Figure 5
From: Telomeric DNA induces apoptosis and senescence of human breast carcinoma cells
T-oligo and telomeric repeat binding factor dominant negative construct (TRF2DN) activate cell cycle- and apoptosis-regulatory proteins in breast cancer cells. (a) Compared with control oligo (C) and diluent (D) alone, T-oligo (T) substantially induced the phosphorylation of p53 (Ser15), p95/Nbs1 (Ser343) and H2AX (Ser139) and the level of E2F1. In MCF-7 cells, T-oligo also induced the phosphorylation of ataxia telangiectasia mutated (ATM; Ser1981) and the levels of p53 and the p53-dependent p21 and BAX proteins. (b) Compared with control oligo (C) and diluent (D), T-oligo (T) only slightly induced the phosphorylation of p53 and H2AX in normal mammary epithelial (NME) cells. (c) Graphic representation of band intensity as fold induction above diluent. (d) adenovirus (Ad)TRF2DN, but not the control Ad-green fluorescent protein (GFP) vector, induced the phosphorylation of H2AX and p53 in MCF-7 cells. c-myc expression confirms successful transfection of the cells with AdTRF2DN. Actin serves as a loading control. One of three representative experiments is shown.