Increased miR-449a expression in colorectal carcinoma tissues is inversely correlated with serum carcinoembryonic antigen.

Previously, microRNA-449a (miR-449a) has been shown to be involved in various types of cancer. However, its role in colorectal carcinoma remains unknown. The present study found that miR-449a expression was significantly increased in cultured colorectal carcinoma cells and cancer tissues obtained from 24 patients diagnosed with colorectal carcinoma, compared with the normal colorectal cells and the adjacent non-tumor tissues. The miR-449a expression in carcinoma tissues revealed an inverse correlation with the levels of serum carcinoembryonic antigen (CEA; R2=0.88). The increased expression of miR-449a appeared in the patients who exhibited normal serum levels of CEA (<5 ng/ml), but not in those with elevated CEA levels (>5 ng/ml). miR-449a expression increased at an early TNM stage (stage II) and did not change significantly at stages III and IV. These results suggested that miR-449a is involved in the development of colorectal carcinoma and may be a potential prognosis indicator.