Abstract
<title>Abstract</title> <p> <bold>Background</bold> Progression to aggressive and treatment-refractory prostate cancer is commonly attributed to tumor-cell-intrinsic androgen receptor (AR) reprogramming and lineage plasticity. However, whether these epithelial changes are coordinated with stromal remodeling and SPP1-expressing tumor-associated macrophage states remains incompletely understood. <bold>Methods</bold> We integrated three single-cell RNA-sequencing datasets, 46 quality-controlled spatial transcriptomic sections and ten bulk transcriptomic cohorts encompassing 2,025 samples across localized prostate cancer, metastatic hormone-sensitive prostate cancer, castration-resistant prostate cancer and metastatic castration-resistant prostate cancer. A stromal–SPP1 macrophage–AR remodeling index was constructed by integrating stromal remodeling, SPP1 macrophage, lineage-plasticity and AR-activity programs. Its clinical associations were evaluated across independent bulk cohorts. Single-cell and spatial analyses were used to identify the cellular origins and tissue organization of the component programs. Myeloid subclustering, focused and LIANA-based ligand–receptor analyses, communication-network virtual silencing, cell-type-restricted scTenifoldKnk perturbation analysis and external druggability annotation were used to investigate candidate regulatory dependencies and translational targets. <bold>Results</bold> The remodeling index was consistently associated with higher Gleason grade, biochemical recurrence (BCR) and advanced or metastatic disease. In GSE116918, each standard-deviation increase in the index was associated with a higher risk of BCR after adjustment for age and Gleason score (hazard ratio 1.73, 95% confidence interval 1.36–2.20). Associations with high-grade disease were reproduced across TCGA-PRAD, GSE116918, GSE70768, GSE70770 and SU2C/PCF 2019. Spatially, stromal and SPP1 macrophage programs co-localized within tissue sections, while the composite remodeling state was associated with lower AR activity and greater lineage plasticity. Single-cell analysis localized stromal remodeling to fibroblasts, SPP1 macrophage programs to myeloid cells, AR activity to luminal or tumor epithelial cells and plasticity programs to basal or club-like epithelial populations. Myeloid refinement identified three SPP1_TAM-like clusters, including an mCRPC-enriched cluster. Ligand–receptor analyses prioritized ECM–integrin, MIF–CD74/CXCR4 and APOE–TREM2/LRP1 signaling. Communication-network silencing identified ITGB1 and CD44 as highly connected interaction hubs, whereas scTenifoldKnk supported compartment-specific regulatory effects of AR in epithelial cells, CD74 in SPP1_TAM-like cells and FN1/COL1A1 in fibroblasts. Integrated evidence prioritized CD74, CXCR4 and CSF1R for further translational investigation. <bold>Conclusions</bold> These findings define a stromal–SPP1 macrophage–AR remodeling state associated with aggressive and treatment-refractory prostate cancer. The results suggest that AR remodeling and lineage plasticity occur within a spatially organized stromal–myeloid ecosystem and nominate CD74-, CXCR4- and CSF1R-centered pathways as candidates for future functional and therapeutic evaluation. </p>