The TGF-beta pathway is activated following treatment with DNA hypomethylating agents. (A) Representative Western blot showing that levels of the TGF-beta effector molecule, phosphorylated SMAD3 (p-SMAD3), increase following addition of 5-Aza-dC or TGF-beta 1 in the SKOV4 and OVCAR3 ovarian cancer cell lines. GAPDH was used as an endogenous control. Combined treatment leads to synergistic induction of p-SMAD3. Similar results were obtained using a SMAD3 reporter luciferase assay (B). The average of three experiments is shown. Error bars, SD. *P < 0.05, **P < 0.01, ***P < 0.001. (C) TGF-beta pathway signature probability scores are increased in 39 cell lines following treatment with 5-Aza-dC.