Expression And Functional Analysis Of MiR-222in Colorectal Cancer Cell Line Hct116and Validation Of Its Target Gene C-Fos

Aim To reveal the pathological role and molecular mechanism of miR-222in theinitiation and progression of colorectal cancer cells, we evaluated the expression andfunction of miR-222in colorectal cancer and further validated its target gene c-Fos.Methods In this study, colorectal cancer cell HCT116was cultured and furtheranalyzed in vitro. The expression of miR-222was detected in colorectal cancer cell lineHCT116and normal colorectal tissues. The expression of c-Fos was also detected byWestern blot. Furthermore, overexpression and silence of miR-222was achieved in thiscolorectal cancer cell line by microRNA mimics and inhibitors, respectively. Theproliferation and apoptosis of cellse was separately evaluated by CCK-8assay and Sub-G1analysis. At the same time, the expression level of c-Fos was detected in HCT116cellsafter transfection with miR-222overexpression or silence.Results1. Compared with normal colorectal tissues,1.82folds of upregulation of miR-222was observed in cell line HCT116，p<0.01;2. The expression level of c-Fos was significantly reduced in colorectal cancer cellline HCT116when compared with that in human normal colorectal tissues(1.51±0.2185vs0.69±0.0918, p<0.01);3. Subjected to miR-222silence with microRNA inhibitor, HCT116cells show asignificant suppression in growth and increase in apoptosis（24h，p<0.05；48h， p<0.01）;4. In colorectal cancer cell line HCT116, the expression of c-Fos wasdown-regulated following miR-222mimics transfection (1.25±0.1336vs0.94±0.0895,p<0.05） and up-regulated with miR-222inhibitor(0.92±0.0909vs1.31±0.1028,p<0.01）.ConclusionThis study gained an insight into the expression profile and function of miR-222incolorectal cancer cell line HCT116. MiR-222silence significantly suppressed the proliferation of HCT116and promoted apoptosis of this cell line. The expression of c-Foswas down-regulated following miR-222mimics transfection and up-regulated withmiR-222inhibitor. We confirmed that c-Fos may be a target gene of miR-222. MiR-222may be served as a diagnostic and therapeutic approach for colorectal carcinomas.