A) 22Rv1 and LNCaP cells were treated with RE-40 for 24 hrs after which whole cell lysates were prepared and analyzed for expression of pro apoptotic protein, Bax, by Western blotting. Equal loading of protein was confirmed by probing with β-actin antibody. B) Apoptosis induction after 24 hrs of 0 and 50 µg/ml RE-40 treatments in 22Rv1 and LNCaP cells was assessed by TUNEL assay. For both cell lines the first column shows: DAPI-stained nuclei appear blue, second column: FITC-stained nuclei appear green showing induction of apoptosis, third column: merged picture of DAPI and FITC. Cells were also treated with etoposide as a positive control for apoptosis. C) Cleaved caspase-3 levels were detected by ELISA in 22Rv1 and LNCaP cells after treatment with 0, 20, 40 and 50 µg/ml RE-40 for 24hrs. Columns, results are mean of two different experiments performed in duplicate; bars, SD. *P<0.05, ***P<0.001, RE-40 treated samples versus controls.