Tyms double (2R) and triple repeat (3R) confers risk for human oral squamous cell carcinoma.

The oral cancer is responsible for approximately 3 % of cases of cancer in Brazil. Epidemiological studies have associated low folate intake with an increased risk of epithelial cancers, including oral cancer. Folic acid has a key role in DNA synthesis, repair, methylation and this is the basis of explanations for a putative role for folic acid in cancer prevention. The role of folic acid in carcinogenesis may be modulated by polymorphism C677T in MTHFR and tandem repeats 2R/3R in the promoter site of TYMS gene that are related to decreased enzymatic activity and quantity and availability of the enzyme, respectively. These events cause a decrease in the synthesis, repair and DNA methylation, which can lead to a disruption in the expression of tumor suppressor genes as TP53. The objective of this study was investigate the distribution of polymorphisms C677T and tandem repeats 2R/3R associated with the development of oral squamous cell carcinoma (OSCC). 53 paraffin-embedded samples from patients who underwent surgery but are no longer at the institution and 43 samples collected by method of oral exfoliation by cytobrush were selected. 132 healthy subjects were selected by specialists at the dental clinics of the Faculdade de Odontologia de Pernambuco-FOP. The MTHFR genotyping was performed by PCR-RFLP, and the TYMS genotyping was performed by conventional PCR. Fisher's Exact test at significant level of 5 %. Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to measure the strength of association between genotype frequency and OSCC development. The results were statistically significant for the tandem repeats of the TYMS gene (p = 0.015). The TYMS 2R3R genotype was significantly associated with the development of OSCC (OR = 3.582; 95 % CI 1.240-10.348; p = 0.0262) and also the genotype 3R3R (OR = 3.553; 95 % CI 1.293-9.760; p = 0.0345). When analyzed together, the TYMS 2R3R + 3R3R genotypes also showed association (OR = 3.518; 95 % CI 11.188-10.348; p = 0.0177). No differences for the MTHFR C677T polymorphisms distribution were found between the oral cancer patients and controls subjects in our study (p = 0.499). Therefore, these data suggest that determination of TYMS tandem repeats could provide information on the comprehension of the risk factors and prevention of the OSCC.

MTR polymorphic variant A2756G and retinoblastoma risk in Brazilian children.

BACKGROUND: Polymorphisms in the genes of folate and methionine metabolism enzymes have been associated with some forms of cancer by affecting DNA synthesis, repair, and methylation. PROCEDURE: A case-control study of 72 retinoblastoma cases and 98 cancer-free children controls was performed to investigate whether the polymorphisms of the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MTR A2756G), carrier of reduced folate 1 (RFC-1 A80G) and thymidylate synthase (TYMS 2R > 3R) altered the risk for retinoblastoma. RESULTS: MTR A2756G AG plus GG genotype frequencies were higher in patients than in controls (45% vs. 26%, P = 0.03). Individual carriers of the variant allele G had a 2.02 (95% CI: 1.05-3.92)-fold increased risk for retinoblastoma. In contrast, no association was observed with respect to MTHFR C677T and A1298C, RFC A80G, and TYMS polymorphisms. CONCLUSIONS: This study presents evidence for an association between the MTR A2756G polymorphism and retinoblastoma susceptibility in a Northeast population from Brazil.

HPV em mucosa oral normal? / HPV in the normal oral cavities?

Este estudo buscou verificar a presença do Papiloma Vírus Humano (HPV) em mucosa oral de indivíduos sãos e relacionar com a idade e possíveis meios de transmissões. A amostra foi constituída por 50 indivíduos, que buscaram atendimento espontâneo nas clínicas odontológicas das Faculdades Estadual e Federal de Pernambuco. Inicialmente foi realizada uma entrevista, seguindo-se o exame clínico e a coleta de material da mucosa oral através de citologia esfoliativa convencional (cytobrush). As amostras foram avaliadas de duas formas, microscopicamente quanto aos aspectos morfológicos buscando-se caracteristicas sugestivas da infecção viral (colocitose, disceratose, binucleação), e pelo teste específico de Reação em Cadeia de Polimerase (PCR) com consensus primer). Consoante o sexo a amostra foi constituída por 30 indivíduos do sexo feminino e 20 do masculino. Observando-se a faixa etária houve variação de 6 até 82 anos de idade; dentre os pesquisados 7% das mulheres era fumante, enquanto 45% dos homens etilistas e tabagistas. A amostra estudada apresentou resultado negativo para a presença do vírus HPV, pelo teste de Reação em Cadeia de Polimerase (PCR), assim como não apresentou nenhuma alteração celular morfológica indicativa do vírus.

The aim of the study was to verify the possible transmission means and to the age. The sample was constituted by 50 individuals, which sought spontaneous assistance in the odontological clinics of the Universidades Estadual e Federal de Pernambuco. It initially was accomplished an interview, after the clinical exam and the material colletion of the oral mucosa through conventional exfoliative cytology (cytobrush). The samples were evaluated by two forms, microscopically regarding the morphologic aspects seeking seggestive characterístics of the viral infection (koilocytosis, disceratoses, binucleation), and by the specific test of Polymarase Chain Reaction (PCR) with consensus primer. Consonant the sex the sample was constituted by 30 individuals of the feminine sex and 20 of the masculine. The variation of the range age was from 6 up to 82 years old; among the searched 7% of the women was smoker, while 45% of the men etilistas and tabagistas. The studied sample introduced negative result for the presence of the HPV, by the Polymerase Chain Reaction (PCR), as well as it did not introduce any morphologic indicative ceccular alteration of vírus.

Identificação do Papilomavirus Humano em mucosa oral de mulheres portadoras do vírus em cérvice uterina atendidas em hospital de referência em oncologia / Identification of Human Papillomavirus in oral mucosa of women which has the viral infection in uterine cervix attended at a referral hospital in oncology

Introduction: Oral cancer is one of the most common types of cancer worldwide, makingit necessary to know the risk factors related to this disease. Although there is a wellestablished association with other risk factors, studies developed so far do not allow todefine precisely the role of Human Papillomavirus in oral carcinogenesis. Objective -Investigate the presence of Human Papillomavirus in oral mucosa of women with HumanPapillomavirus in the uterine cervix. Material and Methods - The analysis includedsamples of 47 women aged 21 to 62 years old. The biological material was obtained byexfoliative cytology (cytobrush) of oral mucosa, and tested by Polymerase Chain Reactionfor identification of HPV. Results - The results showed cytopathological interpretation,light microscopy, 5/47 (10.63%) with changes indicative of Human Papillomavirus. Inlaboratory tests 8/47 (17, 02%) of the collections of buccal swabs were positive for HumanPapillomavirus-DNA. Conclusion - The Human Papillomavirus detection by PCRtechnique was more sensitive in identifying the Human Papillomavirus in oral mucosa.This study does not allow a definitive conclusion about the relationship of HPV in thecervix and oral mucosa.

Introdução: O câncer de boca é um dos tipos mais comuns de câncer no mundo, tornando-se necessário o conhecimento dos fatores de risco relacionados a essa doença. Apesar deexistir uma associação bem estabelecida com outros fatores de risco, os estudos desenvolvidosaté hoje não permitem definir com precisão qual o papel do HPV na carcinogêneseoral. Objetivo: Investigar a presença do HPV na mucosa oral de mulheres portadoras deHPV na cérvice uterina. Material e Método - Foram analisadas amostras de 47 mulheresna faixa etária de 21 até 62 anos de idade. O material biológico foi obtido por citologiaesfoliativa (cytobrush) da mucosa oral, e testado para identificação do HPV através datécnica de PCR. Resultados - Os resultados apontaram na interpretação citopatológica,à microscopia óptica, 5/47 (10.63%) com alterações indicativas de HPV. Nos testeslaboratoriais (PCR) 8/47 (17,02%) das coletas dos esfregaços bucais apresentaram-sepositivas para o HPV-DNA. Conclusões - A detecção do HPV pela técnica de PCR mostrouser mais sensível na identificação do HPV na mucosa oral. Esse estudo não permite umaconclusão definitiva sobre a relação entre o HPV na cérvice uterina e na mucosa oral.