Capillary electrophoresis of urinary prostate glycoproteins assists in the diagnosis of prostate cancer

Abstract

Prostate marker assays are widely used for detection of prostate cancer (PCa) but are associated with considerable sensitivity and specificity problems. Therefore, we investigated prostatic protein glycosylation profiles as a potential biomarker. We determined the urinary asparagine-linked glycan (N-glycan) profile of prostatic proteins of healthy volunteers (n = 25), patients with benign prostate hyperplasia (BPH; n = 62) and newly diagnosed PCa patients (n = 42) using DNA-sequencer-assisted fluorophore-assisted carbohydrate electrophoresis. Through squeezing of the prostate, a sufficient amount of prostatic proteins was obtained for direct structural analyses of N-glycan structures. N-glycans of PCa compared to BPH were characterized by a significant decrease in triantennary structures (p = 0.047) and overall fucosylation (p = 0.026). Prostate-specific antigen (PSA) and the urinary glycoprofile marker showed comparable overall receiver operating characteristic curve analysis as well as in the diagnostic gray zone with serum PSA values between 4 and 10 μg/L. However, when combining PSA and the urinary glycoprofile marker, the latter gave an additive diagnostic value to serum PSA (p ≤ 0.001). In conclusion, N-glycosylation profiling demonstrated differences between BPH and PCa. These changes could lead to the discovery of a new biomarker for PCa.