The dominance of China 1 in the spectrum of Epstein-Barr virus strains from Cantonese patients with nasopharyngeal carcinoma.

Nasopharyngeal carcinoma is a disease with a remarkable geographic and ethnic distribution, and has a high incidence in southern China. Infection with Epstein-Barr virus (EBV) is an important contributing factor. The profile of EBV strains in Cantonese patients from Guangdong, the nasopharyngeal carcinoma endemic region in southern China, is described on the sequence variations in latent membrane protein 1 carboxyl-terminus. The results show that China 1 was the dominant EBV strain detected in both the tumor biopsies and samples of throat washings, whereas multiple strains, including China 1, China 2, B95-8, and Med, were detected in blood samples. In addition, a new strain named China 4 was found in blood samples. These findings suggest that the host population is susceptible to the predominant China 1 strain in the nasopharyngeal carcinoma endemic region of China, but its relationship with the host remains to be characterized further.

[Family-based association study of XRCC1 gene polymorphisms in nasopharyngeal carcinoma].

OBJECTIVE: To test the association between XRCC1 gene polymorphisms and susceptibility of nasopharyngeal carcinoma in Cantonese nuclear families through a family-based association study. METHODS: A total of 2134 study subjects from 457 Cantonese nuclear families were recruited in the study. Each family had two parents and at least one offspring with nasopharyngeal carcinoma. Genotyping for three single nucleotide polymorphisms in XRCC1 gene, including rs1799782 (C > T), rs25489 (G > A) and rs25487 (G > A), were performed with PCR-RFLP assay. The genotype data were analyzed with family-based association test (FBAT) software to check linkage and association between the three genetic markers and susceptibility of nasopharyngeal carcinoma. RESULTS: FBAT analysis showed XRCC1 gene genotypes and haplotypes were not significantly associated with nasopharyngeal carcinoma in our study population (rs1799782: chi(2) = 1.006, P = 0.605; rs25489: chi(2) = 0.470, P = 0.790; rs25487: chi(2) = 2.563, P = 0.278; haplotype: chi(2) = 3.004, P = 0.557, global statistic). For rs25487, the G allele (major allele) showed increased transmission under dominant model (Z = 1.985, P = 0.047). Whereas the C allele (minor allele) exhibited reduced transmission under recessive model (Z = -1.985, P = 0.047). However, no increased/reduced transmission was observed under additive model and with global statistic. CONCLUSION: There is no evidence of an association between polymorphisms in XRCC1 gene and susceptibility of nasopharyngeal carcinoma in Cantonese nuclear families is observed in this study.