Cloning and Sequencing Full Length of Canine Brca2 and Rad51 cDNA.

Ochiai, Kazuhiko; Morimatsu, Masami; Tomizawa, Nobuyuki; Syuto, Bunei

doi:10.1292/jvms.63.1103

Cited by 30 publications

(32 citation statements)

References 18 publications

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“…Germ line mutations in BRCA1 and BRCA2 are thought to account for 5% to 10% of all breast cancer in women (36,37), and our results suggest that they also predispose to CMTs based on candidate gene association. In this study, we were able to detect association to risk factors conferring ∼4-fold increased risk for both BRCA1 and BRCA2 to CMT using data from only 212 cases and 143 controls ( Table 2).…”

Section: Discussionmentioning

confidence: 62%

Mammary Tumor Development in Dogs Is Associated with BRCA1 and BRCA2

et al. 2009

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Breast cancer is a major contributor to overall morbidity and mortality in women. Several genes predisposing to breast cancer have been identified, but the majority of risk factors remain unknown. Even less is known about the inherited risk factors underlying canine mammary tumors (CMT). Clear breed predispositions exist, with 36% of English springer spaniels (ESS) in Sweden being affected. Here, we evaluate 10 human breast cancer genes (BRCA1, BRCA2, CHEK2, ERBB2, FGFR2, LSP1, MAP3K1, RCAS1, TOX3, and TP53) for association with CMTs. Sixty-three single-nucleotide polymorphisms (SNPs; four to nine SNPs per gene) were genotyped by iPLEX in female ESS dogs, 212 CMT cases and 143 controls. Two genes, BRCA1 and BRCA2, were significantly associated with CMT (Bonferroni corrected P = 0.005 and P = 0.0001, respectively). Borderline association was seen for FGFR2. Benign and malignant cases were also analyzed separately. Those findings supported the association to BRCA1 and BRCA2 but with a stronger association to BRCA1 in malignant cases. Both BRCA1 and BRCA2 showed odds ratios of ∼4. In conclusion, this study indicates that BRCA1 and BRCA2 contribute to the risk of CMT in ESS, suggesting that dogs may serve as a good model for human breast cancer.

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Section: Discussionmentioning

confidence: 62%

Mammary Tumor Development in Dogs Is Associated with BRCA1 and BRCA2

et al. 2009

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“…This low degree of sequence identity predicts the presence of a species-specifi c function of Brca2. To explore the general function of Brca2 from a comparative perspective, we previously cloned and sequenced canine orthologs of Brca2 and Rad51 (12). In this study, we used yeast and mammalian two-hybrid assays to investigate the interaction between canine Rad51 and the C-terminus of canine Brca2, and the involvement of the C-terminus in irradiation-induced Rad51 focus formation.…”

Section: The Cooh-terminus Of Canine Brca2 Interacts With Canine Rad51mentioning

confidence: 99%

Brca2 C-terminus interacts with Rad51 and contributes to nuclear focus formation in double-strand break repair of DNA

Ochiai¹,

Morimatsu²,

Yoshikawa³

et al. 2004

Biomed. Res.

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In humans and mice, the interaction between the breast cancer susceptibility protein, BRCA2, and RAD51 recombinase is essential for DNA repair by homologous recombination, the failure of this process can predispose to cancer. Cells with mutated BRCA2 are hypersensitive to ionizing radiation (IR) and exhibit defective DNA repair. Using yeast and mammalian two-hybrid assays, we demonstrate that canine Rad51 protein interacts specifi cally with the C-terminus of canine Brca2. In support of the biological signifi cance of this interaction, we found that radiation-induced focus formation of Rad51 in COS-7 cells was compromised by forced expression of the C-terminus of canine Brca2. A similar result was obtained for the murine C-terminus. These data suggest that the C-terminal domain of canine Brca2 functions to bind Rad51 and that this domain contributes to the IR-induced assembly of the Rad51 complex in vivo.The BRCA2 tumor-suppressor gene is a breast cancer susceptibility gene isolated through positional cloning using data from families with inherited breast cancer (24). Human BRCA2 encodes a nuclear protein of 3,418 amino acids. Two regions of Brca2 protein associate with Rad51, which plays a central role in mediating homologous recombination events, and can promote strand-exchange in vitro (1, 3). One region has eight repeats of a domain called the BRC repeats, encoded in exon 11 (2,8,22). The role of this domain in DNA repair has been well characterized in human studies: for example, the overexpression of BRCA2 BRC repeats prevented the formation of Rad51 foci after the induction of DNA double-strand breaks by irradiation (1,18,26).The other region is a single domain in the extreme C-terminus, distinct from the BRC repeats, encoded in exon 27 (16). While the BRC repeats interact with Rad51 in both humans and mice, the C-terminus interacts with Rad51 in mice only (2). The importance of the C-terminal region of murine Brca2 for the interaction with Rad51 is supported by data from cells and mice with a truncation mutation of this region. Cells with a deletion in the C-terminus of Brca2 were hypersensitive to irradiation (4, 10). Mice with the C-terminus deleted have a signifi cantly increased overall tumor incidence and decreased survival (9). Although murine models support a role for Brca2 as a tumor suppressor, the differences in the functional domains of murine and human Brca2 called into question the applicability of mice for understanding the general function of Brca2 in mammals.As mammary tumors in dogs resemble adenocarcinoma in women more closely than does experimentally induced cancer in inbred laboratory animals, the dog is a suitable animal for studying

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“…We previously cloned and sequenced canine orthologs of BRCA2 and Rad51 (20). In female dogs, mammary tumors are the most frequent neoplasm (23).…”

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confidence: 99%

Insertion/deletion polymorphism in the BRCA2 nuclear localization signal

et al. 2005

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Mutations in human BRCA2 confer an increased risk of female breast cancer. In this study, we found a novel insertion/deletion polymorphism (10204insAAA causing amino acid change M3332IK) in canine BRCA2, which is located in the putative second nuclear localization signal (NLS2) and C-terminal Rad51-binding region. The nuclear localization of the insAAA C-terminus was more efficient than localization of the delAAA sequence when NLS1 was mutated. Strong, comparable Rad51 binding was observed for both the insAAA and delAAA C-termini. Dogs with the insertion/deletion polymorphism will provide a new model for studying the function of BRCA2.The human breast cancer susceptibility gene BRCA2 encodes a large tumor-suppressor protein of 3,418 amino acids (1, 27, 31). The BRCA2 protein plays important roles in the maintenance of genomic stability in DNA recombination and double strandbreak repair through its interaction with Rad51 recombinase (4,17,27,28,31,33). BRCA2 interacts with Rad51 via eight BRC repeats in the central region (4, 27, 31). An independent interaction with Rad51 via the extreme C-terminus of Brca2 was believed to be a mouse-specific event (4, 16, 28), but a recent study of human BRCA2 demonstrated an interaction via the C-terminus (8). This interaction has been shown to regulate Rad51 nucleoprotein filament formation and the nuclear transport of Rad51 (6,29,33,35). Loss of BRCA2 function via mutation leads to genomic instability and tumorigenesis (1,18,27,31).The BRCA2 protein is localized to the nucleus, which is consistent with its role in DNA recombination and repair (4, 26). In human BRCA2, three nuclear localization signals (NLSs) have been identified and named NLS1, NLS2, and NLS3. Spain et al. (30) and Yano et al. (34) demonstrated the roles of these NLSs in human BRCA2 using GFP-tagged sequences, and suggested a relationship between the mislocalization of BRCA2 and tumorigenesis. In fact, the smallest reported cancer-associated mutation is a truncation that removes 224 residues containing the three NLSs from the C-terminal (11). Therefore, truncation mutations, which constitute the majority of tumorigenic mutations of BRCA2, prevent localization of BRCA2 to the nucleus and consequently result in dysfunction (10,30,34).

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Cloning and Sequencing Full Length of Canine Brca2 and Rad51 cDNA.

Cited by 30 publications

References 18 publications

Mammary Tumor Development in Dogs Is Associated with BRCA1 and BRCA2

Mammary Tumor Development in Dogs Is Associated with BRCA1 and BRCA2

Brca2 C-terminus interacts with Rad51 and contributes to nuclear focus formation in double-strand break repair of DNA

Insertion/deletion polymorphism in the BRCA2 nuclear localization signal

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