DLL4 Knockout HAP1 Polyclonal Cells are a heterogeneous population of HAP1 cells engineered by CRISPR/Cas9-mediated gene disruption to abolish DLL4 expression. This polyclonal pool contains diverse knockout alleles, providing a robust loss-of-function model without clonal bias. The cells are suitable for studying DLL4-dependent processes in a human near-haploid background.
HAP1 is a near-haploid human cell line derived from the KBM-7 chronic myeloid leukemia cell line. Its stable haploid karyotype facilitates straightforward genetic manipulation and functional genomics screens, making it an ideal platform for CRISPR-based knockout studies. The cells retain key signaling networks, including Notch pathway components, enabling mechanistic investigation of gene function in a simplified genomic context.
DLL4 encodes a transmembrane ligand of the Notch family that plays a critical role in angiogenesis and vascular development. DLL4 is transcriptionally regulated by VEGF, HIF-1??, and FOXC2, and its expression is modulated by ETS transcription factors. Upon binding to Notch1 or Notch4 receptors, DLL4 triggers ADAM10- and ??-secretase-mediated proteolytic cleavage, releasing the Notch intracellular domain (NICD). NICD translocates to the nucleus, where it associates with RBPJ and MAML to activate transcription of target genes such as HES1, HEY1, HEY2, and EphrinB2. DLL4 also interacts with EGFL7 and is regulated by glycosyltransferases like LFNG and ubiquitin ligase MIB1. This signaling establishes a feedback loop within the VEGF-VEGFR2 axis, driving endothelial tip cell selection and vessel sprouting.
In the HAP1 background, DLL4 knockout disrupts Notch-mediated transcriptional programs, providing a simplified system to dissect DLL4 canonical signaling without confounding endothelial-specific phenotypes. Although HAP1 cells are leukemic in origin, they express necessary pathway components, allowing investigation of ligand-receptor dynamics, post-translational processing, and target gene activation. This model is valuable for analyzing DLL4 function in cancer biology, as Notch signaling contributes to tumor angiogenesis and maintenance of cancer stem cells.
These knockout cells are suitable for functional genomics, Notch signaling studies, and angiogenesis research. They support anti-angiogenic drug screening (e.g., DAPT sensitivity assays), co-culture angiogenesis assays, and endothelial cell differentiation models. Representative experimental approaches include Western blotting, RT-qPCR, immunofluorescence, Notch reporter assays, flow cytometry, migration assays, and phospho-Akt analysis. Researchers can use the polyclonal population to assess DLL4-dependent phenotypes in high-throughput screens or pathway-focused studies. For further information, please contact Ascent Research.
