Integrated Analysis of Altered lncRNA, circRNA, microRNA, and mRNA Expression in Hepatocellular Carcinoma Carrying TERT Promoter Mutations.

ABSTRACT

Background and Objectives: Telomerase reverse transcriptase (TERT) promoter mutations are one of the most common mutations responsible for the development of hepatocellular carcinoma (HCC). Noncoding RNAs (ncRNAs) play a regulatory role in different cancers through the long noncoding RNA (lncRNA)/circular RNA (circRNA)-microRNA (miRNA)-mRNA axis. The aim of the study was to explore the influence of TERT promoter mutations on the ncRNA regulatory network in HCC. Methods: Four tumor samples with a wildtype TERT promoter and four tumor samples with TERT promoter mutations (sequencing cohort) were collected from HCC patients for high-throughput next-generation sequencing. Selected ncRNAs and mRNAs were validated by qPCR in 15 HCC tumors with a wildtype TERT promoter and seven HCC tumors with TERT promoter mutations (validation cohort, including the sequencing cohort). Results: In the mutant TERT promoter group, 536 lncRNAs, 21 circRNAs, 41 miRNAs, and 266 mRNAs were significantly up-regulated, while 1745 lncRNAs, 23 circRNAs, 32 miRNAs, and 1117 mRNAs were significantly down-regulated (P < 0.05) compared with the findings in wildtype group. AL360169.3-201, LINC02672-203, hsa_circ_0021412, hsa-miR-29b-1-5p, hsa-miR-4699-5p, hsa-miR-199a-5p, REG3A, SFRP5, and GSTM1 were verified at the RNA expression level to validate the sequencing results. A differentially expressed lncRNA/circRNA-miRNA-mRNA network was constructed to explore the effects of TERT promoter mutations on ncRNA regulation. Two ncRNA regulatory axes associated with TERT promoter mutations (hsa_circ_0003154/hsa_circ_0008952/IGLL5-AS1/LINC576/LINC575-hsa-miR-1260b -CLPTM1L/GSTM1 and hsa_circ_0031584/LINC2101-hsa-miR-214-3p-CD151) had carcinogenic potential. Conclusion: This study provides novel insights into the role of TERT promoter mutations on ncRNAs regulatory network in HCC progression.