Post-translational switch of DHCR24 acetylation sustains sterol synthesis and promotes HCC via the 7-ketocholesterol/p62 axis

Dysregulated cholesterol synthesis fuels cancer progression, but its precise role in hepatocellular carcinoma (HCC) remains unclear. Here, we identify elevated acetylation of 24-dehydrocholesterol reductase (DHCR24) at Lys254 as a hallmark of HCC. Both total DHCR24 and its K254 acetylation independently predict poor patient survival. Acetylation stabilizes DHCR24, sustaining hepatic cholesterol synthesis and promoting tumorigenesis. Mechanistically, DHCR24 acetylation enhances 7-ketocholesterol accumulation, which upregulates p62 and drives HCC growth in vitro and in vivo. Pharmacologic inhibition of DHCR24 expression and acetylation with the US Food and Drug Administration (FDA)-approved drug irbesartan suppresses cell proliferation and reduces tumor burden in xenograft and carcinogen-induced mouse models. Reduced p62 expression parallels the antitumor effects. These findings define DHCR24 acetylation as a metabolic switch linking sterol synthesis to oncogenesis and highlight the DHCR24-7-ketocholesterol-p62 axis as a therapeutic target for HCC.