EBV-positive Group Research Articles

Epstein-Barr Virus and p16INK4A Methylation in Squamous Cell Carcinoma and Precancerous Lesions of the Cervix Uteri

Methylation of p16 is an important mechanism in cervical carcinogenesis. However, the relationship between cervical squamous cell carcinoma (SCC) and Epstein-Barr virus (EBV) remains controversial. Here, we explored whether EBV infection and/or p16 gene inactivation would play any role in cervical carcinogenesis. Eighty-two specimens included 41 invasive SCCs, 30 cervical intraepithelial neoplasm (CIN; CIN 1, 11 cases, CIN II, 3 cases, CIN III 16 cases) and 11 nonneoplastic cervices. EBV was detected by polymerase chain reaction (PCR) for EBNA-1 and in situ hybridization for EBER-1. The p16 methylation-status and the expression of p16 protein were studied by methylation-specific PCR and immunohistochemistry, respectively. The materials were divided into four groups: 1) nonneoplastic cervices, 2) CIN I, 3) CIN II-III and 4) invasive SCCs. p16 methylation and p16 immunoexpressions increased in CIN and invasive SCCs than nonneoplastic tissue. p16-methylation and p16-immunoreactivities were higher in the EBV-positive group (p=0.009, p<0.001) than in the EBV-negative group. EBV was detected more frequently in CIN and SCCs than nonneoplastic cervices. In conclusion, a correlation between p16 methylation, p16 immunoreactivity and the detection of EBV strongly suggested that the cooperation of EBV and p16 gene may play a synergic effect on cell cycle deregulation.

Population Based Genotyping of Human Leukocyte Antigen (HLA) in Hodgkin Lymphoma: EBV Positive HL Is Associated with HLA Class I and EBV Negative HL Is Associated with HLA Class III.

An inherited susceptibility to Hodgkin Lymphoma (HL) is indicated by the variation in incidence among race/ethnicity groups, aggregation of the disease in families and by association with human leukocyte antigens (HLA). In this study we conducted a detailed screening analysis of the complete HLA region in EBV-positive and EBV-negative patients with HL.In total, 200 patients and 348 family-based controls of the Caucasian population of the Northern Netherlands participated in this population-based study. Paraffin embedded tissue of all patients was obtained and used for revision according to the WHO classification. In addition, analysis of EBV status was performed. 54 patients were EBV-positive (33 NS, 14 MC, and 7 other classical cases) and 146 patients were EBV-negative (124 NS, 4 MC, 13 NLP, and 5 other classical cases). 33 microsatellite markers located in the HLA region 6p21 were used for genotype screening.Allele, genotype and two-locus haplotype association analyses were used to search for differences between EBV-positive and negative patients and family controls using a t-test to assess significance. In the EBV-positive patient group, HL was associated with an allele of 126 bp for D6S265 and an allele of 284 bp for D6S510 (p=0.00031). These markers are located in the HLA class I subregion. Individuals homozygous for 126 allele of D6S265 were observed in 34.4% of the EBV-positive patient group and 5.2% of controls (odds ratio (OR)= 6.6). The odds ratio for individuals heterozygous for 126 allele of D6S265 was lower (OR= 2.5).In addition, Haplotype Sharing Statistics (HSS) was used to search for differences in haplotype sharing between patients and family controls. The HSS assumes that haplotype segments of patients from a founder population are conserved in the region spanning a disease locus.The HSS analysis showed strongest haplotype sharing around marker D6S273 in patients compared to controls (p<0.0001). The sharing was less evident in the EBV-positive subgroup compared to the EBV-negative subgroup, possibly due to low power. D6S273 is located at the telomeric end of the HLA class III region nearby TNF-alpha, TNF-beta and heat shock protein genes. Our results indicate that part of the HLA class I and part of the HLA class III region are associated with susceptibility to classical HL, with the HLA class I association being specific for EBV positive HL. We will further analyze both regions aiming to find genes and polymorphisms associated with the development of HL.

The comparison of the prognosis between Epstein-Barr virus (EBV)-positive gastric carcinomas and EBV-negative ones.

The relationship between the degree of lymphocytic infiltration into the tumor and the prognosis has not been completely evaluated between Epstein-Barr virus (EBV)-positive and -negative gastric carcinoma (GC). Although the average numbers and the grades of the infiltrating CD8+T cells, natural killer cells, dendritic cells, Ki67-positive cells were significantly greater in EBV-positive GCs than in -negative GCs, there was no significant survival improvement in EBV-positive group. These findings suggest that the infiltration of lymphocytes in the EBV-positive GC does not necessarily meant better prognosis and that the EBV status is not a significant prognostic factor in the patients with gastric cancer.

Epstein-Barr virus-associated gastric lymphomas are distinct from mucosa-associated lymphoid tissue-type lymphomas: genetic abnormalities of p53 gene.

The authors studied 46 primary gastric lymphomas for expression of the p53 gene by immunohistochemistry and screened for mutations in p53 exon 5-8 by polymerase chain reaction-single strand conformation polymorphism. Twenty-five specimens cases were also analyzed for loss of heterozygosity (LOH) of chromosomal region 17p12-13.1. In 36 lymphomas negative for Epstein-Barr virus (EBV) infection, of which 29 were of mucosa-associated lymphoid tissue (MALT) type, p53 genetic changes were found in 47.2% but correlated poorly with overexpression. Only 20% of the mutations involved exon 7. There were recurrent mutations of intron 7, intron 6, and exon 6. In contrast, the 10 EBV-positive cases, none of MALT type, had a much higher rate of mutation, and all showed both p53 overexpression and p53 mutation and/or LOH, and 87.5% had mutations involving exon 7. Four of these involved codon 242, not seen in the EBV-negative group. Splicing mutations of intron 8 were seen in three specimens, two involving the same nucleotide position. In four of five specimens, LOH analysis identified microsatellite instability, allelic loss, or both. The Helicobacter pylori infection rate in the EBV-positive group (20%) was much lower than in the EBV-negative group (91.7%). These differences between the two groups suggest involvement of different carcinogens. Mutation of codon 242 has not been specifically associated with other tumors and may represent a mutational hot spot in the EBV-positive lymphomas.