Transcriptome profiling of CXCR2+ neuroendocrine (NE) tumor cells purified from patients' fresh prostate adenocarcinoma

The development of therapy resistance is inevitable in prostate cancer (PCa) despite maximal inhibition of androgen receptor (AR) signaling. Here, we for the first time purified a rare AR-negative NE-cell subset from primary fresh human PCa tissue based on cell-surface receptor CXCR2 and showed that they possess gene signatures of lethal cancer through transcriptional profiling. Functional studies demonstrate CXCR2 to be a driver of NE cells' key phenotypes, including loss of AR expression, lineage plasticity, and resistance to hormonal-therapy. Furthermore, CXCR2-driven NE cells are critical for the tumor microenvironment by providing a survival niche for the bulk AR+ luminal cells. Importantly, inhibition of CXCR2 by a chemical inhibitor or genetic manipulation dramatically inhibits aggressive PCa cells in-vitro and in-vivo, demonstrating a central role of NE cells in human PCa. Therefore, we firmly established that targeting NE cells through CXCR2 represents a novel, AR-independent therapeutic strategy that will eliminate all tumor cells (NE and luminal), achieving superior therapeutic efficacy. Overall design: We performed RNA-seq analysis of theTrop2+CXCR2+ (NE tumor cells) and Trop2+CXCR2- (luminal type tumor cells) populations isolated from patients' fresh PCa tissue immediately after radical prostatectomy. We also did RNA-seq on basal cells population purified through Trop2+CXCR2-CD49f+ markers from benign prostate tissue for comparison. To study the CXCR2-induced gene network, we established CXCR2 overexpressed LNCaP (LNCaP-CXCR2) cell line and examined the gene expression profiles in LNCaP and LNCaP-CXCR2 cells.