FIGURE 5.

ATP and UTP promote cell proliferation in breast cancer tissue with minimal effect in normal breast tissue. In contrast, ATP induces cell death only when applied at very high concentration. (A‐D) Representative images (A,C) and corresponding quantifications (B,D) of bromodeoxyuridine (BrdU) incorporation in organoids freshly isolated from breast cancer tissue (A,B) and normal breast tissue (C,D). The organoids (n = 5‐6) were incubated with BrdU for 6 h under control conditions or with ATP or UTP present at the indicated concentrations. All images are shown at the same magnification; the scale bars represent 100 μm. (E + F) Representative images (E) and corresponding quantifications (F) of cell death in freshly isolated breast cancer organoids stained with calcein and ethidium homodimer‐1 (EthD‐1). The isolated organoids (n = 4) were evaluated after a 2‐h control period or following incubation with ATP at the indicated concentration. All images are shown at the same magnification; the scale bar represents 100 μm. Data were compared by one‐way ANOVA followed by Dunnett's posttest. *P < .05; **P < .01; ***P < .001, NS: not significantly different vs control