Estudo comparativo da correlação entre HPV, EBV, p53 e Telomerase em carcinoma de células escamosas oral em adultos e adultos jovens

• Autor(a) principal: Venturi, Beatriz da Rocha Miranda
• Data de Publicação: 2004
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/17906
• topic: Carcinoma de células escamosas oral; Vírus oncogênicos; Marcadores tumorais; Neoplasia bucal; Carcinoma de células escamosas; Marcador biológico de tumor; Medicina; Patologia Buco-dental; CNPQ::CIENCIAS DA SAUDE::MEDICINA::ANATOMIA PATOLOGICA E PATOLOGIA CLINICA

Oral Squamous Cell Carcinoma (OSCC) usually occurs in patients over 60 years old, with alcohol and tobacco history. Its occurrence in young patients may show distinct molecular mechanisms and may include the participation of other risk factors, such as Human Papillomavirus (HPV) and Epstein-Barr virus (EBV), both with oncogenic role. HPV and EBV may interfere in the p53 pathway, a tumor supressor protein, and telomerase expression, inducing neoplasic cells proliferation. This study evaluated 20 cases of OSCC, which were divided in two groups of ten. The first group, named Group A, was made of 10 cases of patients aged 45 years old or less. The second group, named Group B, was made of 10 cases of patients older than 45 years old. The purpose of this study was to analyze the association among HPV, EBV (LMP1), p53 and telomerase (hTERT) in OSCC of patients from the age group of usual manifestation, compared to the group of younger patients, using immunohistochemical technique. It was also evaluated the difference referring the presence of risk factors, tobacco and alcohol, and the histological grade. In group B, the results showed 90% of hTERT immunopositivity and greater correlation with risk factors, and both results had statistical significance. In group A, there was 40% of immunopositivity for hTERT and alcohol and tobacco use were less common. LMP1 was detected in 30% of the 20 cases and all patients belonged to group A. In this group, there was also a greater number of less differentiated histological grade lesions. The p53 was detected in 60% of all cases, without any difference between the groups. It was also of notice that the hTERT positive neoplasias were equally p53 positive, which suggested a synergism between both regarding neoplasic proliferation induction. HPV positivity was identified only in one case of the more aged group. The results suggest, on one hand, that OSCC in young patients may present a distinct biological behavior, probably more aggressive, less associated with conventional risk factors, such as tobacco and alcohol, and with a participation of other exogenous agents, such as EBV. On the other hand, p53 presence in OSCC of any age group shows its importance in the oral carcinogenesis process. Telomerase expression indicates that neoplasic cells can use this mechanism for its continuous replication, especially in p53 positive and more aged patient s tumors.