The ALOX5 Knockout A-549 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal population of A-549 human lung carcinoma epithelial cells, engineered to disrupt the ALOX5 gene. This polyclonal knockout product provides a heterogeneous loss-of-function model for studying the roles of 5-lipoxygenase (ALOX5) in cellular processes without the clonal selection artifacts of single-cell-derived lines. The knockout is achieved through CRISPR/Cas9-mediated gene disruption, resulting in the elimination of functional ALOX5 protein expression across the population.
The A-549 host cell line was originally derived from the lung adenocarcinoma of a 58-year-old male and exhibits an epithelial morphology. As a widely used in vitro model for human lung adenocarcinoma, A-549 cells retain characteristics of non-small cell lung cancer, including oncogenic mutations and invasive behavior. They serve as a robust platform for tumor cell signaling, drug response, and lung cancer biology studies.
ALOX5 encodes arachidonate 5-lipoxygenase, the key initiating enzyme in leukotriene biosynthesis. It catalyzes the oxygenation of arachidonic acid to 5-hydroperoxyeicosatetraenoic acid (5-HPETE) and subsequently to leukotriene A? (LTA?). This reaction requires the 5-lipoxygenase-activating protein (FLAP/ALOX5AP). Upstream activation of ALOX5 involves calcium mobilization and phosphorylation by kinases in the MAPK and protein kinase C (PKC) pathways, and its expression is regulated by cytokines such as IL-4 and GM-CSF. Once formed, LTA? is converted by LTA? hydrolase to the potent chemoattractant leukotriene B? (LTB?) or conjugated with glutathione by LTC? synthase to form the cysteinyl leukotrienes (LTC?, LTD?, LTE?). These lipid mediators signal through specific G-protein-coupled receptors: LTB? binds to BLT1 and BLT2, while the cysteinyl leukotrienes activate CysLT1 and CysLT2 receptors. Downstream effects include promoting inflammatory cytokines, chemotaxis, and survival. ALOX5 also interacts with cPLA2 (PLA2G4A) and other regulatory proteins to amplify inflammatory signals. In addition, ALOX5 has been implicated in ferroptosis, an iron-dependent form of regulated cell death.
In the context of A-549 lung cancer cells, knockout of ALOX5 disrupts the leukotriene synthesis cascade, thereby eliminating the production of LTB? and cysteinyl leukotrienes. This model is particularly relevant because A-549 cells express arachidonic acid pathway components, and leukotrienes promote tumor proliferation, migration, and the inflammatory microenvironment. By ablating ALOX5 activity, these polyclonal knockout cells can be used to dissect the contribution of leukotriene signaling to lung adenocarcinoma phenotypes, including apoptosis resistance, invasion, and crosstalk with stromal cells. The heterogeneous nature of the polyclonal population may better reflect tumor heterogeneity and allows assessment of pathway dependency without the potential bias of clonal expansion.
These polyclonal knockout cells are ideal for functional assays including western blotting, RT-qPCR, ELISA or LC-MS lipidomics, and cell-based assays for proliferation, colony formation, migration, and apoptosis. They support leukotriene pathway studies, lung cancer inflammation research, drug target validation, ferroptosis investigation, and tumor microenvironment analysis. For further technical details or to inquire about custom products, please contact Ascent Research.
