Multi-Omics and Single-Cell Dissection Reveals EXT1 as a Glycosylation-Linked Therapeutic Target in Cancer.

Background

Glycosylation and inflammation are pivotal in tumor progression, yet the specific glycosyltransferases bridging these processes remain poorly defined. This study investigated Exostosin-1 (EXT1), a key enzyme in heparan sulfate (HS) biosynthesis, as a mechanistic bridge connecting inflammation, stromal remodeling, and immune evasion-driven cancers.

Methods

We used a multi-omics approach including Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression on The Cancer Genome Atlas (TCGA) pan-cancer cohorts, transcriptomics, survival, single-cell RNA sequencing (scRNA-seq), DNA methylation profiling, pathway enrichment analysis (MetaCore), molecular docking, and immunohistochemistry (IHC) on pancreatic adenocarcinoma (PAAD) and lung adenocarcinoma (LUAD) tissue microarrays.

Results

EXT1 was identified as one of only two genes overlapping inflammation- and glycosylation-related gene sets, strongly associated with poor overall survival (OS), disease-specific survival (DSS), and progression-free survival (PFS) across cancers, particularly in PAAD and LUAD. Pan-cancer profiling revealed broad EXT1 upregulation. ScRNA-seq localizedEXT1to stromal cells (pancreatic stellate cells, fibroblasts) and epithelial cells co-expressed with immune checkpoint markers. EXT1 promoter hypomethylation correlated with high expression and poor survival. Enrichment analysis of EXT1-correlated genes highlighted activation of critical pro-tumorigenic pathways, including transforming growth factor-β (TGF-β), lysophosphatidic acid (LPA), epidermal growth factor receptor-phosphoinositide 3-kinase-AKT-mitogen-activated protein kinase (EGFR-PI3K-AKT-MAPK), integrin-focal adhesion kinase-Rho GTPase (integrin-FAK-Rho), and epithelial-mesenchymal transition (EMT) pathways. IHC validated stage-dependent EXT1 overexpression in both PAAD and LUAD.

Conclusion

This multi-omics study identifies EXT1 as a novel link between glycosylation and inflammation. It functions as a driver of stromal activation, immune checkpoint engagement, and tumor progression. EXT1 represents a clinically relevant biomarker and a promising therapeutic target in inflammation-driven cancers like PAAD and LUAD.