Abstract: Objective To explore the effect of miRNA-210 down-regulation on radiosensitivity of radiation-resistant nasopharyngeal carcinoma cells. Methods The radiation-resistant nasopharyngeal carcinoma cells(CNE-2R) were established by dose gradient method. The miRNA microarray was used for detecting miRNA expression profiles of the CNE-2 cells and CNE-2R cells, and miR-210 was verified by qPCR. After LV-hsa-miR-210-inhibition were infected CNE-2R cells, the miR-210 in 210-inhibition cells were verified by qPCR. Apoptosis and cell cycle of 210-inhibition and CNE-2R cells were detected by flow cytometry, the survival fraction of cells were detected by clone formation assay. Results There were 93 miRNAs expression remarkable changed over>2 fold in CNE-2R cell lines which we established, compared with CNE-2. 210-inhibition, which expressing a low level of miR-210 had a higher apoptosis rate than CNE-2R cells(P<0.05). The proportion of 210-inhibition cells in the G2/M phase were more than in the CNE-2R cells(P<0.05), and the S phase of they were less than in the CNE-2R cells(P<0.05). The survival fractions of 210-inhibition cells significantly reduced, compared with CNE-2R cells. Conclusions Down-regulation of microRNA-210 can enhance radiosensitivity in radiation-resistant nasopharyngeal carcinoma cells, which may be used as a new target for the treatment of radiation resistance.

Key words: nasopharyngeal carcinoma, microRNA-210, radiation resistance