title: Bcl-2 blocks cisplatin-induced apoptosis by suppression of ERK-mediated p53 accumulation in B104 cells.
abstract: Bcl-2 has been reported to inhibit neurotoxicity induced by cisplatin. However, neither the mechanism of cisplatin-induced neurotoxicity nor the mechanism by which Bcl-2 confers neuroprotection is clear. In this study, the signaling pathways involved in cisplatin-induced neurotoxicity were examined using a rat neuroblastoma cell line, B104. Treatment of B104 cells with cisplatin induced apoptosis, accompanying the accumulation of p53 and Bax protein. Interestingly, extracellular signal-regulated kinase 1/2 (ERK1/2) activities of MAP kinases were markedly enhanced prior to cisplatin-induced accumulation of p53 and Bax. Inhibition of ERK1/2 activities using PD98059, a selective MEK inhibitor, blocked the apoptotic cell death preventing cisplatin-induced accumulation of p53 and Bax. These results suggest that ERK mediates cisplatin-induced p53 activation to trigger apoptosis in B104 cells. Overexpression of Bcl-2 in B104 cells resulted in the complete resistance to cisplatin-induced apoptosis blocking ERK activation and the subsequent signaling pathway of p53. Our study clearly demonstrates that the action site of Bcl-2 localizes upstream of ERK in cisplatin-induced apoptotic signaling pathway.
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: S A
authors.initials: SA
authors.lastname: Park
authors.forename: H J
authors.initials: HJ
authors.lastname: Park
authors.forename: B I
authors.initials: BI
authors.lastname: Lee
authors.forename: Y H
authors.initials: YH
authors.lastname: Ahn
authors.forename: S U
authors.initials: SU
authors.lastname: Kim
authors.forename: K S
authors.initials: KS
authors.lastname: Choi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002945:Cisplatin / Q000494:pharmacology; D015870:Gene Expression / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009447:Neuroblastoma; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D051381:Rats; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D051028:bcl-2-Associated X Protein
chemical_list: D000970:Antineoplastic Agents; C494828:Bax protein, rat; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D020928:Mitogen-Activated Protein Kinases; D002945:Cisplatin