Tracking prostate carcinogenesis over time through urine proteome profiling in an animal model: an exploratory approach

The urgent need for new tools for the early diagnosis of prostate cancer (PCa) has prompted us to investigate the proteomic profile of urine during the course of prostate carcinogenesis. Using an established animal model of prostate adenocarcinoma, we performed a comprehensive analysis of the proteomic profile of urine from healthy animals and animals with adenocarcinoma at two time points. At the second time point of prostate carcinogenesis, the incidence of pre-neoplastic and neoplastic lesions was 100%. GeLC-MS/MS and subsequent bioinformatic analysis revealed several proteins involved in prostate carcinogenesis. Increased levels of retinol-binding protein 4 and decreased levels of cadherin-2 appear to be characteristic of early stages of the disease, whereas increased levels of enolase-1 and T-kininogen 2 and decreased levels of isocitrate dehydrogenase 2 describe more advanced stages. With increasing age, urinary levels of clusterin and corticosteroid-binding globulin increase and neprilysin levels decrease, all of which appear to play a role in prostatic hyperplasia or carcinogenesis. The present exploratory analysis could be considered an important starting point for studies targeting specific human urinary proteins for the early detection of age-related maladaptive changes in the prostate that may lead to cancer.