Changes of radiosensitivity of cervical cancer cell line Siha transfected with miR-124 mimics

WANG Mengjie; MENG Bi; LI Hao; GAO Fei; YE Ting; LIU Yangchen

doi:10.3969/j.issn.1002-266X.2017.35.003

Abstract：Objective To observe the effect of microRNA124 (miR-124)overexpression on the radiosensitivity of cervical cancer Siha cells and its mechanism. Methods The cervical cancer Siha cells were divided into the observation group and control group. The miR-124 mimics were transfected into the observation group. The expression levels of miR-124 and signal transducer and activator of transcription 3 (STAT3)in the two groups were detected by real-time fluorescent quantitative PCR. Colony formation assay was used to detect the radiosensitivity of the two groups cells. Clone formation as-say was used to detect the cell radiosensitivity. Flow cytometry was used to detect the cell cycle distritution and apoptosis rate after radiation. Results The observation group and the control group had the D0 parameters of 1. 062 Gy and 1. 542 Gy,the Dq parameters of 1. 605Gy and 1. 970Gy,the SF2 parameters of 0. 527 and 0. 685,respectively. Compared with the control group,the radiation sensitization enhancement ratio (SER)was 1. 451. At 24 h after transfection,the relative expression levels of miR-124 in the observation group and the control group were 89. 3 ± 13. 6 and 1. 0 ± 0. 1,respectively, and the relative expression levels of STAT3 mRNA were 0. 3 ± 0. 03 and 1. 0 ± 0. 1,respectively;significant difference was found between these two groups (all P < 0. 05). In the observation group,the percentage of cells in G 0 / G1 phase was 82. 49% ± 1. 97%,was 11. 87% ± 1. 38% in S phase,and 5. 64% ± 0. 72% in G 2 / M phase;meanwhile,they were 74. 58% ± 1. 28%,19. 88% ± 0. 26%,5. 54% ± 1. 05%,respectively,in the control group. Compared with the control group,the percentage of cells in G 0 / G1 phase was higher,while the percentage of cells in S phase was lower,and signifi-cant difference was found between these two groups (all P < 0. 05). Compared with the control group,the percentage of cells in G2 / M phase was not significantly different (P > 0. 05). The apoptosis rates after X-irradiation were 45. 87% ± 3. 16% in observation group,versus 37. 27% ± 0. 87% in the control group,and significant difference was found between these two groups (P < 0. 05). Conclusions Overexpression of miR-124 may enhance radiosensitivity of cervical cancer Si-ha cells. The mechanism may be that overexpression of miR-124 can inhibit the expression of STAT3 in cervical cancer Siha cells,and then induce the cell cycle arrest in G 0 / G1 phase,promote the apoptosis,and thereby enhance the radiosensitivity of cervical cancer Siha cells.