Dynamic Profiles of Internal m7G Methylation on mRNAs in the Progression from HBV Infection to Hepatocellular Carcinoma

Background: Emerging evidence indicates a robust association between internal RNA N7-methylguanosine (m7G) modification and hepatocarcinogenesis. However, the precise implications of altered internal m7G modifications within mRNA on the progression of Hepatitis B Virus (HBV)-induced Hepatocellular Carcinoma (HCC) remain inadequately elucidated.

Methods: This study utilized a previously published dataset from the Gene Expression Omnibus (GEO) that includes samples of normal liver tissue, HBV positive (HP) liver tissue, and HP HCC tissue to investigate the profiling of mRNA internal m7G methylation. The STRING database and in vitro experiments were employed for the screening and validation of key m7G-related genes. The Cancer Genome Atlas cohorts were utilized to analyze the association of these key genes with the prognosis of HCC patients.

Results: Comparative analyses revealed internal m7G modification alterations in 1546 mRNAs between HP liver and normal liver tissues, and in 3424 mRNAs between HP HCC and HP liver tissues. Following Protein-Protein Interaction (PPI) network analyses, validation experiments confirmed sustained high levels of internal m7G methylation modifications in EZH2, SMARCA4, and YY1. Furthermore, these genes were found to exhibit m7G modification-dependent expression changes during the transition from HBV infection to HCC, and were closely associated with the prognosis of HCC patients.

Conclusions: This study provides validation of substantial dynamic alternations in mRNA internal methylation profiles during the HBV infection to HCC. EZH2, SMARCA4, and YY1 emerge as promising molecular targets within this intricate regulatory landscape, offering avenues for further research and potential therapeutic exploration.