Inducing apoptosis of human nasopharyngeal carcinoma cell line CNE-2Z by bcl-xL short hairpin RNA.

BACKGROUND & OBJECTIVE: Recent studies showed overexpression of bcl-x(L) in human nasopharyngeal carcinoma (NPC) cell line CNE-2Z; it may play a pivotal role in tumorigenesis, metastasis, and drug resistance of NPC. This study was to explore inducing effect of bcl-x(L) short hairpin RNA (shRNA) on apoptosis of CNE-2Z cells. METHODS: After transfection of recombinant plasmid pmU6-RNAi expressing bcl-x(L) shRNA, apoptotic CNE-2Z cells were detected by fluorescent staining and flow cytometry (FCM). mRNA levels of bcl-x(L), bcl-2, survivin, and caspase-3 was detected by reverse transcription-polymerase chain reaction (RT-PCR); while protein levels of Bcl-x(L), Caspase-3, and P53 were detected by Western blot. RESULTS: When treated with pmU6-RNAi for 24 h, an obvious apoptotic peak of CNE-2Z cells appeared; cell shrinkage, chromatin condensation, and nuclear fragmentation were observed in most cells under fluorescent microscope. RT-PCR analysis showed that pmU6-RNAi down-regulated mRNA levels of bcl-x(L), bcl-2, and caspase-3, but had little or no effect on mRNA level of survivin; Western blot analysis showed an obvious reduction in protein levels of Bcl-x(L) and Caspase-3, and a great increase in protein level of P53. CONCLUSIONS: bcl-x(L) shRNA can induce apoptosis of CNE-2Z cells, which may be closely related to down-regulation of bcl-2, caspase-3 and p53. bcl-x(L) shRNA may be helpful for developing gene therapy for NPC.