miR-20b-5p Functions as Tumor Suppressor microRNA by targeting CyclinD1 in Colon Cancer
Abstract Background MicroRNA functions as an oncogenic regulator or tumor suppressor in various human tumors. Bioinformatics analysis revealed that miRNA-20b is related to the tumorigenesis, however, the function of miRNA-20b in colon cancer is still not clear. Methods Apoptosis, cell cycle, expression of CCND1/CDK/FOXM1 axis in HCT116 cells were examined by flow cytometry, western blot, and Immunohistochemistry. Wound-healing migration assay and transwell assay were performed to test the migration and invasion of tumor cells. Bioinformatics and microarray analysis was performed for further mechanical research. Subcutaneous xenograft mouse models was to verify the function of miR-20b-5p in vivo. Results We found that miRNA-20b-5p inhibited the cell cycle, migration and invasion of CC cells, but had no effect on cell apoptosis. CyclinD1(CCND1) was identified as a direct target of miR-20b-5p. Overexpression of miRNA-20b-5p downregulated CCND1 level in HCT-116 cells. Mechanistically, the inhibiton of cell cycle, migration and invasion of CC cells by miRNA-20b-5p is through regulating the CCND1/CDK4/FOXM1 axis. Additionally, we found that miRNA-20b-5p could inhibit the tumorigenesis in murine CC xenograft models in Balb/c nude mice. Conclusion Therefore, our findings demonstrated that miR-20b-5p may serve as a tumor suppressor in CC by negatively regulating CCND1 and that miR-20b-5p may be a potential therapeutic target for the management and treatment of colon cancer.