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Previous issue date: 2016-02-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Os sistemas de reparo do DNA desempenham um papel cr?tico na prote??o do genoma humano contra danos causados por agentes cancer?genos presentes no ambiente. Muta??es em genes de reparo de DNA podem ser respons?veis pelo desenvolvimento de tumores e de resist?ncia das c?lulas malignas a agentes quimioterap?uticos. A principal via de reparo de danos oxidativos do DNA ? a via de reparo por excis?o de bases. O objetivo deste estudo foi investigar a imunoexpress?o da APE-1 e XRCC-1, que s?o prote?nas envolvidas no reparo do DNA por excis?o de bases, e sua associa??o com par?metros cl?nicos e histopatol?gicos em carcinoma epidermoide de l?ngua oral (CELO), a fim de investigar um poss?vel valor progn?stico para essas prote?nas. A express?o de APE-1 e XRCC-1 foi avaliada por meio de imuno-histoqu?mica em 50 casos de CELO. Os dados cl?nicos foram coletados no prontu?rio m?dico de cada paciente e a grada??o histopatol?gica foi efetuada para cada caso. A an?lise estat?stica com os testes de Qui-quadrado e Exato de Fisher foi realizada para determinar a associa??o entre as express?es das prote?nas e caracter?sticas cl?nico-patol?gicas; adotou-se um valor de signific?ncia de p<0,05. APE-1 foi altamente expressa no n?cleo e no citoplasma em 56% dos casos. XRCC-1 mostrou alta express?o apenas no n?cleo em 60% dos casos. A alta express?o de XRCC-1 foi significativamente associada aos est?dios cl?nicos I e II (p = 0,02). Ambas as prote?nas n?o foram associadas a outros par?metros cl?nicos ou grada??o histopatol?gica. Por fim, nossos resultados demonstraram que as prote?nas de reparo do DNA por excis?o de bases APE-1 e XRCC-1 est?o positivamente expressas em CELO, no entanto, n?o est?o relacionadas com par?metros cl?nicos e histol?gicos, exceto a associa??o de XRCC-1 com melhor estadiamento cl?nico. Os resultados deste experimento indicam que a express?o imuno-histoqu?mica dessas prote?nas n?o possui valor progn?stico para esta neoplasia. / DNA repair systems play a critical role in protecting the human genome from damage caused
by carcinogens present in the environment. Mutations in DNA repair genes may be
responsible for tumor development and resistance of malignant cells to chemotherapeutic
agents. The major pathway for oxidative DNA damage repair is the base excision repair
pathway. The objective of this study was to investigate the immunoexpression of APE-1 and
XRCC-1, which are proteins involved in DNA base excision repair and its association with
clinical and histopathological parameters in oral tongue squamous cell carcinoma (OTSCC),
in order to investigate a possible prognostic value for those proteins. The expression of APE-1
and XRCC-1 was evaluated semi-quantitatively by immunohistochemistry in 50 OTSCC
cases. Clinical data was collected from patients? medical charts and histopathological grading
was performed for each case. Statistical analysis (Chi-square and Fisher?s exact tests;
significance of 5%) was performed to determine the association between protein expressions
and clinico-pathological characteristics. APE-1 was highly expressed in nucleus and
cytoplasm in 56% of cases. XRCC-1 showed overexpression only in nucleus in 60% of cases.
High expression of XRCC-1 was significantly associated to clinical stages I and II (P=0.02).
Both proteins were not associated to other clinical parameters or histopathological grading.
Our findings demonstrate that DNA base excision repair proteins APE-1 and XRCC-1 are
upregulated in OTSCC, however, they are not related to clinical and histologic parameters,
except for XRCC-1 association to better clinical staging. Our results indicate that the
immunohistochemical expression of these proteins has no association with prognostic
parameters in this tumor.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/20962 |
| Date | 19 February 2016 |
| Creators | Concei??o, Thalita Santana |
| Contributors | 28444361453, http://lattes.cnpq.br/9512014003639405, Silveira, Ericka Janine Dantas da, 02869049420, http://lattes.cnpq.br/2186658404241838, Colleta, Ricardo Della, 13957746841, Freitas, Roseana de Almeida |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM PATOLOGIA ORAL, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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