The Ahr Knockout H-4-II-E Cell Line is a CRISPR/Cas9-edited knockout cell line derived from the rat H-4-II-E hepatoma cell line, providing a loss-of-function model for the aryl hydrocarbon receptor (AhR) gene. This knockout background eliminates endogenous AhR expression, enabling precise dissection of AhR-dependent signaling and xenobiotic metabolism in hepatocyte-derived cells.
The H-4-II-E host cell line originates from the Reuber H35 rat hepatoma, chemically induced by N,N’-2,7-fluorenylenebisacetamide in ACI rats. This hepatocellular carcinoma model retains liver-like metabolic capabilities and tumorigenic properties, making it a standard platform for carcinogenesis, drug metabolism, and hepatotoxicity research. Parental H-4-II-E cells express functional AhR and respond to ligands such as TCDD, offering a direct reference for knockout comparisons.
AhR functions as a ligand-activated transcription factor sensing xenobiotics and endogenous ligands including TCDD, benzo[a]pyrene, FICZ, kynurenine, and indole-3-carbinol. In the cytoplasm, AhR is stabilized by HSP90, XAP2, and p23. Ligand binding triggers nuclear translocation and heterodimerization with ARNT, followed by binding to XRE/DRE elements to induce detoxification genes such as CYP1A1, CYP1B1, UGT1A1, and NQO1. AhR also modulates cell cycle regulators (p27, cyclin D1, c-Myc), apoptosis (BAX), and immune mediators (IL-6, IL-22, IDO1) through crosstalk with NF-??B (RelA), Nrf2, ER??, and ??-catenin pathways.
In the hepatocellular carcinoma context, AhR ablation disrupts dioxin- and PAH-induced detoxification enzyme expression, allowing investigation of receptor contributions to metabolic activation of procarcinogens and hepatocarcinogenesis. The knockout line also facilitates study of AhR-dependent immune modulation in the liver microenvironment, given interactions with IL-22 and IDO1. Furthermore, it serves as a tool to distinguish receptor-mediated from off-target toxicity mechanisms of environmental pollutants and pharmaceuticals.
The Ahr Knockout H-4-II-E Cell Line is suited for environmental toxicology, drug metabolism, and cancer biology applications. Key assays include EROD activity measurements, XRE luciferase reporter gene assays, ChIP-qPCR for AhR binding, and RNA-seq transcriptomics. RT-qPCR and Western blotting confirm Ahr disruption and monitor downstream targets like CYP1A1 and CYP1B1, while TCDD cytotoxicity dose-response curves and immunofluorescence assess functional consequences. For product specifications and ordering, please contact Ascent Research.
