Role of cytokines in intercellular signalling.

<p>(a) 3–10 ng/ml TGF-β1 had no effect on proliferation of MCF7 in mass culture (3 days incubation of proliferation test with vital dye alamarBlue). Inhibition of Mv1Lu cells confirmed the activity of TGF-β1. (b) No effect of 3–10 ng/ml TGF-β1 on colony formation of MCF7 cells. (c) Detection of cytokines expressed in CM from 15 Gy irradiated and unirradiated MCF7 cultures. No significant difference was observed (P = 0.46–0.95). The presence of the CM-mediated inhibitory effect on colony formation was verified in each experiment (not shown). Mean±standard errors (n = 3) are shown. None of the complete set of 36 cytokines tested showed a significant difference (P = 0.18–0.96). See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0084991#pone.0084991.s001" target="_blank">Figure S1</a>.