MicroRNA-320a suppresses human colon cancer cell proliferation by directly targeting β-catenin

Recent profile studies of microRNA (miRNA) expression have documented a deregulation of miRNA (miR-320a) in human colorectal carcinoma. However, its expression pattern and underlying mechanisms in the development and progression of colorectal carcinoma has not been elucidated clearly. Here, we performed real-time PCR to examine the expression levels of miR-320a in colon cancer cell lines and tumor tissues. And then, we investigated its biological functions in colon cancer cells by a gain of functional strategy. Further more, by the combinational approaches of bioinformatics and experimental validation, we confirmed target associations of miR-320a in colorectal carcinoma. Our results showed that miR-320a was frequently downregulated in cancer cell lines and colon cancer tissues. And we demonstrated that miR-320a restoration inhibited colon cancer cell proliferation and beta-catenin, a functionally oncogenic molecule was a direct target gene of miR-320a. Finally, the data of real-time PCR showed the reciprocal relationship between miR-320a and beta-catenin's downstream genes in colon cancer tissues. These findings indicate that miR-320a suppresses the growth of colon cancer cells by directly targeting beta-catenin, suggesting its application in prognosis prediction and cancer treatment. (C) 2012 Elsevier Inc. All rights reserved.