Identification of potential prognostic long non-coding RNA for predicting survival in intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is an aggressive biliary epithelial tumor with poor prognosis. There are increasing evidences that long non-coding RNAs (lncRNAs) are dysregulated in multifarious tumors, revealing potential significant role of lncRNAs in tumorigenesis.We used the ICC dataset retrieved from The Cancer Genome Atlas and the Gene Expression Omnibus database to obtain the lncRNAs expression profiles and identify potential prognostic lncRNAs for predicting the prognosis in ICC. Univariate and multivariate Cox regression analyses were performed to construct a prognostic index (PI). Furthermore, coexpression analysis and functional assessment were performed to initially investigate the function of these prognostic lncRNAs.A total of 255 differentially expressed lncRNAs (DElncRNAs) were identified among two RNA sequencing dataset of a total 63 ICC patients with 98 samples using R platform. Thirteen of 255 DElncRNAs were identified as prognostic lncRNAs and used for a PI. Patients with high PI were associated with poor prognostic (P = .0064), and the Cox regression showed consistent result (P = .042). The time-dependent receiver operating characteristic analysis showed the PI performed well in ICC survival prediction with an area under curve of 0.921, 0.801, and 0.717 for 1-, 3-, and 5-year survival, respectively.In conclusion, we included 13 identified prognostic DElncRNAs and constructed a prognostic signature/PI. ICC patient with higher PI was associated with poorer prognosis. However, the clinical role as well as biological functions of constructed PI and these prognostic DElncRNAs need to be verified in future study.