The CBL Knockout HeLa Polyclonal Cells represent a CRISPR/Cas9-mediated gene disruption population derived from the human cervical adenocarcinoma HeLa cell line, designed to introduce loss-of-function alleles in the endogenous CBL locus. This polyclonal product consists of a heterogeneous pool of edited cells harboring various knockout alleles, providing a robust and reproducible loss-of-function model without the need for clonal isolation. The heterogeneous nature ensures representation of diverse genetic backgrounds while maintaining the consistency of the parental HeLa phenotype. This tool is optimized for researchers investigating CBL-dependent regulation of receptor tyrosine kinase (RTK) signaling, ubiquitin-mediated proteolysis, and oncogenic signal transduction.
Established from a cervical adenocarcinoma biopsy in 1951, the HeLa cell line is one of the most extensively utilized immortalized human epithelial cell lines in biomedical research. It retains characteristic features of epithelial tumor cells, including robust activation of RTK pathways such as EGFR and PDGFR signaling, making it an ideal host for studying CBL function. HeLa cells are known for their aggressive growth properties and chromosomal instability, which contribute to their versatility in cancer biology, signal transduction, and drug discovery. Their well-characterized signaling networks and ease of genetic manipulation allow for straightforward generation and validation of knockout polyclonal populations, providing a physiologically relevant context for studying CBL-mediated signal attenuation.
CBL encodes an E3 ubiquitin-protein ligase that serves as a critical negative regulator of RTK signaling. Upon phosphorylation by SRC family kinases, CBL binds via its SH2 domain to activated RTKs such as EGFR, PDGFR, and MET, often facilitated by adaptor proteins GRB2 and CRK. It then ubiquitinates these receptors, with the aid of ubiquitin-conjugating enzymes like UBE2D1, targeting them for lysosomal or proteasomal degradation and terminating downstream signaling. CBL also ubiquitinates SRC kinase, further attenuating signal output. Thus, CBL acts downstream of multiple growth factors and upstream of the ubiquitin-proteasome system, regulating signal duration and amplitude critical for cell proliferation and survival.
In the HeLa cellular context, loss of CBL function leads to sustained activation of RTK pathways, as EGFR and PDGFR escape ligand-induced degradation and continue to propagate signals through cascades such as RAS-MAPK and PI3K-AKT. This dysregulation mimics common oncogenic mutations observed in acute myeloid leukemia, myeloproliferative disorders, and Noonan syndrome-like disorder, and contributes to the transformed phenotype of cervical adenocarcinoma cells. Consequently, the CBL knockout HeLa polyclonal cells serve as a powerful model for dissecting the tumor-suppressive functions of CBL and for exploring the consequences of unchecked RTK signaling in epithelial cancers. The model allows researchers to study how CBL loss alters cellular behaviors such as anchorage-independent growth and resistance to apoptosis, shedding light on mechanisms of tumorigenesis and potential therapeutic vulnerabilities.
Typical applications include western blotting for EGFR and phospho-ERK, ubiquitination and co-immunoprecipitation assays, and functional readouts such as MTT proliferation, Annexin V apoptosis, and migration assays. This model is suited for RTK signaling regulation studies, oncogenic mutation modeling, ubiquitin-mediated proteolysis research, and drug resistance evaluation. For detailed technical specifications, please contact Ascent Research.
