Abstract:

Objective To investigate the effect of miR-6732-3p expression on the radio-sensitivity of human nasopharyngeal carcinoma CNE-2R cells. Methods The expression of miR-6732-3p in CNE-2 and CNE-2R cell lines was detected by RT-qPCR. After transfection of CNE-2R cells with miR-6732-3p lentivirus，CNE-2R cells were divided into CNE-2R（normal control group）， miR-6732-3p NC （transfection control group），and miR-6732-3p inhibition（transfection group）. The expression of miR- 6732-3p in each group was detected by RT-qPCR. The proliferation ability，apoptosis ability and radio-sensitivity of cells before and after transfection were detected by CCK-8 assay，flow cytometry and cloning formation assay，respectively. Results The RT-qPCR showed that the expression level of miR-6732-3p in CNE-2R cells was significantly higher than that of CNE-2 cells（P=0.036）. After transfection of CNE-2R cells with lentivirus，the expression level of miR-6732-3p in the transfection group was lower than those in the transfection control group and the normal control group（P＜0.05）. CCK-8 assay results showed that compared with the two control groups，the cell growth of the transfection group was inhibited （P ＜0.001）；the survival fraction （SF） of the transfection group was significantly reduced under different irradiation doses（P＜0.001）. The flow cytometry detection results showed that the apoptotic rate of transfection group after non-irradiation（0 Gy） and 8 Gy irradiation was significantly increased than that of the transfection control group and the normal control group（P＜0.05）. The cloning formation assay indicated that the radiobiological parameters D0，Dq and SF2 in the transfection group were lower than those of the two control groups（P<0.05）；the SF of the transfection group was also lower than the two control groups under different irradiation doses（P＜0.001）. Conclusions Silencing miR-6732-3p expression can significantly improve the radio-sensitivity of nasopharyngeal carcinoma CNE-2R cells，providing a new idea for molecular targeted therapy of radio-resistance in nasopharyngeal carcinoma.

Key words: Nasopharyngeal carcinoma, Radio-sensitivity, miR-6732-3p