Fig. 4

Anti-interleukin-8 (αIL-8) decreased vascular endothelial growth factor (VEGF) and CCL5 secretion, which affected estrogen receptor positive (ER+) breast cancer cells (BCC) dissemination. For monolayer co-cultures, breast pre-adipocytes were differentiated for 5 days before ER+ BCC were added at 4 × 10³ cells/well. For zebrafish experiments, breast pre-adipocytes were differentiated for 12 days, MCF-7 cells were cultured + β-estradiol (E2) 1 nM for 48 h and labeled with 4 µg/ml Fast DiI™ oil red dye before injected into the perivitelline space of 2 days old zebrafish embryos, which expressed enhanced green fluorescent protein in endothelial cells. (A) MCF-7 cells were co-cultured with 50% breast adipocytes (BAd) in the presence or absence of αIL-8, anti-VEGF (αVEGF), or control isotype (Iso) antibodies at 1 µg/ml during 3 days in the presence of E2 1 nM, and secreted cytokines were quantified as described in Section “Materials and Methods,” n = 5–4 in each group. (B) T47D cells were co-cultured with 50% BAd in the presence or absence of αIL-8, αVEGF, or control Iso antibodies at 1 µg/ml during 3 days in the presence of E2 1 nM, and secreted cytokines were quantified as described in Section “Materials and Methods,” n = 6–5 in each group. (C) MCF-7 cells were injected in zebrafish embryos alone or in combination with 50% BAd ± anti-CCL5 (αCCL5) or Iso control antibody at 0.1 mg/ml and E2 1 nM, as described in Section “Materials and Methods.” MCF-7 dissemination was analyzed 3 days post-injections, n = 13–27 in each group. Representative images of zebrafish embryos are shown. Arrows show disseminated BCC cells. BV = blood vessels. Results are presented as mean ± SEM, Student’s t-test, *p < 0.05, ***p < 0.001. Data are representative of at least two independent experiments.