This product consists of a polyclonal population of human HAP1 cells in which the CBL gene has been disrupted by CRISPR/Cas9-mediated gene editing, yielding a heterogeneous loss-of-function model. The polyclonal format provides a population-level knockout suitable for studying CBL-dependent signaling without clonal isolation, facilitating experiments that assess the aggregate effect of target-gene disruption. This cell pool is a versatile tool for functional genomics and drug discovery applications focused on ubiquitin-mediated regulation of tyrosine kinase signaling.
HAP1 is a near-haploid suspension cell line derived from a male patient with chronic myeloid leukemia (CML). Its near-haploid karyotype simplifies genetic manipulation and knockout generation, as only one allele typically needs to be disrupted to achieve a null phenotype. The cell line retains key hematopoietic and myeloid signaling features, making it a widely adopted system for CRISPR-based knockout screens and mechanistic studies in a leukemic background.
The CBL gene encodes an E3 ubiquitin ligase that negatively regulates receptor tyrosine kinase (RTK) signaling. CBL is recruited to activated receptors such as EGFR and PDGFR, promoting their ubiquitination and lysosomal degradation. Upstream regulators include activated RTKs themselves and Src family kinases FYN and LYN; CBL interacts with adaptor proteins GRB2, CRK, and SHC, and the E2 enzyme UBE2D. Downstream, CBL terminates signaling through the GRB2?CRAS?CRAF?CMEK?CERK and PI3K?CAKT?CmTOR cascades. Loss of CBL abolishes this negative regulation, leading to sustained pathway activation and oncogenic transformation, especially in myeloid cells.
In the HAP1 CML background, CBL knockout recapitulates key aspects of myeloid malignancies driven by hyperactive RTK signaling. CBL loss-of-function mutations are recurrent in juvenile myelomonocytic leukemia, acute myeloid leukemia, and myelodysplastic syndromes, where they contribute to prolonged MAPK and PI3K pathway activity. The HAP1 polyclonal CBL knockout population provides a tractable model to dissect how CBL deficiency alters intracellular signaling dynamics, cell proliferation, and drug responses in a myelogenous context. This system thus bridges the gap between biochemical analyses of CBL function and the pathophysiology of CBL-mutant diseases.
This knockout pool supports diverse assays: western blotting and phospho-flow cytometry for signaling analysis, proliferation and colony formation assays for growth phenotypes, and ubiquitination assays or immunoprecipitation to probe CBL?Csubstrate interactions. Drug sensitivity testing with RTK inhibitors reveals therapeutic vulnerabilities. Thus, the model is suited for functional genomics of myeloproliferative disorders, target validation in CBL-mutant cancers, and studying ubiquitin-mediated signal termination. For additional information, please contact Ascent Research.
