Comprehensive analysis of long noncoding RNA-associated competing endogenous RNA network in cholangiocarcinoma.

Background: Long non-coding RNAs (lncRNAs) can interact with microRNAs (miRNAs) as a competing endogenous RNA (ceRNA) to regulate the expression of target genes, which can largely influence on tumorigenesis and tumor progression. However, the role of lncRNA-mediated ceRNAs in cholangiocarcinoma (CCA) remains unknown. This study aimed to develop novel lncRNAs as well as their action mechanisms in CCA.

Methods: The expression profiles of lncRNAs, miRNAs, and mRNAs of 36 CCA tissues and 9 non-tumor bile duct tissues were obtained from The Cancer Genome Atlas (TCGA) database. The differentially expressed RNAs werre identified using the DESeq package in R. The ceRNA network was constructed in CCA based on bioinformatics generated from miRcode, miRTarBase, miRDB, and TargetScan. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed using "DAVID 6.8" and R packages "Clusterprofile". Survival analysis was performed based on Kaplan-Meier curve analysis.

Results: We identified a total of 1411 differentially expressed lncRNAs, 3494 mRNAs, and 64 miRNAs between CCA and matched normal tissues. By combining the data predicted by databases with intersection RNAs, a lncRNA-miRNA-mRNA ceRNA network consisting of 116 lncRNAs, 14 miRNAs and 59 mRNAs was established. According to the survival analysis, we detected 11 DElncRNA to have a significant impact on the overall survival in patients with CCA (P < 0.05).

Conclusions: Our study identified novel lncRNAs associated with CCA progression and prognosis and provided data to further understand lncRNA-mediated ceRNA regulatory mechanisms in the pathogenesis of CCA.