Extended Data Fig. 3: Factors secreted by MDSCs promote insensitivity to ADT in androgen-dependent mouse and human prostate cancer cell lines and the CXCR2 antagonist impairs tumour recruitment of MDSCs in PtenPC−/− mice.
From: IL-23 secreted by myeloid cells drives castration-resistant prostate cancer
a, Representative dot plot reporting the BM-MDSCs after in vitro differentiation. Data were validated in two biological independent experiments. b, Experimental scheme. c, Cell proliferation of MyC-CaP cells (none, n = 5; conditioned medium (C.M.) from BM-MDSCs, n = 3; FAD, n = 13; FAD and BM-MDSCs, n = 13 biological independent samples). d, Percentage of annexin V− and 7AAD− MyC-CaP cells. e, Percentage of annexin V+ and 7AAD+ MyC-CaP cells. f, qRT–PCR analyses of the indicated genes in MyC-CaP cells. g, h, i, Cell proliferation of VCaP (none, n = 4; conditioned medium from human BM-MDSCs, n = 4; FAD, n = 7; FAD and human BM-MDSCs, n = 8 biological independent samples), 22Rv1 (none, n = 4; conditioned medium from human BM-MDSCs, n = 8; FAD, n = 8; FAD and human BM-MDSCs, n = 4 biological independent samples) and PC3 (none, n = 4; conditioned medium from human BM-MDSCs, n = 8; FAD, n = 4; FAD and human BM-MDSCs, n = 8 biological independent samples) prostate cancer cells. j, Tumour MDSC frequencies determined by flow cytometry of prostate tumours of CTX PtenPC−/− mice treated or not with CXCR2 antagonist (αCXCR2) at completion of the study (12 weeks after CTX). CTX castration-sensitive, n = 3; CTX and CXCR2 antagonist castration-sensitive, n = 3; CTX castration-resistant, n = 4; CTX and CXCR2 antagonist castration-resistant, n = 7 biological independent mice. k, Cell proliferation of TRAMP-C1 cells after 72 h of treatment with CXCR2 antagonist. l, qRT–PCR analyses of the indicated genes in TRAMP-C1 cells after 24 h of treatment (fold change compared to the FAD condition). k, l, Aggregated data from three independent experiments are reported, fold change compared to the FAD condition. c–l, Data are mean ± s.e.m. c–f, n = 3 biological independent samples. d, e, g–j, Statistical analyses (unpaired two-sided Student’s t-test): ns, not significant; *P < 0.05; **P < 0.01; ***P < 0.001. c, f, Statistical analyses (two-sided unpaired Student’s t-test followed by Wilcoxon signed-rank test): *P < 0.05.
