MiR-34b inhibits the proliferation and promotes apoptosis in colon cancer cells by targeting Wnt/β-catenin signaling pathway

Colon cancer is one of the leading cause of cancer deaths that is severely threatening human health. Several microRNAs (miRNAs) have been found to be associated with the tumor genesis of colon cancer. The present study determined the expression of miR-34b in patients with colon cancer and studied the molecular mechanism of miR-34b in the proliferation and apoptosis of human colon cancer Caco-2 cells in vitro. In colon cancer patients, the expression of miR-34b was decreased in tumor tissues when compared with the adjacent non-tumor tissues. Furthermore, overexpression of miR-34b inhibited proliferation, migration and invasion, while promoted apoptosis in colon cancer cells. The online bioinformatics sites predicted possible regulatory genes of miR-34b and luciferase reporter assay verify that beta-catenin was a direct target of miR-34b. Furthermore, miR-34b overexpression significantly decreased the expression of genes associated with Wnt/beta-catenin signaling pathway. In conclusion, our results suggest that miR-34b may inhibit migration and invasion of human colon cancer cells by regulating Wnt/beta-catenin signaling and miR-34b may be a key target for the treatment and diagnosis of colon cancer.