ADAM12-programmed ECM-CAF remodeling activates PI3K–AKT and enforces an immune-excluded microenvironment to drive bladder cancer progression and therapy resistance

Tumor-associated fibroblast-mediated matrix remodeling is an important feature of invasive immune-rejection bladder cancer, but its pathogenic mechanism and potential therapeutic targets are still unclear. The matrix and immune interaction network and core related genes in bladder cancer were systematically investigated by combining single-cell transcriptome data analysis and fibroblast GWAS data with TCGA and GEO data deconvolution, WGCNA, drug response prediction, multiplex immunofluorescence, and in vitro and in vivo validation experiments of cells and animals. ADAM12's functional validation. The findings demonstrated that the tumor-associated fibroblast ECM-CAF subgroup infiltration was evident in bladder cancer and was substantially associated with the upregulation of the core genes ADAM12 and TP53-biased basal-like program. These were characterized by the deposition of dense matrix, the upregulation of numerous immune checkpoints, the rejection and dysfunction of T cells, and a decrease in immunogenicity. Multiplex immunofluorescence localization of bladder cancer and normal bladder tissue showed that ADAM12 was significantly associated with the progression of non-muscle invasive bladder cancer to muscle invasive bladder cancer and the infiltration of ECM-CAF. Knockdown of ADAM12 inhibited the proliferation, migration, and invasion of bladder cancer cells, reduced the activation of the PI3K-AKT-mTOR pathway, and inhibited bladder cancer xenograft growth and lung metastasis. ADAM12 overexpression triggered the PI3K-AKT-mTOR pathway, enhanced the development and lung metastasis of bladder cancer xenografts, and markedly increased the invasion, migration, and proliferation of bladder cancer cells. The above results indicate that ADAM12, as a matrix-driven factor, links matrix remodeling, PI3K-AKT signaling pathway and bladder cancer immunosuppression, and has good prognostic and therapeutic stratification potential, providing new ideas for precision targeted intervention and treatment of bladder cancer.