Expression levels of serum miRNA-195 in different types of patients with cholangiocarcinoma and its value to determine the prognosis thereof

This study aimed to investigate the expression levels of microRNA-195 (miRNA-195) in different types of patients with cholangiocarcinoma (CCA) and its correlation with the prognosis. Serum samples were collected from different types of patients with CCA (I, II, III, IV) and normal cases, followed by detection of expression of miRNA-195 using quantitative polymerase chain reaction (qPCR). The serum samples of 204 patients with CCA, including 75 cases of type I, 68 cases of type II, 35 cases of type III and 26 cases of type IV and 200 healthy subjects were selected. The baseline clinicopathological data of patients with CCA were assessed and recorded, and patients were followed up constantly. The receiver operating characteristic (ROC) curve was established, and the area under the ROC curve (AUC) was calculated to evaluate the difference of miRNA-195 expression levels between patients with CCA and normal controls. Survival curves were set up for groups with high and low expression levels via the Kaplan-Meier method, and the log-rank test was used to evaluate the difference of survival curves between the two groups. The expression of miR-195 in patients with CCA was significantly lower than that in the normal control group, with a sensitivity of 0.78 and a specificity of 0.76, and it was positively correlated with the pathological grade of CCA. Additionally, the expression level of serum miRNA-195 was associated with lymph node metastasis (P=0.009) and tumor-node-metastasis (TNM) classification (P=0.010). The survival analysis revealed that the prognosis in patients with CCA in types III and IV was poorer than that in those with types I and III who had a low expression of miRNA-195 (P=0.0026). The results show that miR-195 is an important marker that reflects the malignant degree of CCA, and it is expected to be a reference marker to determine the prognosis of CCA.