Fig. 8

Concentration of granulocyte colony-stimulating factor (G-CSF) in culture (in vitro) and in serum (in vivo) in mice bearing different breast cancer cell lines compared to the number of myeloid derived suppressor cells (MDSCs) in spleen. a The 4T1, 4T07, 67NR, 66Cl4 and 168FARN were seeded on separate T25 flasks and cultured for 48 h. G-CSF concentrations from culture supernatants were determined by ELISA. b Balb/cByJ mice were subcutaneously injected with 1 × 10⁶ 4T1 cells (n = 5), 5 × 10⁶ 4T07 cells (n = 3), 1 × 10⁶ 168FARN (n = 3), 1 × 10⁶ 67NR (n = 5) and 3 × 10⁶ 66Cl4 (n = 5). When tumor volumes reached 500 mm³, blood and spleens were harvested. Serum G-CSF concentrations were determined by ELISA. c Absolute numbers of MDSCs (CD11b⁺Ly6G⁺Ly6C⁺) among splenocytes from the same tumor-bearing mice were determined by flow cytometry. Results are representative of two independent experiments. Data are presented as mean ± standard error (*p < 0.05, **p <30.01 via one-way analysis of variance with Tukey’s post-hoc analysis)