Teses em Neurociências e Biologia Celular (Doutorado) - PPGNBC/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2390
O Doutorado Acadêmico pertence ao Programa de Pós-Graduação em Neurociências e Biologia Celular (PPGNBC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).
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Item Acesso aberto (Open Access) Análise de patógenos orais entre indivíduos portadores de câncer gástrico e indivíduos sem câncer(Universidade Federal do Pará, 2021-06) OLIVEIRA, Gyselle Ribeiro de Carvalho; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099; https://orcid.org/0000-0002-4872-234XThe loss of teeth and lack of oral hygiene have been associated with the risk of developing gastric cancer in several populations evidenced in epidemiological studies. In this study, we quantitatively compared the proportion of oral pathogens in individuals with gastric cancer and individuals without cancer in a referral hospital in the city of Belém, Brazil. This study evaluated 192 patients with gastric cancer and 192 patients without cancer. Periodontal clinical examination was performed, and all individuals were submitted to the collection of salivary and dental biofilms. When comparing the median periodontal indexesin the gastric and cancer-free groups, it was statistically significant in the gastric cancer group compared to the probing depth of the periodontal pocket. Levels of bacterial DNA were observed in saliva and dental plaque, with a statistically significant difference between individuals with cancer and without neoplasia in all the bacteria surveyed. Significant relationships between biological agents and gastric cancer have been found in bacterial species that cause high rates of periodontal pathology and caries. The results suggest a different quantitative association in the presence of oral pathogens between individuals without cancer and patients with gastric cancer. As noted, it cannot be said that the bacteria present in the oral cavity increase the risk of gastric cancer or are aggravating factors of the disease. However, it is worth mentioning that, as it is part of the digestive system, the lack of care for the oral cavity can negatively affect the treatment of patients with gastric cancer.Item 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/0000-0002-4872-234XThe 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.