Fig. 5.

Role of SIRPα in the macrophage-dependent antitumor effect of MY-1 on murine bladder cancer cells. (A and D) CFSE-labeled MB49 cells were cocultured for 16 h with BMDMs from WT or Sirpa^−/− mice in the presence of control IgG, MY-1 (A), or P84 (D), each at 10 μg/mL, after which the number of cancer cells was determined as in Fig. 2A. (B) WT or Sirpa^−/− BMDMs were treated with control IgG or MY-1 (each at 10 μg/mL) for 48 h, after which culture supernatants were collected and assayed for TNFα. (C) Tumor volume for Sirpa^−/− mice injected subcutaneously with MB49 cells and treated intraperitoneally with either control IgG or MY-1 (each at 200 μg) according to the indicated schedule. (E) TNFα production by C3H BMDMs treated with control IgG, MY-1, or P84 (each at 10 μg/mL) for 48 h was determined as in B. (F) Tumor volume for C3H mice injected subcutaneously with MBT2 cells and treated intraperitoneally with control IgG, MY-1, or P84 (each at 200 μg) according to the indicated schedule. All quantitative data are means ± SEM for three separate experiments, each performed in triplicate (n = 9 for each group) (A, B, D, and E), or for n = 10 mice (C) or n = 9 (control IgG or P84) or 10 (MY-1) mice (F) per group examined in two separate experiments. *P < 0.05, **P < 0.01, ***P < 0.001, NS by Welch and Brown–Forsythe ANOVA with Dunnett’s T3 multiple-comparison test (A, B, D, and E) or by two-way repeated-measures ANOVA with the Greenhouse–Geisser correction and Šídák's multiple-comparison test (C and F).