The IDH3B Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population featuring targeted disruption of the IDH3B gene in the A-549 human lung adenocarcinoma epithelial cell line. This loss-of-function model provides a powerful tool for dissecting the role of the mitochondrial NAD+-dependent isocitrate dehydrogenase ?? subunit in cellular metabolism and signaling. The polyclonal nature of the knockout pool ensures representation of diverse editing outcomes while maintaining a consistent loss-of-function phenotype across the population, making it suitable for functional studies without the need for single-cell cloning.
A-549 cells were established from the lung carcinoma of a 58-year-old Caucasian male and are widely recognized as a model of type II alveolar epithelium. These adherent epithelial cells are extensively used in lung cancer biology, respiratory infection research, and studies of metabolic reprogramming. Their robust growth characteristics and well-characterized transcriptomic and metabolic profiles make them an ideal host for investigating mitochondrial enzyme function in a disease-relevant context.
IDH3B encodes the ?? subunit of the mitochondrial isocitrate dehydrogenase complex, which catalyzes the oxidative decarboxylation of isocitrate to ??-ketoglutarate in the TCA cycle, coupled to NAD+ reduction to NADH. Interaction with the IDH3A and IDH3G subunits is essential for holoenzyme activity. IDH3B function is transcriptionally regulated by HIF-1?? under hypoxia, regulated by SIRT3-mediated deacetylation, and controlled at the translational level by mTOR. Disruption of IDH3B impairs TCA cycle flux, reducing ??-ketoglutarate and NADH production. This alters the activity of ??-ketoglutarate-dependent dioxygenases, including HIF-1?? prolyl hydroxylases, TET DNA demethylases, and JmjC histone demethylases, thereby affecting HIF-1?? stability, DNA methylation patterns, and histone modifications.
In the A-549 lung adenocarcinoma background, IDH3B knockout is significant for probing the intersection of mitochondrial metabolism and oncogenic signaling. The resultant decrease in ??-ketoglutarate may stabilize HIF-1??, promoting a pseudo-hypoxic response that drives glycolytic metabolism and tumor aggressiveness. Additionally, altered epigenetic landscapes mediated by TET and JmjC enzymes can influence gene expression programs related to cell proliferation, differentiation, and drug resistance. This model enables detailed investigation of how TCA cycle dysfunction contributes to cancer metabolic reprogramming and mitochondrial disorders.
This polyclonal knockout cell population supports a wide array of research applications, including cancer metabolism studies, TCA cycle flux analysis, and investigation of ??-ketoglutarate signaling. It is particularly suited for Seahorse metabolic flux assays, LC-MS-based metabolomics to quantify TCA intermediates, and NADH/NAD+ ratio measurements. Downstream molecular analyses such as Western blotting for IDH3B, HIF-1??, and epigenetic modifiers, RT-qPCR for HIF-1?? target genes, and DNA methylation or histone modification profiling can be performed. Functional assays like proliferation, clonogenic, and apoptosis analyses further enable assessment of phenotypic consequences. For further information, please contact Ascent Research.
