Fig. 3.

Radiation induces BMP-mediated SIRT1 expression. a Fold change of SIRT1 mRNA in benign prostate and prostate cancer patients, obtained from R2-Genomics analysis is expressed (n = 95). b SIRT1 mRNA expression was measured in 22Rv1 under serum-free conditions with 50 ng/ml BMP4, in the context of increasing doses of TRC105 (0.05, 0.1, 0.5, 1, 5, or 10 µg/ml) or with 50 ng/ml noggin. SIRT1 mRNA expression was normalized to GAPDH and to serum-treated control. c Western blot for phosphorylated Smad1/5, SIRT1, and β-actin expression was measured in 22Rv1 cells following serum starvation and treatment with 50 ng/ml BMP4. Densitometric quantitation is indicated under each band. d SIRT1 and p21 protein expression was measured 72 h after irradiating (4 Gy) 22Rv1 and PC3 cells in the presence of IgG or TRC105 prior to irradiation. e γ-H2AX (green) was immunolocalized in PC3 cells following treatment with IgG, TRC105, and 4 Gy irradation at 4 h. Cells were nuclear counterstained with DAPI (blue). Foci per nuclei were quantified (n = 100) (****p < 0.0001 as compared to control). f Clonogenic survival assay was performed on p53-null PC3 cells at indicated doses of radiation. No significant (NS) radiation sensitization was had with TRC105 compared to IgG control. mRNA expression are reported as a mean ± S.D. (**p < 0.01, ***p < 0.001, ****p < 0.0001, compared to control)