Anti-neoplastic effects of ErPC3 and ionizing radiation on prostate cancer cells. The prostate cancer cell lines PC3, DU145, and LNCaP, were irradiated (RT) with 2, 5, or 10 Gy (A-C) or treated with 1-100 µM ErPC3, as indicated (D-F). 48 h after treatment a WST-1 Assay was performed. The absorption correlates with the number of viable cells and was normalized to that of untreated controls. PC3 (A) and DU145 (B) were not affected by ionising radiation whereas the number of viable LNCaP cells was reduced 48 h after irradiation (C). All cell lines responded to ErPC3-treatment in a concentration-dependent manner. The androgen-independent cell line PC3 was most sensitive to ErPC3 (D). 25 µM ErPC3 reduce the number of viable PC3 cells by approximately 50% whereas 50 µM ErPC3 were needed to affect the viability of DU145 (E) and PC3 cells (F).