The DIABLO Knockout HT29 Polyclonal Cells product provides a CRISPR/Cas9-edited polyclonal cell population derived from the HT29 human colorectal adenocarcinoma line, engineered for targeted disruption of the DIABLO (SMAC) gene. This knockout model enables loss-of-function studies of the pro-apoptotic factor DIABLO in a well-characterized epithelial colorectal cancer background. The polyclonal knockout population is generated using CRISPR/Cas9 technology to introduce gene disruptions across the cell pool, offering a robust tool for investigating DIABLO-dependent apoptotic signaling pathways without the need for clonal isolation.
The HT29 parental cell line is a widely used model of human intestinal epithelium, isolated from a colorectal adenocarcinoma. These cells harbor a mutant TP53 gene, are microsatellite stable (MSS), and retain the capacity to differentiate under appropriate culture conditions. HT29 cells are extensively employed in cancer research, particularly for studying colorectal tumor biology, drug permeability, and intestinal epithelial function. Their epithelial origin and well-documented growth characteristics make them an ideal host for genetic manipulation aimed at dissecting apoptosis and chemoresistance mechanisms.
DIABLO (Direct IAP Binding Protein with Low pI, also known as SMAC) is a mitochondrial protein that functions as a critical pro-apoptotic factor. Upon apoptotic stimuli, DIABLO is released into the cytosol following mitochondrial outer membrane permeabilization (MOMP), a process regulated by BAX, BAK, and BH3-only proteins such as BIM and BID under the control of p53 and genotoxic stress. Once in the cytoplasm, DIABLO directly binds and neutralizes inhibitor of apoptosis proteins (IAPs) including XIAP, cIAP1, and cIAP2, thereby relieving their suppression of caspases. This facilitates the activation of key executioner caspases, primarily CASP3 and CASP7, downstream of the initiator caspase CASP9. Thus, DIABLO acts as a key link between mitochondrial permeabilization and the execution phase of intrinsic apoptosis.
In the HT29 colorectal cancer context, DIABLO knockout presents a powerful system to study apoptosis resistance, a hallmark of cancer. HT29 cells exhibit altered apoptotic signaling due to mutant TP53, and the elimination of DIABLO further compromises the intrinsic apoptotic pathway. This model allows researchers to examine how loss of DIABLO impacts IAP-mediated survival signaling, caspase activation thresholds, and cellular responses to chemotherapeutic agents or targeted therapies. It is particularly valuable for investigating mechanisms of chemoresistance in colorectal cancer, where upregulation of IAPs or defective DIABLO release may contribute to therapeutic failure.
This DIABLO knockout cell pool is suited for a range of experimental applications including the dissection of apoptotic signaling networks, screening of pro-apoptotic compounds, and evaluation of drug candidates targeting the IAP-caspase axis. Researchers can assess DIABLO-dependent apoptosis using assays such as western blotting for DIABLO release, caspase-3/7 activity measurements, cytochrome c release assays, Annexin V/PI staining, and co-immunoprecipitation with XIAP. Mitochondrial fractionation can further distinguish between mitochondrial and cytosolic DIABLO pools. For detailed product information, validation data, or technical support, please contact Ascent Research.
