100 DNA AND CELL BIOLOGY Volume 26, Number 2, 2007 © Mary Ann Liebert, Inc. Pp. 100–107 DOI: 10.1089/dna.2006.0534 The Association of 5-Reductase II (SRD5A2) and 17 Hydroxylase (CYP17) Gene Polymorphisms with Prostate Cancer Patients in the Turkish Population ILKE HACER ONEN, 1 ABDULLAH EKMEKCI, 1, * MUZAFFER EROGLU, 2 FAZLI POLAT, 3 and HASAN BIRI 3 ABSTRACT To date, research has led to the invention of multiple genes and their single nucleotide polymorphisms (SNPs) and environmental factors that influence the prostate cancer (PCa) pathogenesis. Therefore, the genes in- volved in these pathways are candidates for PCa predisposition. It is thought that polymorphisms of 5-re- ductase II (SRD5A2) and 17 hydroxylase (CYP17) genes are likely to increase susceptibility. The aim of this study was to investigate the risk association of SRD5A2 and CYP17 gene polymorphisms in the development and progression of PCa in the Turkish population. In this study, 100 PCa patients and 105 healthy controls were studied. SRD5A2 and CYP17 gene polymorphisms were determined by real-time PCR and polymerase chain reaction-restriction length polymorphisms (PCR-RFLP) techniques. First, the AT and TT genotypes of SRD5A2 gene at codon 49 were not observed. Second, there was no significant association between the poly- morphisms at codon 89 and the risk of PCa. Third, in the CYP17 gene, the A1A1 genotype is more common (46%) in cases than controls (32.4%). The odds ratios (ORs) of the A1A1 genotype was found at 1.69 (95% confidence interval [CI], 0.77–3.74) compare with the A2A2 genotype. Genotyping results of the SRD5A2 and CYP17 genes were also analyzed in relation to prostate-specific antigen (PSA) levels, Gleason score (GS), and tumor stage, but no statistically significant difference was observed (P  0.05). Finally, we conclude that there was no evidence of an association between CYP17 (P  0.134) and SRD5A2 (P  0.784) polymorphism and PCa risk in the Turkish population. INTRODUCTION P ROSTATE CANCER (PCa) is one of the most common diseases in developed countries (Makridakis et al., 1997; Gsur et al., 2000; Nwosu et al., 2001). PCa is a multifactorial disease, yet its etiology is still unclear. It is thought that advanced age, eth- nicity, family history, diet, environmental, and genetic factors are the most important risk factors (Lunn et al., 1999; Kittles et al., 2001; Nwosu et al., 2001). There is a relationship be- tween development of prostatic diseases and the high level of androgens (Kittles et al., 2001). After castration, males neither develop benign prostate hyperplasia (BPH) nor PCa (Bjelfman et al., 1997; Schatzl et al., 2002). It is assumed that variations in the androgen metabolism pathway may affect the develop- ment and progression of the disease (Lunn et al., 1999; Kittles et al., 2001). It is found that PCa incidence varies among eth- nic groups (Jemal et al., 2003). The reasons for the ethnic dif- ferences in PCa incidence could be polymorphism of genes as- sociated with androgen metabolism including SRD5A2 and CYP17 (Habuchi et al., 2000; Zeigler-Johnson et al., 2002). Increased level of dihydrotestosterone (DHT)—the most po- tent androgen in prostate—could affect the risk of developing PCa. 5-reductase (SRD5A2) converts testosterone to DHT with NADPH as the cofactor (Makridakis et al., 1997). Poly- 1 Department of Medical Biology and Genetics, 3 Department of Urology, Faculty of Medicine, Gazi University, Besevler, Ankara, Turkey. 2 Department of Urology, Faculty of Medicine, Abant Izzet Baysal University, Golkoy, Bolu, Turkey.