NRF2 and Keap1 Genetic Polymorphisms in Breast Cancer

• Autor(a) principal: Costa, Diana Raquel Careano da
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/12896
• topic: Cancro da Mama; Keap1; Nrf2; Polimorfismos Genéticos; Snps; Domínio/Área Científica::Ciências Médicas::Ciências Biomédicas

Cancer is one of the diseases with the highest mortality rate, with breast cancer being the most frequent and with the highest mortality rate in females. Human exposure to oxidative stress may be correlated with the development of several pathologies, including cancer. The pathways involved in oxidative stress represent a risk factor for the development of breast cancer. One of the most important factors in oxidative stress regulation is the NF-E2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) (Nrf2-Keap1) complex. The regulation of this complex may be compromised, due to somatic mutations that influence the loss of negative regulation or the presence of Single Nucleotide Polymorphisms in the promoter region of the NRF2 gene, which may be related to changes in the expression of this transcription factor and its biological consequences. Genetic polymorphisms have become potential research targets in breast cancer due to their influence on carcinogenesis and their possible association becomes a key element for future research. The main objective of this work was to identify Single Nucleotide Polymorphisms not described in the literature in the polymorphic regions of the NRF2 and KEAP1 genes in 40 patients with histologically confirmed hormone-dependent breast cancer and to establish a possible association with the histological grade of the tumour. To identify the polymorphisms under study, PCR and Sanger sequencing were used. In order to be able to relate and compare the results obtained in the blood with the tumour tissue, the technique of extracting gDNA from mouse paraffin-embedded tissue was optimized, using 9 samples of mouse mammary tissue. Polymorphisms rs6721961, rs6706649, rs35652124 from NRF2 and rs1048290 from KEAP1 were identified in all samples, and de novo mutations were not identified. These results emphasize the need to study the tumour tissue and verify if it presents alterations in gene expression and appearance of new tumour-related mutations. The gDNA extraction from paraffin-embedded tissue samples from mouse mammary sections was successful, so the protocol was properly optimized, allowing it to be replicated, in future, in human samples.