Upregulation of gastric adenocarcinoma predictive long intergenic non-coding RNA promotes progression and predicts poor prognosis in perihilar cholangiocarcinoma.

Perihilar cholangiocarcinoma (PHCC) is one of the most aggressive and complex types of cancer with a poor survival. Despite advances in PHCC diagnosis and treatment, the biology of this tumor remains poorly understood. Recent studies have suggested long non-coding RNAs (lncRNAs) as crucial determinants of cancer progression. However, the role of lncRNAs in PHCC is rarely reported and the function of gastric adenocarcinoma predictive long intergenic non-coding RNA (GAPLINC) in PHCC has yet to be elucidated. The present study observed a significant upregulation of GAPLINC in PHCC cell lines and clinical specimens (P<0.05). Furthermore, by comparing clinicopathological characteristics with expression data, high GAPLINC expression was revealed to be associated with the T stage (P=0.013), N stage (P<0.001) and Tumor-Node-Metastasis stage (P<0.001) of PHCC. Furthermore, Kaplan-Meier analysis demonstrated that GAPLINC expression was associated with poor overall survival and progression-free survival rates in PHCC. Furthermore, univariate and multivariate COX regression analyses identified high GAPLINC expression as a risk factor of a poor prognosis in PHCC. GAPLINC upregulation promoted the migration and invasion of PHCC cells in Transwell and Matrigel assays, respectively, while GAPLINC deficiency inhibited PHCC cell metastasis. Furthermore, PHCC cells with GAPLINC overexpression exhibited markedly increased proliferation ability in a Cell Counting kit-8 assay. However, GAPLINC interference significantly suppressed cell proliferation. In conclusion, GAPLINC may promote PHCC progression and may serve as a potential prognostic marker and therapeutic target of PHCC.