Increased expression of peroxiredoxin II confers resistance to cisplatin

Peroxiredoxin II (Pm II) has been known to be induced by various oxidative stimuli and to play an important protective role from oxidative damage by h ydrogen peroxide (H2O2) In this study, we observed that cisplatin as well a s H2O2 induced Pm II expression. To examine the correlation between the inc reased expression of Pm II and chemoresistance, we prepared a Pix II-overex pressing cell line, SNU638 cells, and found it to be more resistant to cell death induced by cisplatin and H2O2 than neo(r)-transfectant cells. We als o observed that enhanced expression of pm II inhibited cisplatin- and H2O2- induced apoptosis, demonstrating that resistance to these cytotoxic agents was due to inhibition of apoptosis. The above results led us to suggest tha t the overexpressed Pix II protein inhibits cisplatin-induced apoptosis, th ereby contributing to chemoresistance of tumor cells, especially to oxidati ve stress producing anticancer drugs.