Prostate carcinoma tissue proteomics for biomarker discovery

BACKGROUND. The advent of the prostate-specific antigen (PSA) test has had a profound impact on the diagnosis and treatment of prostate carcinoma. However, the use of PSA levels alone for screening for prostate carcinoma was compromised by the variations in the amount of PSA produced by the benign prostatic tissue specimens. Proteins were involved in various pathways that determine the behavior of a cell. Therefore, information regarding proteins may reveal drug targets and/or markers for early detection. METHODS. The authors used surface-enhanced laser desorption/ionization time-of-flight mass spectrometry to determine the protein profiles from fresh tissues of the prostate. Laser capture microdissection was performed to isolate pure populations of cells. RESULTS. The authors identified a protein with an average m/Z of 24,782.56 +/- 107.27 that was correlated with the presence of prostate carcinoma. Furthermore, using laser capture micro dissection, they demonstrated that the origin of this protein, which the authors designated PCa-24, was derived from the epithelial cells of the prostate. PCa-24 expression was detected in 16 of 17 (94%) prostate carcinoma specimens but not in paired normal cells. In addition, this protein was not expressed in any of the 12 benign prostatic hyperplasia specimens that were assayed. CONCLUSIONS. PCa-24 may be useful a marker for prostate carcinoma. (C) 2003 American Cancer Society.