N6-Methyladenosine Reader YTHDF3-Mediated CEBPA Translation Maintains Genomic Stability and Stem Cells Function to Prevent Liver Injury and Hepatocellular Carcinoma [Ribo-seq]

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) induced by chronic liver damage is a major cause of cancer mortality, but its precise epigenetic mechanisms are severely under studied. In addition, the role of N6-methyladenine (m6A) reader YTHDF3 in human diseases remains poorly understood. METHODS: Liver injury and hepatocarcinogenesis in mice were induced by chemical. CRISPR/Cas9 technology was used to construct Ythdf3 and Mettl14 knockout mice. Hepatic cell population characteristics was determined by means of 10X single-cell RNA-seq and flow cytometry. Cell proliferation and DNA damage were evaluated by immunofluorescence, immunohistochemistry, and western blot. Liver organoids were cultured to examine liver stem cells function. MeRIP-seq was used to reveal alterations in m6A methylation patterns impacted by chemical-induced liver injury. RIP-seq and Ribo-seq were applied to identify YTHDF3 targets and determine translation efficiency. Small interfering RNAs and dCas13b-FTO-sgRNA plasmids were used to evaluate the function of YTHDF3 and CEBPA in vitro. RESULTS: YTHDF3 depletion exacerbated chemical-induced liver injury with a reduction in functional hepatocytes and stem cells. Furthermore, METTL14 and YTHDF3-dependent RNA m6A dysregulation induced DNA damage and promoted development of HCC. Mechanistically, knockout of Ythdf3 impeded the translation of CCAAT/enhancer-binding protein-alpha (CEBPA), subsequently inhibited expression of PARP1 and PRDX2 to promote DNA damage and induce genomic instability, finally leading to liver injury and HCC. CONCLUSIONS: m6A/YTHDF3/CEBPA regulatory axis plays an essential role in governing cell fates and genomic stability, thereby preventing liver injury and HCC, and offers potential therapeutic avenue for targeting YTHDF3 and CEBPA in the treatment of HCC. Overall design: Ribo-seq was applied to determine translation efficiency of YTHDF3 targets in mouse.