Other diseases combining the phenotype of chromosomal instabilities and neoplastic development are Fanconi anemia and breast cancers associated with mutant BRCA1 and BRCA2 genes.
Our data expand the clinical spectrum associated with biallelic BRCA1 mutations, ranging from embryonic lethality to a mild FA-like phenotype and no chromosome fragility.
RAD6B is a major mediator of triple negative breast cancer cisplatin resistance: Regulation of translesion synthesis/Fanconi anemia crosstalk and BRCA1 independence.
Several components of the Fanconi anaemia (FA) family of proteins allow the formation of the DNA repair complex foci formed by proteins such as BRCA1/2 and RAD51.
Since the Fanconi anemia (FA) pathway coordinates several DNA repair pathways, including homologous recombination in which BRCA1 and BRCA2 play important roles, we investigated whether this pathway harbors other predictors of PARP inhibitor sensitivity.
Taken together, our results show that loss of Brca1 in murine BM causes hematopoietic defects similar to those seen in people with FA, which provides strong evidence that Brca1 is critical for normal hematopoiesis and that Brca1 is a bona fide FA-like gene.
Taken together, our results show that loss of Brca1 in murine BM causes hematopoietic defects similar to those seen in people with FA, which provides strong evidence that Brca1 is critical for normal hematopoiesis and that Brca1 is a bona fide FA-like gene.
The BRCA1 associated C-terminal helicase (BACH1, designated FANCJ) is implicated in the chromosomal instability genetic disorder Fanconi anemia (FA) and hereditary breast cancer.
The BRCA1-associated FANCJ helicase is among those helicases able to unwind G4 DNA in vitro, and FANCJ mutations are associated with breast cancer and linked to Fanconi anemia.
The identification of breast cancer susceptibility genes (for example, BRCA1/FANCS and BRCA2/FANCD1) as being major players in the FA pathway has led to a surge in molecular studies, resulting in the concept of the FA-BRCA pathway.
The link between BRCA1 dysfunction and basal-like breast cancer or triple-negative breast cancer (TNBC) has been suggested; however, the associations of other factors involved in the Fanconi anemia (FA)/BRCA pathway with the pathogenesis of basal-like breast cancer remain unidentified.
The proteins involved in FA act coordinately in the cellular response to DNA cross-links in a pathway that has been shown to interact physically or functionally with a variety of other proteins involved in DNA repair or cell cycle control, notably BRCA1, Rad51,ATM,ATR, and Nbs1.
Therefore, the ATR- and BRCA1-mediated FA pathway is required for the activation of a G2/M checkpoint and for DNA damage repair in response to the endogenous signal of rereplication.
Using chromosomal stability after ICL damage as the end point, we find that BRCA1 functions in more than just the FA pathway for genome maintenance, whereas BRCA2 appears to act predominantly in the FA pathway.
Using targeted capture and massively parallel genomic sequencing, 151 subjects with USC were assessed for germline mutations in 30 tumor suppressor genes, including BRCA1 (breast cancer 1, early onset), BRCA2, the DNA mismatch repair genes (MLH1 [mutL homolog 1], MSH2 [mutS homolog 2], MSH6, PMS2 [postmeiotic segregation increased 2]), TP53 (tumor protein p53), and 10 other genes in the Fanconi anemia-BRCA pathway.
We also find that 18 VOUS BRCA1 and BRCA2 variants that are listed in BRCA Exchange are present at least once in the homozygous state in patients who lack features of Fanconi anemia.
We found that acquired cisplatin-resistant NSCLC-derived A549/DR cells exhibited markedly enhanced FA and HR repair pathway capacities compared to its parental A549 cells and another independent NSCLC-derived cell line, Calu-1, which possesses a moderate innate resistance to cisplatin. siRNA-mediated silencing of the FA-associated genes FANCL and RAD18 and the HR-associated genes BRCA1 and BRCA2 significantly potentiated the sensitivity of A549/DR cells to cisplatin compared to A549 and Calu-1 cells, suggesting that the acquired cisplatin resistance in A549/DR cells may be attributed to enhanced FA and HR pathway capacities responsible for ICL repair.
We showed that BRCA1 mediates the recruitment of FANCD2 by gammaH2AX to damaged chromatin and cells deficient or depleted of H2AX exhibit an FA-like phenotype, including an excess of chromatid-type chromosomal aberrations and hypersensitivity to MMC.