Phenethyl isothiocyanate-induced apoptosis in p53-deficient PC-3 human prostate cancer cell line is mediated by extracellular signal-regulated kinases.
Previous studies have suggested that p53 is required for apoptosis induction by phenethyl isothiocyanate (PEITC), which is a highly promising cancer chemopreventive agent. Here, we report that p53 is not required for PEITC-induced apoptosis in the PC-3 human prostate cancer cell line and that the PEITC-induced apoptosis is mediated by extracellular signal-regulated kinases (ERK1/2). Exposure of PC-3 cells to an apoptosis-inducing concentration of PEITC (10 microM) resulted in a rapid and sustained activation of ERK1/2 that was evident as early as 1 h after PEITC treatment and persisted for the duration of the experiment (24-h after PEITC exposure). The PEITC-mediated activation of ERK1/2 was associated with an increase in phosphorylation of its substrate Elk-1 at Ser383. The PEITC-induced activation of ERK1/2 as well as apoptosis was abolished in the presence of mitogen-activated protein/ERK kinase 1 (a kinase upstream of ERK1/2) inhibitor PD98059. Exposure of PC-3 cells to 10 microM PEITC also resulted in a time-dependent activation of p38 protein kinase that was associated with increased phosphorylation of activating transcription factor 2 at Thr71. Even though the PEITC-induced activation of p38 protein kinase was abrogated in the presence of its specific inhibitor SB202190, inhibition of p38 protein kinase activation did not prevent PEITC-induced apoptosis. In contrast to previous reports in other cellular systems, c-Jun NH(2)-terminal kinases were not activated by PEITC treatment in PC-3 human prostate carcinoma cell line. In conclusion, the results of the present study indicate that p53 is not essential for PEITC-induced apoptosis and that the PEITC-induced apoptosis in PC-3 human prostate carcinoma cell line is mediated by ERKs. Thus, it seems reasonable to postulate that PEITC may be effective against tumors with normal as well as mutant p53.
Xiao
Dong
D
Department of Pharmacology and the University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
Singh
Shivendra V
SV
D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D004789:Enzyme Activation; D006801:Humans; D017879:Isothiocyanates / Q000494:pharmacology*; D048369:MAP Kinase Kinase 1; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency*; D048051:p38 Mitogen-Activated Protein Kinases
D016588:Anticarcinogenic Agents; D017879:Isothiocyanates; D016159:Tumor Suppressor Protein p53; C058305:phenethyl isothiocyanate; D017346:Protein Serine-Threonine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases