Abstract / Summary
Abstract Immune checkpoint blockade only generates durable anti-tumor responses in a minor subset of gastric carcinoma patients; transcriptomic evidence indicates stromal fibroblast remodeling is the core driver of immunotherapeutic failure, yet no defined molecular cascade links extracellular matrix stiffening, neural-like cell reprogramming and poor treatment response. We integrated single-cell profiles, Visium spatial sequencing and bulk transcript datasets covering 757 gastric cancer patient specimens to characterize a fibroblast-restricted neurogenesis mimicry (NM) transcriptional program. Matrix-remodeling POSTN⁺/FAP⁺ and structural COL1A1⁺/COL1A2⁺ fibroblast subsets carried elevated NM module scores; CellChat ligand-receptor mapping proved laminin and CD99 signal cascades restructure intercellular communication within high-NM tissue microregions. Unsupervised clustering built upon the 136 fibroblast-specific NM signature separated all enrolled patients into three subgroups with divergent long-term survival trajectories. Ten independent survival prediction algorithms were benchmarked, and random survival forest (RSF) delivered optimal predictive power with an average C-index of 0.84, with stable performance recorded across eight fully independent validation cohorts. Reverse single-cell projection localized all bulk-derived prognostic risk signals to stromal fibroblast and endothelial cell populations. SHAP interpretable modeling paired with scTenifoldKnk single-gene virtual knockout identified a ten-gene functional module centered on VCAN; these genes exclusively expressed in high-NM fibroblasts and correlated with epithelial-mesenchymal transition, invasive phenotypes and angiogenic activity. After adjusting age, gender and pathological stage covariates, continuous RSF risk scores retained independent prognostic capacity. High-risk lesions recorded elevated TIDE values and M2 macrophage enrichment, consistent with an immune-excluded cold tumor phenotype. Visium spatial mapping localized NM fibroblast hotspots adjacent to disordered microvessels and dense fibrotic stromal borders. Cell-free biophysical binding assays (SPR/BLI) paired with in vivo orthotopic syngeneic models validated the dual oncogenic effects of NM-high fibroblasts: VCAN-rich extracellular matrix forms physical barriers to trap cytotoxic CD8⁺ T cells, while paracrine VCAN directly binds Integrin β1 to activate AKT/ERK signaling, inducing neuron-like transdifferentiation and accelerating gastric carcinoma progression. Multi-dimensional profiling infers fibroblast-dependent neurogenesis mimicry acts as a druggable stromal driver for gastric cancer progression and immunotherapy resistance, with VCAN-laden matrix walls representing a precise therapeutic target to reverse immune exclusion.