Objective: To investigate the expression of long non-coding RNA CBR3-AS1 (lncRNA CBR3-AS1) in cholangiocarcinoma (CCA) and its clinical significance. 
Methods: The expressions of lncRNA CBR3-AS1 in CCA tissue and tumor adjacent tissue as well as in CCA cells and normal biliary epithelial cells were determined by qRT-PCR. The relations of lncRNA CBR3-AS1 expression with the clinicopathologic variables and survival rates of the CCA patients were analyzed. The CCA cells were transfected with lncRNA CBR3-AS1 overexpression plasmid (overexpression group), negative control plasmid (control group) and lncRNA CBR3-AS1 silencing sequences (silencing group) respectively, and then, the proliferative and invasion abilities in each group of cells were examined by MTT and Transwell assay.
Results: The lncRNA CBR3-AS1 expression in CCA tissue was significantly higher than that in tumor adjacent tissue, and in CCA cells was significantly higher than that in normal biliary epithelial cells (all P<0.05). The lncRNA CBR3-AS1 expression was significantly associated with the lymph node metastasis, TNM stage and recurrence of the CCA patients (all P<0.05). The overall survival rate in CCA patients with high lncRNA CBR3-AS1 expression was significantly lower than that in those with low lncRNA CBR3-AS1 expression (P=0.004). The lncRNA CBR3-AS1 expression (P=0.020) and TNM stage (P=0.014) were independent risk factors for overall survival rate of the CCA patients. Compared with the CCA cells in control group, the proliferative and invasion abilities were significantly increased in CCA cells in overexpression group, which were significantly reduced in CCA cells in silencing group (all P<0.05).
Conclusion: LncRNA CBR3-AS1 expression is increased in cholangiocarcinoma, which is closely associated with the malignant features of CCA and poor prognosis of the patients.