Profiling Urine Glycosylation of PSA and other Glyco-Biomarkers in Prostate Cance

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DESCRIPTION (provided by applicant): Urine represents an easily available yet largely discarded potential source of biomarkers of urogenital cancers. Biomarkers of cancer appear in urine, even from remote cancers such as lung and breast. We observed significant levels of both prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) in the urine from healthy individuals, consistent with some earlier findings. While PSA is the current biomarker for prostate cancer (PC), its reliability is hampered by variations in the baseline level between individuals, and the inconsistency in measurements made by the variety of kits available. There is an urgent need for establishing a clinically pertinent assay for the characterization of PSA (and PAP) produced in PC, benign prostatic hyperplasia (BPH) and that released by healthy cells, one that can be reliably used for the early detection, prognosis and monitoring of prostate cancer. Both PSA and PAP are glycosylated and changes in glycosylation go hand-in-hand with cancer. Recent reports have shown that changes occur in the glycosylation of PSA in cancer but were measured in different body fluids (serum for PC and seminal fluid for healthy), and effectively in only one patient. We have developed a method (GlycoMatic) for profiling glycosylation at individual sites in enriched proteins. We will refine isolation approaches to enrich the PSA, PAP and such other prostate-specific glycoproteins as may be detected in clinical samples. We will test the technique against standards and standards spiked into urine samples from healthy individuals, the ability to get reproducible determinations, and the stability of the glycoproteins when stored under less than ideal conditions. To eliminate any changes attributable to genetic or epigenetic make-up, variations in the individual PSA and PAP glycosylation profiles will be established using urines from 60 normal volunteers. Information on variables such as age and ethnicity will be factored into the analyses which will result from a population with a significant minority component. The PSA and PAP glycosylation profiles will be determined for a cohort of 60 (of each) PC and benign prostatic hyperplasia (BPH) patients and compared to that from the healthy volunteers. The ability to obtain glycosylation profiles for clinical trials is a new field. Thus, computational methods will be established that show the reliability of the data within individuals, within each classification of the disease, and correlated with disease status, Gleason score and PSA serum levels. This research breaks new ground and will establish the clinical applicability for the use of glycosylation profiles of biomarker proteins in the early detection, prediction and monitoring of cancer. It will also identify and distinguish any changes due to ethnicity. Prostate specific antigen (PSA) is a well-established test for the early detection and monitoring of prostate cancer (PC). Despite this, its determination is hampered by variation in the basal level between individuals, and the inconsistency in measurements made by the variety of kits available. PSA produced in cancer is modified (glycosylated) and this limited clinical trial will establish the differences, and determine if these are specific enough to clearly distinguish PC produced PSA from that normally produced by a healthy prostate. Prostatic acid phosphatase, an earlier glycoprotein biomarker of prostate cancer, will be similarly studied. Analyses will be performed in urine, leading to the possibility of a self-administered test for PC.