Squamous cell carcinoma of the head and neck (SCCHN) comprises a large group of cancers in the oral cavity and nasopharyngeal area that typically arise in older males in association with alcohol/tobacco usage. Within the oral cavity, the mobile tongue is the most common site for tumour development. The incidence of tongue squamous cell carcinoma (TSCC) is increasing in younger people, which has been suggested to associate with a viral aetiology. Two common human oncogenic viruses, human papilloma virus (HPV) and Epstein-Barr virus (EBV) are known causes of certain types of SCCHN, namely the oropharynx and nasopharynx, respectively. EBV infects most adults worldwide through oral transmission and establishes a latent infection, with sporadic productive viral replication and release of virus in the oral cavity throughout life. In view of the prevalence of EBV in the oral cavity and recent data indicating that it infects tongue epithelial cells and establishes latency, we examined 98 cases of primary squamous cell carcinoma of the mobile tongue and 15 cases of tonsillar squamous cell carcinoma for the presence of EBV-encoded RNAs (EBERs), EBV DNA and an EBV-encoded protein, EBNA-1. A commercially available in situ hybridisation kit targeting EBER transcripts (EBER-ISH) showed a positive signal in the cytoplasm and/or nuclei of tumour cells in 43% of TSCCs. However, application of control probes and RNase A digestion using in-house developed EBER-ISH showed identical EBER staining patterns, indicating non-specific signals. PCR analysis of the BamH1 W repeat sequences did not identify EBV genomes in tumour samples. Immunohistochemistry for EBNA-1 was also negative. These data exclude EBV as a potential player in TSCC in both old and young patients and highlight the importance of appropriate controls for EBER-ISH in investigating EBV in human diseases.

• MeSH
• DNA virů analýza   metabolismus   MeSH
• dospělí MeSH
• hybridizace in situ MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• nádory jazyka patologie   virologie   MeSH
• polymerázová řetězová reakce MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• spinocelulární karcinom patologie   virologie   MeSH
• tonzilární nádory patologie   virologie   MeSH
• virus Epsteinův-Barrové - jaderné antigeny genetika   metabolismus   MeSH
• virus Epsteinův-Barrové genetika   izolace a purifikace   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH

Epigenetic modifications are essential regulators of biological processes. Decreased DNA methylation of OAS2 (2'-5'-Oligoadenylate Synthetase 2), encoding an antiviral protein, has been seen in psoriasis. To provide further insight into the epigenetic regulation of OAS2, we performed pyrosequencing to detect OAS2 DNA methylation status at 11 promoter and first exon located CpG sites in psoriasis (n = 12) and two common subtypes of squamous cell carcinoma (SCC) of the head and neck: tongue (n = 12) and tonsillar (n = 11). Compared to corresponding controls, a general hypomethylation was seen in psoriasis. In tongue and tonsillar SCC, hypomethylation was found at only two CpG sites, the same two sites that were least demethylated in psoriasis. Despite differences in the specific residues targeted for methylation/demethylation, OAS2 expression was upregulated in all conditions and correlations between methylation and expression were seen in psoriasis and tongue SCC. Distinctive methylation status at four successively located CpG sites within a genomic area of 63 bp reveals a delicately integrated epigenetic program and indicates that detailed analysis of individual CpGs provides additional information into the mechanisms of epigenetic regulation in specific disease states. Methylation analyses as clinical biomarkers need to be tailored according to disease-specific sites.

• MeSH
• 2',5'-oligoadenylátsynthetasa genetika   metabolismus   MeSH
• CpG ostrůvky * MeSH
• epigeneze genetická * MeSH
• lidé MeSH
• metylace DNA MeSH
• nádory hlavy a krku genetika   metabolismus   patologie   MeSH
• nádory jazyka genetika   metabolismus   patologie   MeSH
• promotorové oblasti (genetika) MeSH
• psoriáza genetika   metabolismus   patologie   MeSH
• retrospektivní studie MeSH
• spinocelulární karcinom genetika   metabolismus   patologie   MeSH
• studie případů a kontrol MeSH
• tonzilární nádory genetika   metabolismus   patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH