Up-regulation of mir-10b predicate advanced clinicopathological features and liver metastasis in colorectal cancer

Given the emerging role of microRNA in tumor disease progression, we investigated the association between miRNA 10b expression, liver metastasis, and clinicopathological of colorectal cancer (CRC). Two hundred and forty-six pairs of samples (including CRC samples and normal adjacent tissues) from CRC patients were collected from May 2004 to May 2009. All samples verified to contain at least 80% tumor cells, and were immediately frozen in liquid nitrogen and stored at -80 degrees C or fixed in 10% formalin for paraffin embedding. The expression of miRNA-10b in CRC tissues was evaluated using a quantitative real-time polymerase chain reaction RT-PCR. Correlation between miR-10b expression and poor clinicopathological of CRC patients were analyzed using Student's t-tests and Chi-square tests. A Kaplan-Meier survival curve was generated following a log-rank test. miR-10b expression was up-regulated in CRC tissues (P < 0.0001) and in patients diagnosed as colorectal liver metastasis (CLM) at initial involvement or during follow-up. When the Tumor Node Metastasis (TNM) stage was taken into consideration, the expression levels of miR-10b were positively correlated with advanced TNM stages. In addition, the miR-10b expression of patients diagnosed as CLM at initial involvement was significantly higher than those without liver metastasis (nCLM). Similarly, those patients developed with CLM during follow-up (FCLM) was also markedly higher than those with nCLM. miR-10b expression was also found correlated with advanced stage (P < 0.0001), lymph node metastasis (P = 0.025), venous infiltration (P = 0.007), poorer differentiation (P = 0.002), and served as an independent prognostic factor of poor overall survival (P < 0.0001). This study demonstrated the expression of miR-10b had strong potential to serve as a noninvasive biomarker for CRC prognosis and predicting liver metastasis.