Navegando por Autor "KATO, Valdenira de Jesus Oliveira"

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Imunoexpressão da proteína PTEN em amostras de carcinoma epidermoide bucal e sua correlação com características clínico-patológicas e sobrevida
(Universidade Federal do Pará, 2016-06-03) KATO, Valdenira de Jesus Oliveira; PONTES, Hélder Antônio Rebelo; http://lattes.cnpq.br/8076555757131891; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
Oral Squamous Cell Carcinoma (OSCC) is the most common malignant neoplastic that affects the oral cavity, accounting for 90% of all cases diagnosed in this anatomic site. Despite the recent advances in the treatment, the survival rate varies from 30 to 50%. Molecular mechanisms which elucidates the agressive behaviour of these lesions help to identify new chemotherapeutics that might be used in the treatment in order to improve the survival rates. The aim of this study was investigating the imunoexpression of PTEN protein through the immunohistochemical technique (IHC) in CEB samples and relate them with clinicopathological features, histological grades and survival and in addition, evaluate the presence of allelic deletion through the Fluorescent In Situ Hybridization technique (FISH). Our results showed that a total from 119 cases of CEB, 31 cases were negative to expression of protein PTEN and 88 cases were positive for PTEN, from which 15 (17,05%) were well differentiated, 43 (48,86%) moderately differentiated and 30 (34,09%) were poorly differentiated. Considering the clinicophatological features, there were not statistically significant correlations with the IHC expression of PTEN. Regarding the survival rates, it was observed that patients presenting lymph node infiltration (N) = 2 or 3 has 4 times greater risk of dying than those presenting N = 0 or 1. Finally, there was a significant association between expression by IHC negative and the result of FISH technique regarding the deletion, and between the positive PTEN expression and the non-deleted result of FISH technique.
Acesso aberto (Open Access)
Significado da expressão de p16INK4A e da perda de heterozigosidade do gene PTEN no carcinoma epidermóide bucal relacionado ao papilomavírus humano
(Universidade Federal do Pará, 2023-06) KATO, Valdenira de Jesus Oliveira; ALCÂNTARA, Diego Di Felipe Ávila; http://lattes.cnpq.br/1794240697748468; https://orcid.org/0000-0001-5045-2265; BURBANO, Rommel Mario Rodríguez; http://lattes.cnpq.br/4362051219348099; https://orcid.org/0000-0002-4872-234X
The p16 and PTEN genes are part of the family of tumor suppressor genes commonly associated with the inactivation of a variety of human cancers. The loss of its expression has been studied worldwide in oral squamous cell carcinoma (OSCC). In this study, we evaluated the hypothesis that p16 cooperates with inactive PTEN during OSCC pathogenesis, especially in tumor aggressiveness and proliferation. For that, 119 OSCC samples were used in which the relationship between HPV infection, p16 expression and PTEN mutations were evaluated throug himmunohistochemistry (IHC), western blot, immunofluorescence and sequencing techniques. The results of this study demonstrated that PTEN has high positivity in patients with more advanced tumor size (p < 0.01) and lymph node metastasis (p = 0.02). Statistical analysis showed that p16 expression was strongly associated with the presence of HPV (p<0.0001), but that its aberrant expression is not related to altered PTEN (p=0.52). It was also observed that 60% of the samples in stage IV (advanced stage of the tumor) were statistically associated with the presence of mutation. It is concluded that PTEN and p16 are suppressor genes that control tumor progression. In the current study, PTEN showed great erreactivity in advanced stages of the disease (greater than seven times). p16 was strongly associated with HPV, but did not show a significant association with any clinical-pathological factor analyzed. Both proteins are of great importance in the prognosis of patients. Viral presence has been shown to decrease tumor aggressiveness. Lesions in advanced stages have a shorter survival, in addition, the presence of mutation was more commonly observed in advanced stages of the disease. It was observed that smoking patients witht he absenceof p16 are significantly associated with a survival rate twice as low.