BRAT1 Knockout Ca Ski Polyclonal Cells provide a heterogeneous population of human Ca Ski cervical carcinoma cells with targeted disruption of the BRCA1-associated ATM activator 1 (BRAT1) gene via CRISPR/Cas9-mediated genome editing. This polyclonal knockout model preserves genetic diversity while enabling pooled analysis of BRAT1 loss-of-function effects, circumventing clonal selection artifacts. The cell pool is derived from the Ca Ski host line, a widely used model for HPV-driven cervical tumorigenesis, and is suitable for investigating DNA damage response networks in an oncogenic background.
The Ca Ski cell line is an adherent epithelial cell line established from a human cervical squamous cell carcinoma of the uterine cervix. These cells are positive for human papillomavirus type 16 (HPV-16), the high-risk viral subtype most frequently associated with cervical cancer. Ca Ski cells retain key features of HPV-induced transformation, including expression of the viral oncoproteins E6 and E7, which functionally inactivate the tumor suppressors p53 and Rb, respectively. This background provides a clinically relevant platform for studying viral?Chost interactions and oncogenic signaling in the context of DNA damage response pathways.
BRAT1 encodes a critical mediator of the ATM-dependent DNA double-strand break (DSB) response. It is recruited to damage sites, facilitating ATM autophosphorylation and activation. BRAT1 promotes ATM-mediated phosphorylation of p53 at Ser15 and CHK2 at Thr68, and interacts with BRCA1, DNA?PKcs, and TopBP1 to coordinate cell cycle arrest and apoptosis. Disruption of BRAT1 impairs these phosphorylation events, attenuating p53 and CHK2 signaling and compromising G1/S and G2/M checkpoints. Downstream, dysregulation affects CDC25C activation and BAX-mediated mitochondrial apoptosis, reducing cellular capacity for proper damage resolution.
In the context of HPV-positive Ca Ski cells, BRAT1 knockout is particularly informative. HPV E6-mediated degradation of p53 already compromises a major tumor-suppressive axis; abrogating BRAT1 further cripples residual ATM?Cp53 pro?apoptotic responses and CHK2-mediated cell cycle regulation. This dual disruption mirrors aspects of genomic instability observed in cervical carcinogenesis and may reveal synthetic lethal interactions exploitable by DNA-damaging chemotherapeutics. The model thus enables dissection of how HPV oncogenes modulate ATM signaling and how loss of DNA repair factors contributes to malignant progression and therapy resistance.
This BRAT1 knockout polyclonal cell pool is a versatile tool for functional genomics, DNA repair deficiency screening, and investigation of HPV?Chost interactions. Researchers can use these cells for western blotting of ATM substrates, ??H2AX immunofluorescence to quantify DSBs, and comet assays for DNA strand breaks. Apoptosis and cell cycle alterations are measurable via Annexin V flow cytometry and propidium iodide staining. Clonogenic survival assays enable chemosensitivity profiling with agents like cisplatin. For technical assistance, contact Ascent Research.
