Effect of circ_0001955 targeted regulation of miR-149 on the radiosensitivity of prostate cancer DU145 cells / 中华放射肿瘤学杂志

ABSTRACT

Objective:To investigate the effect and molecular mechanism of circ_0001955 on the radiosensitivity of prostate cancer DU145 cells.Methods:The si-con, si-circ_0001955, miR-con and miR-149 were transfected into DU145 cells and recorded as the si-con group, si-circ_0001955 group, miR-con group, miR-149 group. The miR-149 and pc-circ_0001955 were co-transfected into DU145 cells and recorded as the miR-149+ pc-circ_0001955 group. Untreated cells were used as the blank control (NC) group. Real-time quantitative PCR was employed to detect the expression levels of circ_0001955 and miR-149. MTT assay was performed to detect cell viability. Flow cytometry was carried out to detect cell apoptosis. Transwell chamber assay was conducted to observe cell migration and invasion. Western blot was performed to detect the expression levels of MMP-2, MMP-9, Cleaved caspase-3, Cleaved caspase-9 and γ-H 2AX proteins. Colony formation assay was employed to determine the cell radiosensitivity. Dual-luciferase reporter assay was conducted to verify the targeting relationship between circ_0001955 and miR-149. Results:The circ_0001955 was highly expressed, whereas the miR-149 was lowly expressed in prostate cancer DU145 cells. Silencing circ_0001955 or over-expressing miR-149 could decrease the cell viability, migration and invasion, down-regulate the expression levels of MMP-2 and MMP-9, up-regulate the expression levels of Cleaved caspase-3 and Cleaved caspase-9, and increase the apoptosis rate (all P<0.05). After 4 Gy dose irradiation, the expression level of γ-H 2AX was up-regulated, the cell survival fraction was decreased, and the sensitivity ratio was 1.38. circ_0001955 could targetedly regulate the expression level of miR-149. After simultaneous overexpression of circ_0001955 and miR-149, cell proliferation activity and the number of migrating and invading cells were increased, cell apoptosis rate was decreased, and cell survival fraction was increased, and the sensitivity ratio was calculated as 0.72. Conclusion:Silencing circ_0001955 can targetedly up-regulate the expression level of miR-149, which inhibits the proliferation, migration, and invasion, induces cell cycle arrest, induces cell apoptosis and increases the radiosensitivity of prostate cancer DU145 cells.