Death receptor 4 (DR4) gene is a candidate tumor suppressor gene that has a role in apoptotic pathway. It was reported in literature that polymorphisms in DR4 gene lead to susceptibility to many cancers. In accordance with this information, we aimed to investigate the association between G422A, C626G, A683C and A1322G polymorphisms in DR4 gene and lung cancer. We selected 60 patients with lung cancer (LC) and 30 healthy, sex and age matched volunteers randomly. Four polymorhisms, G422A, C626G, A683C and A1322G, in DR4 gene were analyzed with Polymerase Change Reaction (PCR)--Restriction Fragment Lenght Polymorphism (RFLP) and Amplification Refractory Mutation System (ARMS) techniques in both groups. Our results showed that there are no statistically significances between the patients and controls in terms of the G422A, C626G, A683C and A1322G polymorphisms in DR4 gene (p > 0,05). Our findings showed no role of DR4 gene polymorphisms in susceptibility to LC and provide a plausible explanation for DR4 genetic heterogeneity in LC susceptibility.

Background: Recent studies have reported that Nramp1 polymorphisms might have an important role in the development of tuberculosis in various populations. In this study, we aimed to determine Nramp1 polymorphisms in our patients with tuberculosis population. Methods: We enrolled 127 patients with active tuberculosis and 116 healthy adults with similar age and gender. Peripheral blood samples were taken for determining the Nramp1 polymorphisms. By using Polymerase Chain Reaction (PCR)-Restriction Fragment Length Polymorphisms (RFLP) technique, we evaluated the polymorphisms of Nramp1 at the regions of D543N and INT4. Results: We found that the Nramp1 polymorphisms at the region of D543N (OR: 0.44, 95%CI: 0.09-2.06 for GA allele) were not a risk factor for tuberculosis. Furthermore, we could not able to detect Nramp1 polymorphism at the regions of INT4 (OR: 0.97, 95%CI: 0.55-1.72 for GC allele and OR: 0.90, 95%CI: 0.21-3.77 for CC allele). Conclusion: The fi ndings of the present study do not support the hypothesis that Nramp1 at the regions of D543 and INT4 might play a role in infl uencing the growth of bacilli and progression of cavitary tuberculosis rather than susceptibility to M. tuberculosis infection. Future studies are needed to elucidate the role of Nramp1 variants in the pathogenesis of tuberculosis (Tab. 3, Ref. 29).