Further evaluation of uPA and PAI-1 as biomarkers for prostatic diseases.

Abstract

To assay for uPA and PAI-1 in prostate tissue from 40 patients with prostatic disease and to examine the robustness of the correlation of the uPA/PAI-1 ratio with benign prostatic hyperplasia (BPH) and prostate cancer (PCa), previously identified in a different cohort of 62 patients. uPA and PAI-1 were extracted from liquid N2 frozen homogenised prostate tissue with TRIS/Triton pH 8.5 buffer and measured by ELISA (FEMTELLE). The concentration of uPA (mean ± SD) was found to be 0.1177 ± 0.0266 (range 0.0070-0.7200; n = 30) and 0.1092 ± 0.0130 (range 0.0040-0.7800; n = 70) for PCa and BPH patients, respectively. The concentration of PAI-1 was found to be 5.236 ± 0.688 ng/mg protein (range 1.10-15.19; n = 30) and 4.975 ± 0.501 ng/mg protein (range 0.20-25.00; n = 70) for PCa and BPH patients, respectively. The mean uPA/PAI-1 ratio was found to be 0.0479 ± 0.0060 (range 0.0043-0.1200; n = 30) in PCa samples and was significantly higher than BPH samples where the ratio was 0.0332 ± 0.0023 (range 0.0040-0.0860; n = 70) (P = 0.0064). In PCa patients older than 68 years, the uPA/PAI-1 ratio was above 0.050 reaching 0.100 in 73-year-old patients. Evaluation of 100 patients with prostatic pathologies (70 PCa; 30 BPH) shows the uPA/PAI-1 ratios in PCa patients to be significantly higher than in BPH patients. This is fully consistent with a previous study on 62 patients (16 were PCa; 46 BPH) where the ratios were 0.055 and 0.031 for PCa and BPH patients, respectively (P = 0.0028). In older PCa patients, uPA/PAI-1 ratios tend to be higher.