This product comprises a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human HAP1 cell line, genetically disrupted at the DKK1 locus to eliminate endogenous DKK1 expression. The polyclonal format provides a heterogeneous pool of cells harboring diverse loss-of-function variants, enabling robust functional studies without requiring clonal isolation. This model is designed for investigating the consequences of DKK1 ablation on Wnt signaling pathways under simplified genomic conditions.
HAP1 is a near-haploid human male adherent cell line originally derived from a chronic myeloid leukemia patient. Its hemizygous genome limits genetic redundancy, making it an exceptionally well-suited host for functional genomics screens and loss-of-function analyses. The near-haploid karyotype facilitates clear gene-phenotype correlations, and the adherent growth properties permit a wide range of cell-based assays. These characteristics establish HAP1 as a versatile platform for dissecting signaling networks with minimal confounding genetic complexity.
DKK1 encodes a secreted glycoprotein that functions as a potent antagonist of the canonical Wnt/??-catenin signaling cascade. It binds to the co-receptors LRP5 and LRP6 in conjunction with Kremen1 and Kremen2, triggering receptor internalization and thereby preventing Wnt ligand-mediated signal transduction. By sequestering LRP5/6, DKK1 promotes ??-catenin degradation via the destruction complex composed of AXIN, APC, and GSK3??, leading to suppression of TCF/LEF-dependent transcription. The DKK1 gene is transcriptionally activated by TP53, the ??-catenin/TCF complex, glucocorticoids, TGF-??, and BMPs, forming autoregulatory loops. In its absence, Wnt ligands such as Wnt1 and Wnt3a can freely engage Frizzled receptors and LRP5/6, resulting in Dishevelled activation, inhibition of the destruction complex, ??-catenin stabilization, and upregulation of downstream targets including MYC, CCND1, AXIN2, and LEF1.
In the HAP1 background, DKK1 knockout elevates basal ??-catenin levels and enhances TCF/LEF transcriptional output, providing a sensitized model for dissecting Wnt-dependent cellular processes. The near-haploid state ensures that functional effects are directly attributable to loss of the single DKK1 allele, minimizing compensatory mechanisms. Researchers can utilize this system to study proliferation, survival, and differentiation dynamics driven by unopposed Wnt signaling, as well as to evaluate chemical modulators of the pathway with high signal-to-noise ratios.
This polyclonal knockout product is applicable across a range of Wnt-related research contexts, including colorectal cancer, hepatocellular carcinoma, multiple myeloma, osteoporosis, and Alzheimer’s disease. Commonly employed assays include Western blotting to quantify ??-catenin protein levels, TOPFlash/FOPFlash dual-luciferase reporter assays for TCF/LEF activity, RT-qPCR measurement of AXIN2, MYC, and CCND1 transcripts, apoptosis and colony formation assessments, and co-immunoprecipitation of LRP6 to monitor receptor interactions. The model is also amenable to high-throughput drug screening aimed at identifying Wnt pathway agonists or inhibitors. For additional information, please contact Ascent Research.
