Down-regulation of miR-126 expression in colorectal cancer and its clinical significance.

MicroRNAs (miRNAs) are non-coding RNAs that regulate the expression of target mRNAs. Altered expression of specific miRNAs in several tumor types has been reported. However, the expression levels of miR-126 in colorectal cancers are unclear. In this study, we compared the expression of miR-126 between colorectal cancer tissues and non-tumor tissues. The expression levels of miR-126 in colorectal cancer tissues were significantly lower than those in non-tumor tissues, and miR-126 overexpression inhibited the growth of colorectal cancer cells. This new information may help to clarify the molecular mechanisms involved in colorectal carcinogenesis and to indicate that miR-126 may be a novel suppressive microRNA and help to differentiate between malignant and normal colorectal tissue.