The ATRAID Knockout HT29 Polyclonal Cells comprise a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human colorectal adenocarcinoma cell line HT29, engineered for targeted disruption of the All-Trans Retinoic Acid-Induced Differentiation and Tumor Suppressor (ATRAID) gene. This loss-of-function model enables systematic investigation of ATRAID-dependent molecular mechanisms in an epithelial colorectal cancer background. The polyclonal format preserves a heterogeneous pool of edited cells, providing a robust platform for studying retinoic acid-mediated signaling, differentiation, and tumor suppression without clonal selection bias, thereby reflecting a more physiologically relevant cellular context.
HT29 is a well-characterized adherent epithelial cell line isolated from a primary colorectal adenocarcinoma of a 44-year-old female, widely employed in cancer biology due to its ability to undergo enterocytic differentiation upon confluence or treatment with inducing agents. These cells harbor mutations in key tumor suppressors and oncogenes, including APC, TP53, and KRAS, rendering them a representative model for studying colorectal cancer progression and therapeutic responses. The HT29 background provides a relevant milieu for dissecting the role of ATRAID in retinoic acid-dependent growth control, as these cells retain functional retinoic acid receptor signaling components and exhibit measurable differentiation and apoptotic responses upon all-trans retinoic acid (ATRA) stimulation.
ATRAID operates downstream of ATRA-activated nuclear hormone receptors, primarily retinoic acid receptor alpha (RAR??) and retinoid X receptor alpha (RXR??), which heterodimerize and bind retinoic acid response elements (RAREs) in the ATRAID promoter, transcriptionally upregulating its expression. Subsequently, ATRAID facilitates cell cycle exit and programmed cell death by modulating the expression of critical downstream effectors: it promotes p21-mediated G1 arrest, suppresses anti-apoptotic Bcl-2, triggers caspase activation, and downregulates cyclin D1. ATRAID interacts with corepressor complexes that modulate its tumor-suppressive activity, and its induction shifts the cellular equilibrium toward growth inhibition and differentiation. Disruption of ATRAID therefore decouples ATRA signaling from its antiproliferative outputs, providing a clean genetic system to interrogate the RAR/RXR-ATRAID axis.
In the HT29 colorectal adenocarcinoma context, ATRAID knockout ablates the ability of ATRA to impose cell cycle arrest and differentiation, instead promoting unchecked proliferation, resistance to apoptosis, and enhanced tumorigenic traits. This model recapitulates aspects of retinoic acid resistance frequently observed in advanced colorectal cancers, where silencing of ATRAID or related effectors contributes to disease progression. Consequently, these polyclonal knockout cells serve as a powerful tool for dissecting the molecular basis of ATRAID-dependent tumor suppression and for evaluating strategies to restore retinoic acid sensitivity in colorectal malignancies.
Researchers can employ the ATRAID Knockout HT29 Polyclonal Cells in a broad array of functional assays: Western blotting and RT-qPCR to quantify changes in ATRAID, p21, Bcl-2, cyclin D1, and caspases; flow cytometry with Annexin V/PI staining for apoptosis and propidium iodide for cell cycle distribution; MTT or resazurin-based viability assays to assess growth inhibition; transwell migration and invasion assays to study metastatic potential; and RNA-seq for transcriptome-wide expression profiling following ATRA treatment. These applications support investigations into retinoic acid signaling dynamics, differentiation therapy mechanisms, and the identification of novel targets overriding tumor-suppressive barriers. For detailed product specifications, protocols, or technical support, please contact Ascent Research.
