Extended Data Fig. 9: Genetic inhibition of IL-23 limits resistance to castration in prostate cancer in TRAMP-C1 allograft model in vivo.
From: IL-23 secreted by myeloid cells drives castration-resistant prostate cancer
a, Schematic representation of the experiment. Six-week-old C57BL/6 males were lethally irradiated and transplanted with bone marrow precursors from Il23aWT and Il23aKO mice. After the bone marrow engraftment, the animals were challenged subcutaneously with TRAMP-C1 cells. When tumours reached approximately 100 mm3, mice were surgically castrated and monitored for tumour progression. b, Haematoxylin and eosin, Ki-67 and pSTAT3(Y705) immunohistochemical staining (Ki-67 and pSTAT3(Y705), brown; nuclei, blue) of representative TRAMP-C1 Il23aWT and TRAMP-C1 Il23aKO mice. Scale bars, 25 μm. c, Quantification of Ki-67+ cells is reported as a percentage of the total number of cells. TRAMP-C1 Il23aWT (n = 8) and TRAMP-C1 Il23aKO (n = 4), one tumour per mouse, mean of three sections per tumour, ≥3 fields per section. Data are mean ± s.e.m. of biologically independent mice. Statistical analyses (unpaired two-sided Student’s t-test): **P < 0.01. d, e, PMN-MDSC frequencies determined by flow cytometry in the tumour and in the spleen of TRAMP-C1 Il23aWT (n = 3) and TRAMP-C1 Il23aKO (n = 3) mice 10 days after castration. Data are mean ± s.e.m. f, Quantification of pSTAT3(Y705) reported as a percentage of the total number of cells. TRAMP-C1 Il23aWT (n = 8) and TRAMP-C1 Il23aKO (n = 4), one tumour per mouse, mean of three sections per tumour, ≥3 fields per section. Statistical analyses (unpaired two-sided Student’s t-test): ***P < 0.001. g, Western blot for RORγ, pSTAT3(Y705) and total STAT3 levels in prostate tumours of TRAMP-C1 Il23aWT and TRAMP-C1 Il23aKO mice. Loading control: HSP90 antibody or total ERK antibody. The western blot was validated at least twice. h, Quantification is reported as mean ± s.e.m. of biological independent experiments: TRAMP-C1 Il23aWT RORγ, n = 9; and TRAMP-C1 Il23aKO RORγ, n = 9; TRAMP-C1 Il23aWT pSTAT3(Y705), n = 4; and TRAMP-C1 Il23aKO pSTAT3(Y705), n = 3. Statistical analyses (unpaired two-sided Student’s t-test): *P < 0.05.
