To investigate the role and mechanism of miRNA-1236 on proliferation in colorectal cancer.

The expression of miRNA-1236 was detect by quantitative real-time PCR. The cell viability of HCT116 cells after transfected with miRNA-1236 was detected by CCK-8. The proliferation of miR-1236 in HCT116 cell was tested by colony formation assay and Ki67 staining. The potential target gene FOXO3a of miR-1236 was screened by bioinformatics. Observing the level of FOXO3a gene with transfection of miRNA-1236 by real-time quantitative PCR detection. Luciferase reports detected the binding site of miRNA-1236 with FOXO3a; The expression of FOXO3a in colorectal cancer was detected by immunohistochemistry. Detected the protein level of FOXO3a, PCNA and Bax in HCT116 cells after transfection with miR-1236 by western blotting. The expression of FOXO3a in colorectal Cancer-Para cancer patients with different cancer stages and genders was detected by TCGA database.

The cell viability of HCT116 cells was significantly increased with the miRNA-1236 mimic compared with negative control group, while it was decreased with the miRNA-1236 inhibitor. The proliferation of HCT116 cells was significantly reduced compared with the negative control group by colony formation assay and Ki67 staining. Bioinformatics predicted potential binding sites between miR-1236 and FOXO3a. Using Western blot and quantitative real-time PCR of reverse transcription to verify that FOXO3a expression was significantly reduced after overexpression of miRNA-1236 than the negative control group, while FOXO3a expression was significantly increased after treat with miRNA-1236 inhibitor. Meanwhile, luciferase results showed that FOXO3a was a direct target gene of miRNA-1236. Simultaneously, FOXO3a was significantly reduced in colorectal cancer tissue.

miRNA-1236 regulate the proliferation of colorectal cancer by targeting FOXO3a, and significantly affects survival of colorectal cancer patients.