KBTBD11 suppresses hepatocellular carcinoma by targeting ENO1-mediated glycolysis.

[BACKGROUND] Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. Enhanced aerobic glycolysis is a hallmark of HCC progression, yet the upstream regulatory mechanisms remain incompletely understood.

[METHODS] An in vivo genome-wide CRISPR-Cas9 screen in an orthotopic HCC model was used to identify metabolic regulators. Functional assays including extracellular flux analysis, ATP and lactate quantification, ROS detection, apoptosis assays, and 3D spheroid culture were performed to evaluate the effects of KBTBD11. Protein interactions were assessed by co-immunoprecipitation, ubiquitination assays, and truncation mutant analysis. Spatial interactions and subcellular localization of KBTBD11 and ENO1 were further validated by proximity ligation assay (PLA) and immunofluorescence staining.

[RESULTS] KBTBD11 was frequently downregulated in HCC and associated with favorable prognosis. Overexpression of KBTBD11 suppressed glycolytic activity, reduced ATP and lactate levels, elevated ROS accumulation, and promoted apoptosis. Mechanistically, KBTBD11 interacted with ENO1 and facilitated its proteasomal degradation via a ubiquitin-dependent pathway. Deletion of either the BTB or Kelch domain of KBTBD11 impaired its ability to bind ENO1. Rescue experiments using ENO1 re-expression or pharmacological inhibition by ENOblock confirmed that the metabolic and phenotypic effects of KBTBD11 were ENO1-dependent.

[CONCLUSIONS] These findings identify KBTBD11 as a negative regulator of ENO1-mediated glycolysis in HCC. By promoting ENO1 degradation, KBTBD11 links ubiquitin signaling to metabolic control and tumor suppression, highlighting a potential therapeutic target for metabolically active liver cancer.