da Costa, D. d. S. A. | bioRxiv Science

bioRxiv2025

EXPRESSION INSIGHTS INTO GASTRIC ADENOCARCINOMA: NETWORK ANALYSIS REVEALS KEY HUB GENES AND FUNCTIONAL MODULES

Gastric cancer remains a leading cause of cancer-related mortality worldwide, with poor survival rates. To uncover its molecular basis, we performed weighted gene coexpression network analysis on RNA-seq data from 119 gastric adenocarcinoma (GAC) and peritumoral tissue (PTT) samples. We identified six key coexpression modules: MEmagenta, MEbrown, MEgreen, and MEturquoise showed strong positive correlations with GAC, whereas MEblack and MEblue were negatively correlated. Hub genes such as COL3A1, PGAM1, and CFL1 were among the most highly expressed in GAC samples compared to PTT. ROC analyses of selected hub genes yielded AUC values exceeding 0.80 for distinguishing GAC from PTT, underscoring their diagnostic potential. Integrating cellular deconvolution with module expression revealed that MEblack hub genes (TFF1, TFF2, GKN1, GKN2 and MUCL3) correlated positively with B-cell abundance and negatively with resting mast cells and neutrophils. Conversely, MEturquoise hub genes (COL1A2, COL3A1, TAGLN and SPARC) correlated strongly with Cance Associated Fibroblasts and inversely with B-cells, reflecting a collagen-rich stroma. We also observed overlapping expression profiles between GAC and PTT, indicating tumor heterogeneity and a molecular continuum between normal and neoplastic tissues. These integrated insights highlight candidate biomarkers and in GAC.

genomics↗

bioRxiv2025

Immune Remodeling and Dysbiosis May Distinguish the Microenvironments of Gastric Adenocarcinoma and Peritumoral Tissue

The gastric tumor microenvironment is dynamically shaped by the interactions between the local microbiota and the host immune system, although the functional integration of these elements remains incompletely understood. In this study, we characterized microbial diversity, immune cell composition, and immune-related gene expression profiles in samples of gastric adenocarcinoma (GAC) and adjacent peritumoral tissue (PTT), aiming to elucidate their functional organization. A total of 106 samples of 75 patients were analyzed using bulk RNA-Seq expression profiling, immune deconvolution, and bacterial taxonomic reconstruction. While alpha diversity remained preserved between GAC and PTT, distinct compositional differences emerged: GAC was enriched with Pseudomonadota, Enterobacteriaceae, and Escherichia, whereas PTT exhibited a predominance of Helicobacteraceae and Helicobacter. Immune deconvolution revealed an expansion of cancer-associated fibroblasts (CAFs) and mast cells in GAC, correlated with higher expression levels of TGFB1 and FOXP3, while neutrophils and B cells predominated in PTT. Integrated analysis demonstrated that GAC formed dense and cohesive networks connecting pro-inflammatory bacteria, activated immune cells, and inflammatory genes such as IL1B, CXCL8, and IFNG. In contrast, PTT exhibited dispersed networks and negative correlations, suggesting a less structured, tolerogenic environment. Our findings indicate that gastric cancer progression involves not only compositional shifts in microbiota and immune cells but also the active construction of functionally integrated inflammatory networks, providing new insights into potential therapeutic targets at the microbiome-immune interface.

genetics↗