Caracterização das lesões impalpáveis (lesões III E IV), e das alterações em TP53 (p53) na detecção precoce do câncer de mama

• Autor(a) principal: Areias, Vivian Rabello
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/16241
• topic: Breast cancer; Diagnosis; Prevention; TP53; Nonpalpable breast lesions; Câncer de mama; Lesões impalpáveis; TP53; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA HUMANA E MEDICA

Nonpalpable breast lesions that are often asymptomatic, may correspond to a stage of progression of the cancer that is difficult to be detected during routine screening. The only possible way for their discovery is through breast images preventive examinations, generally mammography, which usually occurs after age 45. Because of these factors, impalpable lesions are often discovered when the developmental stage of the disease is already advanced and therapeutic interventions are less aggressive.This study aimed to characterize impalpable tumors by the analysis of genetic (mutation and instability) and epigenetic (methylation of the promoter region) of DNA regions related to TP53 tumor suppressor gene from impalpable lesions extracted from biopsies of women living in the state of Rio de Janeiro. Were investigated 34 tissue samples from breast cancer by DNA sequencing in exons 5-8 of TP53. In this region, no mutation was found, this result may be related to the initial type of injury according to data of the radiological lesions of categories 3 and 4 of scale BIRADS . In order to check the status of methylation of the promoter region of the TP53 gene, we analyzed 30 pairs from samples (blood and tumor) of patients with suspected breast cancer, by MSPPCR technique. No tumor sample showed a change in the state of methylation in the promoter region of TP53 as compared to the normal sample. One possible reason for the disparity in the results between this study and the other studies may be related with the applied techniques. The characterization of the nonpalpable lesions just started this work in which we could verify that the mutation in TP53 may be a later event. Therefore, the breast lesion, in its different forms, remains the subject investigated by this group. We have been worked for expanding the number of samples, so as to link the new possibilities of molecular diagnostics in clinical practice in tumors and biological fluids