Requirement for ERK activation in cisplatin-induced apoptosis.
Cisplatin activates multiple signal transduction pathways involved in coordinating cellular responses to stress. Here we demonstrate a requirement for extracellular signal-regulated protein kinase (ERK), a member of the mitogen-activated protein kinase family in mediating cisplatin-induced apoptosis of human cervical carcinoma HeLa cells. Cisplatin treatment resulted in dose- and time- dependent activation of ERK. That elevated ERK activity contributed to cell death by cisplatin was supported by several observations: 1) PD98059 and U0126, chemical inhibitors of the MEK/ERK signaling pathway, prevented apoptosis; 2) pretreatment of cells with TPA, an activator of the ERK pathway, enhanced their sensitivity to cisplatin; 3) suramin, a growth factor receptor antagonist that greatly suppressed ERK activation, likewise inhibited cisplatin-induced apoptosis; and, finally, 4) HeLa cell variants selected for cisplatin resistance showed reduced activation of ERK following cisplatin treatment. Cisplatin-induced apoptosis was associated with cytochrome c release and subsequent caspase-3 activation, both of which could be prevented by treatment with the MEK inhibitors. However, the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone protected HeLa cells against apoptosis without affecting ERK activation. Taken together, our findings suggest that ERK activation plays an active role in mediating cisplatin-induced apoptosis of HeLa cells and functions upstream of caspase activation to initiate the apoptotic signal.
Wang
X
X
Cell Stress and Aging Section, Laboratory of Biological Chemistry, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224-6825, USA.
Martindale
J L
JL
Holbrook
N J
NJ
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002070:Butadienes / Q000494:pharmacology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008954:Models, Biological; D009570:Nitriles / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D015398:Signal Transduction; D013498:Suramin / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors
D000590:Amino Acid Chloromethyl Ketones; D000970:Antineoplastic Agents; D002070:Butadienes; D015853:Cysteine Proteinase Inhibitors; D003574:Cytochrome c Group; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007211:Indoles; D009570:Nitriles; C113580:U 0126; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C007293:DAPI; D013498:Suramin; C482128:MAP2K2 protein, human; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D013755:Tetradecanoylphorbol Acetate; D002945:Cisplatin; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one