Some new characteristics of urinary Tamm-horsfall glycoprotein-its possible use as a prostate cancer biomarker

INTRODUCTION: In the present study, we examined concentrations and chemical forms of urinary Tamm-Horsfall glycoprotein (THP) in patients with prostate cancer (PCa) as well as in healthy subjects with the aim of establishing whether urinary THP can serve as a novel tumor marker for PCa METHODS: To determine the significance of THP in PCa cases, urinary THP concentrations were measured by an enzyme-linked immunosorbent assay in samples obtained from 25 healthy subjects and 25 PCa patients. The glycosylphosphatidylinositol (GPI) anchor of THP was determined by two-dimensional electrophoresis and mass spectrometry examinations. Serial lectin affinity chromatography was performed to identify the sugar chain in urinary THP using samples from 6 of the healthy subjects and 6 of the PCa patients. RESULTS: The concentration of urinary THP was significantly higher in the PCa patients than in the healthy subjects (p= 0.0446). Our results confirmed that none of the tested THP samples exhibited a GPI-anchor when examined using two-dimensional mass spectrometry. Interestingly, the amount of biantennary complex type of sugar chains with fucose in THP was lower in the healthy subjects, while the amounts of high-mannose type and hybrid type sugar moieties in THP were lower in the PCa patients. CONCLUSIONS: This is the first study to show the unique characteristics of urinary THP in PCa patients. Additional studies may validate the significance of THP as a urine biomarker for PCa.