Study on LncRNA SOX21-AS1 Affecting Biological Behavior of Colorectal Cancer Cells by Targeting MiR-202-5p / 胃肠病学

ABSTRACT

Background: Long non-coding RNA (lncRNA) could participate in the process of tumorigenesis by regulating the expression of miRNA, but the molecular mechanism of lncRNA in the development and metastasis of colorectal cancer has not been elucidated. Aims: To investigate the molecular mechanism of lncRNA SOX21-AS1 affecting the biological process of colorectal cancer cells by regulating the expression of microRNA-202-5p (miR-202-5p). Methods: The colorectal cancer HCT116 and SW480 cells were transfected with SOX21-AS1 small interfering RNA (si-SOX21-AS1), miR-202-5p mimics and its inhibitor. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the mRNA expressions of SOX21-AS1 and miR-202-5p. Cell proliferation was detected by MTT assay. Flow cytometry was used to detect cell apoptosis. Transwell experiments were used to detect cell migration and invasion. Dual luciferase reporter assay was used to validate the targeted regulatory relationship between SOX21-AS1 and miR-202-5p. Western blotting was used to detect the protein expressions of cyclin D1, MMP-2 and cleaved caspase-3. Results: The mRNA expression of SOX21-AS1 in colorectal cancer cells was significantly higher than that in normal colonic mucosal epithelial cells (P<0.05), while the mRNA expression of miR-202-5p was significantly decreased (P<0.05). Silencing SOX21-AS1 or up-regulating miR-202-5p significantly inhibited proliferation, migration and invasion of HCT116, SW480 cells, the cell apoptosis rate was significantly increased (P<0.05), and significantly inhibited the protein expressions of cyclin D1 and MMP-2 (P<0.05), however, the protein expression of cleaved caspase-3 was significantly increased (P<0.05). SOX21-AS1 could bind to miR-202-5p and negatively regulate the expression and activity of miR-202-5p. Inhibition of miR-202-5p expression reversed the effect of silencing SOX21-AS1 on proliferation, apoptosis, migration and invasion of colorectal cancer cells. Conclusions: Silencing SOX21-AS1 inhibits the proliferation, migration and invasion of colorectal cancer cells and induces cell apoptosis by up-regulating the expression of miR-202-5p.