Sequence Variation Analysis of Epstein-Barr Virus Nuclear Antigen 1 Gene in the Virus Associated XXXX .

@entity706 @entity5 @entity189 @entity281 @entity2025 @entity356
@entity2025 ( @entity2025 ) nuclear antigen 1 (EBNA1) is the only viral protein expressed in all @entity2025 -positive @entity5 as it is essential for the maintenance, replication and transcription of the virus genome. According to the polymorphism of residue 487 in EBNA1 gene, @entity2025 isolates can be classified into five subtypes: P-ala, P-thr, V-val, V-leu and V-pro. Whether these EBNA1 subtypes contribute to different tissue tropism of @entity2025 and are consequently associated with @entity5 remain to be determined. To elucidate the relationship, one hundred and ten @entity2025 -positive @entity706 tissues of different types from Northern China, a non- @entity189 endemic area, were tested for the five subtypes by nested-PCR and DNA sequencing. In addition, @entity2025 type 1 and type 2 classification was typed by using standard PCR assays across type-specific regions of the EBNA3C genes. Four EBNA1 subtypes were identified: V-val (68.2%, 75/110), P-thrV (15.5%, 17/110), V-leuV (3.6%, 4/110) and P-ala (10.9%, 12/110). The distribution of the EBNA1 subtypes in the four @entity706 groups was not significantly different (p = 0.075), neither was that of the @entity2025 type 1/type 2 (p = 0.089). Compared with the previous data of @entity356 ( @entity356 ), @entity189 ( @entity189 ) and throat washing (TW) from healthy donors, the distribution of EBNA1 subtypes in @entity706 differed significantly (p = 0.016), with a little higher frequency of P-ala subtype. The @entity2025 type distribution between @entity706 and the other three groups was significantly different (p = 0.000, p = 0.000, p = 0.001, respectively). The proportion of type 1 and type 2 mixed @entity281 was higher in @entity706 than that in @entity356 , @entity189 and TW. In @entity706 , the distribution of EBNA1 subtypes in the three @entity2025 types was not significantly different (p = 0.546). These data suggested that the variation patterns of EBNA1 gene may be geographic-associated rather than @entity5 -specific and the role of EBNA1 gene variations in tumorigenesis needs more extensive and deep explorations.
