Fig. 1

bCAFs reduce BCL-2 dependency in luminal breast cancers. a Outgrowth of CAFs from partially enzymatically digested tissue of human breast tumor resections (left panel) and the resulting in vitro primo-culture (right panel) showing a homogenous fibroblastic phenotype. b Immunofluorescence of Pan Cytokeratin (green) in bCAFs and ZR-75-1 cell line, nuclei were stained in blue (4′,6-diamidino-2-phenylindole, DAPI). c Immunofluorescence of α-smooth muscle actin (α-SMA) and Fibroblast activation protein (FAP) (green) in NF and CAF (left panel) and in NHLF+ /- TGF-β (right panel), nuclei were stained in blue (4′,6-diamidino-2-phenylindole, DAPI). Images of fibroblasts (NF, CAF, left) or (NHLF+ /- TGF-β, right) contraction of collagen gels after 3 h. d-i Protective effects of media conditioned by bCAFs on ZR-75-1 cells (e, f, h, i) or T-47D cells (g). The indicated tumor cells were treated for 48 h with (e) Doxorubicin (2.5 µM)/5-Fluorouracil (27.5 µM)/Cisplatin (55 µM) or (f, g, h, i) ABT-737 (1 µM or 5 µM, as indicated) in presence of non-conditioned media (Control) or media conditioned for 48 h by normal fibroblast (NF), normal human lung fibroblast (NHLF) (pre-treated or not by TGFβ, overnight), or cancer-associated fibroblasts (CAFs) as indicated. Percentage of positive Annexin-V-FITC apoptotic cells was measured by flow cytometry in e, f, g; percentage of cytochrome C negative cells was measured by flow cytometry in h; Caspase 9 activity was measured by caspase Glo assay and expressed as fold change relative to the control (untreated w/o CAFs conditioned media) in i. Data are means ± SEM from three independent experiments. P-value was determined by two-way ANOVA. ***P < 0.001, ****P < 0.0001, ns: not significant