Expression of MiR-20a-5p and its target gene in colon cancer and its effect on the proliferation and apoptosis of colon cancer cells.

Abstract. We investigated the expression of micro ribonucleic acid (miR)-20a-5p and its target gene, breast cancer metastasis suppressor 1 like (BRMS1L), in colon cancer tissues and their effects on the proliferation and apoptosis of colon cancer cells. The dual luciferase assay was used to detect the targeted regulation of miR-20a-5p on BRMS1L. The expression levels of miR-20a-5p and BRMS1L in colon cancer tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). MiR-20a-5p mimic and mimic negative control (NC) were transfected into the colon cancer cell line SW480 by the liposome transient transfection method. The MTT assay, monoclonal formation of cancer cells, and flow cytometry were used to detect cell proliferation and apoptosis. The expres-sion level of miR-20a-5p in colon cancer tissues was significantly higher than that in adjacent tissues, and the expression level of BRMS1L was significantly lower than that in adjacent tissues. The expression level of miR-20a-5p was significantly correlated with tumor-node-metastasis (TNM) stage, lymph node metastasis, in-vasion depth, and differentiation degree. The higher the expression level of miR-20a-5p, the more advanced the TNM stage and invasion depth, and the easier it is for lymph nodes to metastasize (p<0.05). Compared with the control and the miR-NC groups, the miR-20a-5p group’s cell proliferation ability, expression of CyclinD1 and B-cell lymphoma-2 (Bcl-2) were significantly increased, while apoptosis ability and caspase-3 protein expression were significantly decreased (p<0.05). The expression of miR-20a-5p in colon cancer tissues and cells in-creased. Overexpression of miR-20a-5p could promote the proliferation of colon cancer cells and inhibit their apoptosis.