Abstract: Objective To explore the effect of silencing circ_0007385 on the biological behavior of colon cancer cells and its possible mechanism. Methods qRT-PCR was performed to detect the circ_0007385 and miR-485-3p expression in colon cancer tissues and adjacent tissues.The correlation of circ_0007385 and miR-485-3p expression levels in colon cancer tissues was analyzed by Pearson method.In vitro cultured human colon cancer cells SW480,si-NC,si-circ_0007385,miR-NC,miR-485-3p mimic,si-circ_0007385 and miR-485-3p Inhibitor were transfected into SW480 cells(si-NC group,si -circ_0007385 group,miR-NC group,miR-485-3p mimic group,si-circ_0007385+miR-485-3p Inhibitor group).The dual luciferase reporter experiment was used to verify the targeting relationship between circ_0007385 and miR-485-3p.CCK-8 method and plate colony formation experiment were used to detect cell proliferation and colony formation.Scratch test and Transwell test were used to detect cell migration.Flow cytometry was used to detect cell apoptosis rate.Western blot method was used to detect the expression of cleaved caspase3 protein.Results The expression level of circ_0007385 in colon cancer tissue was higher than that in adjacent tissues(P<0.05),while the expression level of miR-485-3p was lower than that in adjacent tissues(P<0.05).circ_0007385 was negatively correlated with miR-485-3p(r=-0.972,P<0.001).circ_0007385 could be targeted to bind miR-485-3p.Transfection of si-circ_0007385 or miR-485-3p mimic could inhibit cell proliferation and migration,the number of colonies formed and migration cells were reduced,and the rate of apoptosis was increased(P<0.05).Co-transfection of si-circ_0007385 and miR-485-3p Inhibitor could restore the effect of transfection of si-circ_0007385 on the biological behavior of cells.Conclusion Silencing circ_0007385 could induce cell apoptosis and inhibit the proliferation and migration in colon cancer by targeting miR-485-3p.

Key words: colon cancer, circ_0007385, miR-485-3p, cell proliferation, apoptosis, migration