the relationship between the roles of brca genes in dna repair and cancer predisposition
BRCA1 BRCA1 and BRCA2 are normally expressed in the cells of breast and other tissue, where they help repair damaged DNA, or destroy cells if DNA cannot be repaired. They are involved in the repair of chromosomal damage with an important role in the error-free repair of DNA double-strand breaks.[10][11] If BRCA1 or BRCA2 itself is damaged by a BRCA mutation, damaged DNA is not repaired properly, and this increases the risk for breast cancer.[12][13] BRCA1 and BRCA2 have been described as "breast cancer susceptibility genes" and "breast cancer susceptibility proteins". The predominate allele has a normal, tumor suppressive function whereas high penetrance mutations in these genes cause a loss of tumor suppressive function which correlates with an increased risk of breast cancer.[14]
p53 Tumor protein p53, also known as p53, cellular tumor antigen p53 (UniProt name), phosphoprotein p53, tumor suppressor p53, antigen NY-CO-13, or transformation-related protein 53 (TRP53), is any isoform of a protein encoded by homologous genes in various organisms, such as TP53 (humans) and Trp53 (mice). This homolog (originally thought to be, and often spoken of as, a single protein) is crucial in multicellular organisms, where it prevents cancer formation, thus, functions as a tumor suppressor.[5] As such, p53 has been described as "the guardian of the genome" because of its role in conserving stability by preventing genome mutation.[6] Hence TP53 is classified as a tumor suppressor gene.[7][8][9][10][11] (Italics are used to denote the TP53 gene name and distinguish it from the protein it encodes.)