The GPX4 Knockout CAL-27 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population designed to disrupt GPX4 in the human CAL-27 tongue squamous cell carcinoma line. This heterogeneous cell pool, generated by Cas9-mediated gene disruption, eliminates glutathione peroxidase 4 function, providing a loss-of-function model for ferroptosis and redox biology. The polyclonal format preserves host cell diversity while minimizing clonal artifacts.
CAL-27 is an epithelial cell line derived from a human tongue squamous cell carcinoma, with malignant features including invasiveness and altered oxidative stress responses. As a head and neck cancer model, it retains relevant signaling pathways and is widely used in drug sensitivity assays and molecular pathology, making it an ideal host for studying GPX4-dependent ferroptosis.
GPX4 encodes a phospholipid hydroperoxide glutathione peroxidase that reduces lipid hydroperoxides using glutathione as a cofactor, thereby preventing ferroptosis. Its expression is regulated by NFE2L2, TP53, selenium, and ATF3. Downstream, GPX4 suppresses lipid peroxidation and maintains mitochondrial function. In the ferroptosis pathway, GPX4 acts as a central guardian against lipid peroxides generated by ACSL4, LPCAT3, and ALOX5. Pharmacological inhibitors RSL3 and FIN56 directly target GPX4, while erastin depletes glutathione via SLC7A11 inhibition, indirectly blocking GPX4 activity.
In CAL-27 cells, GPX4 knockout abrogates glutathione-dependent lipid peroxide reduction, rendering cells highly susceptible to ferroptosis, as outlined in the mechanistic summary. This model enables dissection of ferroptosis induction and resistance mechanisms in head and neck cancer, where redox homeostasis is often perturbed. The polyclonal nature allows assessment of intercellular variability in ferroptosis sensitivity and facilitates identification of compensatory pathways upon GPX4 loss in malignant epithelial cells.
Applications include ferroptosis studies, cancer cell death research, and drug screening for ferroptosis inducers. Researchers can perform lipid peroxidation assays (C11-BODIPY), cell viability assays with erastin or RSL3, glutathione quantification, and mitochondrial membrane potential measurements. Further analysis involves western blotting, RT-qPCR, and flow cytometry for cell death. These tools support high-throughput screening of ferroptosis modulators and mechanistic investigations of GPX4 survival pathways in head and neck oncology. For additional information or technical inquiries, please contact Ascent Research.
