In this study, we show that exposure of human
lung cancer A549 cells to
cisplatin (
cis-diamminedichloroplatinum, CDDP) promotes production of
nitric oxide (NO) through generation of
reactive oxygen species (ROS) and resulting upregulation of inducible
NO synthase (iNOS). The incubation of the cells with a NO donor,
diethylenetriamine NONOate, not only reduced the CDDP-induced cell death and apoptotic alterations (induction of
CCAAT-enhancer-binding protein homologous
protein and
caspase-3 activation), but also elevated proteolytic activity of
26S proteasome, suggesting that the activation of
proteasome function contributes to the reduction of CDDP sensitivity by NO. Monitoring expression levels of six
aldo-keto reductases (AKRs) (1A1, 1B1, 1B10, 1C1, 1C2, and 1C3) during the treatment with the NO donor and subsequent CDDP sensitivity test using the specific inhibitors also proposed that upregulation of AKR1B10 by NO is a key process for acquiring the CDDP resistance in A549 cells. Treatment with CDDP and NO increased amounts of
nitrotyrosine protein adducts, indicative of
peroxynitrite formation, and promoted the induction of AKR1B10, inferring a relationship between
peroxynitrite formation and the
enzyme upregulation in the cells. The treatment with CDDP or a ROS-related
lipid aldehyde,
4-hydroxy-2-nonenal, facilitated the iNOS upregulation, which was restored by increasing the AKR1B10 expression. In contrast, the facilitation of NO production by CDDP treatment was hardly observed in AKR1B10-overexpressing A549 cells and established CDDP-resistant
cancer cells (A549, LoVo, and PC3). Collectively, these results suggest the NO functions as a key regulator controlling AKR1B10 expression and
26S proteasome function leading to gain of the CDDP resistance.