The CASP3 Knockout K-562 Polyclonal Cells consist of a CRISPR/Cas9-edited polyclonal cell population derived from the K-562 cell line, in which the CASP3 gene has been disrupted to eliminate caspase-3 function. As a polyclonal knockout pool, these cells provide a heterogeneous yet consistent model for studying apoptosis without the biases of single-cell cloning.
The parental K-562 cell line is a human chronic myelogenous leukemia (CML)-derived lymphoblast line originally isolated from the pleural effusion of a patient in blast crisis. K-562 cells are Philadelphia chromosome-positive and express the BCR-ABL1 fusion oncoprotein, which drives constitutive tyrosine kinase activity and promotes survival signaling. These cells exhibit properties of multipotent hematopoietic precursors and are widely employed as a model for CML, erythroid differentiation, and general mechanisms of leukemia cell biology.
CASP3 encodes caspase-3, a critical executioner caspase that functions downstream of both intrinsic and extrinsic apoptotic signaling. Upon cleavage of caspase-3 by initiator caspases such as caspase-8 or caspase-9, the activated protease cleaves a variety of cellular substrates, including PARP1, DFFA, and ROCK1, leading to hallmark features of apoptosis such as DNA fragmentation, chromatin condensation, and membrane blebbing. Upstream regulators of caspase-3 activation include death receptor ligands (e.g., FASLG, TNF), cytochrome c released from mitochondria, APAF1, p53, and BCL2 family members such as BAX and BID. Interaction with inhibitors like XIAP and BIRC5 further modulates its activity. This signaling network positions caspase-3 as a central executioner in apoptotic cell death.
In the K-562 background, the presence of BCR-ABL1 drives strong pro-survival signaling that often dampens apoptotic responses. Disruption of CASP3 in these cells creates a powerful tool for isolating the contributions of caspase-3?Cdependent apoptosis to drug sensitivity and resistance. This model allows researchers to assess whether cell death induced by chemotherapeutic agents, kinase inhibitors, or death receptor agonists requires caspase-3, and to explore alternative cell death pathways when executioner caspase activity is ablated. Consequently, the CASP3 knockout polyclonal K-562 cells facilitate studies of apoptosis escape mechanisms in leukemia.
These cells are suited for a broad range of experimental applications, including apoptosis resistance profiling, drug sensitivity screening, and mechanistic dissection of cell death signaling. Representative assays include Western blot analysis of caspase-3 and cleaved PARP, induction of apoptosis with staurosporine followed by Annexin V staining and flow cytometry, measurement of caspase-3/7 enzymatic activity, and cell viability assays with common chemotherapeutics. The polyclonal knockout population maintains reproducibility across experiments while reflecting natural heterogeneity in editing outcomes, making it ideal for routine functional genomics and drug discovery workflows. For further information, please contact Ascent Research.
