The CASP6 Knockout DLD-1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population with targeted disruption of the CASP6 gene. This loss-of-function model bypasses potential confounding effects from pharmacological inhibitors and preserves endogenous caspase-6 regulatory context in a heterogeneous DLD-1 background. The polyclonal format avoids clonal bias while enabling robust functional studies.
DLD-1 is a human colorectal adenocarcinoma cell line characterized by microsatellite instability (MSI-H) and a KRAS G13D mutation. Widely used in colon cancer research, this epithelial line provides a disease-relevant platform for examining how CASP6 loss impacts tumor cell behavior, including apoptosis regulation and therapeutic responses.
Caspase-6 acts as an executioner caspase, cleaving substrates such as lamin A/C, PARP, and ??-catenin during apoptosis, and also processes tau and huntingtin in neurodegeneration. Upstream regulators include caspase-8, caspase-9, and granzyme B, while inhibitors XIAP and survivin (BIRC5) suppress its activity. In the intrinsic pathway, cytochrome c, APAF1, and caspase-9 form the apoptosome that activates caspase-3 and then caspase-6; extrinsic signaling proceeds via caspase-8. BAX, BCL2, and p53 targets PUMA and NOXA govern mitochondrial integrity upstream. Caspase-6 also interacts with RIPK1 in necroptosis and inflammatory signaling.
Knocking out CASP6 in DLD-1 cells specifically abrogates the execution-phase proteolysis mediated by this caspase, thereby conferring apoptosis resistance to stimuli that trigger the mitochondrial or death receptor pathways. This model allows dissection of caspase-6-specific functions in colorectal cancer, including its potential roles in DNA repair, nuclear envelope breakdown, and modulation of cell migration, independent of caspase-3/7.
Key applications include studying apoptosis evasion in colon cancer, evaluating caspase-6-dependent substrates like lamin A/C and PARP via Western blotting, and measuring cell viability and caspase activity after chemotherapeutic challenge (e.g., 5-FU, oxaliplatin). Apoptosis assays (Annexin V, TUNEL), immunofluorescence, and migration/invasion assays can further define the functional consequences. RT-qPCR may reveal transcriptional changes downstream of caspase-6 loss. Additionally, the model is suitable for screening caspase-6-specific inhibitors. For further information, please contact Ascent Research.
