Cooking oil fumes improve lung adenocarcinoma cell survival through c-IAP2 induction

Cooking oil fumes (COF) exposure was demonstrated to be associated with lung cancer development in Taiwanese nonsmoking women. Previous studies identified Cox-2 overexpression and oxidative DNA damage in lung adenocarcinoma cells after exposure to COF. Involvement of COF in lung tumorigenesis may be associated with cell survival, as well as proliferation of lung adenocarcinoma. To test this hypothesis, A549, a lung adenocarcinoma cell line, was used, and MTT assay data showed that the cell viability of A549 was significantly increased in a concentration-dependent manner by COF treatment for 48 h. Flow cytometery results indicated that the proportion of A549 cell at S-phase was markedly increased after exposure of COF. To elucidate whether the anti-apoptotic c-IAP2 (IAP2) was involved in COF-improved cell survival, IAP2 protein levels was determined by Western blot, and the results showed it was significantly induced by COF in a concentration-dependent manner. Moreover, the suppression of BAY, a nuclear factor (NF)-kappaB binding inhibitor, or the COF-induced IAP2 protein levels indicated that NF-kappaB activation by COF may partly be involved in IAP2 induction. These results showed that the positive impact of COF on cell survival and proliferation of A549 lung tumor cells may be through an induction of IAP2 overexpression.