Abstract
The incidence of extrahepatic cholangiocarcinoma (ECC) is the highest of all the cholangiocarcinoma cases. However, the molecular mechanism of ECC genesis and progression remains unclear. Long non-coding RNAs (lncRNAs) have been revealed to perform critical regulatory roles in cancer biology. In order to understand lncRNA expression patterns and their potential function in ECC, a transcriptome analysis of lncRNA and mRNA expression was performed in ECC and paired adjacent non-cancerous tissues using Agilent human lncRNA + mRNA arrayV4.0 (4×180 K format). It was identified that 268 lncRNAs and 459 mRNAs were differentially expressed in ECC. Among these, 78 lncRNAs and 66 mRNAs were upregulated >2-fold compared with adjacent non-cancerous tissues, and 190 lncRNAs and 393 mRNAs were downregulated in the ECC samples. Differences in lncRNA expression between ECC and paired adjacent non-cancerous tissues were confirmed using reverse transcription-quantitative polymerase chain reactionas proof of principle. Functional analysis of co-expressed mRNAs with lncRNAs indicated that these dysregulated lncRNAsmay be involved in known ECC-associated biological processes and pathways. The present findings indicated that mRNAs and lncRNAs perform important roles in the development and progression of ECC. The present findings may lay the foundation for future efforts to understand the role of lncRNAs and develop novel biomarkers in ECC.