The BRAT1 Knockout CAL-27 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population derived from the CAL-27 human oral squamous cell carcinoma line, engineered for targeted disruption of the BRAT1 gene. This loss-of-function model enables investigation of BRAT1-dependent cellular processes without reliance on small-molecule inhibitors or RNA interference approaches, providing a stable genetic background for functional studies. The polyclonal format preserves heterogeneous edits across the population, reflecting mixed genotypes that can be advantageous for studying overall gene disruption effects in a tumor-relevant context.
The parental CAL-27 cell line is an adherent epithelial line established from a tongue squamous cell carcinoma of a 56-year-old male, representing a widely used model for oral cancer biology. These cells exhibit tumorigenic properties and are characterized by robust in vitro growth and responsiveness to genotoxic stress, making them suitable for DNA damage response analyses. CAL-27 cells retain key signaling pathways relevant to head and neck squamous cell carcinoma, including DNA repair and apoptotic networks, thus providing a clinically pertinent platform for knockout studies.
BRAT1 (BRCA1-associated ATM activator 1) functions as a scaffold protein essential for ATM kinase activation following DNA double-strand breaks. Mechanistically, BRAT1 interacts directly with ATM and DNA-PKcs, and is recruited to damage sites in a BRCA1-dependent manner, where it facilitates ATM autophosphorylation and subsequent phosphorylation of downstream effectors such as p53 (at Ser15), CHK2 (at Thr68), and H2AX (??H2AX). This signaling cascade orchestrates cell cycle checkpoint arrest and apoptosis. BRAT1 also regulates mitochondrial homeostasis under oxidative stress, linking DNA damage responses to metabolic adaptation. Upstream triggers include DNA double-strand breaks and reactive oxygen species; downstream transcriptional programs involve p53-mediated gene expression.
In the CAL-27 oral cancer context, BRAT1 disruption is expected to impair ATM signaling, compromising the DNA damage response and potentially sensitizing cells to DNA-damaging therapeutics. Given that oral squamous cell carcinomas often exhibit defective DNA repair pathways, this knockout model can recapitulate aspects of genomic instability and therapy resistance. The polyclonal knockout format preserves some cellular heterogeneity, mirroring tumor heterogeneity and enabling the evaluation of BRAT1 loss on proliferation, apoptosis, and drug sensitivity within a tumorigenic epithelial background.
This product is suitable for diverse research applications, including dissecting ATM-mediated signaling networks, evaluating DNA damage repair kinetics, and screening chemotherapeutic agents such as cisplatin or etoposide. Researchers can employ Western blotting to assess phospho-ATM and downstream phosphorylation dynamics, immunofluorescence microscopy to quantify ??H2AX foci formation, flow cytometry for cell cycle profiling and apoptosis detection, colony formation assays to measure clonogenic survival, and comet assays to monitor DNA strand breaks. The model also supports investigations into neurodevelopmental disorders linked to BRAT1 mutations. For further technical inquiries, please contact Ascent Research.
