MicroRNA-139-3p indicates a poor prognosis of colon cancer.

MicroRNAs (miRNAs) play an important role in the regulation of gene expression and are involved in almost biological procession. Recently, miR-139-5p has been reported to be downregulated in some types of cancer, and inhibits cancer cell invasion and metastasis. However, there are few reports on the role of miR-139-3p in cancer. In this study, we examined the expression level of miR-139-3p in 63 pairs of colon cancer and adjacent paracancerous tissues using quantitative reverse transcription PCR. The levels of miR-139-3p in colon cancer tissues were significantly lower than those in adjacent noncancerous tissues. There was an inverse correlation between the level of miR-139-3p and patient's age. Lower level of miR-139-3p was significantly associated with poor overall survival, especially in patients with TNM stages I and II. In conclusion, miR-139-3p has potential as a prognostic biomarker for colon cancer. Further prospective studies are required to validate this result.