The Brca1 Knockout ID8 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of murine ovarian surface epithelial cells with disrupted Brca1 gene function. This heterogeneous knockout pool provides a robust loss-of-function model without clonal selection bias, enabling studies of BRCA1-dependent mechanisms in DNA repair, cell cycle regulation, and tumor suppression.
Derived from the spontaneously immortalized C57BL/6 mouse ID8 ovarian surface epithelial line, these cells faithfully mimic the ovarian surface epithelium and its ovulation repair cycle. Their syngeneic background permits tumor modeling without immune rejection, making them a standard for ovarian cancer and homologous recombination deficiency studies.
BRCA1 is a pivotal tumor suppressor that orchestrates DNA double-strand break repair through homologous recombination. It forms a stable heterodimer with BARD1, and this complex is recruited to damage sites where it interacts with CtIP, the MRE11-RAD50-NBS1 complex, and PALB2 to facilitate DNA end resection. BRCA1 then promotes the loading of RAD51 recombinase onto single-stranded DNA, a critical step in strand exchange. Upstream, the ATM/ATR kinases and CHK2 phosphorylate BRCA1 in response to DNA damage, linking it to cell cycle checkpoint activation. Downstream, BRCA1 transcriptionally regulates effectors such as p53, p21, GADD45, and BAX, thereby coupling repair with cell cycle arrest or apoptosis. Loss of BRCA1 disrupts these pathways, causing unrepaired DNA damage and genomic instability.
In ID8 ovarian surface epithelial cells, Brca1 deletion recapitulates the early molecular lesions seen in hereditary ovarian cancers. The ovarian surface epithelium is the presumed cell-of-origin for high-grade serous ovarian carcinoma, and BRCA1 inactivation in this lineage creates a permissive environment for malignant transformation. This model enables the study of tissue-specific consequences of Brca1 loss, including defective ovulation repair, accumulation of DNA damage, and susceptibility to further oncogenic hits. Moreover, the polyclonal nature better mimics the heterogeneity of tumor cell populations and avoids artifacts from clonal selection.
These Brca1 knockout cells are ideal for preclinical cancer research, especially PARP inhibitor sensitivity assays exploiting homologous recombination deficiency. They are suited for colony formation, cell cycle flow cytometry, and ??H2AX immunofluorescence to quantify DNA damage. Homologous recombination reporter assays directly measure repair capacity, and syngeneic C57BL/6 mouse models enable tumorigenicity and metastasis studies. This product is a versatile tool for DNA repair, tumor suppressor, and targeted therapy research. For further information, contact Ascent Research.
