Rac1 prevents cisplatin‐induced apoptosis through down‐regulation of p38 activation in NIH3T3 cells

In this study, the role of V12‐Rac1 in the cisplatin‐induced apoptosis was investigated. Cisplatin‐induced apoptosis is associated with cytochrome c release, which can be inhibited by V12‐Rac1 expression. The analysis of mitogen‐activated protein kinase activity indicated that V12‐Rac1 expression led to a decrease in p38 activity after exposure to cisplatin but not c‐jun N‐terminal kinase and extracellular signal‐regulated kinase. Using pharmacological inhibitors, it was found that only p38 is a critical mediator in the cisplatin‐induced apoptosis of NIH3T3 cells. This suggests that V12‐Rac1 can stimulate the anti‐apoptotic signaling pathway in response to cisplatin, and that decreased p38 activity caused by V12‐Rac1 expression in cisplatin‐treated NIH3T3 cells is crucial for V12‐Rac1‐dependent cell survival.