Cancer-associated fibroblast-derived CCL5 promotes cisplatin resistance in neuroendocrine prostate cancer

Chemoresistance remains a significant challenge in the treatment of neuroendocrine prostate cancer (NEPC), a highly aggressive and lethal subtype of prostate cancer. Here, we identify a tumor-stromal interaction mediated by the CCL5/CCR5 signaling axis that drives cisplatin resistance. Cisplatin-induced DNA damage promotes a cGAS-STING–dependent senescence program in cancer-associated fibroblasts (CAFs), resulting in the secretion of CCL5, a key senescence-associated secretory phenotype factor. CAF-derived CCL5 binds to CCR5 on tumor cells, promoting the formation of a CCR5/β-arrestin1/p85 complex that activates the PI3K/AKT signaling pathway. This activation enhances DNA repair, protecting tumor cells from cisplatin-induced apoptosis. Pharmacologic inhibition of the CCL5/CCR5 pathway using maraviroc, an FDA-approved CCR5 antagonist, sensitizes NEPC cells to cisplatin treatment and significantly prolongs survival in an NEPC mouse model. These findings establish the CCL5/CCR5 axis as a critical mediator of tumor-stromal crosstalk and provide a promising therapeutic strategy for overcoming chemoresistance in NEPC.