Hierarchical involvement of Bak, VDAC1 and Bax in cisplatin-induced cell death Academic Article uri icon

Overview

MeSH Major

  • Apoptosis
  • Cisplatin
  • Signal Transduction
  • Voltage-Dependent Anion Channel 1
  • bcl-2 Homologous Antagonist-Killer Protein
  • bcl-2-Associated X Protein

abstract

  • Following the screening of a battery of distinct small-interfering RNAs that target various components of the apoptotic machinery, we found that knockdown of the voltage-dependent anion channel 1 (VDAC1) was particularly efficient in preventing cell death induced by cisplatin (CDDP) in non-small cell lung cancer cells. Both the downregulation of VDAC1 and its chemical inhibition with 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid reduced the apoptosis-associated modifications induced by CDDP, including mitochondrial transmembrane potential dissipation and plasma membrane permeabilization. VDAC1 inhibition strongly reduced the CDDP-induced conformational activation of Bax, yet had no discernible effect on the activation of Bak, suggesting that VDAC1 acts downstream of Bak and upstream of Bax. Accordingly, knockdown of Bak abolished the activation of Bax, whereas Bax downregulation had no effect on Bak activation. In VDAC1-depleted cells, the failure of CDDP to activate Bax could be reversed by means of the Bcl-2/Bcl-X(L) antagonist ABT-737, which concomitantly restored CDDP cytotoxicity. Altogether, these results delineate a novel pathway for the induction of mitochondrial membrane permeabilization (MMP) in the course of CDDP-induced cell death that involves a hierarchical contribution of Bak, VDAC1 and Bax. Moreover, our data suggest that VDAC1 may act as a facultative regulator/effector of MMP, depending on the initial cytotoxic event.

publication date

  • July 10, 2008

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1038/onc.2008.63

PubMed ID

  • 18362892

Additional Document Info

start page

  • 4221

end page

  • 32

volume

  • 27

number

  • 30