Prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) are glycoproteins secreted by prostate epithelial cells, and have a long clinical history of use as serum biomarkers of prostate cancers. These two proteins and many other prostatic-derived proteins are present at significantly higher concentrations in seminal plasma and expressed prostatic secretions (EPS) in urine following a digital rectal exam prostate massage. New advances in mass spectrometry instrumentation and techniques have fueled a renewed emphasis on characterizing alterations in glycan structures on proteins associated with cancers. Previous published studies on a handful of samples have suggested that the presence of different N-linked glycan structures on PSA and PAP could distinguish benign prostate diseases from prostate cancer. Our preliminary data on PSA and PAP glycans derived from large seminal plasma cohorts and comparisons of individual sample spots has confirmed this. A combination of multiple mass spectrometry and ELISA- based approaches to characterizing N-linked glycans derived from PSA and PAP in prostatic fluids are proposed. This approach specifically tests the hypothesis that multiple glycan structural changes are detectable and consistently occur on secreted prostatic proteins like PSA and PAP as prostate cancers progress in disease severity. Our approach represents a paradigm shift for prostate cancer biomarker strategies away from the traditional serum or tissue based sources. It also emphasizes the development of diagnostic assays based on the well described changes in carbohydrate expression of surface and secreted glycoproteins associated with the cancer phenotype. To accomplish these goals, we have assembled a synergistic collaborative team with expertise in prostate cancer translational research and proteomics combined with glycan analysis specialists. The requisite clinical samples, instrumentation and glycan analysis workflows are available to accomplish the following specific aims. 1) Identify N-linked glycan biomarkers on PAP and PSA in proximal prostatic fluids reflective of prostate cancer pathology and disease state. 2) The detection and pre-validation of prostate-disease specific PAP and PSA glycoforms in a large-scale cohort of EPS urines obtained after digital rectal exams. Specific sialic acid and fucose targeted lectin ELISAs will be developed. 3) Identify additional candidate prostatic disease glycoprotein biomarkers in the EPS sample cohort using iTRAQ comparisons, including a comprehensive profile of the glycan changes across disease states. We expect that characterization of the glycans on PSA and PAP will identify molecular markers that improve prostate cancer detection and risk stratification.

Public Health Relevance

The current strengths and limitations of the PSA serum test for early detection and treatment of prostate cancers are well documented, and it is clear new diagnostic biomarkers are needed for this disease. We propose to characterize cancer specific changes in the glycan components of proteins in fluids secreted by the prostate. Identification of these molecular markers will improve prostate cancer detection and risk stratification prior to biopsy and prostatectomy procedures.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
7R01CA135087-04
Application #
8211028
Study Section
Cancer Biomarkers Study Section (CBSS)
Program Officer
Kagan, Jacob
Project Start
2009-03-27
Project End
2014-01-31
Budget Start
2012-04-16
Budget End
2014-01-31
Support Year
4
Fiscal Year
2012
Total Cost
$254,870
Indirect Cost
$61,602
Name
Medical University of South Carolina
Department
None
Type
Schools of Medicine
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Jones, E Ellen; Dworski, Shaalee; Canals, Daniel et al. (2014) On-tissue localization of ceramides and other sphingolipids by MALDI mass spectrometry imaging. Anal Chem 86:8303-11
Jones, Elizabeth Ellen; Powers, Thomas W; Neely, Benjamin A et al. (2014) MALDI imaging mass spectrometry profiling of proteins and lipids in clear cell renal cell carcinoma. Proteomics 14:924-35
Powers, Thomas W; Neely, Benjamin A; Shao, Yuan et al. (2014) MALDI imaging mass spectrometry profiling of N-glycans in formalin-fixed paraffin embedded clinical tissue blocks and tissue microarrays. PLoS One 9:e106255
Drake, Richard R; Kislinger, Thomas (2014) The proteomics of prostate cancer exosomes. Expert Rev Proteomics 11:167-77
Principe, Simona; Jones, E Ellen; Kim, Yunee et al. (2013) In-depth proteomic analyses of exosomes isolated from expressed prostatic secretions in urine. Proteomics 13:1667-71
Powers, Thomas W; Jones, E Ellen; Betesh, Lucy R et al. (2013) Matrix assisted laser desorption ionization imaging mass spectrometry workflow for spatial profiling analysis of N-linked glycan expression in tissues. Anal Chem 85:9799-806
Roper, Stephen M; Zemskova, Marina; Neely, Benjamin A et al. (2013) Targeted glycoprotein enrichment and identification in stromal cell secretomes using azido sugar metabolic labeling. Proteomics Clin Appl 7:367-71
Nyalwidhe, Julius O; Betesh, Lucy R; Powers, Thomas W et al. (2013) Increased bisecting N-acetylglucosamine and decreased branched chain glycans of N-linked glycoproteins in expressed prostatic secretions associated with prostate cancer progression. Proteomics Clin Appl 7:677-89
Principe, Simona; Kim, Yunee; Fontana, Simona et al. (2012) Identification of prostate-enriched proteins by in-depth proteomic analyses of expressed prostatic secretions in urine. J Proteome Res 11:2386-96
Yang, Lifang; Nyalwidhe, Julius O; Guo, Siqi et al. (2011) Targeted identification of metastasis-associated cell-surface sialoglycoproteins in prostate cancer. Mol Cell Proteomics 10:M110.007294

Showing the most recent 10 out of 12 publications