Targeting NAT10 inhibits hepatocarcinogenesis via ac4C-mediated.

Hepatocellular carcinoma (HCC) is characterized by high morbidity and mortality, withlimited effective treatment options. NAT10 is the only known acetyltransferase formRNA ac4C modification and is recognized as a biomarker for HCC, promoting itsprogression. However, the critical role of NAT10 in hepatocarcinogenesis remains tobe fully elucidated, and the identification of suitable small-molecule inhibitors targetingNAT10 is of great interest. Here, we report that NAT10 promotes HCC progression bystabilizing SMAD3 mRNA through ac4C modification. Clinically, NAT10 is highlyexpressed in HCC tissues and is significantly associated with poor prognosis.Functionally, NAT10 downregulation inhibits HCC cell proliferation, invasion, andepithelial-mesenchymal transition (EMT), while promoting anoikis in vitro.Additionally, NAT10 depletion significantly impairs tumor growth, metastasis, andhepatocarcinogenesis in vivo. Mechanistically, NAT10 enhances oncogene SMAD3mRNA stability via ac4C modification, thereby activating TGF-β signaling pathway.We also identify a novel small-molecule inhibitor, NAT10-2023, which effectivelyblocks NAT10 activity. Notably, NAT10-2023 treatment significantly reducesintracellular RNA ac4C modification levels and disrupts NAT10-RNA interactions,leading to suppressed tumor progression. Overall, NAT10 drives HCC progression viaSMAD3 mRNA stability regulation and NAT10-2023 could be a promising therapeuticcandidate for targeting NAT10 in cancer treatment.