Figure 3

TG2-mediated IL-6 allows anchorage-independent survival of cancer cells. (a) Control and TG2-knocked-down MDA-MB-231 cells were cultured in serum-free medium consisting of a 1:1 mixture of Ham F-12 and DMEM, supplemented with growth factors. Visible spheres were counted under a microscope on day 8 after plating. Data represent mean ± SD based on three independent experiments using samples from triplicate cell cultures. (b) Phase-contrast microscopy of day 8 spheres generated from the MDA-MB-231 cell line. Data shown are representatives of three independent experiments. (c) cIAP2 and Bcl-2 expression was analyzed with Western blot after culture for the indicated time in sphere medium. (d) TG2, fibronectin (FN), N-cadherin (N-Cad), and vimentin expression of control, TG2-knocked-down, and IL-6-knocked-down MDA-MB-231 cells analyzed with Western blot. IL-6, interleukin 6; SD, standard deviation; TG2, transglutaminase 2.