The DLAT Knockout HT29 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human colorectal adenocarcinoma HT29 line, created to disrupt the DLAT gene. This heterogeneous pool serves as a loss-of-function model for studying the DLAT-encoded E2 subunit of the pyruvate dehydrogenase (PDH) and alpha-ketoglutarate dehydrogenase complexes, which are central to mitochondrial metabolism. The polyclonal format avoids clonal artifacts, allowing evaluation of diverse editing outcomes and robust phenotypic assessment.
HT29 cells originate from a primary colorectal adenocarcinoma and maintain epithelial characteristics, including polarization and mucus secretion. They are widely employed in colorectal cancer research and intestinal biology studies due to their ability to switch between glycolytic and oxidative metabolism, making them particularly suitable for examining perturbations in central carbon metabolism. This metabolic plasticity underscores their value in dissecting the consequences of DLAT disruption.
DLAT encodes the E2 subunit that forms the structural core of the pyruvate dehydrogenase complex and also functions in the alpha-ketoglutarate dehydrogenase complex. It catalyzes the transfer of the acetyl group from dihydrolipoamide to coenzyme A, a crucial step linking glycolysis to the TCA cycle. DLAT activity is dynamically regulated by pyruvate dehydrogenase kinases (PDK1?C4) and phosphatases (PDP1, PDP2), which respond to hormonal and energy signals such as insulin, glucagon, and AMPK. Within the PDH complex, DLAT interacts with PDHA1, PDHB, DLD, and PDHX, and it partners with OGDH and DLST in the alpha-ketoglutarate dehydrogenase complex. Knockout of DLAT disrupts acetyl-CoA and NADH generation, impacting downstream TCA cycle enzymes including citrate synthase, isocitrate dehydrogenase, and succinate dehydrogenase, and ultimately altering lipid synthesis, cholesterol biosynthesis via HMG-CoA reductase, and histone acetylation.
In HT29 cells, knockout of DLAT cripples the PDH complex, markedly reducing the conversion of pyruvate to acetyl-CoA and restricting TCA cycle flux. This metabolic blockade compels cells to rely on alternative fuels such as glutamine and fatty acids, reshaping cellular energetics, redox balance, and proliferation. The model thus recapitulates key elements of colorectal cancer metabolic reprogramming and offers a platform to investigate adaptive mechanisms and therapeutic targets associated with impaired glucose oxidation.
These polyclonal knockout cells support diverse experimental approaches. Metabolic flux can be evaluated by Seahorse XF analysis of OCR and ECAR to gauge mitochondrial respiration and glycolysis. Molecular validation is performed using Western blotting and RT-qPCR for DLAT and PDH components. Functional assays include cell proliferation (MTT, BrdU), apoptosis (Annexin V), and colony formation. Drug screening for metabolic inhibitors can identify compounds selective for DLAT-deficient cells. Metabolomic profiling and pyruvate dehydrogenase activity assays further characterize the metabolic consequences. For further information, please contact Ascent Research.
