Decreased miR-154 expression and its clinical significance in human colorectal cancer

Background: miRNA-154 (miR-154) has been identified as a tumor suppressor in several types of human cancers. However, its clinical significance in colorectal cancer (CRC) is still unclear. The aim of this study was to analyze the association of miR-154 expression with clinicopathologic features and prognosis in CRC patients. Methods: Quantitative RT-PCR was performed to evaluate miR-154 levels in 169 pairs of CRC specimens and adjacent noncancerous tissues. Then, the associations of miR-154 expression with clinicopathological factors or survival of patients suffering CRC were determined. Results: The expression levels of miR-154 in CRC tissues were significantly lower than those in corresponding noncancerous tissues (P < 0.001). Decreased miR-154 expression was significantly associated with large tumor size, positive lymph node metastasis, and advanced clinical stage. Moreover, the univariate analysis demonstrated that CRC patients with low miR-154 expression had poorer overall survival (P = 0.006). The multivariate analysis identified low miR-154 expression as an independent predictor of poor survival. Conclusions: These findings suggested that miR-154 downregulation may be associated with tumor progression of CRC, and that this miR may be an independent prognostic marker for CRC patients.