OBJECTIVETo explore the effect of c-FLIP expression on drug resistance of Kasumi-1 leukemia cells and its mechanisms.

METHODSTet-on inducible system was used to construct the conditional expression vector of c-FLIP by cloning the c-FLIP gene into lentivirus vector pLVX-Tight-Puro, then the Kasumi-1 cells were transfected with lentivirus pLVX-Tight-Puro-c-FLIP. The expression of c-FLIP was induced by doxycycline(Dox) for different time and doses, and verified by qRT-PCR and Western blot. On the basis of the overexpression of c-FLIP, the Kasumi-1-c-FLIP cells were treated with CH11 and PB in order to induce apoptosis, and the Giemsa staining was used to show the apoptotic cell morphology.

RESULTSqRT-PCR and Western blot showed the overexpression of c-FLIP, the CH11 and PB can induce Kasumi-1 cell apoptosis, while the c-FLIP overexpression weakened this effects. Western blot showed that the c-FLIP blocked the caspase-8 activation.

CONCLUSIONThe overexpression of c-FLIP inhibits the apoptosis caused by CH11 and PB, and leads to drug resistance in leukemia cells.