1. ¹Department of Urology, SUNY Upstate Medical University, Syracuse, New York, USA
2. ²Department of Medicine, SUNY Upstate Medical University, Syracuse, New York, USA
3. ³Department of Obstetrics and Gynecology, Ohio State University, Columbus, Ohio, USA
4. ⁴VA Medical Center, Syracuse, New York, USA

Correspondence: GP Haas, Department of Urology, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA. E-mail: haasg@upstate.edu

Received 10 May 2005; Revised 16 July 2005; Accepted 20 July 2005; Published online 20 September 2005.

Abstract

Prostate-specific membrane antigen (PSMA) is a target for immunotherapy of prostate cancer. It has been shown that antibodies against PSMA inhibited the in vivo growth of LNCaP tumor. In the present study, monoclonal antibodies against four epitopes in PSMA were raised. MAb 24.4E6 (IgG1), specific for the epitope (residues 638–657) in PSMA, significantly reduced the growth rate of established LNCaP tumor in SCID mice. Mouse IgG was detected in the tumor of mice treated with 24.4E6, but not with an unrelated MAb. These results suggest that this epitope may be the main target in PSMA for antibody therapy of prostate cancer.