Loss of EMILIN-1/integrin axis drives microenvironmental reprogramming in gastric tumorigenesis.

BACKGROUND

EMILIN-1 is an extracellular matrix glycoprotein with tumor-suppressive functions. While its loss is implicated in cancer progression, its specific role in the gastric tumor microenvironment and its clinical relevance remain poorly defined.

METHODS

Using in vitro cellular systems and genetically modified mouse models we investigated the consequences of impaired EMILIN-1 function on gastric epithelial transformation, stromal remodeling, and fibroblast reprogramming. Histopathological analysis, gene expression profiling, and functional assays were employed to assess phenotypic changes in epithelial, fibroblastic, and endothelial compartments.

RESULTS

We found that gastric cancer (GC) cells downregulate EMILIN-1 in stromal fibroblasts and lymphatic endothelial cells via paracrine signaling, leading to reduced EMILIN-1 deposition and disrupted lymphatic organization. Mechanistically, the interaction between EMILIN-1 and α4β1 integrin, which is absent in GC cells, modulates tumor cell proliferation; loss of this axis allows tumor cells to escape ECM-mediated growth control. Furthermore, EMILIN-1 downregulation reprograms fibroblasts into a pro-tumorigenic phenotype, which enhances GC cell migration and clonogenic potential. EMILIN-1 loss-of-function (E955A) mice showed increased susceptibility to pre-neoplastic lesions, a finding mirrored in human dysplastic tissues where EMILIN-1 was markedly reduced.

CONCLUSION

Our findings establish EMILIN-1 as a master regulator of gastric tissue integrity. Its loss creates a tumor-permissive microenvironment by disrupting epithelial homeostasis, impairing lymphatic structure, and promoting fibroblast activation. The consistent reduction of EMILIN-1 in early human dysplasia highlights its potential as a novel stromal biomarker for early GC risk stratification. Moreover, restoring the EMILIN-1/integrin axis represents a promising therapeutic strategy to re-establish growth control and suppress tumor progression.