The BID Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human A-549 lung adenocarcinoma line, engineered to disrupt the BID gene. This polyclonal pool provides a loss-of-function model for investigating BID-dependent apoptotic signaling without clonal selection biases. Disruption of BID eliminates full-length BH3-only protein, enabling systematic dissection of its role in death receptor-mediated and mitochondrial apoptosis pathways.
The parental A-549 cell line, from adenocarcinoma of a 58-year-old male, is a widely used model of type II alveolar epithelial cells. A-549 cells retain key lung adenocarcinoma features, including mutant KRAS and wild-type TP53, making them valuable for studying oncogenic signaling and tumor cell death. Their well-characterized responses to extrinsic apoptotic stimuli, such as TNF-?? and Fas ligand, render them ideal for examining BID-mediated crosstalk between death receptor activation and mitochondrial outer membrane permeabilization.
BID encodes a pro-apoptotic BH3-only BCL-2 family protein that links extrinsic and intrinsic apoptosis. Full-length BID is cytosolic; upon activation, it is cleaved by caspase-8, Granzyme B, or cathepsins to generate tBID. tBID translocates to mitochondria, interacting with BAX and BAK to promote their oligomerization and cytochrome c release, which triggers Apaf-1-mediated caspase-9 activation and caspase-3 cleavage. BID is regulated by death receptors (Fas, TNFR1) and p53, and counterbalanced by anti-apoptotic BCL-2, BCL-XL, and MCL-1.
In A-549 cells, BID knockout allows interrogation of mitochondrial apoptosis contributions to drug sensitivity, radiation response, and death receptor signaling. A-549 cells show moderate chemoresistance; ablating BID provides a clean genetic system to distinguish BID-dependent from BID-independent cell death. This model is powerful for evaluating TRAIL-based therapies, SMAC mimetics, or BH3-mimetic drugs that engage intrinsic apoptosis.
The knockout cells suit apoptosis pathway analysis, cancer cell death studies, and drug sensitivity screening. Key assays include western blotting for caspase cleavages, flow cytometry with Annexin V/PI, JC-1 mitochondrial membrane potential assay, cytochrome c release ELISA, caspase activity assays, co-immunoprecipitation of tBID-BAX, and immunofluorescence for BAX translocation. This polyclonal population is a robust tool for dissecting BID-dependent networks. For further details, contact Ascent Research.
