Description

The Casp8 Knockout MC-38 Cell Line is a CRISPR/Cas9-edited knockout cell line featuring stable disruption of Casp8 in the MC-38 murine colon adenocarcinoma background. This loss-of-function model enables precise dissection of caspase-8?Cdependent signaling pathways in a syngeneic colorectal cancer context. By eliminating caspase-8 expression, researchers can investigate consequences of impaired death receptor signaling, altered apoptotic and necroptotic responses, and potential compensatory mechanisms in tumor cells.

MC-38 cells are a widely used C57BL/6-derived colon adenocarcinoma line that forms aggressive tumors in immunocompetent hosts. Their syngeneic nature and defined immunogenicity make them a standard model for immuno-oncology studies, including checkpoint blockade and adoptive T cell therapies. The C57BL/6 background facilitates integration with transgenic hosts for in vivo mechanistic investigations.

Caspase-8, the initiator caspase of the extrinsic apoptosis pathway, is activated upon death receptor ligation (Fas, TRAIL receptors, TNFR1) and FADD recruitment within the DISC. Active caspase-8 cleaves executioner caspases-3 and -7 and processes Bid, linking to mitochondrial apoptosis. Caspase-8 also suppresses necroptosis by cleaving RIPK1, thereby restraining RIPK1/RIPK3/MLKL necrosome formation. Additionally, caspase-8 interacts with FLIP and cIAP1/2 to modulate NF-??B signaling, underscoring its central role in cell fate decisions.

In MC-38 cells, caspase-8 knockout abolishes extrinsic apoptosis, conferring resistance to death receptor agonists such as TRAIL and potentially shifting cell death toward necroptosis. This model allows examination of how caspase-8 loss impacts tumor growth, immune cell infiltration, and response to immunotherapies, thereby illuminating mechanisms of immune evasion and therapeutic resistance in colorectal cancer. Moreover, caspase-8 deficiency may unlock necroptotic death in the presence of caspase inhibition, providing a platform to study RIPK1/RIPK3/MLKL pathway dynamics.

Key applications include screening for caspase-8 modulators, necroptosis signaling studies using phospho-RIPK3 and phospho-MLKL readouts, co-immunoprecipitation of DISC components, and apoptosis assays such as Annexin V/PI staining. The line is also suited for syngeneic tumor models to assess tumor progression and immunotherapy responses. Standard techniques like Western blotting for caspase-8 fragments and flow cytometry for death receptor expression are directly applicable. For further information or to request a quotation, please contact Ascent Research.