title: Association of the interleukin-2 polymorphisms with interleukin-2 serum levels and risk of nasopharyngeal carcinoma.
abstract: Nasopharyngeal carcinoma (NPC) is one of the most common cancers in southern China. In addition to environmental factors such as Epstein-Barr virus infection and chemical carcinogen exposure, genetic susceptibility has been reported to play a key role in the development of this disease. Interleukin-2 (IL-2) is an immunoregulatory cytokine produced by T cells and plays an important role in antitumor immunity. Variations in the DNA sequence of the IL-2 gene may lead to altered cytokine production and/or activity, and thus modulate an individual's susceptibility to NPC. To test this hypothesis, we investigated whether IL-2 gene polymorphisms and its serum levels are associated with NPC in a Chinese population. We analyzed single-nucleotide polymorphisms of IL-2 gene -330 T/G and +114 T/G in 180 patients with NPC and 200 age- and sex-matched controls, using polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods, and serum IL-2 levels were measured by enzyme-linked immunosorbent assay. Serum IL-2 levels were decreased in patients with NPC compared with controls (p < 0.01). There were significant differences in the genotype and allele frequencies of IL-2 gene -330 T/G polymorphism between the group of patients with NPC and the control group (p < 0.05). Moreover, genotypes carrying the IL-2 -330 G variant allele were associated with decreased serum IL-2 levels compared with the homozygous wild-type genotype in patients with NPC. Carrying the IL-2 -330 G variant allele was associated with a decreased ability to produce IL-2, which may contribute to NPC susceptibility.
authors.affiliation: Department of Medical Laboratory, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China. weiyesheng@yahoo.com.cn
authors.forename: Ye-Sheng
authors.initials: YS
authors.lastname: Wei
authors.forename: Yan
authors.initials: Y
authors.lastname: Lan
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Jian-Chu
authors.initials: JC
authors.lastname: Wang
mesh_terms: D000483:Alleles; D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D002681:China / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D004854:Herpesvirus 4, Human / Q000235:genetics; D006720:Homozygote; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics*; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors
chemical_list: D007376:Interleukin-2