The predicted target gene validation, function, and prognosis studies of miRNA-22 in colorectal cancer tissue

MicroRNAs are known as small, non-coding, and single-stranded RNAs which can regulate cell proliferation, differentiation, and apoptosis and involve in the development of tumors. In this study, colorectal cancer tissue morphological change in different prognosis in patients was observed by hematoxylin and eosin staining. Thereafter, differentially expressed miR-22 and TIAM1 gene were detected using quantitative polymerase chain reaction and western blot in different colorectal cancer tissues. Meanwhile, luciferase reporter gene system was used to verify the relationship between miR-22 and TIAM1. Eventually, the survival curve was plotted according to follow-up records of patients with colorectal cancer and the expression levels of miR-22 and TIAM1 in different tumor tissues. The hematoxylin and eosin results showed the poor pathological features in the 1-year survival group. The expression level of miR-22 was upregulated and TIAM1 was inhibited, correlating with the extension of patients' survival time. Our results indicated that miR-22 and TIAM1 might play a regulatory role in the occurrence and development of colorectal cancer which were consistent with the survival curve analysis results. Furthermore, the luciferase in miR-22 co-transfected with pmiR-RB-REPORT- TIAM1 group was significantly lower than pmiR-RB-REPORT- TIAM1-mut and Si groups. Collectively, these data suggest that miR-22 may suppress the expression of its target gene TIAM1. The low miR-22 level or the high TIAM1 level will indicate the poor prognosis in colorectal cancer patients.