MiR-375-3p enhanced radiosensitivity of colorectal cancer cells by inhibiting homologous recombination repair of DSBs
10.3760/cma.j.cn112271-20211027-00425
- VernacularTitle:miR-375-3p抑制DNA双链断裂的同源重组修复增强结直肠癌细胞放射敏感性的研究
- Author:
Changyong LI
1
;
Meng JIA
;
Qi WANG
;
Linjun YAN
;
Zhidong WANG
;
Zhenhua QI
Author Information
1. 军事科学院军事医学研究院辐射医学研究所 北京市放射生物学重点实验室，北京 100850
- Keywords:
Colorectal cancer;
miR-375-3p;
Homologous recombination repair;
RAD51;
Radiosensitivity
- From:
Chinese Journal of Radiological Medicine and Protection
2022;42(3):168-174
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effect of miR-375-3p on DNA damage repair and radioresistance of colorectal cancer cells.Methods:After overexpression of miR-375-3p in HCT116 and HT29, cell proliferation ability was detected by CCK-8 assay, clone formation ability was detected by clone formation assay, apoptosis was detected by Annexin V-FITC/PI double staining method and cell cycle distribution was detected by flow cytometry, and the formation of γ-H2AX foci were used to analyze homologous recombination (HR) repair efficiency. Bioinformatics was used to predict the downstream target genes of miR-375-3p in the HR repair pathway. A dual luciferase reporter gene assay was used to validate the regulation effect of miR-375-3p on Rad51 gene. The expression of miR-375-3p in HCT116 cells irradiated with 60Co γ-rays at 2 and 6 Gy was measured by RT-qPCR. The inhibition effect of miR-375-3p on the radiosensitivity of HCT116 cells was analyzed after irradiation with different doses of 0, 1, 2, 4 and 6 Gy. Results:Overexpression of miR-375-3p inhibited the proliferation and colony formation ability, induced G1 phase cycle arrest and cell apoptosis of colorectal cancer cells, enhanced DSBs formation, inhibited Rad51 expression, and significantly decreased HR repair efficiency ( t = 10.055, P < 0.05). Dual luciferase reporter gene assay demonstrated that miR-375-3p bound to Rad51 3′UTR region ( t = 5.013, P< 0.05). In addition, irradiation increased miR-375-3p expression, and inhibition of miR-375-3p expression reduced radiosensitivity of colorectal cancer cells ( t=6.460, 5.619, 10.150, P<0.05). Conclusions:miR-375-3p inhibited the homologous recombination repair efficiency of DSBs and enhanced the radiosensitivity of colorectal cancer cells.
