Exon Skipping of Ste20- Like Kinase Enhances Glycolysis and Tumor Progression by Activating Enolase 1–Mediated Phosphoenolpyruvate Production

Abstract RNA splicing is frequently dysregulated in tumors. Aberrant RNA splicing can alter tumor metabolism, highlighting the need to elucidate the alternative splicing events that shape the metabolic landscape. In this study, we identified exon skipping in Ste20-like kinase (SLK) that results in a variant isoform (SLKv), which promotes glycolysis in tumor cells. Mechanistically, SLKv enhanced the activity of enolase 1 (ENO1) by binding and phosphorylating the serine 2 residue. This modification increased the efficiency of ENO1 in catalyzing the production of phosphoenolpyruvate (PEP). The accumulation of PEP further accelerated glycolysis by binding to and activating the glycolytic enzymes hexokinase 2, phosphofructokinase muscle, and phosphoglycerate mutase 1. TGFβ promoted exon skipping of SLK by upregulating the splicing factor KHDRBS1. Targeting SLKv hindered glycolysis and tumorigenesis. These findings establish SLKv as a critical promoter of glycolysis and a metabolic target for cancer therapy. Significance: An alternatively spliced variant of SLK stimulates tumor growth by activating ENO1 to promote phosphoenolpyruvate production and glycolysis, indicating that targeting this splicing alteration is a strategy to overcome cancer metabolic rewiring.