Infertile men with abnormal semen analyses have a 20-fold greater incidence of testicular cancer compared to the general population. Patients and physicians should be aware that one of the causes of infertility could be cancer, particularly testicular cancer.
Purpose: Neutral endopeptidase (NEP) is a cell-surface peptidase that inactivates neuropeptide growth factors implicated in prostate cancer progression. The clinical significance of decreased NEP expression observed in prostate cancer is unclear. We investigated whether decreased NEP expression in localized prostate cancers is associated with prostate-specific antigen (PSA) relapse after radical prostatectomy.Experimental Design: NEP expression patterns were examined by immunohistochemistry in 223 men, who underwent radical prostatectomy between 1990 and 2000 at the Veterans Administration Medical Center (New York, NY) with available representative tissues and adequate follow up. We also examined whether hypermethylation of the NEP promoter contributes to down-regulation of NEP protein expression in a subset of patients that showed decreased NEP expression (n ؍ 22).Results: Three patterns of NEP expression were observed: (a) membranous expression similar to benign prostate epithelium (n ؍ 82; 37%); (b) complete loss of NEP expression in prostate cancer compared with adjacent benign prostate glands (n ؍ 105; 47%); and (c) heterogeneous NEP expression (n ؍ 36; 16%). In a multivariate analysis, complete loss of NEP expression was associated with PSA relapse after controlling for grade, stage, pretreatment PSA, and race simultaneously (hazard ratio, 1.99; 95% confidence interval, 1.13-3.52; two-sided 2 P ؍ 0.017). In addition, DNA hypermethylation of the NEP promoter was frequently (73%) identified in a subset of 22 of cases that showed decreased NEP expression.Conclusion: Our data suggest that decreased NEP expression might contribute to progression of localized prostate cancer after surgery. Data also suggest that methylation is an important mechanism of NEP protein silencing. Larger prospective studies are required for confirmation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.