miR-203 is a predictive biomarker for colorectal cancer and its expression is associated with BIRC5.

The purpose of this study was to explore the role of miR-203 in colorectal cancer (CRC) and evaluate the correlation between miR-203 and BIRC5. The expressions of miR-203 in the tissues of 122 CRC patients (with non-tumor tissues as controls) and those from 30 healthy donors were detected by TaqMan® MicroRNA assay. BIRC5s expressions in CRC and non-tumor tissues were detected by immunohistochemistry. Significantly less miR-203 was expressed in CRC tissues (P < 0.05) than in non-tumor tissues. Furthermore, low expression level of miR-203 was correlated with distant metastasis (DM), lymph node metastasis (LNM), and TNM stage (P < 0.05), but there were no significant differences between tumor size or gender. The positive expression rates of BIRC5 in CRC and non-tumor tissues were 73.77 % (90/122) and 30.32 % (37/122), respectively. The expression intensity of BIRC5 in CRC was significantly higher than that of non-tumor tissues (P < 0.05). It was significantly correlated with DM, LNM, and TNM stage (P < 0.05). Finally, miR-203 expression was negatively associated with that of BIRC5 (r = -0.8150, P < 0.05). In conclusion, miR-203 was down-regulated in CRC tissues and involved in the onset and progression of CRC. The expressions of miR-203 and BIRC5 in CRC were significantly negatively correlated, suggesting that BIRC5 may be regulated by miR-203. miR-203 is a potential suppressor and predictive biomarker for CRC.