The CAT Knockout CAL-27 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population derived from human CAL-27 cells, with constitutive disruption of the catalase (CAT) gene. This loss-of-function model enables investigation of catalase’s role in detoxifying intracellular hydrogen peroxide and maintaining redox homeostasis. The polyclonal nature ensures diverse gene-editing events, avoiding clonal biases and providing robust functional studies. The knockout abolishes catalase activity, leading to accumulation of hydrogen peroxide and elevated oxidative stress, which impairs redox homeostasis and alters cellular responses to oxidative challenges.
The CAL-27 cell line is an adherent epithelial model derived from a squamous cell carcinoma of the tongue, widely used for human head and neck squamous cell carcinoma (HNSCC) research. Originally established from a 56-year-old male patient, CAL-27 cells express epidermal growth factor receptor (EGFR) and exhibit anchorage-independent growth, reflecting aggressive tumor behavior. It retains key tumor characteristics such as invasive potential and deregulated signaling, making it suitable for studying oxidative stress responses in cancer, where antioxidant defenses often modulate disease progression and therapy resistance.
Catalase (CAT) is a primary antioxidant enzyme that decomposes hydrogen peroxide into water and oxygen, protecting cells from oxidative injury. Transcriptionally controlled by NFE2L2 (NRF2) under the influence of oxidative stress, insulin, and PPAR??, it collaborates with superoxide dismutase and glutathione peroxidase to sustain redox equilibrium. CAT knockout disrupts this network, causing hydrogen peroxide build-up, dysregulation of PI3K/AKT signaling, and loss of ROS-mediated apoptosis inhibition, while affecting interactions with PEX5 and KEAP1-driven stress pathways. The resulting oxidative imbalance can modulate transcription of antioxidant genes and sensitize cells to exogenous stressors.
In the CAL-27 background, catalase loss permits dissection of antioxidant defense contributions to malignant phenotypes. This model is valuable for investigating acatalasemia-related pathology and oxidative stress-driven cancer progression. By elevating intracellular ROS, it reveals redox-sensitive signaling vulnerabilities and chemosensitivity patterns specific to HNSCC, aiding identification of therapeutic targets dependent on oxidative stress adaptation. Furthermore, the polyclonal nature preserves genetic diversity, allowing assessment of heterogeneous responses to oxidative insults across the population, which is critical for translational research aiming to predict tumor behavior.
This polyclonal knockout model supports a variety of experimental readouts, including catalase activity quantification, Western blotting for catalase expression, ROS detection with DCFDA, cell viability assays under hydrogen peroxide challenge, apoptosis evaluation through caspase activity or annexin V staining, and migration/invasion studies using transwell or wound-healing assays. It is particularly suited for dissecting oxidative stress biology, cancer redox signaling, chemoresistance mechanisms, and antioxidant defense pathways in head and neck cancer. For further technical information and support with assay design, please contact Ascent Research.
