The BAK1 Knockout CAL-27 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the human tongue squamous cell carcinoma line CAL-27. This product features targeted disruption of the BAK1 gene, generating a heterogeneous cell pool with loss-of-function mutations. These polyclonal knockout cells serve as a model for investigating BAK-dependent apoptotic signaling in oral cancer. The CRISPR/Cas9-mediated gene disruption provides a genetically defined system for dissecting intrinsic apoptosis and evaluating drug responses in BAK-deficient cells.
The CAL-27 cell line was established from a squamous cell carcinoma of the tongue and is widely used as a model for head and neck squamous cell carcinoma (HNSCC). CAL-27 cells exhibit epithelial morphology and harbor TP53 mutations with dysregulated apoptosis signaling. They are commonly employed in oral cancer biology, therapeutic resistance, and drug screening studies. BAK1 knockout in this background enables examination of how BAK loss alters apoptotic sensitivity and tumor cell survival.
BAK1 encodes the pro-apoptotic BAK protein, an effector of the intrinsic apoptotic pathway. Upon activation by BH3-only proteins (BID, BIM, PUMA), BAK oligomerizes at the mitochondrial outer membrane, forming pores that release cytochrome c. Cytochrome c binds APAF1, activating caspase-9 and downstream caspases-3/-7. Anti-apoptotic proteins BCL-2, BCL-XL, and MCL-1 inhibit BAK pore formation. Upstream signals, including TP53 and cellular stress, induce BH3-only proteins. BAK1 knockout disrupts mitochondrial permeabilization and caspase activation.
In CAL-27 oral cancer cells, BAK1 knockout abrogates a key apoptotic pathway. Oral squamous cell carcinomas often exhibit defective apoptosis, contributing to treatment resistance. This polyclonal model allows investigation of compensatory mechanisms, such as reliance on BAX or upregulation of anti-apoptotic BCL-2 proteins. It is valuable for assessing BH3 mimetic sensitivity and identifying BAK-dependent versus BAK-independent killing. The heterogeneous population mimics tumor variability for studying clonal responses to apoptotic stimuli.
Research applications include elucidating BAK-dependent apoptosis, evaluating BH3 mimetic efficacy, and profiling drug sensitivity. Representative assays include western blotting for BAK, Annexin V apoptosis assays, caspase-3/7 activity assays, cytochrome c release, and mitochondrial membrane potential measurements. Cell viability assays with venetoclax, navitoclax, or S63845 can delineate specificity. Co-immunoprecipitation of BCL-2 family complexes further dissects interactions. This product supports studies of compensatory survival pathways. For technical inquiries, contact Ascent Research.
