The xeroderma pigmentosum group C gene polymorphisms and genetic susceptibility of nasopharyngeal carcinoma

Nasopharyngeal cancer (NPC) is a multi-factorial disease, and the genetic background may be a crucial etiologic factor. The xeroderma pigmentosum complementation group C (XPC) is mainly involved in DNA damage repair, and the sequence variants in XPC gene may modulate DNA repair capacity and consequently lead to an individual's susceptibility to NPC. The aims of this study were to examine the association between XPC Val499Ala, Lys939Gln, PAT polymorphisms and the genetic susceptibility of nasopharyngeal carcinoma (NPC) in Chinese population.

We analyzed the three XPC gene polymorphisms in 153 patients with NPC and 168 age- and sex-matched controls in a Chinese population, using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) procedure.

There were significant differences in the genotype and allele distribution of XPC Val499Ala among cases and controls. The 499Val allele carriers were associated with a significantly increased risk of NPC compared with the non-carriers (OR=1.603; 95%CI,1.160 approximately 2.216, p=0.005). Consistent with the results of the genotype analysis, the 499Val/939Lys/PAT haplotype was associated with a significantly increased risk of NPC as compared with the 499Ala/939Lys/PAT haplotype (OR=1.901;95% CI, 1.284 approximately 2.814, p=0.002). The interaction between the Val499Ala polymorphism and gender or smoking status did not been found in NPC risk.

Our data demonstrated that XPC 499Val allele and its haplotype were strongly associated with NPC, which indicated that Val499Ala polymorphism may be a contributing factor in the NPC development.