ENOPH1 orchestrates KRASG12D/G13D-driven glycolytic reprogramming and colorectal cancer progression through modulating the TGF-β/SMAD pathway.

Abstract

Oncogenic KRAS mutations (G12D/G13D) drive metabolic reprogramming in colorectal cancer (CRC), yet targetable downstream effectors remain poorly defined. Here, we identify enolase-phosphatase 1 (ENOPH1) as an essential transducer directly upregulated by the KRAS-MEK-ERK axis. ENOPH1 is markedly elevated in KRAS-mutant patient tumors and is required for CRC proliferation, migration, invasion, and tumor growth in vivo. Mechanistically, ENOPH1 sustains oncogenic TGF-β/SMAD signaling through a non-catalytic mechanism: it promotes TGFβ transcription and secretion, while concurrently suppressing the E3 ligase STUB1 to prevent ubiquitin-mediated degradation of SMAD4 and preserve p-SMAD2/3 phosphorylation and nuclear accumulation. Notably, ENOPH1 depletion does not alter cellular methylation potential (SAM/SAH ratio), and reconstitution with the catalytic-dead D16A mutant effectively restores SMAD4 abundance, p-SMAD2/3 levels, and cell proliferation, indicating a mechanism largely independent of its canonical enzymatic activity. Downstream, TGF-β/SMAD-induced glycolysis serves as an indispensable metabolic engine powering epithelial-mesenchymal transition (EMT); pharmacological inhibition of glycolysis with 2-deoxy-d-glucose (2-DG) abolishes TGF-β1-restored EMT and malignant phenotypes, phenocopying SMAD2/3 silencing. Together, our findings establish ENOPH1 as a non-catalytic molecular hub linking KRAS signaling, TGF-β output, and glycolytic addiction, uncovering a rational therapeutic vulnerability for KRASG12D/G13D-driven CRC.