Abstract:ObjectiveTo construct the inhibitor of the shRNA of apoptosis protein (human inhibitor of apoptosis protein2，hIAP-2) for combination of inhibition hIAP-2 gene with radiotherapy, and to investigate its effect on the radiosensitivity of CNE1 nasopharyngeal carcinoma cell line.MethodsMTT assay was used for determing the optimal dose of radiation. Four hIAP2shRNA silencing fragments were built and CNE1 cells were transfected by liposome. The best silencing shRNA sequences were screened with realtime quantitative PCR (QPCR) and Western blot (WB). CNE1 cells were transfected with the best silencing shRNA sequences and divided into transfected irradiated group and nontransfected irradiated group. In both groups, expression of hIAP2 gene and protein was detected by realtime QPCR and WB, apoptosis by flow cytometry, and cell invasion by transwell.ResultsMTT assay demonstrated 4 Gy as the optimal radiation dose. The results of QPCR and WB test showed that four hIAP2shRNA could effectively inhibit the expression of hIAP2 mRNA and protein (P<0.05), and hIAP2shRNA2 had the most significant silencing effect (P<0.05).The results also showed statistically significant differences of hIAP2 gene and protein expression between the transfected group and the untransfected group (P<0.05). Flow cytometry showed statistically significant difference of the apoptosis rate between the transfected group and untransfected group (P<0.05). Meanwhile, transwell test showed statistically significant difference of the invasion ability between the two groups (P<0.05).ConclusionsTransfection of silenced hIAP-2 gene can increase nasopharyngeal carcinoma cell apoptosis rate and reduce its invasion, which may play a role in radiosensitization.