Hipoexpressão de miR-205ab e miR-218a associada ao pior prognóstico em pacientes com câncer de mama

• Autor(a) principal: Paes, Juliana Fracalossi
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/0013000008p6w
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/9265
• topic: Câncer de mama; microRNA; hsa-miR-205ab; hsa-miR- 218; BRCA1; Breast cancer; MEDICINA::ANATOMIA PATOLOGICA E PATOLOGIA CLINICA

Introduction: MicroRNAs are small molecules of single-stranded non-coding RNAs that regulate gene expression in the post-transcriptional phase and are being evaluated as prognostic and predictive markers in breast cancer. Objective: The aim of this study was to evaluate the expression of hsa-miR-205ab and hsa-miR-218a microRNAs and BRCA1 protein in breast cancer samples and their associations with the pathological and prognostic clinical aspects of tumors. Method: A group of 92 breast cancer cases was evaluated for clinical-pathological aspects, five-year survival, expression of BRCA1, hsa-miR-205ab and hsa-miR-218a. BRCA1 expression was assessed by immunohistochemistry and the quantification of the miRNAs by quantitative PCR in real time. The clinical-pathological aspects were compared in relation to the expression of BRCA1, hsa-miR- 205ab and hsa-miR-218a using the Mann-Whitney test. Survival curves were generated by the Kaplan-Meyer method and compared by the long-rank method. Results: The group of tumors comprised 56 cases of non-triple-negative breast carcinomas and 36 tumors with triple-negative phenotype. Hypoexpression of hsa-miR-205ab and hsa-miR-218a was associated with larger tumors (> 2 cm), presence of lymph node metastasis and distant metastasis, the highest histological grade, triple negative phenotype, absence of expression of BRCA1 and lower survival. (P = 0.044), more advanced stages (p = 0.005), lymph node involvement (p = 0.038), presence of distant metastasis (p = 0, 0008) and absence of BRCA1 expression (p = 0.039). Conclusion: The hypoexpression of hsa-miR-205ab and hsa-miR-218a was associated with factors of poor prognosis, absence of BRCA1 expression and the lowest survival rate in breast cancer patients evaluated in this study.