Comprehensive characterization of the prostate tumor microenvironment identifies CXCR4/CXCL12 crosstalk as a novel antiangiogenic therapeutic target in prostate cancer

Abstract

Background Crosstalk between neoplastic and stromal cells fosters prostate cancer (PCa) progression and dissemination. Insight in cell-to-cell communication networks provides new therapeutic avenues to mold processes that contribute to PCa tumor microenvironment (TME) alterations. Here we performed a detailed characterization of PCa tumor endothelial cells (TEC) to delineate intercellular crosstalk between TEC and the PCa TME. Methods TEC isolated from 67 fresh radical prostatectomy (RP) specimens underwent multi-omic ex vivo characterization as well as orthogonal validation of both TEC functions and key markers by immunohistochemistry (IHC) and immunofluorescence (IF). To identify cell–cell interaction targets in TEC, we performed single-cell RNA sequencing (scRNA-seq) in four PCa patients who underwent a RP to catalogue cellular TME composition. Targets were cross-validated using IHC, publicly available datasets, cell culture expriments as well as a PCa xenograft mouse model. Results Compared to adjacent normal endothelial cells (NEC) bulk RNA-seq analysis revealed upregulation of genes associated with tumor vasculature, collagen modification and extracellular matrix remodeling in TEC. PTGIR, PLAC9, CXCL12 and VDR were identified as TEC markers and confirmed by IF and IHC in an independent patient cohort. By scRNA-seq we identified 27 cell (sub)types, including endothelial cells (EC) with arterial, venous and immature signatures, as well as angiogenic tip EC. A focused molecular analysis revealed that arterial TEC displayed highest CXCL12 mRNA expression levels when compared to all other TME cell (sub)populations and showed a negative prognostic role. Receptor-ligand interaction analysis predicted interactions between arterial TEC derived CXCL12 and its cognate receptor CXCR4 on angiogenic tip EC. CXCL12 was in vitro and in vivo validated as actionable TEC target by highlighting the vessel number- and density- reducing activity of the CXCR4-inhibitor AMD3100 in murine PCa as well as by inhibition of TEC proliferation and migration in vitro. Conclusions Overall, our comprehensive analysis identified novel PCa TEC targets and highlights CXCR4/CXCL12 interaction as a potential novel target to interfere with tumor angiogenesis in PCa. Graphical Abstract

The activity of cytokines in dental pulp

“…CXCL12 has a strong chemotactic effect on lymphocytes. In adults, CXCL12 has an important role in angiogenesis 10 . Local low concentrations of IL‐1 mainly exert immunomodulatory effects 11 .…”

Endothelial deletion of TBK1 contributes to BRB dysfunction via CXCR4 phosphorylation suppression

“…3F, G , clustering analyses linked the differentially expressed phosphoproteins to associated biological processes and pathways. Among the proteins, CXCR4 participates in cytokine-mediated signaling pathways and positive regulation of cell growth, which is shown to be related to endothelial/ vascular development [ 12 ].

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Theranostics of Primary Prostate Cancer: Beyond PSMA and GRP-R

“…CXCR4 overexpression has also been reported in prostate cancer; studies have shown that CXCR4 is a key regulator of tumor dissemination [ 12 ]. An in vitro study comparing adjacent normal endothelial cells to prostate tumor vasculature highlighted CXCR4 as a potential novel target to interfere with prostate cancer angiogenesis [ 29 ].…”