Protein SUMOylation confers sorafenib resistance in human hepatocellular carcinoma via the induction of PKM2-mediated glycolysis.

Sorafenib resistance remains a major challenge in the treatment of hepatocellular carcinoma (HCC). Through an in vivo CRISPR/Cas9 screen, we identified protein SUMOylation as a key pathway enriched in sorafenib-resistant HCC tumors. SUMO1 expression was significantly upregulated in resistant tumors and cell lines, and its modulation directly influenced sorafenib sensitivity both in vitro and in vivo. Proteomic analysis revealed that SUMO1 overexpression enhanced glycolysis, and metabolic assays confirmed increased extracellular acidification rate (ECAR) and decreased oxygen consumption rate (OCR) in SUMO1-high cells. We further identified PKM2 as a key SUMOylation target, mediated by the E3 ligase TRIM28. The SUMOylation of PKM2 increased its enzymatic activity, promoted aerobic glycolysis, and conferred sorafenib resistance. The inhibition of PKM2 with Compound 3k reversed glycolytic flux and restored sorafenib sensitivity. Clinically, SUMOylated PKM2 was highly expressed in HCC tumors and was associated with the expression of markers of glycolysis and sorafenib resistance in HCC. Our study revealed a novel SUMO1-PKM2 axis that drives glycolysis and sorafenib resistance in HCC, suggesting a potential therapeutic target for overcoming drug resistance.