Fig. 1.
Cancer cells interact with tumor-associated macrophages through SEMA3A. A Quantitative real-time PCR (qRT-PCR) analysis of the expression of SEMA3A in nine prostate cancer tissue samples collected before and after androgen deprivation therapy (ADT). Data are expressed as the fold change relative to SEMA3A expression before ADT. B, C Representative IHC staining (scale bar = 50 μm, n = 5/group, red arrows indicate CD68-positive cells) of hormone-sensitive prostate cancer (HSPC) and castration-resistant prostate cancer (CRPC) and the correlation between IHC scores for SEMA3A and CD68. D Kaplan–Meier curves for biochemical recurrence (BCR) in prostate cancer patients were analyzed according to combined SEMA3A and CD68 expression (n = 140). E Cell counts based on migration assays performed with THP1 cells or monocytes sorted from healthy donors in the presence of conditioned medium (CM) from C4-2B, enzalutamide-treated C4-2B (C4-2B-enza) or SEMA3AKO C4-2B cells. Expression of M1- and M2-related genes in THP1 cells (F) or sorted monocytes (G) in the presence of CM from C4-2B, C4-2B-enza or C4-2B-enza/SEMA3AKO cells. Cell counts based on migration assays performed with THP1 cells (H) or monocytes (I) in the presence of CM from C4-2B cells, CM from C4-2B-enza cells, a recombinant human SEMA3 Fc chimeric protein or an NRP1 inhibitor. Western blotting was performed to investigate the expression of p-PI3K, PI3K, AKT1, p-ERK1/2, ERK1/2, and IL-10 in THP1 cells (J) or monocytes (K) in the presence of CM from C4-2B cells, CM from C4-2B-enza cells, the SEMA3/Fc or the NRP1 inhibitor. Beta-actin served as the internal control. L C4-2B cells cultured with or without THP1 cells in the presence of SEMA3AKO cells or the NRP1 inhibitor EG00229 (500 µg/mL) were injected into the prostate glands of NOD/SCID mice subjected to castration/enzalutamide (ENZ) treatment. The mice were sacrificed at the 12th week after injection. M Photon flux was examined in different groups of mice. The results are presented as the fold increase in tumor growth over time. *p < 0.05; **p < 0.01; ***p < 0.001; and NS not significant