The endothelial nitric oxide synthase Glu-298-Asp polymorphism and its mRNA expression in the peripheral blood of patients with prostate cancer and benign prostatic hyperplasia Karina Marangoni MSc, Adriana F. Neves MSc, Alexandra M. Cardoso MSc, Weruska Karyna Santos BS, Paula C. Faria MSc, Luiz R. Goulart PhD * Federal University of Uberla ˆndia, Institute of Genetics and Biochemistry, Molecular Genetics Laboratory, Campus Umuarama, Block 2E, Room 24, 38400-902 Uberla ˆndia, MG, Brazil Accepted 24 September 2005 Abstract Background: The endothelial nitric oxide synthase (ecNOS) has an important role in vascular development and in the carcinogenesis process of prostate cancer (PCa). The nitric oxide (NO) production may promote cancer progression by providing a selective growth advantage to tumor cells, by angiogenic stimulus and by direct DNA damage. Methods: The present study aimed at evaluating the ecNOS Glu-298-Asp polymorphism by the PCR-RFLP technique, associating genotypes with gene expression levels and the tumor biomarker, Prostate Cancer Antigen (DD3), through semi-quantitative RT-PCR. Pre-surgical peripheral blood samples from 160 patients were analyzed: 84 PCa, 11 prostate intraepithelial neoplasia (PIN) and 65 benign prostatic hyperplasia (BPH). Results: The GG and GT Glu-298-Asp genotypes were associated with positive DD3 expression in the peripheral blood, presenting a 3.32-fold higher risk of PCa occurrence. There was no association between genotypes and ecNOS mRNA expression levels; however, the presence of the G allele is closely related to the hematogenous dissemination event of tumoral cells, as evidenced by the DD3 positivity. The higher G allele frequency among pT3 and pT4 staged PCa patients suggests that this would be associated with advanced phenotypes of the disease and may also be contributing to higher NO levels, causing cancer progression. Conclusions: The G allele may have a secondary influence on the prostate cancer predisposition, but an essential role on the event of tumor cells hematogenous dissemination, probably due to the angiogenic stimulus. # 2005 International Society for Preventive Oncology. Published by Elsevier Ltd. All rights reserved. Keywords: Endothelial nitric oxide synthase; Polymorphism; Prostate cancer antigen; Gene expression; ecNOS; Glu-298-Asp polymorphism; Prostatic hyperplasia; Angiogenic stimulus; Reactive oxygen species; Prostate intraepithelial neoplasia; mRNA expression levels; Allelic frequencies; Predisposition 1. Introduction Tumor biological aggressiveness as well as the clinical outcome can present strong variations in human prostate cancer. Detection of genetic alterations may be a useful tool as a molecular indicator of prognosis. Cytogenetic and molecular analyses have demonstrated that human chromosome arm 7q contains a gene that may play an important role in the progression of the human prostate cancer (PCa) [1–5]. The endothelial nitric oxide synthase (ecNOS) is located at 7q35–q36 and seems to have an important role in vascular development, maintenance of the vascular tone and tumor growth in human prostate cancer [6]. The nitric oxide synthases (NOS) are a family of enzymes responsible for the generation nitric oxide (NO) from the amino acid L-arginine [7,8]. The net effects of NO depend on its available concentration, target cell, and interactions with reactive oxygen species (ROS), metal ions, and proteins [9,10]. www.elsevier.com/locate/cdp Cancer Detection and Prevention 30 (2006) 7–13 * Corresponding author. Tel.: +55 34 3218 2478; fax: +55 34 3218 2203. E-mail address: lrgoulart@ufu.br (L.R. Goulart). 0361-090X/$30.00 # 2005 International Society for Preventive Oncology. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.cdp.2005.09.004