Betty K. Martin

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The role of Brca2 in gametogenesis has been obscure because of embryonic lethality of the knockout mice. We generated Brca2-null mice carrying a human BAC with the BRCA2 gene. This construct rescues embryonic lethality and the mice develop normally. However, there is poor expression of the transgene in the gonads and the mice are infertile, allowing(More)
RAD51C is a member of the RecA/RAD51 protein family, which is known to play an important role in DNA repair by homologous recombination. In mice, it is essential for viability. Therefore, we have generated a hypomorphic allele of Rad51c in addition to a null allele. A subset of mice expressing the hypomorphic allele is infertile. This infertility is caused(More)
BRCA1, a well-known tumor suppressor with multiple interacting partners, is predicted to have diverse biological functions. However, so far its only well-established role is in the repair of damaged DNA and cell cycle regulation. In this regard, the etiopathological study of low-penetrant variants of BRCA1 provides an opportunity to uncover its other(More)
To date, inheritance of a mutant BRCA1 or BRCA2 gene is the best-established indicator of an increased risk of developing breast cancer. Sequence analysis of these genes is being used to identify BRCA1/2 mutation carriers, though these efforts are hampered by the high frequency of variants of unknown clinical significance (VUSs). Functional evaluation of(More)
Numerous missense mutations in human BRCA1 gene have been linked to predisposition to breast cancer. However, the functional significance of the majority of these mutations remains unknown. We have examined the molecular basis for three such cancer-causing mutations. The first mutation, a T-->G transversion in codon 64, is predicted to change a conserved(More)
RecA/Rad51 protein family members (Rad51, Rad51b, Rad51c, Rad51d, Xrcc2, and Xrcc3) are essential for DNA repair by homologous recombination, and their role in cancers has been anticipated. Here we provide the first direct evidence for a tumor suppressor function for a member of the Rad51 family. We show that Rad51c deficiency leads to early embryonic(More)
Single-nucleotide substitutions and small in-frame insertions or deletions identified in human breast cancer susceptibility genes BRCA1 and BRCA2 are frequently classified as variants of unknown clinical significance (VUS) due to the availability of very limited information about their functional consequences. Such variants can most reliably be classified(More)
Poly (ADP-ribose) polymerase (PARP) inhibitor (PARPi) olaparib has been approved for treatment of advanced ovarian cancer associated with BRCA1 and BRCA2 mutations. BRCA1- and BRCA2-mutated cells, which are homologous recombination (HR) deficient, are hypersensitive to PARPi through the mechanism of synthetic lethality. Here we examine the effect of PARPi(More)
The oncogenic role of microRNA-155 (miR-155) in leukemia is well established but its role in other cancers, especially breast cancer, is gradually emerging. In this study we examined the effect of mir-155 loss in a well-characterized spontaneous breast cancer mouse model where Brca1 and Trp53 are deleted by K14-Cre. miR-155 is known to be up-regulated in(More)