Prev. Article Next Article Table of Contents

Article

Proteomic Analysis of Conditioned Media from the PC3, LNCaP, and 22Rv1 Prostate Cancer Cell Lines: Discovery and Validation of Candidate Prostate Cancer Biomarkers

Supporting Info

Girish Sardana^†^‡, Klaus Jung^§, Carsten Stephan^§ and Eleftherios P. Diamandis*^†^‡

Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada, Department of Urology, Charit

Universit

tsmedizin Berlin, Germany, and Department of Clinical Biochemistry, University Health Network and Toronto Medical Laboratories, Toronto, Ontario, Canada.

J. Proteome Res., 2008, 7 (8), pp 3329–3338

DOI: 10.1021/pr8003216

Publication Date (Web): June 26, 2008

†

University of Toronto.

‡

Mount Sinai Hospital.

CharitUniversittsmedizin Berlin.

* To whom correspondence should be addressed. Dr. E. P. Diamandis, Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, 60 Murray Street, Room 6-201, Toronto, Ontario, M5T 3L9, Canada. Tel: 416-586-8443. Fax: 416-619-5521. Email: ediamandis@mtsinai.on.ca.

University Health Network and Toronto Medical Laboratories.

Abstract

Early detection of prostate cancer is problematic due to the lack of a marker that has high diagnostic sensitivity and specificity. The prostate specific antigen (PSA) test, in combination with digital rectal examination, is the gold standard for prostate cancer diagnosis. However, this modality suffers from low specificity. Therefore, specific markers for clinically relevant prostate cancer are needed. Our objective was to proteomically characterize the conditioned media from three human prostate cancer cell lines of differing origin [PC3 (bone metastasis), LNCaP (lymph node metastasis), and 22Rv1 (localized to prostate)] to identify secreted proteins that could serve as novel prostate cancer biomarkers. Each cell line was cultured in triplicate, followed by a bottom-up analysis of the peptides by two-dimensional chromatography and tandem mass spectrometry. Approximately, 12% (329) of the proteins identified were classified as extracellular and 18% (504) as membrane-bound among which were known prostate cancer biomarkers such as PSA and KLK2. To select the most promising candidates for further investigation, tissue specificity, biological function, disease association based on literature searches, and comparison of protein overlap with the proteome of seminal plasma and serum were examined. On the basis of this, four novel candidates, follistatin, chemokine (C-X-C motif) ligand 16, pentraxin 3 and spondin 2, were validated in the serum of patients with and without prostate cancer. The proteins presented in this study represent a comprehensive sampling of the secreted and shed proteins expressed by prostate cancer cells, which may be useful as diagnostic, prognostic or predictive serological markers for prostate cancer.

View: Full Text HTML | Hi-Res PDF | PDF w/ Links