H. pylori infection amplifies oncogenic functions of CXCL8, CXCL1, CCL20, and MMP1 in gastric cancer: Evidence from network biology and functional assays.

Helicobacter pylori (H.pylori) infection is a primary driver of chronic gastric inflammation and carcinogenesis, yet the molecular networks bridging bacterial infection and malignant transformation are not fully characterized. This study aimed to identify H.pylori-associated hub genes through integrated systems biology and to functionally validate their roles in gastric cancer progression. Weighted gene co-expression network analysis (WGCNA) was applied to GEO datasets (GSE60427 and GSE60662) to identify phenotype-associated modules. Genomic alterations, promoter methylation, and immune infiltration patterns were analyzed using TCGA-STAD, cBioPortal, and UALCAN. Experimental validation was performed in AGS and MKN45 cells. Two independent 2 × 2 factorial designs were used to evaluate hub-gene knockdown and overexpression separately in the presence or absence of H. pylori infection. Mechanistic insights were gained through virulence factor mutants (Δ-cagA and Δ-vacA), pathway inhibitors, and dual-luciferase reporter assays for miRNA-targeting validation. WGCNA identified CXCL8, CXCL1, CCL20, and MMP1 as central hub genes, all of which exhibited significantly elevated mRNA expression in gastric cancer tissues and cell lines. These genes exhibited frequent copy number amplifications and significant promoter hypomethylation. Functional assays showed that hub-gene silencing attenuated H. pylori-associated proliferation, migration, and invasion, whereas hub-gene overexpression promoted these malignant phenotypes and further enhanced the effects associated with infection. Mechanistically, H.pylori infection upregulates these genes via a CagA-dependent activation of the NF-κB and MAPK signaling pathways. Furthermore, specific miRNAs (e.g., miR-302c-3p, miR-203a-3p) were identified as direct post-transcriptional regulators of this axis. CXCL8, CXCL1, CCL20, and MMP1 constitute a unified transcriptional axis driven by H.pylori infection that promotes malignant progression. This CagA-responsive gene set serves as a robust biomarker panel for gastric cancer prognosis and represents a promising therapeutic target for disrupting the infection-inflammation-cancer sequence.