A Metabolic Switch Controlling Liver Cancer Evolution from Senescent NASH Hepatocytes

Hepatocellular carcinoma (HCC) originates from differentiated hepatocytes undergoing compensatory proliferation in livers damaged by viruses or nonalcoholic steatohepatitis (NASH). While increasing HCC risk, NASH triggers TP53-dependent hepatocyte senescence, which we found to parallel hypernutrition-induced DNA breaks. How this tumor-suppressive response is bypassed to license accumulation of oncogenic mutations and enable HCC progression was previously unknown. We identified the gluconeogenic enzyme fructose-1,6-bisphosphatase 1 (FBP1) as a TP53 target that is elevated in senescent-like NASH hepatocytes but suppressed through promoter hypermethylation and proteasomal degradation in most human HCCs. FBP1 first declines in metabolically-stressed premalignant disease-associated hepatocytes and HCC progenitor cells, paralleling the protumorigenic activation of AKT and NRF2. By accelerating FBP1 and TP53 degradation AKT and NRF2 enhance the proliferation and metabolic activity of previously senescent HCC progenitors. The senescence-reversing NRF2-FBP1-AKT-TP53 metabolic switch, operative in mice and humans, also enhances proliferation-enabled accumulation of DNA damage-induced somatic mutations that drive NASH to HCC progression.