Objectives:This study aimed to comprehensively investigate the molecular landscape
of gastric cancer (GC) by integrating various bioinformatics tools and experimental validations.Methodology:GSE79973 dataset, limma package, STRING, UALCAN, GEPIA, OncoDB,
cBioPortal, DAVID, TISIDB, Gene Set Cancer Analysis (GSCA), tissue samples, RT-qPCR,
and cell proliferation assay were employed in this study.Results:Analysis of the GSE79973 dataset identified 300 differentially expressed genes
(DEGs), from which COL1A1, COL1A2, CHN1, and FN1 emerged as pivotal hub genes using
protein-protein interaction network analysis. Subsequent validation across The Cancer Genome
Atlas (TCGA) datasets confirmed their up-regulation in GC tissues compared to normal controls.
Promoter methylation analysis revealed decreased methylation levels of these hubs in GC
tissues, suggesting their potential role in tumorigenesis. Mutational analysis using cBioPortal
showcased frequent mutations in these genes, particularly FN1, further highlighting their significance
in GC pathogenesis. Survival analysis indicated their correlation with reduced overall
survival rates among GC patients, supported by the development of a robust prognostic model.
Prediction of hub-associated miRNAs and gene enrichment analysis provided insights into their
regulatory mechanisms and downstream pathways, implicating their involvement in extracellular
matrix remodeling and cell migration. Drug sensitivity analysis revealed correlations between
hub gene expression and drug response, while RT-qPCR validation confirmed their upregulation
in clinical GC samples. Finally, functional assays demonstrated the impact of FN1
knockdown on cellular proliferation, colony formation, and wound healing capacities.Conclusion:Overall, this study elucidates the crucial role of COL1A1, COL1A2, CHN1, and
FN1 in GC pathogenesis and underscores their potential as diagnostic markers and therapeutic
targets.