Hepatitis B virus (HBV) infection is the most prominent risk factor for developing hepatocellular carcinoma (HCC), which can increase the incidence of HCC by more than 100 times. Accumulated evidence has revealed that non-coding RNAs (ncRNAs) play a regulatory role in various tumors through the long non-coding RNA (lncRNA)–microRNA (miRNA)–mRNA regulation axis. However, the involvement of the ncRNA regulatory network in the progression of HBV infection-induced HCC remains elusive. In the current work, five tumor samples from patients with hepatitis B surface antigen (HBsAg)-positive HCC and three tumor samples from patients with HBsAg-negative HCC were collected for whole-transcriptome sequencing. Between the two groups, 841 lncRNAs, 54 miRNAs, and 1118 mRNAs were identified to be differentially expressed (DE). The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that DE genes were mainly involved in cancer-related pathways, including Wnt and MAPK signaling pathways. The Gene Expression Omnibus (GEO) analysis further validated the selected DE mRNAs. The DE lncRNA–miRNA–mRNA network was built to explore the effect of HBV infection on the regulation of ncRNAs in HCC. These findings provide novel insights into the role of HBV infection in the progression of HCC.

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.

Histone lactylation acts as a master regulator in tumor development, but its role in a noncoding RNA (ncRNA) network remains unclear. This study aims to reveal the interaction between H3K18la and the lncRNA-miRNA-mRNA regulatory network in hepatocellular carcinoma (HCC). Transcriptome sequencing and ChIP sequencing were performed in HCC and adjacent normal tissues. Cut&Run and qPCR were used to validate the H3K18la enrichment on LINC02732 and CD44 promoter. Dual luciferase reporter assay, qPCR and Western blotting were used to verify the LINC02732-miR-1291-ASF1B axis. Co-Immunoprecipitation was performed to validate ASF1B recruiting p300. CCK8 and mouse subcutaneous tumor formation were performed to demonstrate this axis promoting HCC. H3K18la enrichment on LINC02732 promoter elevates its expression in both HCC samples and cell lines, therefore enhancing ASF1B expression via sponging miR-1291. Moreover, ASF1B, a histone chaperone, promotes H3K18la by recruiting lactyltransferase p300, forming an ASF1B-H3K18la positive feedback loop. The axis upregulates CD44 expression and promotes HCC in vitro and in vivo. These findings demonstrated the influence of H3K18la on the LINC02732-miR-1291-ASF1B axis and the novel role of ASF1B in histone lactylation by recruiting p300, which together promoted HCC proliferation.