The CASP3 Knockout HeLa Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population in which the endogenous CASP3 gene has been targeted for disruption. This mixed population of gene-edited cells provides a versatile loss-of-function tool for dissecting caspase-3 biology without the need for single-cell cloning. The polyclonal nature preserves heterogeneous responses to apoptotic stimuli, making it suitable for population-level studies.
HeLa cells are an immortalized human cervical adenocarcinoma epithelial cell line that is HPV-18 positive and characterized by rapid proliferation. As the first established human cell line, HeLa cells have been extensively used in cancer biology and signal transduction research. Their well-characterized signaling networks and ease of manipulation make them an ideal host for studying apoptosis, where they display robust caspase activation upon death receptor ligation or intrinsic pathway triggering.
Caspase-3 is a critical executioner caspase activated downstream of both intrinsic and extrinsic apoptotic pathways. It is cleaved and activated by initiator caspases such as caspase-8 (downstream of death receptors like Fas and TRAIL) and caspase-9 (activated via the cytochrome c/Apaf-1 apoptosome). Active caspase-3 proteolytically processes key substrates, including PARP, DFF45/ICAD, lamin A, fodrin, and gelsolin, leading to DNA fragmentation, nuclear dismantling, and cytoskeletal collapse. Its activity is regulated by IAPs such as XIAP and Survivin, which are antagonized by SMAC/DIABLO released from mitochondria. p53 contributes to caspase-3 activation by transcriptionally regulating genes that facilitate mitochondrial outer membrane permeabilization.
Disruption of CASP3 in HeLa cells generates a model in which the execution phase of apoptosis is compromised, enabling dissection of caspase-3-specific contributions to cell death. Since HeLa cells harbor HPV-18 E6/E7 oncoproteins that inactivate p53 and Rb, they provide a background where caspase-3 activation can be studied in the context of compromised tumor suppressor pathways. The CASP3 knockout HeLa polyclonal cells are expected to exhibit resistance to diverse apoptotic stimuli, including intrinsic inducers such as staurosporine and extrinsic ligands like TNF-related apoptosis-inducing ligand (TRAIL). This model facilitates the study of caspase-independent cell death modalities and the investigation of compensatory mechanisms that may emerge upon loss of this key executioner.
Typical applications include mechanistic studies of apoptotic signaling, screening for caspase-3-dependent drug sensitivity, and pathway deconvolution in oncology research. Researchers commonly employ these knockout cells in Western blotting for cleaved caspase-3 and PARP, Annexin V and TUNEL apoptosis assays, fluorogenic caspase activity measurements, RT?qPCR analysis of downstream gene expression, and flow cytometric detection of apoptotic markers. The polyclonal nature allows for the assessment of population-level heterogeneity in death responses and the evaluation of off-target drug effects in a caspase-3-null background. For further details or custom requirements, please contact Ascent Research.
