Urinary CD14 as a potential biomarker for benign prostatic hyperplasia - discovery by combining MALDI-TOF-based biostatistics and ESI-MS/MS-based stable-isotope labeling.

Purpose: Quest for specific urinary biomarkers for benign prostatic hyperplasia (BPH).

Experimental Design: Proteomics studies were conducted with urines of the training set to discovering marker candidates that could differentiate BPH from normal subjects by matching results deduced from MALDI-TOF of individual samples and results deduced from nanoLC-ESI-MS/MS-based stable isotope dimethyl labeling of two pooled samples (BPH and normal). Samples were digested before analysis and such an approach takes into account the subject-to-subject variation and differential amount, as well as protein identification.