ObjectiveTo investigate the effect of miR-1229-5p on the biological function of SW480 cells and the mechanism of action.

MethodsTransient transfection was used to overexpress miR-1229-5p in SW480 cells, and cell cloning, EdU assay, MTT, cell scratching transwell migration and invasion assays were performed to detect the effects of miR-1229-5p mimics group and control group on the biological functions of colorectal cancer cells SW480.Subcutaneous tumorigenesis assay was performed in nude mice after transfection with miR-1229-5p lentivirus to observe the effect of miR-1229-5p on cell proliferation ability in vivo.In addition, X-linked inhibitor of apoptosis associated factor 1 (XAF1) was screened by predictive software as a potential downstream target gene of miR-1229-5p and the effect of miR-1229-5p on its protein expression was examined.The XAF1 overexpression plasmid was transfected in SW480 cells, and miR-1229-5p was cotransfected with miR-1229-5p to verify that miR-1229-5p promoted the proliferation and invasion of SW480 cells by targeting XAF1.

ResultsThe proliferation, migration and invasion ability of miR-1229-5p mimics group were increased compared with miR-NC group (P < 0.01).The tumor volume of miR-1229-5p group was higher than that of miR-NC group (P < 0.01).The expression level of target gene XAF1 in miR-1229-5p group was lower than that in miR-NC group (P < 0.01), and the promotion effect of miR-1229-5p mimics on cell proliferation and invasion could be reversed after transfection of XAF1 plasmid (P < 0.01).

ConclusionsmiR-1229-5p can promote the proliferation and invasion of colorectal cancer cells SW480 by targeting XAF1.