X Steven Wan1, Y Anne Xu, Jeffrey H Ware, Ann R Kennedy. 1. Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104--6072, USA. xswan@mail.med.upenn.edu
Abstract
BACKGROUND: Prostate specific antigen (PSA) has been widely used as a biomarker for the screening and diagnosis of prostate cancer. PSA in serum predominantly exists as a complex with alpha-1-antichymotrypsin (ACT), and measurement of free PSA and the PSA-ACT complex may improve the utility of the serum PSA assay for differential diagnosis of prostate cancer and non-malignant prostate diseases, such as benign prostatic hyperplasia (BPH). METHODS: Monoclonal antibodies (MAbs) against PSA, ACT, and the PSA-ACT complex were produced by immunizing mice with an incubated mixture of PSA and ACT, and characterized by Western blot analyses and several enzyme-linked immunosorbant assay (ELISA) methods. RESULTS: The MAbs produced in this study are capable of distinguishing the PSA-ACT complex from free PSA and ACT. Four MAbs have been selected and utilized to construct three ELISA systems for the separate measurements of free PSA, the PSA-ACT complex, and total PSA. CONCLUSIONS: The three PSA assay systems developed in this study can specifically measure free PSA, total PSA, and the PSA-ACT complex with equal molar sensitivity. It is expected that these PSA assay systems could be useful in the diagnosis of prostate cancer. Copyright 2003 Wiley-Liss, Inc.
BACKGROUND:Prostate specific antigen (PSA) has been widely used as a biomarker for the screening and diagnosis of prostate cancer. PSA in serum predominantly exists as a complex with alpha-1-antichymotrypsin (ACT), and measurement of free PSA and the PSA-ACT complex may improve the utility of the serum PSA assay for differential diagnosis of prostate cancer and non-malignant prostate diseases, such as benign prostatic hyperplasia (BPH). METHODS: Monoclonal antibodies (MAbs) against PSA, ACT, and the PSA-ACT complex were produced by immunizing mice with an incubated mixture of PSA and ACT, and characterized by Western blot analyses and several enzyme-linked immunosorbant assay (ELISA) methods. RESULTS: The MAbs produced in this study are capable of distinguishing the PSA-ACT complex from free PSA and ACT. Four MAbs have been selected and utilized to construct three ELISA systems for the separate measurements of free PSA, the PSA-ACT complex, and total PSA. CONCLUSIONS: The three PSA assay systems developed in this study can specifically measure free PSA, total PSA, and the PSA-ACT complex with equal molar sensitivity. It is expected that these PSA assay systems could be useful in the diagnosis of prostate cancer. Copyright 2003 Wiley-Liss, Inc.