The CASP9 Knockout Raji Polyclonal Cells are a polyclonal knockout cell population derived from Raji B lymphocytes, engineered via CRISPR/Cas9-mediated disruption of the CASP9 locus. This product provides a loss-of-function model for the initiator caspase of the intrinsic apoptotic pathway, enabling precise dissection of mitochondrial apoptosis signaling.
The host cell line, Raji, is an Epstein-Barr virus (EBV)-positive B lymphoblastoid line originating from a Burkitt lymphoma patient. Raji cells are widely utilized as a model for B-cell malignancies, displaying robust proliferation and characteristic B-lymphocyte features including surface immunoglobulin expression and antigen-presenting capabilities. Their transformed phenotype, coupled with EBV-driven signaling, often results in altered apoptotic regulation, providing a clinically relevant context for interrogating cell death pathways in lymphoma.
CASP9 is the apical initiator caspase of the intrinsic apoptosis pathway. Cytochrome c released from mitochondria binds APAF1 to form the apoptosome, which recruits and activates CASP9. Active CASP9 subsequently cleaves executioner caspases CASP3 and CASP7, triggering cellular dismantling. The pathway is regulated by BCL2 family proteins controlling mitochondrial permeability, upstream kinases AKT and ERK, and the tumor suppressor p53. The inhibitor XIAP directly suppresses CASP9 and CASP3, while Smac/DIABLO relieves this inhibition upon mitochondrial release.
In Raji cells, CASP9 knockout uncovers apoptosis resistance mechanisms inherent to EBV-positive B-cell lymphomas. These lymphoblastoid cells often exhibit dysregulated apoptosis due to viral oncoproteins and constitutive survival signaling. CASP9 disruption decouples mitochondrial damage from cellular death, enabling investigation of bypass mechanisms or alternative death pathways. This model is valuable for studying therapy-refractory Burkitt lymphoma and for identifying synergistic targets.
Typical experiments include Annexin V/PI apoptosis assays, cytochrome c release detection, caspase activity measurements, and immunoblotting for CASP9, CASP3, and PARP cleavage. Viability assays and drug sensitivity testing with BH3 mimetics like venetoclax are supported, as are co-immunoprecipitation and RT-qPCR. These polyclonal knockout cells facilitate functional genomics, high-throughput pro-apoptotic drug screening, and mechanistic studies of caspase signaling in B-cell malignancies. For technical support, contact Ascent Research.
