MicroRNA-302a Functions as a Putative Tumor Suppressor in Colon Cancer by Targeting Akt

Micro RNAs (miRNAs) are important regulators involved in various physical and pathological processes, including cancer. The miRNA-302 family has been documented as playing a critical role in carcinogenesis. In this study, we investigated the role of miRNA-302a in colon cancer. MiRNA-302a expression was detected in 44 colon cancer tissues and 10 normal colon tissues, and their clinicopathological significance was analyzed. Cell proliferation and cell cycle analysis were performed on colon cancer cells that stably expressed miRNA-302a. The target gene of miRNA-302a and the downstream pathway were further investigated. Compared with normal colon tissues, miRNA-302a expression was downregulated in colon cancer tissues. Overexpression of miRNA-302a induced G1/S cell cycle arrest in colon cancer cells, and suppressed colon cancer cell proliferation both in vitro and in vivo. Furthermore, miRNA-302a inhibited AKT expression by directly binding to its 3′ untranslated region, resulting in subsequent alterations of the AKT-GSK3β-cyclin D1 pathway. These results reveal miRNA-302a as a tumor suppressor in colon cancer, suggesting that miRNA-302a may be used as a potential target for therapeutic intervention in colon cancer.