The -137G/C Polymorphism in Interleukin-18 Gene Promoter Contributes to Chronic Lymphocytic and Chronic Myelogenous Leukemia Risk in Turkish Patients

摘要

Objective: Interleukin-18 (IL-18) is a cytokine that belongs to the IL-1 superfamily and is secreted by various immune andnonimmune cells. Evidence has shown that IL-18 has both anticancer and procancer effects. The aim of this study was toevaluate the relationship between IL-18 gene polymorphisms and susceptibility to chronic lymphocytic leukemias (CLL) andchronic myelogenous leukemias (CML) in Turkish patients.Materials and Methods: The frequencies of polymorphisms (rs61667799(G/T), rs5744227(C/G), rs5744228(A/G), andrs187238(G/C)) were studied in 20 CLL patients, 30 CML patients, and 30 healthy individuals. The genotyping was performedby polymerase chain reaction and DNA sequencing analysis.Results: Significant associations were detected between the IL-18 rs187238(G/C) polymorphism and chronic leukemia. Ahigher prevalence of the C allele was found in CML cases with respect to controls. The GC heterozygous and CC homozygousgenotypes were associated with risk of CML when compared with controls. However, prevalence of the C allele was notsignificantly high in CLL cases with respect to controls. There was only a significant difference between the homozygous CCgenotype of CLL patients and the control group; thus, it can be concluded that the CC genotype may be associated with therisk of CLL. Based on our data, there were no significant associations between the IL-18 rs61667799(G/T), rs5744227(C/G),or rs5744228(A/G) polymorphisms and CLL or CML.Conclusions: IL-18 gene promoter rs187238(G/C) polymorphism is associated with chronic leukemia in the Turkishpopulation. However, due to the limited number of studied patients, these are preliminary results that show the associationbetween -137G/C polymorphism and patients (CLL and CML). Further large-scale studies combined with haplotype andexpression analysis are required to validate the current findings.