BRCA1 methylationThe local hypermethylation of BRCA1 (Breast Cancer Susceptibility Protein-1), a tumour suppressor gene, coupled with global DNA hypomethylaton at CpG islands, which are characteristic of BRCA1-related cancers of the breast and presumably also of the ovaries.
BRCA1 prevents global DNA hypomethylation by upregulating expression of DNMT1, which encodes a methylation maintenance enzyme that is a transcriptional target of BRCA1. Reduced expression of BRCA1 correlates with reduced levels of DNMT1 and reduced methylation of CpG islands.
BRCA1 methylation is associated with medullary carcinoma and metaplastic carcinoma.
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