Objective To investigate the effect of miRNA-125a on biological behavior of colon cancer through regulating SMURF1.

Methods The expression of miRNA-125a and SMURF1 in the serum of colon cancer patients were detected by qRT-PCR and their correlation with clinical indicators related to colon cancer was analyzed. The microRNA target gene database predicted the combination of miRNA-125a target gene and SMURF1 which was also verified by luciferase reporter gene method. qRT-PCR and Western blot were used to detect the effect of miRNA-125a mimic on the mRNA and protein expression of SMURF1. HE staining was used to detect the expression of SMURF1 in colon cancer tissues; CCK-8 method, cell scratch test and flow cytometry were used to identify the effects of SMURF1 on the proliferation, migration and cycle of SW480 cells. The mouse model of colon cancer xenografts was constructed and the effect of miRNA-125a mimics on tumor growth in mice was detected by weighing and PCNA staining.

Results The expression of miRNA-125a in the serum of patients with colon cancer was negatively correlated with the clinical indicators of colon cancer. The expression of SMURF1 was positively correlated with the clinical indicators of colon cancer. The expression level of miRNA-125a in colon cancer tissues was significantly reduced. The miRNA-125a mimic inhibited SMURF1 mRNA translation and protein levels. The expression of SMURF1 in colon cancer tissues was significantly increased. miRNA-125a mimics could inhibit the proliferation, migration and cell cycle accumulation of SW480 cells. However, this inhibitory effect could be compensated by the increased expression of SMURF1. miRNA-125a mimics inhibited the growth of colon cancer and SMURF1 expression in mice.

Conclusion miRNA-125a plays an inhibitory role in the development of colon cancer by down-regulating the expression of SMURF1, and it is a potential target for the diagnosis and treatment of colon cancer.