Human agonistic antibody to tumor necrosis factor-related apoptosis-inducing ligand receptor 2 induces cytotoxicity and apoptosis in prostate cancer and bladder cancer cells.

Department of Urology, Kagawa University Faculty of Medicine, Kagawa, Japan.
Urology (Impact Factor: 2.13). 03/2007; 69(2):395-401. DOI: 10.1016/j.urology.2006.12.007
Source: PubMed

ABSTRACT Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in a variety of tumor cells through two of its receptors: TRAIL-R1 and TRAIL-R2. In this study, we investigated the susceptibility of human prostate cancer and bladder cancer cells to HGS-ETR2, a human monoclonal agonistic antibody specific for TRAIL-R2.
The cell surface expression of TRAIL-R1 and TRAIL-R2 on prostate cancer and bladder cancer cells was determined using flow cytometry. Cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and caspase activities were measured by a quantitative colorimetric assay.
HGS-ETR2 effectively induced apoptotic cell death in DU145, PC3, and LNCaP human prostate cancer cells and J82 and T24 human bladder cancer cells. The increased effectiveness of HGS-ETR2 for inducing cell death might have been affected by differences in the cell surface expression of the two TRAIL receptors, in that TRAIL-R2, but not TRAIL-R1, was frequently expressed in the prostate cancer and bladder cancer cells. HGS-ETR2 significantly activated the caspase cascade, including caspase-3, -6, -8, and -9, which were the downstream molecules of the death receptors in prostate cancer cells. Caspase-3, -6, and -9 were also significantly activated with HGS-ETR2-induced apoptosis in the bladder cancer cells.
These findings suggest the potential utility of TRAIL-R2 antibody as a novel therapeutic agent against prostate cancer and bladder cancer.

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