SIAH2-WNK1 Signaling Drives Glycolytic Metabolism and Therapeutic Resistance in Colorectal Cancer.

Colorectal cancer (CRC) progression and therapy resistance are driven in part by metabolic reprogramming and the persistence of cancer stem-like cells (CSCs). The seven in absentia homolog 2 (SIAH2)/with-no-lysine kinase 1 (WNK1) signaling axis has emerged as a potential regulator of these processes, yet its functional role in CRC metabolism and tumor-stroma crosstalk remains incompletely understood. Integrated analyses of The Cancer Genome Atlas-Colon Adenocarcinoma (TCGA-COAD) and Gene Expression Omnibus (GEO, GSE17538) datasets revealed significant upregulation of SIAH2 and WNK1 in CRC tissues, with strong positive correlations to glycolysis- and hypoxia-associated genes, including PFKP, LDHA, BPGM, ADH1A, ADH1B, and HIF-1α. Single-cell and clinical profiling further demonstrated preferential enrichment of SIAH2 in undifferentiated, stem-like tumor cell populations. Functional studies across multiple CRC cell lines showed that SIAH2 silencing suppressed proliferation, clonogenic growth, tumor sphere formation, and cell-cycle progression, whereas SIAH2 overexpression exerted opposite effects. Seahorse extracellular flux analyses established that SIAH2 promotes glycolytic capacity and metabolic flexibility. At the protein level, SIAH2 regulated glycolytic enzymes and WNK1/hypoxia-inducible factor-1α (HIF-1α) signaling, effects that were amplified by cancer-associated fibroblast (CAF)-derived conditioned medium. CAF exposure enhanced SIAH2 expression, CSC spheroid growth, and resistance to fluorouracil, leucovorin, and oxaliplatin (FOLFOX) chemotherapy, whereas SIAH2 depletion effectively abrogated these effects. Collectively, these findings identify the SIAH2/WNK1 axis as a central metabolic regulator linking glycolysis, CSC maintenance, and microenvironment-driven therapy resistance in CRC, highlighting its potential as a therapeutic target.