Xenbase Image ID: 147668

Figure 6. Ectodermin Limits Smad4 Nuclear Accumulation and TGF-β-Induced Growth Arrest (A–D) Immunofluorescence localization of endogenous Smad4 in control-siRNA- and Ecto-siRNA-depleted HeLa cells, untreated or treated for 90 min with 5 ng/ml TGF-β1 (see Experimental Procedures). Nuclei of the same cells were stained with Hoechst (A′–D′). (E) Western blotting for samples shown in (A)–(D) to demonstrate quantitative depletion of endogenous Ecto by RNAi. (F) Quantitations of HeLa cells displaying nuclear Smad4 (same as pictures shown in [A]–[D]). (A) 18%, n = 266; (B) 46%, n = 536; (C) 49%, n = 305; (D) 79%, n = 965. Error bars are standard deviations. (G) Growth-inhibitory effect of Activin on mock and Ecto-siRNA-treated HepG2 cells, as measured by BrdU incorporation. Columns show the percentage of cells in active DNA synthesis. Inset: the number of BrdU-positive cells in unstimulated cultures was given an arbitrary value of 100%; all other values (Activin treatments) are shown relative to this. Activin is more effective upon Ecto knockdown. (H) Time course of p21WAF1 induction by Activin (20 ng/ml) in mock and Ecto-depleted HepG2 cells. t = 0 is 48 hr after transfection of siRNA. Note that induction of p21WAF1 has an earlier onset and reaches higher levels upon Ecto knockdown. Image published in: Dupont S et al. (2005) Copyright © 2005. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

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