differentiated HL-60 cells. However, caspase-9/-3-mediated cytotoxicity can be induced in TPA-differentiated cells if they are pretreated with a protein kinase C (PKC) or a mitogen activated protein kinase (MEK) inhibitor. Taken together, this study demonstrates that TPA-differentiated HL-60 cells inhibit caspases-9/-3-mediated cytotoxicity through the PKC and MEK signaling pathways.
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Affiliation(s)
- Giou-Teng Yiang
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
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11
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Ross KR, Corey DA, Dunn JM, Kelley TJ. SMAD3 expression is regulated by mitogen-activated protein kinase kinase-1 in epithelial and smooth muscle cells. Cell Signal 2007; 19:923-31. [PMID: 17197157 DOI: 10.1016/j.cellsig.2006.11.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 11/01/2006] [Accepted: 11/07/2006] [Indexed: 10/23/2022]
Abstract
SMAD3 is a transcription factor that mediates TGF-beta1 signaling and is known to be important in many of the cellular processes that regulate fibrosis and inflammation. Although several studies have examined SMAD3 activation, little is known about the control of SMAD3 expression. It is well established that the mitogen-activated protein kinase (MAPK) pathway is responsive to TGF-beta1 stimulation and coordinates with SMAD signaling in many cases; therefore, the hypothesis of this study is that the MAPK pathway will be involved in the regulation of SMAD3 expression. Using a SMAD3 promoter construct, we demonstrate that inhibition of either c-Jun-N-terminal kinase (JNK) or p38 activity has little effect on SMAD3 promoter function. Inhibition of mitogen-activated protein kinase kinase-1 (MEK1) with either PD98059 or UO126, however, results in a substantial dose-dependent inhibition of SMAD3 promoter activity. Further studies confirm that promoter activity correlates with protein expression by demonstrating reduced SMAD3 protein expression in A549 cells and airway smooth muscle cells after treatment with MEK1 inhibitors. Positive regulation of SMAD3 expression is also demonstrated by expression of a constitutively active (ca)-MEK1 construct, where the presence of ca-MEK1 resulted in increased SMAD3 protein expression. These data lead to the conclusion that MEK1 is an important regulator of SMAD3 expression.
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Affiliation(s)
- Kristie R Ross
- Department of Pediatrics, Case Western Reserve University, and Rainbow Babies and Children's Hospital, Cleveland, OH 44106-4948, USA
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12
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Abstract
PURPOSE To study the regulation by mitomycin C (MMC) of 1-cys peroxiredoxin (Prx) expression during the corneal wound-healing process and its induction pathway in cultured bovine keratocytes (BKs). METHODS Rat corneas were excised at 4 hours, 12 hours, 1 day, 3 days, and 7 days after photorefractive keratectomy (PRK). Expression of 1-cys Prx in the corneas was examined by Northern blot and immunoblot analyses. Cultured BKs were exposed to 0.02% MMC for 5 minutes and maintained under normal culture conditions for different time periods. Subsequently, levels of 1-cys Prx and extracellular signal-regulated kinase (ERK)1/2 expression were measured by immunoblot analysis using polyclonal 1-cys Prx, ERK1/2, or phospho-ERK1/2 antibodies. To inhibit ERK1/2 activation, the BKs were pretreated with 50 micromol/mL PD98059 for 1 hour before MMC exposure and incubated in complete medium with or without PD98059 for 24 hours. MMC-induced cytotoxicity was determined by colorimetric cell-counting kit-8 assay. RESULTS Increased levels of 1-cys Prx expression were seen in wounded rat corneas at 12 hours after injury and reached the highest level between 1 and 3 days, during which time active proliferation occurred. Induction of 1-cys Prx expression was obvious in proliferating BKs stimulated by growth factors. MMC treatment in cultured BKs resulted in increased expression of 1-cys Prx and phospho-ERK1/2 in a time-dependent manner. Treatment with 50 micromol/mL PD98059 significantly inhibited the active ERK1/2 and 1-cys Prx expression induced by MMC, leading to synergistic cytotoxicity in the BKs. CONCLUSION 1-Cys Prx may function as an important enzyme in cell proliferation during the postinjury corneal wound-healing process. Furthermore, the induction of 1-cys Prx expression through the ERK1/2 signaling pathway may contribute to cellular defense against cytotoxic agents, thus playing an important role in cell survival.
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Affiliation(s)
- Jhang Ho Pak
- Department of Ophthalmology and Asan Institute for Life Sciences, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Pungnap-2 dong, Songpa-gu, Seoul 137-756, Korea
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13
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Hristova M, Heuvelmans S, van der Vliet A. GSH-dependent regulation of Fas-mediated caspase-8 activation by acrolein. FEBS Lett 2007; 581:361-7. [PMID: 17222828 PMCID: PMC2323510 DOI: 10.1016/j.febslet.2006.12.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 12/14/2006] [Indexed: 10/23/2022]
Abstract
Activation of the cysteine protease caspase-8 by the death receptor Fas (CD95/APO-1) in B lymphoblastoid SKW6.4 cells or Jurkat T cells is associated with GSH depletion. Conversely, GSH depletion by the aldehyde acrolein (3-30 microM) was associated with inhibition of Fas-induced caspase-8 activation, although GSH depletion by buthionine sulfoximine (BSO) did not affect caspase-8 activation. In contrast to BSO, acrolein caused a loss of caspase-8 cysteine content in association with direct alkylation of caspase-8. Our findings indicate that inhibition of caspase-8 by thiol-reactive agents such as acrolein is not due to GSH depletion but caused by direct protein thiol modifications.
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Affiliation(s)
- Milena Hristova
- Department of Pathology, College of Medicine, University of Vermont, 89 Beaumont Avenue, Burlington, VT 05405, USA
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14
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Mishra S, Mishra JP, Kumar A. Activation of JNK-dependent pathway is required for HIV viral protein R-induced apoptosis in human monocytic cells: involvement of antiapoptotic BCL2 and c-IAP1 genes. J Biol Chem 2006; 282:4288-4301. [PMID: 17158886 DOI: 10.1074/jbc.m608307200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human immunodeficiency virus (HIV) accessory protein viral protein R (Vpr) plays a key role in virus replication and induces cell cycle arrest and apoptosis in various cell types including T cells and neuronal and tumor cells following infection with Vpr-expressing HIV isolates or exposure to the extracellular Vpr protein. The C-terminal Vpr peptide encompassing amino acids 52-96 (Vpr-(52-96)) is required for exerting the apoptotic effects, whereas the N-terminal Vpr-(1-45) peptide is responsible for virus transcription. We demonstrate that Vpr-(52-96) induced apoptosis in human promonocytic THP-1 cells and primary monocytes through the mitochondrial pathway in a caspase-dependent manner. To understand the regulation of Vpr-induced apoptosis, we investigated the signaling pathways, particularly the MAPKs, and the transcription factors involved. Although both Vpr-(52-96) and Vpr-(1-45) peptides induced phosphorylation of all the three members of the MAPKs, Vpr-(52-96)-activated JNK selectively induced apoptosis in monocytic cells through the mitochondrial pathway as determined by using JNK inhibitors SP60025, dexamethasone, curcumin, and JNK-specific small interfering RNAs. Furthermore Vpr-(52-96)-induced apoptosis was mediated by inhibition of downstream antiapoptotic Bcl2 and c-IAP1 genes whose expression could be restored following pretreatment with JNK-specific inhibitors. Overall the results suggest that Vpr-(52-96)-activated JNK plays a key role in inducing apoptosis through the down-regulation of antiapoptotic Bcl2 and c-IAP1 genes.
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Affiliation(s)
- Sasmita Mishra
- Biochemistry, Microbiology, and Immunology, University of Ottawa K1H 8M5 and Children's Hospital of Eastern Ontario, Ottawa, Ontario K1H 8L1, Canada
| | - Jyoti P Mishra
- Biochemistry, Microbiology, and Immunology, University of Ottawa K1H 8M5 and Children's Hospital of Eastern Ontario, Ottawa, Ontario K1H 8L1, Canada
| | - Ashok Kumar
- Biochemistry, Microbiology, and Immunology, University of Ottawa K1H 8M5 and Children's Hospital of Eastern Ontario, Ottawa, Ontario K1H 8L1, Canada; Pathology and Laboratory Medicine and Children's Hospital of Eastern Ontario, Ottawa, Ontario K1H 8L1, Canada; Departments of Children's Hospital of Eastern Ontario, Ottawa, Ontario K1H 8L1, Canada; Infectious Disease and Vaccine Research Centre, Research Institute, Children's Hospital of Eastern Ontario, Ottawa, Ontario K1H 8L1, Canada.
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15
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Lee DY, Lee MW, Lee HJ, Noh YH, Park SC, Lee MY, Kim KY, Lee WB, Kim SS. ERK1/2 activation attenuates TRAIL-induced apoptosis through the regulation of mitochondria-dependent pathway. Toxicol In Vitro 2006; 20:816-23. [PMID: 16563693 DOI: 10.1016/j.tiv.2006.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Revised: 11/25/2005] [Accepted: 01/05/2006] [Indexed: 12/29/2022]
Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) functions as an extracellular signal, which triggers apoptosis in tumor cells. In order to characterize the molecular events involved in TRAIL cytotoxic signaling, we attempted to determine the role of extracellular signal-regulated kinase 1/2 (ERK1/2), as well as its downstream targets in TRAIL-treated HeLa cells. Here we demonstrate that TRAIL exposure resulted in the activation of ERK1/2, and the elevation of anti-apoptotic Bcl-2 protein levels. ERK1/2 inhibition with PD98059 promoted cell death via the down-regulation of Bcl-2 protein levels, together with increasing mitochondrial damage, including the collapse of mitochondrial membrane potential, the release of cytochrome c from mitochondria to cytoplasm and caspase activity. These results suggest that the ERK1/2 activation is a kind of survival mechanism to struggle against TRAIL-induced stress condition in early stage, via activating cellular defense mechanisms like as the up-regulation of the Bcl-2/Bax ratio, as well as several mitochondrial events.
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Affiliation(s)
- Do Yeon Lee
- Department of Anatomy and Cell Biology, College of Medicine, Chung-Ang University, 221 Huksuk-dong, Dongjak-ku, Seoul 156-756, Republic of Korea
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16
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Scheller C, Knöferle J, Ullrich A, Prottengeier J, Racek T, Sopper S, Jassoy C, Rethwilm A, Koutsilieri E. Caspase inhibition in apoptotic T cells triggers necrotic cell death depending on the cell type and the proapoptotic stimulus. J Cell Biochem 2006; 97:1350-61. [PMID: 16365881 DOI: 10.1002/jcb.20670] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
CD95 (Fas/Apo-1) triggers apoptotic cell death via a caspase-dependent pathway. Inhibition of caspase activation blocks proapoptotic signaling and thus, prevents execution of apoptosis. Besides induction of apoptotic cell death, CD95 has been reported to trigger necrotic cell death in susceptible cells. In this study, we investigated the interplay between apoptotic and necrotic cell death signaling in T cells. Using the agonistic CD95 antibody, 7C11, we found that caspase inhibition mediated by the pancaspase inhibitor, zVAD-fmk, prevented CD95-triggered cell death in Jurkat T cells but not in A3.01 T cells, although typical hallmarks of apoptosis, such as DNA fragmentation or caspase activation were blocked. Moreover, the caspase-independent cell death in A3.01 cells exhibited typical signs of necrosis as detected by a rapid loss of cell membrane integrity and could be prevented by treatment with the radical scavenger butylated hydroxyanisole (BHA). Similar to CD95-induced cell death, apoptosis triggered by the DNA topoisomerase inhibitors, camptothecin or etoposide was shifted to necrosis when capsase activation was inhibited. In contrast to this, ZVAD was fully protective when apoptosis was triggered by the serpase inhibitor, Nalpha-tosyl-phenyl-chloromethyl ketone (TPCK). TPCK was not protective when administered to anti-CD95/ZVAD-treated A3.01 cells, indicating that TPCK does not possess anti-necrotic activity but fails to activate the necrotic death pathway. Our findings show (a) that caspase inhibition does not always protect apoptotic T cells from dying but merely activates a caspase-independent mode of cell death that results in necrosis and (b) that the caspase-inhibitor-induced shift from apoptotic to necrotic cell death is dependent on the cell type and the proapoptotic stimulus.
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Affiliation(s)
- Carsten Scheller
- Institute of Virology and Immunobiology, University of Würzburg, Versbacher Strasse 7, 97078 Würzburg, Germany.
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Vargo MA, Voss OH, Poustka F, Cardounel AJ, Grotewold E, Doseff AI. Apigenin-induced-apoptosis is mediated by the activation of PKCdelta and caspases in leukemia cells. Biochem Pharmacol 2006; 72:681-92. [PMID: 16844095 DOI: 10.1016/j.bcp.2006.06.010] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Revised: 05/31/2006] [Accepted: 06/01/2006] [Indexed: 11/20/2022]
Abstract
Apigenin, a flavone abundantly found in fruits and vegetables, exhibits antiproliferative, anti-inflammatory, and antimetastatic activities through poorly defined mechanisms. In the present study, the treatment of different cell lines with apigenin resulted in selective antiproliferative and apoptotic effect in monocytic and lymphocytic leukemias. Apigenin-induced-apoptosis was mediated by the activation of caspase-9 and caspase-3. Apigenin was found intracellularly and localized to the mitochondria. Treatment of monocytic cells with apigenin was accompanied by an increase in reactive oxygen species (ROS) and phosphorylation of the MAPKs, p38 and ERK. However, the inhibition of ROS, p38 or ERK failed to block apoptosis, suggesting that these cellular responses induced by apigenin are not essential for the induction of apoptosis. In addition, apigenin induced the activation of PKCdelta. Pharmacological inhibition of PKCdelta, the expression of dominant-negative PKCdelta and silencing of PKCdelta in leukemia cells showed that apigenin-induced-apoptosis requires PKCdelta activity. Together, these results indicate that this flavonoid provides selective activity to promote caspase-dependent-apoptosis of leukemia cells and uncover an essential role of PKCdelta during the induction of apoptosis by apigenin.
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Liu Y, Borchert GL, Surazynski A, Hu CA, Phang JM. Proline oxidase activates both intrinsic and extrinsic pathways for apoptosis: the role of ROS/superoxides, NFAT and MEK/ERK signaling. Oncogene 2006; 25:5640-7. [PMID: 16619034 DOI: 10.1038/sj.onc.1209564] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Proline oxidase (POX), often considered a 'housekeeping enzyme' might play an important role in apoptosis. We have shown that POX generated proline-dependent reactive oxygen species (ROS), specifically superoxide radicals, and induced apoptosis through the mitochondrial (intrinsic) pathway. In our current report, we used DLD-1 colorectal cancer cells stably transfected with the POX gene under the control of a tetracycline-inducible promoter and found POX-stimulated expression of tumor necrosis factor-related apoptosis inducing ligand (TRAIL), DR5 and cleavage of caspase-8. Importantly, apoptosis measured by flow cytometry was partially inhibited by Z-IETD-FMK, a specific inhibitor of caspase-8. These findings suggest that the extrinsic (death receptor) pathway also is activated by POX. Furthermore, the mechanism of this effect on the extrinsic pathway, specifically, the induction of TRAIL by POX, may be mediated by NFAT transcription factors. Additionally, POX expression also dramatically decreased phosphorylation of MEK and ERK, and the decrease was partially reversed by expression of manganese superoxide dismutase (MnSOD). Overexpression of constitutively active form of MEK, acMEK, partially blocked POX-induced apoptosis. These findings suggest the involvement of MEK/ERK signaling and further confirm the role of ROS/superoxides in POX-induced apoptosis. Combined with previously published data, we conclude that POX may induce apoptosis through both intrinsic and extrinsic pathways and is involved in nuclear factor of activated T cells (NFAT) signaling and regulation of the MEK/ERK pathway. It is suggested that, as a nutrition factor, POX may modulate apoptosis signals induced by p53 or other anti-cancer agents and enhance apoptosis in stress situations.
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Affiliation(s)
- Y Liu
- Metabolism and Cancer Susceptibility Section, Laboratory of Comparative Carcinogenesis, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
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19
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Cagnol S, Van Obberghen-Schilling E, Chambard JC. Prolonged activation of ERK1,2 induces FADD-independent caspase 8 activation and cell death. Apoptosis 2006; 11:337-46. [PMID: 16538383 DOI: 10.1007/s10495-006-4065-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Prolonged ERK/MAPK activation has been implicated in neuronal cell death in vitro and in vivo. We found that HEK293 cells, recently reported to express neuronal markers, are exquisitely sensitive to long term ERK stimulation. Activation of an inducible form of Raf-1 (Raf-1:ER) in HEK293 cells induced massive apoptosis characterized by DNA degradation, loss of plasma membrane integrity and PARP cleavage. Cell death required MEK activity and protein synthesis and occurred via the death receptor pathway independently of the mitochondrial pathway. Accordingly, prolonged ERK stimulation activated caspase 8 and strongly potentiated Fas signaling. The death receptor adaptator FADD was found to be rapidly induced upon ERK activation. However using RNA interference and ectopic expression, we demonstrated that neither FADD nor Fas were necessary for caspase 8 activation and cell death. These findings reveal that prolonged ERK/MAPK stimulation results in caspase 8 activation and cell death.
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Affiliation(s)
- S Cagnol
- Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR6543, Université de Nice Sophia-Antipolis, Centre Antoine Lacassagne, 33 Ave Valombrose, 06189, Nice, France
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20
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Betito S, Cuvillier O. Regulation by sphingosine 1-phosphate of Bax and Bad activities during apoptosis in a MEK-dependent manner. Biochem Biophys Res Commun 2006; 340:1273-7. [PMID: 16414356 DOI: 10.1016/j.bbrc.2005.12.138] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Accepted: 12/19/2005] [Indexed: 11/28/2022]
Abstract
Herein we report that the prosurvival sphingolipid sphingosine 1-phosphate regulates the activities of both Bad and Bax during apoptosis of Jurkat cells. First, sphingosine 1-phosphate treatment results in Bad inactivation via the ERK/Rsk-1 pathway. Second, sphingosine 1-phosphate blocks the translocation of Bax to the mitochondria induced by Fas ligation. MEK inhibition by PD98059 or U0126 not only abrogates sphingosine 1-phosphate-induced Bad phosphorylation, but also its cytoprotective effect. Furthermore, inhibition of both mitochondrial cytochrome c efflux and Bax translocation to the mitochondria by sphingosine 1-phosphate could be overcome by PD98059 or U0126. Hence, the MEK/ERK pathway seems to be crucial for the survival effects initiated by sphingosine 1-phosphate.
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Affiliation(s)
- Susan Betito
- Inserm U466, Institut Louis Bugnard, BP 84225, 31432 Toulouse Cedex 4, France
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21
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Lee MW, Bach JH, Lee HJ, Lee DY, Joo WS, Kim YS, Park SC, Kim KY, Lee WB, Kim SS. The activation of ERK1/2 via a tyrosine kinase pathway attenuates trail-induced apoptosis in HeLa cells. Cancer Invest 2006; 23:586-92. [PMID: 16305985 DOI: 10.1080/07357900500283036] [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: 01/15/2023]
Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) serves as an extracellular signal that triggers apoptosis in tumor cells. To characterize the molecular events involved in TRAIL-induced apoptotic signaling, we investigated the role of extracellular signal-regulated kinase 1/2 (ERK1/2) in HeLa cell death. Here we show that TRAIL-activated ERK1/2 through a tyrosine kinase-dependent pathway, subsequently elevated anti-apoptotic Bcl-2 protein levels. ERK1/2 inhibition with PD98059 promoted apoptotic cell death through the downregulation of ERK1/2 activity and Bcl-2 protein levels. Moreover, tyrosine kinase inhibition with Genistein in TRAIL-induced apoptosis effectively attenuated ERK1/2 activity and enhanced apoptotic cell death. Taken together, our results indicate that ERK1/2 activation via tyrosine kinase pathway plays a protective role as the cellular defense mechanism through the upregulation of Bcl-2 protein levels in TRAIL-induced apoptosis.
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Affiliation(s)
- Myoung Woo Lee
- Department of Anatomy, College of Medicine, Chung-Ang University, Seoul, Korea
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22
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Kutuk O, Pedrech A, Harrison P, Basaga H. Pramanicin induces apoptosis in Jurkat leukemia cells: a role for JNK, p38 and caspase activation. Apoptosis 2005; 10:597-609. [PMID: 15909121 DOI: 10.1007/s10495-005-1894-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Pramanicin is a novel anti-fungal drug with a wide range of potential application against human diseases. It has been previously shown that pramanicin induces cell death and increases calcium levels in vascular endothelial cells. In the present study, we showed that pramanicin induced apoptosis in Jurkat T leukemia cells in a dose- and time-dependent manner. Our data reveal that pramanicin induced the release of cytochrome c and caspase-9 and caspase-3 activation, as evidenced by detection of active caspase fragments and fluorometric caspase assays. Pramanicin also activated c-jun N-terminal kinase (JNK), p38 and extracellular signal-regulated kinases (ERK 1/2) with different time and dose kinetics. Treatment of cells with specific MAP kinase and caspase inhibitors further confirmed the mechanistic involvement of these signalling cascades in pramanicin-induced apoptosis. JNK and p38 pathways acted as pro-apoptotic signalling pathways in pramanicin-induced apoptosis, in which they regulated release of cytochrome c and caspase activation. In contrast the ERK 1/2 pathway exerted a protective effect through inhibition of cytochrome c leakage from mitochondria and caspase activation, which were only observed when lower concentrations of pramanicin were used as apoptosis-inducing agent and which were masked by the intense apoptosis induction by higher concentrations of pramanicin. These results suggest pramanicin as a potential apoptosis-inducing small molecule, which acts through a well-defined JNK- and p38-dependent apoptosis signalling pathway in Jurkat T leukemia cells.
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Affiliation(s)
- O Kutuk
- Biological Sciences and Bioengineering Program, Sabanci University, 34956 Tuzla, Istanbul, Turkey
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23
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Solhaug A, Øvrebø S, Mollerup S, Låg M, Schwarze PE, Nesnow S, Holme JA. Role of cell signaling in B[a]P-induced apoptosis: characterization of unspecific effects of cell signaling inhibitors and apoptotic effects of B[a]P metabolites. Chem Biol Interact 2005; 151:101-19. [PMID: 15698582 DOI: 10.1016/j.cbi.2004.12.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Revised: 12/15/2004] [Accepted: 12/15/2004] [Indexed: 12/01/2022]
Abstract
Here we show that several cell signaling inhibitors have effect on cyp1a1 expression and the metabolism of benzo[a]pyrene (B[a]P) in Hepa1c1c7 cells. The CYP1A1 inhibitor alpha-naphthoflavone (alpha-NF), the p53 inhibitor pifithrin-alpha (PFT-alpha), the ERK inhibitors PD98059 and U0126, and the p38 MAPK inhibitors SB202190 and PD169316 induced the expression and level of cyp1a1 protein. On the other hand, during the first h the inhibitors appeared to reduce the metabolism of B[a]P as measured by the generation of tetrols and by covalent binding of B[a]P to macromolecules. In contrast, the phosphatidylinositol-3 (PI-3) kinase inhibitor wortmannin, had neither an effect on the cyp1a1 expression nor the B[a]P-metabolism. In order to avoid these unspecific effects, we characterized the mechanisms involved in the apoptotic effects of B[a]P-metabolites. B[a]P and the B[a]P-metabolites B[a]P-7,8-DHD and BPDE-I induced apoptosis, whereas B[a]P-4,5-DHD had no effect. B[a]P, B[a]P-7,8-DHD and BPDE-I induced an accumulation and phosphorylation of p53, while the Bcl-2 proteins Bcl-xl, Bad and Bid were down-regulated. Interestingly, the levels of anti-apoptotic phospho-Bad were up-regulated in response to B[a]P as well as to B[a]P-7,8-DHD and BPDE-I. Both p38 MAPK and JNK were activated, but the p38 MAPK inhibitors were not able to inhibit BPDE-I-induced apoptosis. PFT-alpha reduced the BPDE-I-induced apoptosis, while both the PI-3 kinase inhibitor and the ERK inhibitors increased the apoptosis in combination with BPDE-I. BPDE-I also triggered apoptosis in primary cultures of rat lung cells. In conclusion, often used cell signaling inhibitors both enhanced the expression and the level of cyp1a1 and more directly acted as inhibitors of cyp1a1 metabolism of B[a]P. However, studies with the B[a]P-metabolite BPDE-I supported the previous suggestion that p53 has a role in the pro-apoptotic signaling pathway induced by B[a]P. Furthermore, these studies also show that the reactive metabolites of B[a]P induce the anti-apoptotic signals, Akt and ERK. Neither the induction nor the activity of p38 MAPK and JNK seems to be of major importance for the B[a]P-induced apoptosis.
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Affiliation(s)
- Anita Solhaug
- Division of Environmental Medicine, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403 Oslo, Norway
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24
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Cousens LP, Goulette FA, Darnowski JW. JAK-mediated signaling inhibits Fas ligand-induced apoptosis independent of de novo protein synthesis. THE JOURNAL OF IMMUNOLOGY 2005; 174:320-7. [PMID: 15611255 DOI: 10.4049/jimmunol.174.1.320] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
There is a growing appreciation for how cells integrate and appropriately respond to competing signals for proliferation and apoptosis. The studies described in this report examined the effects of exposure to the cytokine IFN-alpha (IFN-alpha-2a) on sensitivity of the human cell lines H9 and SKW6.4 to Fas ligand (FasL)-induced apoptosis. In a concentration-dependent manner, FasL induced apoptosis, as shown by Western blot analysis of procaspase 8 and poly(ADP-ribose) polymerase cleavage after 3-h exposure and by cytofluorometric analysis of sub-G(0)-G(1) cellular DNA content after 24-h exposure. H9 and SKW6.4 cell lines responded to 10,000 IU/ml IFN-alpha-2a, as evidenced by decreased cell proliferation and tyrosine phosphorylation of Stat1 and Stat3 proteins without significant cytotoxicity. The effects of cytokine exposure on apoptosis were examined; incubation in medium containing 10,000 IU/ml IFN-alpha-2a for 1 h before FasL treatment significantly reduced all above-mentioned hallmarks of apoptosis. Surprisingly, these antiapoptotic effects of IFN-alpha-2a were independent of de novo protein synthesis, because they occurred in both the absence and the presence of cycloheximide. However, chemical inhibitors of JAK completely abrogated the effects of IFN-alpha-2a on FasL-induced apoptosis, indicating a direct role for JAK-mediated protein phosphorylation in modulating sensitivity to apoptosis. Together, these data suggest a novel mechanism, independent of protein synthesis, by which cytokine signals through JAKs can interact with and attenuate this receptor-mediated apoptotic process.
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Affiliation(s)
- Leslie P Cousens
- Department of Medicine, Division of Medical Oncology, Brown University and Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA.
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25
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Abstract
Melanoma is a form of skin cancer that has a poor prognosis and which is on the rise in Western populations. If detected early, it is easily treated by surgical excision. However, once melanoma metastasises it is notoriously resistant to existing therapies and for many patients the outlook is dismal. Thus a full description of melanoma etiology and a full understanding of the genetic lesions that underlie this disease is required to allow us to develop new and effective therapeutic strategies for its treatment. RAF proteins are a family of serine/threonine-specific protein kinases that form part of a signalling module that regulates cell proliferation, differentiation and survival. In mammals there are three isoforms, A-RAF, B-RAF and C-RAF, and recently it was shown that the B-RAF isoform is mutated in a high proportion of melanomas. In light of these exciting findings, we review what we have learned about B-RAF and its role in cutaneous melanoma.
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Affiliation(s)
- Vanessa C Gray-Schopfer
- Signal Transduction Team, Cancer Research UK Centre of Cell and Molecular Biology, The Institute of Cancer Research, London, UK
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26
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Gali-Muhtasib HU, Diab-Assaf M, Haddadin MJ. RETRACTED ARTICLE: Quinoxaline 1,4-dioxides induce G2/M cell cycle arrest and apoptosis in human colon cancer cells. Cancer Chemother Pharmacol 2004; 55:369-378. [PMID: 15538569 DOI: 10.1007/s00280-004-0907-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2004] [Accepted: 07/30/2004] [Indexed: 10/26/2022]
Abstract
We have recently shown that quinoxaline 1,4-dioxide (QdNO) derivatives, namely 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide (DCQ), 2-benzoyl-3-phenyl-quinoxaline 1,4-dioxide (BPQ) and 2-acetyl-3-methyl-quinoxaline 1,4-dioxide (AMQ), suppress the growth of T-84 human colon cancer cells. Here we show that the growth-suppressive effects of QdNOs are due to their ability to induce cell cycle arrest and/or apoptosis. While AMQ blocked more than 60% of cells at the G2/M phase without inducing apoptosis, DCQ caused a significant increase in apoptotic cells with no noticeable effects on the cycling of cells. Treatment with BPQ resulted in G2/M cell cycle arrest and induction of apoptosis. With regard to the effects of QdNOs on molecules that regulate apoptosis and the G2 to M transition, both BPQ and AMQ inhibited the expression of cyclin B, while DCQ significantly decreased the levels of Bcl-2 and increased Bax expression. Next, we investigated whether transforming growth factor-beta1 (TGF-beta1) and/or extracellular signal-regulated kinase (ERK) mediate the antiproliferative and apoptotic effects of QdNOs in colon cancer cells. Interestingly, the above QdNOs increased differentially total TGF beta1 mRNA expression and decreased TGF alpha mRNA and ERK phosphorylation. None of these QdNOs induced changes in TGF beta-2 mRNA expression. The addition of a specific inhibitor of MEK greatly enhanced apoptosis in cells treated with DCQ, suggesting that the inhibition of ERK phosphorylation may explain, to an extent, the apoptogenic effects of this compound. Taken together, these findings provide insights into possible molecular mechanisms of growth inhibition by QdNOs that could aid in their evaluation for anticancer therapy.
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Affiliation(s)
| | - Mona Diab-Assaf
- Department of Biology, American University of Beirut, Beirut, Lebanon
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27
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Oh HM, Choi SC, Lee HS, Chun CH, Seo GS, Choi EY, Lee HJ, Lee MS, Yeom JJ, Choi SJ, Han WC, Oh JM, Chung YT, Chun JS, Lee KM, Jun CD. Combined action of extracellular signal-regulated kinase and p38 kinase rescues Molt4 T cells from nitric oxide-induced apoptotic and necrotic cell death. Free Radic Biol Med 2004; 37:463-79. [PMID: 15256218 DOI: 10.1016/j.freeradbiomed.2004.04.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2003] [Revised: 04/05/2004] [Accepted: 04/28/2004] [Indexed: 11/20/2022]
Abstract
The mechanisms that regulate nitric oxide (NO)-induced apoptosis, especially in T cell apoptosis, are largely uncharacterized. Here, we report that protection from NO-induced cell death by phorbol 12-myristate 13-acetate (PMA) is dependent on both p38 and extracellular signal-regulated kinase (ERK) activation. Exposure of Molt4 cells to NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP) induced both apoptotic and necrotic modes of cell death along with a sustained increase in p38 kinase phosphorylation. However, the p38 inhibitor SB202190 only slightly protected Molt4 cells from NO toxicity. In contrast, PMA rapidly phosphorylated both p38 kinase and ERK, and the phosphorylation statuses were not altered in the presence of SNAP. Interestingly, although each mitogen-activated protein kinase (MAPK) inhibitor by itself had only a modest effect, the combination of inhibitors for both MAPKs almost completely abolished the protective effect of PMA. Furthermore, dominant negative or catalytically inactive variants that modulate p38 and ERK mimicked the effects of MAPK inhibitors. We located the action of p38 and ERK upstream of the p53/mitochondrial membrane potential loss and caspases cascade. Together, these findings suggest that the PMA-induced activations of ERK and p38 kinase are parallel events that are both required for inhibition of NO-induced death of Molt4 cells.
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Affiliation(s)
- Hyun-Mee Oh
- Department of Microbiology and Immunology, Wonkwang University School of Medicine, Iksan, Chonbuk 570-749, South Korea
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28
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Hasegawa A, Cheng X, Kajino K, Berezov A, Murata K, Nakayama T, Yagita H, Murali R, Greene MI. Fas-disabling small exocyclic peptide mimetics limit apoptosis by an unexpected mechanism. Proc Natl Acad Sci U S A 2004; 101:6599-604. [PMID: 15084739 PMCID: PMC404091 DOI: 10.1073/pnas.0401597101] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Fas ligand- (FasL) mediated apoptosis is an important element of tissue-specific organ damage. We have developed biologically active small exocyclic peptide mimetics that disable apoptotic functions of Fas. The most effective mimetic binds to both its receptor and FasL with comparable affinity. In vitro, the most effective antagonist blocked FasL-induced cytotoxicity completely and specifically. In vivo, the antagonistic mimetic also prevented Concanavilin A (Con A) induced hepatitis, a CD4(+) T cell-mediated animal model of liver injury. Although current approaches prevent Fas receptor signaling by excluding FasL binding to Fas, the small molecule mimetics reported here disable Fas by promoting a defective Fas-FasL receptor complex. This event desensitizes FasL-mediated apoptosis by inhibiting extracellular signal regulated kinase activity and up-regulating NF-kappaB.
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Affiliation(s)
- Akihiro Hasegawa
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, 252 John Morgan Building, 36th and Hamilton Walk, Philadelphia, PA 19104-6082, USA
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29
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Zhang L, Pelech S, Uitto VJ. Bacterial GroEL-like heat shock protein 60 protects epithelial cells from stress-induced death through activation of ERK and inhibition of caspase 3. Exp Cell Res 2004; 292:231-40. [PMID: 14720522 DOI: 10.1016/j.yexcr.2003.08.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bacterial heat shock proteins (hsps) can have various effects on human cells. We investigated whether bacterial hsp60s can protect epithelial cells from cell death by affecting the mitogen-activated protein kinase (MAPK) signal pathways. Cell protection was studied by adding bacterial hsp60s to skin keratinocyte cultures (HaCaT cell line) before UV radiation. The results show that hsp60 significantly protected against UV radiation-induced cell death. Effects of UV radiation and exogenous hsp60 on phosphorylation of MAPKs and on activation of caspase 3 were examined by Western blot analysis. UV radiation strongly induced phosphorylation of p38 MAPK and formation of active caspase 3. A p38 inhibitor, SB 203580, totally blocked UV radiation-mediated activation of caspase 3. Preincubation with hsp60 strongly induced phosphorylation of ERK1/2 and inhibited UV radiation-mediated activation of caspase 3. PD 98059, a specific inhibitor of the ERK1/2 pathway, blocked this inhibitory effect of exogenous hsp60. Studies on the association between activity of MAPKs or caspase 3 and cell death showed that the ERK1/2 pathway inhibitor reversed protective effect of hsp60 while specific inhibition of p38 and caspase 3 reduced cell death. These results indicate that in HaCaT cells UV radiation mediates cell death through activation of p38 followed by caspase 3 activation. Exogenous hsp60 partially protects against UV radiation-mediated epithelial cell death through activation of ERK1/2, which inhibits caspase 3 activation.
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Affiliation(s)
- Liangxuan Zhang
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, British Columbia, Vancouver, Canada V6T 1Z3
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30
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Solhaug A, Refsnes M, Holme JA. Role of cell signalling involved in induction of apoptosis by benzo[a]pyrene and cyclopenta[c,d]pyrene in Hepa1c1c7 cells. J Cell Biochem 2004; 93:1143-54. [PMID: 15449320 DOI: 10.1002/jcb.20251] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The reactive metabolites of benzo[a]pyrene (B[a]P) and cyclopenta[c,d]pyrene (CPP) induced an accumulation/phosphorylation of p53 in Hepa1c1c7 cells, whereas inhibition of p53 reduced the apoptosis. Judged by the inhibiting effect of wortmannin, phosphatidyl-inositol-3 (PI-3) kinases such as DNA-dependent protein kinase (DNA-PK), ATM (ataxia-telangiectasia mutated), and/or ATR (ATM related kinase), appeared to be involved in the DNA damage recognition and the B[a]P-/CPP-induced accumulation of p53. B[a]P and CPP also induced phosphorylation of jun-N-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). While inhibition of JNK had no effects on the B[a]P-/CPP-induced apoptosis, inhibition of p38 MAPK activity reduced this effect. Interestingly, survival signals such as phosphorylation of Akt and Bad seemed to be induced by the B[a]P-/CPP-compounds. Furthermore, also extracellular signal-regulated kinase (ERK)1/2 was activated and seemed to function as a survival signal in B[a]P-/CPP-induced apoptosis.
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Affiliation(s)
- Anita Solhaug
- Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo, Norway
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31
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Abstract
During the process of oncogenic transformation, melanoma cells escape from normal growth-control mechanisms and acquire the ability to invade surrounding tissues and organs. The Ras/Raf/MEK/ERK pathway is a major pathway involved in the control of growth signals, cell survival and invasion. Melanomas are known to harbour activating mutations of both Ras and BRAF, suggesting that the downstream effector ERK may be playing a major role in the oncogenic behaviour of these tumours. The past few years have seen a growth in the understanding of the role of ERK and the MAP kinase pathway in melanoma. The aim of the current review is to assess the role of ERK in melanoma behaviour and to determine whether modulation of these kinases could offer new therapeutic opportunities.
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Affiliation(s)
- Keiran S M Smalley
- Section of Medicine, Institute of Cancer Research, London, United Kingdom.
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32
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Affiliation(s)
- Mireia Gómez-Angelats
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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33
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Abstract
Fas (Apo-1, CD95) and Fas-Ligand (FasL, CD95L) are typical members of the TNF receptor and TNF ligand family, respectively, with a pivotal role in the regulation of apoptotic processes, including activation-induced cell death, T-cell-induced cytotoxicity, immune privilege and tumor surveillance. Impairment of the FasL/Fas system has been implicated in liver failure, autoimmune diseases and immune deficiency. Thus, the FasL/Fas system was mainly appreciated with respect to its death-inducing capabilities. However, there is increasing evidence that activation of Fas can also result in non-apoptotic responses like cell proliferation or NF-kappaB activation. While the apoptotic features of the FasL/Fas system and the pathways involved are comparably well investigated, the pathways that are utilized by Fas to transduce proliferative and activating signals are poorly understood. This review is focused on the non-apoptotic functions of the FasL/Fas system. In particular, the similarities and differences of the molecular mechanisms of apoptotic and non-apoptotic Fas signaling are addressed.
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Affiliation(s)
- Harald Wajant
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, Germany.
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34
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Desbarats J, Birge RB, Mimouni-Rongy M, Weinstein DE, Palerme JS, Newell MK. Fas engagement induces neurite growth through ERK activation and p35 upregulation. Nat Cell Biol 2003; 5:118-25. [PMID: 12545171 DOI: 10.1038/ncb916] [Citation(s) in RCA: 233] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2002] [Revised: 11/14/2002] [Accepted: 12/09/2002] [Indexed: 11/09/2022]
Abstract
Fas (also known as CD95), a member of the tumour-necrosis receptor factor family of 'death receptors', can induce apoptosis or, conversely, can deliver growth stimulatory signals. Here we report that crosslinking Fas on primary sensory neurons induces neurite growth through sustained activation of the extracellular-signal regulated kinase (ERK) pathway and the consequent upregulation of p35, a mediator of neurite outgrowth. In addition, functional recovery after sciatic nerve injury is delayed in Fas-deficient lpr mice and accelerated by local administration of antibodies against Fas, which indicates that Fas engagement may contribute to nerve regeneration in vivo. Our findings define a role for Fas as an inducer of both neurite growth in vitro and accelerated recovery after nerve injury in vivo.
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Affiliation(s)
- Julie Desbarats
- Department of Physiology, McGill University, Montréal, Quebec, Canada, H3G 1Y6.
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35
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Ramachandiran S, Huang Q, Dong J, Lau SS, Monks TJ. Mitogen-activated protein kinases contribute to reactive oxygen species-induced cell death in renal proximal tubule epithelial cells. Chem Res Toxicol 2002; 15:1635-42. [PMID: 12482247 DOI: 10.1021/tx0200663] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal kinases (JNK/SAPK), and p38 mitogen-activated protein kinase (MAPK) were all rapidly activated in a ROS-dependent manner during 2,3,5-tris-(glutathion-S-yl)hydroquinone (TGHQ)-mediated oxidative stress and oncotic cell death in renal proximal tubule epithelial cells (LLC-PK1). TGHQ-induced phosphorylation of ERK1/2 and JNK MAPKs required epidermal growth factor receptor (EGFR) activation, whereas p38 MAPK activation was EGFR independent. In contrast to their established roles in cell survival, TGHQ-activated ERK1/2 and p38 MAPK (but not JNK) appear to contribute to cell death, since inhibition of ERK1/2 or p38 MAPKs with PD098059 or SB202190 respectively, attenuated TGHQ-mediated cell death. TGHQ increased AP-1 and NFkappaB DNA-binding activity, but whereas pharmacological inhibition of ERK1/2 or p38 MAPKs attenuated AP-1 DNA binding activity, it potentiated TGHQ-mediated NFkappaB activation. Consistent with a role for NFkappaB activation in the cytoprotective response to ROS in renal epithelial cells, an anti-NFkappaB peptide SN50 suppressed the protective effects of ERK inhibition (PD098059 treatment). The data provide evidence that the activation of MAPKs by ROS in renal epithelial cells plays an important role in oncotic cell death, and NF-kB is involved in the cytoprotective effects of PD098059.
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Affiliation(s)
- Sampath Ramachandiran
- Center for Molecular & Cellular Toxicology, Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, USA
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36
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Gouaze V, Andrieu-Abadie N, Cuvillier O, Malagarie-Cazenave S, Frisach MF, Mirault ME, Levade T. Glutathione peroxidase-1 protects from CD95-induced apoptosis. J Biol Chem 2002; 277:42867-74. [PMID: 12221075 DOI: 10.1074/jbc.m203067200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Through the induction of apoptosis, CD95 plays a crucial role in the immune response and the elimination of cancer cells. Ligation of CD95 receptor activates a complex signaling network that appears to implicate the generation of reactive oxygen species (ROS). This study investigated the place of ROS production in CD95-mediated apoptosis and the role of the antioxidant enzyme glutathione peroxidase-1 (GPx1). Anti-CD95 antibodies triggered an early generation of ROS in human breast cancer T47D cells that was blocked by overexpression of GPx1 and inhibition of initiator caspase activation. Enforced expression of GPx1 also resulted in inhibition of CD95-induced effector caspase activation, DNA fragmentation, and apoptotic cell death. Resistance to CD95-mediated apoptosis was not due to an increased expression of anti-apoptotic molecules and could be reversed by glutathione-depleting agents. In addition, whereas the anti-apoptotic protein Bcl-xL prevented CD95-induced apoptosis in MCF-7 cells, it did not inhibit the early ROS production. Moreover, Bcl-xL but not GPx1 overexpression could suppress the staurosporine-induced late generation of ROS and subsequent cell death. Altogether, these findings suggest that GPx1 functions upstream of the mitochondrial events to inhibit the early ROS production and apoptosis induced by CD95 ligation. Finally, transgenic mice overexpressing GPx1 were partially protected from the lethal effect of anti-CD95, underlying the importance of peroxide formation (and GPx1) in CD95-triggered apoptosis.
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Affiliation(s)
- Valerie Gouaze
- INSERM U466, Laboratoire de Biochimie Médicale, Centre Hospitalier Universitaire de Rangueil, Toulouse Cedex 9, France
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37
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Shonai T, Adachi M, Sakata K, Takekawa M, Endo T, Imai K, Hareyama M. MEK/ERK pathway protects ionizing radiation-induced loss of mitochondrial membrane potential and cell death in lymphocytic leukemia cells. Cell Death Differ 2002; 9:963-71. [PMID: 12181747 DOI: 10.1038/sj.cdd.4401050] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2001] [Revised: 02/28/2002] [Accepted: 03/05/2002] [Indexed: 11/09/2022] Open
Abstract
MEK/ERK-mediated signals have recently been found to inhibit Fas-mediated cell death through inhibition of caspase-8 activity. It remains unknown whether MEK/ERK-mediated signals affect ionizing radiation (IR)-induced cell death. Here we demonstrate that MEK/ERK-mediated signals selectively inhibit IR-induced loss of mitochondrial membrane potential (DeltaPsi(m)) and subsequent cell death. In Jurkat cells, TPA strongly activated ERK and inhibited the IR-induced caspase-8/Bid cleavage and the loss of DeltaPsi(m). The inhibitory effect of TPA was mostly abrogated by pretreatment of a specific MEK inhibitor PD98059, indicating that the effect depends upon MEK/ERK-mediated signals. Moreover, BAF-B03 transfectants expressing IL-2 receptor (IL-2R) beta(c) chain lacking the acidic region, which is responsible for MEK/ERK-mediated signals, revealed higher sensitivity to IR than the transfectants expressing wild-type IL-2R. Interestingly, the signals could neither protect the DeltaPsi(m) loss nor cell death in UV-irradiated cells. These data imply that the anti-apoptotic effect of MEK/ERK-mediated signals appears to selectively inhibit the IR-induced cell death through protection of the DeltaPsi(m) loss. Our data enlighten an anti-apoptotic function of MEK/ERK pathway against IR-induced apoptosis, thereby implying its contribution to radioresistance.
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Affiliation(s)
- T Shonai
- Department of Radiology, Sapporo Medical University School of Medicine, S-1, W-16, Chuo-ku, Sapporo, 060-8543, Japan
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38
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Pardo OE, Arcaro A, Salerno G, Raguz S, Downward J, Seckl MJ. Fibroblast growth factor-2 induces translational regulation of Bcl-XL and Bcl-2 via a MEK-dependent pathway: correlation with resistance to etoposide-induced apoptosis. J Biol Chem 2002; 277:12040-6. [PMID: 11815602 DOI: 10.1074/jbc.m109006200] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The involvement of fibroblast growth factor-2 (FGF-2) in the biology of small cell lung cancer (SCLC) has not previously been investigated. Here we report that FGF-2 prevented etoposide-induced apoptosis in H-510 SCLC cells. Phosphatidylinositol 3-kinase/protein kinase B signaling did not mediate this effect because FGF-2 failed to activate phosphatidylinositol 3-kinase or protein kinase B. In contrast, the mitogen-activated extracellularly regulated kinase kinase (MEK) was crucial for this response because its inhibition abolished the prosurvival properties of FGF-2. Moreover, in H-69 SCLC cells, the failure of FGF-2 to prevent etoposide-induced apoptosis correlated with uncoupling from MEK activation. However, the introduction of an activated MEK rendered these cells resistant to etoposide killing. Cell rescue relied on de novo protein synthesis, and the anti-apoptotic proteins Bcl-X(L) and Bcl-2 were up-regulated in a MEK-dependent fashion within 4 h of FGF-2 treatment. Contrary to previous reports, we found that this up-regulation occurred at the translational rather than the transcriptional level. Indeed, actinomycin D failed to prevent up-regulation of Bcl-X(L) and Bcl-2, and FGF-2 did not increase the mRNA levels or the stability of these proteins. The induction of the pro-apoptotic protein Bad by etoposide was also blocked by FGF-2 in a MEK-dependent fashion. Thus, MEK/extracellularly regulated kinase signaling is critical in the coordinate modulation of both pro- and anti-apoptotic Bcl-2 family members by FGF-2.
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Affiliation(s)
- Olivier E Pardo
- Cancer Research United Kingdom Lung Cancer Biology Group and the Medical Research Council Clinical Sciences Centre, Hammersmith Campus of Imperial College, Ducane Road, London W12 0NN, United Kingdom
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Frankel SK, Van Linden AA, Riches DW. Heterogeneity in the phosphorylation of human death receptors by p42(mapk/erk2). Biochem Biophys Res Commun 2001; 288:313-20. [PMID: 11606045 DOI: 10.1006/bbrc.2001.5761] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phosphorylation of murine CD120a by p42(mapk/erk2) has been shown to inhibit its ability to initiate apoptosis while preserving signaling events such as NF-kappaB activation. Therefore, we sought to determine if p42(mapk/erk2) was also capable of phosphorylating additional human death receptors within the TNF receptor superfamily. These studies showed that CD120a and DR3 are significantly phosphorylated by p42(mapk/erk2) but Fas, DR4 and DR5 are not. Additionally, we demonstrated that (i) the p42(mapk/erk2)-dependent phosphorylation of CD120a and DR3 occurred on Ser and Thr residues, (ii) p42(mapk/erk2) phosphorylated residues located in the membrane proximal regions but not the death domains of CD120a and DR3, (iii) Ser 253 is a preferred site of phosphorylation on CD120a, and (iv) the p42(mapk/erk2)-dependent phosphorylation of the DR3 cytoplasmic domain occurred exclusively at non-p42/44(mapk/erk2/1) consensus sites. These findings suggest that human death receptors segregate into two groups along lines of phylogeny with respect to Ser/Thr phosphorylation by p42(mapk/erk2).
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Affiliation(s)
- S K Frankel
- Program in Cell Biology, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206, USA
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40
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Tran SE, Holmstrom TH, Ahonen M, Kahari VM, Eriksson JE. MAPK/ERK overrides the apoptotic signaling from Fas, TNF, and TRAIL receptors. J Biol Chem 2001; 276:16484-90. [PMID: 11278665 DOI: 10.1074/jbc.m010384200] [Citation(s) in RCA: 249] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The tumor necrosis factor (TNF), Fas, and TNF-related apoptosis-inducing ligand (TRAIL) receptors (R) are highly specific physiological mediators of apoptotic signaling. We observed earlier that a number of FasR-insensitive cell lines could redirect the proapoptotic signal to an anti-apoptotic ERK1/2 signal resulting in inhibition of caspase activation. Here we determine that similar mechanisms are operational in regulating the apoptotic signaling of other death receptors. Activation of the FasR, TNF-R1, and TRAIL-R, respectively, rapidly induced subsequent ERK1/2 activation, an event independent from caspase activity. Whereas inhibition of the death receptor-mediated ERK1/2 activation was sufficient to sensitize the cells to apoptotic signaling from FasR and TRAIL-R, cells were still protected from apoptotic TNF-R1 signaling. The latter seemed to be due to the strong activation of the anti-apoptotic factor NF-kappaB, which remained inactive in FasR or TRAIL-R signaling. However, when the cells were sensitized with cycloheximide, which is sufficient to sensitize the cells also to apoptosis by TNF-R1 stimulation, we noticed that adenovirus-mediated expression of constitutively active MKK1 could rescue the cells from apoptosis induced by the respective receptors by preventing caspase-8 activation. Taken together, our results show that ERK1/2 has a dominant protecting effect over apoptotic signaling from the death receptors. This protection, which is independent of newly synthesized proteins, acts in all cases by suppressing activation of the caspase effector machinery.
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Affiliation(s)
- S E Tran
- Turku Centre for Biotechnology, POB 123, FIN-20521, University of Turku, Turku, Finland
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41
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Kang KW, Cho MK, Lee CH, Kim SG. Activation of phosphatidylinositol 3-kinase and Akt by tert-butylhydroquinone is responsible for antioxidant response element-mediated rGSTA2 induction in H4IIE cells. Mol Pharmacol 2001; 59:1147-56. [PMID: 11306698 DOI: 10.1124/mol.59.5.1147] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The protective adaptive response to electrophiles and reactive oxygen species is mediated by enhanced expression of phase II detoxifying genes, including glutathione S-transferases, through activation of antioxidant response element (ARE). The current study was designed to investigate the role of phosphatidylinositol 3-kinase (PI3-kinase)-Akt and mitogen-activated protein (MAP) kinase signaling pathways in the induction of rGSTA2 by tert-butylhydroquinone (t-BHQ). Nuclear ARE complex was activated 1 to 6 h after treatment of H4IIE cells with t-BHQ. The rGSTA2 mRNA level was elevated 6 to 24 h after t-BHQ treatment, which led to the enzyme induction. Activities of PI3-kinase and Akt were increased 10 min through 6 h after t-BHQ treatment, whereas wortmannin or LY294002, PI3-kinase inhibitors, completely abolished ARE binding activity and increases in rGSTA2 mRNA and protein. Extracellular signal-regulated kinase (ERK), p38 MAP kinase, and c-Jun N-terminal kinase (JNK) were all activated by t-BHQ. Treatment with PD98059, an ERK inhibitor, however, increased rGSTA2 mRNA and further enhanced t-BHQ-induced expression of rGSTA2. Neither SB203580 nor overexpression of JNK1 dominant negative mutant altered t-BHQ-inducible rGSTA2 expression. These results demonstrated that t-BHQ activated PI3-kinase and Akt, which was responsible for ARE-mediated rGSTA2 induction, and that ERK might negatively regulate rGSTA2 expression, whereas activation of p38 MAP kinase or of JNK by t-BHQ was not associated with the enzyme induction.
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Affiliation(s)
- K W Kang
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
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42
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Abstract
As animals respond to environmental stress with a set of default reactions described as the "fight-or-flight" response, so do epithelial and endothelial cells when they are confronting stressors in their microenvironment. This review will summarize a growing body of data suggesting the existence of a set of stereotypical cellular reactions to stress, provide some examples of diseases that are characterized by excessive flight reactions, describe the cellular mechanisms whereby the fight-or-flight reaction is accomplished, as well as cellular mechanisms triggering either fight or flight. It is proposed that cell-matrix adhesion is a sensitive indicator of the severity of stress. This indicator is interfaced with several default programs for cellular survival or death, thus dictating the fate of the cell. Some diagnostic and therapeutic applications of the concept, presently used and potentially useful, are outlined. The essential feature of this concept is its ability to categorize cellular events in terms of either type of default reaction, predict the details of each, and potentially exploit them clinically.
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Affiliation(s)
- M S Goligorsky
- Department of Medicine, State University of New York, Stony Brook, New York 11794-8152, USA.
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Mandic A, Viktorsson K, Heiden T, Hansson J, Shoshan MC. The MEK1 inhibitor PD98059 sensitizes C8161 melanoma cells to cisplatin-induced apoptosis. Melanoma Res 2001; 11:11-9. [PMID: 11254111 DOI: 10.1097/00008390-200102000-00002] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The regulation of apoptosis is believed to be dependent on the balance of the activities of different intracellular signalling systems. Activation of the SAPK/JNK pathway is implied in pro-apoptotic signalling, while activation of the MEK1/ERK pathway may have a viability-promoting effect. We show here that treatment with the MEK1 inhibitor PD98059 sensitizes the human melanoma cell line C8161 to cisplatin-induced apoptosis. In these cells, cisplatin at 40 microM did not elicit significant cell death, whereas massive cell death was seen when cells were pretreated for 20 h with 40 microM PD98059 before the addition of cisplatin. Concomitant addition of PD98059 and cisplatin did not have any sensitizing effect, and PD98059 on its own did not induce apoptosis. However, in three other human melanoma cell lines PD98059 did not potentiate cisplatin-induced apoptosis. Instead, in one of these cell lines (AA), PD98059 protected against cisplatin-induced cytotoxicity. We conclude that blocking of the MEK1/ERK pathway may, in some instances, potentiate the cytotoxic effect of cisplatin on human melanoma cell lines, whereas in other instances it may have a protective effect. Thus it cannot be regarded as a general approach to sensitizing melanoma cells to drug-induced apoptosis.
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Affiliation(s)
- A Mandic
- Radiumhemmet's Research Laboratory, Cancer Center Karolinska, Karolinska Institute and Hospital, Stockholm, Sweden
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44
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Abstract
The ageing immune system shows a gradual decline in responsiveness to antigens and tumours due to the emergence of immunosenescence. The main functions of T cells are activation, anergy and apoptosis and these are all affected during ageing. Apoptosis is vital in controlling cell numbers, deleting self-reactive T cells and maintaining immune surveillance. One of the principle instigators of death involves the CD95:CD95-ligand interaction and as T cells age both receptor and ligand levels increase. This view will describe the current knowledge of the apoptotic susceptibility of ageing T cells and evaluate the factors that may affect the apoptotic capability of immunosenescent T cells.
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Affiliation(s)
- J D McLeod
- Centre for Research in Biomedicine, Faculty of Applied Sciences, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK.
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45
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Iryo Y, Matsuoka M, Wispriyono B, Sugiura T, Igisu H. Involvement of the extracellular signal-regulated protein kinase (ERK) pathway in the induction of apoptosis by cadmium chloride in CCRF-CEM cells. Biochem Pharmacol 2000; 60:1875-82. [PMID: 11108803 DOI: 10.1016/s0006-2952(00)00510-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
When CCRF-CEM cells were incubated with 5-40 microM CdCl(2,) apoptosis was observed most clearly at 10 microM. Prior to the development of apoptosis, mitogen-activated protein kinases (MAPKs), i.e. extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK, were activated with different sensitivity to CdCl(2) exposure. ERK and p38 MAPK were phosphorylated with incubation of 1 microM CdCl(2,) but higher than 20 microM CdCl(2) was required for the clear phosphorylation of JNK. In the time-course study, ERK and p38 MAPK were phosphorylated earlier than JNK after CdCl(2) exposure. The in vitro activities of MAPKs also increased in response to CdCl(2) exposure. Pretreatment with an intracellular Ca(2+) chelator, 1, 2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl) ester (BAPTA/AM), suppressed almost completely CdCl(2)-induced phosphorylation of JNK and p38 MAPK, but not ERK phosphorylation, indicating that the activation of JNK and p38 MAPK depends on the intracellular Ca(2+) but that of ERK does not. On the other hand, treatment with a MAPK/ERK kinase (MEK) inhibitor, U0126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene ), suppressed CdCl(2)-induced ERK activation and the apoptosis as well. The inhibition of p38 MAPK activity with SB203580 (4-[4-fluorophenyl]-2-[4-methylsulfinylphenyl]-5-[4-pyridyl]1H- imidaz ole) did not protect cells from apoptosis. The present results showed that the activation of ERK, JNK, and p38 MAPK is differently regulated in CCRF-CEM cells exposed to CdCl(2,) and that the ERK pathway seems to be responsible for the induction of apoptosis by CdCl(2) exposure in this human T cell line.
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Affiliation(s)
- Y Iryo
- Environmental Toxicology, University of Occupational and Environmental Health, 807-8555, Kitakyushu, Japan
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Holmström TH, Schmitz I, Söderström TS, Poukkula M, Johnson VL, Chow SC, Krammer PH, Eriksson JE. MAPK/ERK signaling in activated T cells inhibits CD95/Fas-mediated apoptosis downstream of DISC assembly. EMBO J 2000; 19:5418-28. [PMID: 11032809 PMCID: PMC314013 DOI: 10.1093/emboj/19.20.5418] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
When T cells are activated, the expression of the CD95 ligand is elevated, with the purpose of inducing apoptosis in target cells and to later eliminate the activated T cells. We have shown previously that mitogen-activated protein kinase (MAPK or ERK) signaling suppresses CD95-mediated apoptosis in different cellular systems. In this study we examined whether MAPK signaling controls the persistence and CD95-mediated termination of an immune response in activated T cells. Our results show that activation of Jurkat T cells through the T cell receptor immediately suppresses CD95-mediated apoptosis, and that this suppression is mediated by MAPK activation. During the phase of elevated MAPK activity, the activation of caspase-8 and Bid is inhibited, whereas the assembly of a functional death-inducing signaling complex (DISC) is not affected. These results explain the resistance to CD95 responses observed during the early phase of T cell activation and suggest that MAPK-activation deflects DISC signaling from activating caspase-8 and Bid. The physiological relevance of the results was confirmed in activated primary peripheral T cells, in which inhibition of MAPK signaling markedly sensitized the cells to CD95-mediated apoptosis.
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Affiliation(s)
- T H Holmström
- Turku Centre for Biotechnology, University of Turku and Abo Akademi University, PO Box 123, FIN-20521 Turku, Finland
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Gibbons GH, Pollman MJ. Death receptors, intimal disease, and gene therapy: are therapies that modify cell fate moving too Fas? Circ Res 2000; 86:1009-12. [PMID: 10827127 DOI: 10.1161/01.res.86.10.1009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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48
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Du J, Suzuki H, Nagase F, Akhand AA, Yokoyama T, Miyata T, Kurokawa K, Nakashima I. Methylglyoxal induces apoptosis in Jurkat leukemia T cells by activating c-Jun N-terminal kinase. J Cell Biochem 2000; 77:333-44. [PMID: 10723098 DOI: 10.1002/(sici)1097-4644(20000501)77:2<333::aid-jcb15>3.0.co;2-q] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Methylglyoxal (MG) is a physiological metabolite, but it is known to be toxic, inducing stress in cells and causing apoptosis. This study examines molecular mechanisms in the MG-induced signal transduction leading to apoptosis, focusing particularly on the role of JNK activation. We first confirmed that MG caused apoptosis in Jurkat cells and that it was cell type dependent because it failed to induce apoptosis in MOLT-4, HeLa, or COS-7 cells. A caspase inhibitor, Z-DEVD-fmk, completely blocked MG-induced poly(ADP-ribose)polymerase (PARP) cleavage and apoptosis, showing the critical role of caspase activation. Inhibition of JNK activity by a JNK inhibitor, curcumin, remarkably reduced MG-induced caspase-3 activation, PARP cleavage, and apoptosis. Stable expression of the dominant negative mutant of JNK also protected cells against apoptosis notably, although not completely. Correspondingly, loss of the mitochondrial membrane potential induced by MG was decreased by the dominant negative JNK. These results confirmed a crucial role of JNK working upstream of caspases, as well as an involvement of JNK in affecting the mitochondrial membrane potential.
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Affiliation(s)
- J Du
- Department of Immunology, Nagoya University School of Medicine, Aichi 466-8550, Japan
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