ABSTRACT
Objective:To investigate the effect and mechanism of circular RNA (cirRNA) on the radiosensitivity of rectal cancer.Methods:The differential circRNAs in radiosensitive and radioresistant rectal cancer tissues (biopsy tissue before radiotherapy and chemotherapy) were detected by gene sequencing, and the effect of circRNAs on the radiosensitivity of colorectal cancer cells was further confirmed in vitro. Results:Through gene sequencing of rectal cancer tissue samples, 64 circRNAs were found to be highly expressed in radiosensitive rectal cancer tissues, and 36 circRNAs were lowly expressed in radiosensitive tissues. Ten differential circRNAs were selected and verified by qRT-PCR, and it was found that circATL2 was highly expressed in radiosensitive rectal cancer tissues. In vitro cell experiment indicated that up-regulation of circATL2 expression could significantly improve the radiosensitivity of rectal cancer. Subsequently, 8 miRNAs lowly expressed in radiosensitive rectal cancer tissues were analyzed. The direct binding relationship between miR-205 and circATL2 was confirmed by dual luciferase reporter assay. The rescue experiment confirmed that circATL2 in rectal cancer regulated the radiosensitivity of rectal cancer through miR-205. Conclusion:circATL2 regulates the radiosensitivity of rectal cancer by binding to miR-205.