To investigate the expression and clinical significance of microRNA (miR)-181b in patients with cholangiocarcinoma.

Clinical data of 100 patients with cholangiocarcinoma (cholangiocarcinoma group) admitted to the 900^th Hospital of Joint Logistics Support Force of PLA from January 2008 to January 2013 were retrospectively analyzed, and 100 healthy volunteers were assigned into the control group. The informed consents of all patients were obtained and the local ethical committee approval was received. In cholangiocarcinoma group, 61 patients were male and 39 female, aged 33-80 years old with a median age of 56 years old. In control group, 66 patients were male and 34 female, aged 30-80 years oldwith a median age of 54 years old. The expression levels of miR-181b in the serum and tissue samples were detected by RT-PCR. The relationship between miR-181b and clinicopathological features of patients and its value in the diagnosis and prognosis were assessed. According to the average expression level of miR-181b in the cancer tissues, patients in cholangiocarcinoma group were divided into the miR-181b high expression group and miR-181b low expression group. The expression levels of miR-181b between two groups were compared by t test. The survival curve was delineated by Kaplan-Meier method. Survival analysis was performed by Log-rank test.

The serum expression of miR-181b in cholangiocarcinoma group was 1.24±0.24, significantly higher than 0.61±0.13 in control group (t=66.59, P<0.05). In cholangiocarcinoma group, the expression of miR-181b in cancer tissues was 2.31±0.14, significantly higher than 1.17±0.11 in the adjacent tissues (t=34.53, P<0.05). The expression level of miR-181b was significantly correlated with tumor diameter, TNM staging and lymph node metastasis (t=-2.10, -2.61, -4.86; P<0.05). The 3-year survival rates in miR-181b low- and high-expression groups were 37.50% and 11.76%, respectively, where significant difference was observed (χ2=9.007, P<0.05).

miR-181b is highly expressed in cholangiocarcinoma patients, which is significantly correlated with TNM staging and clinical prognosis. Patients with high expression of miR-181b has poorer prognosis.