Recent findings indicate that advanced stage cancers shun the tumor suppressive actions of TGF beta and inexplicably utilize the cytokine as a tumor promoter. We investigated the effect of TGF beta 1 on the survival and proliferation of invasive prostate (PC3) and bladder (T24) cancer cells. Our study indicated that TGF beta 1 decreased cell viability and induced apoptosis in invasive human PC3 and 124 cells via activation of p38 MAPK-JNK-Caspase9/8/3 pathway. Surprisingly, no change in the phosphorylation of pro-survival Akt kinase was observed. We postulate that TGF beta 1 pathway may be utilized for specifically targeting urological cancers without inflicting side effects on normal tissues. (C) 2012 Elsevier Inc. All rights reserved.