Increased expression of miRNA-182 in colorectal carcinoma: an independent and tissue-specific prognostic factor

Increasing evidence has revealed that miRNAs play a pivotal role in multiple processes of carcinogenesis, and are being explored as diagnostic, prognostic and predictive biomarker. In this study, we investigated the status of miR-182 expression in colorectal carcinoma (CRC) by in situ hybridization and its underlying clinicopathologic significance for patients with CRC. We found that 79/138 (57.25%) CRCs had high-level expression of miR-182, while 17/67 (25.37%) normal mucosa tissues had high-level expression of miR-182. The expression level of miR-182 was remarkably up-regulated in CRC tissues compared with non-neoplastic normal tissues (P < 0.001). The over-expression of miR-182 in cancer parenchyma cells in CRC were strongly correlated with T-stage (P = 0.020), lymph node metastasis (P = 0.003), distant metastasis (P = 0.002), and Dukes' stage (P = 0.005) in patients with CRC. Patients with high-level expression of miR-182 had short overall survival time than those with low-level expression of miR-182 (P < 0.001). Univariate and multivariate survival analyses further showed that miR-182 expression was a potential unfavorable prognostic factor for CRC, suggesting a potential application of miR-182 in prognosis prediction and therapeutic application in CRC.