CBL Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population featuring targeted disruption of the CBL gene in the Raji human B lymphocyte line. This loss-of-function model enables investigation of CBL, an E3 ubiquitin ligase and adaptor that negatively regulates receptor tyrosine kinase (RTK) signaling. The polyclonal composition reflects the genetic diversity of the Raji parental line, minimizing clonal artifacts and supporting robust functional analyses.
The Raji cell line is an Epstein-Barr virus (EBV)-positive Burkitt lymphoma model derived from a human B lymphocyte. Widely used in immunology and cancer research, Raji cells recapitulate features of B-cell malignancies and EBV-associated lymphomagenesis, providing a relevant background for studying B-cell signaling and oncogenic transformation. Their well-characterized B-cell receptor (BCR) pathway and sensitivity to apoptosis modulation make Raji cells a classic platform for investigating lymphoid biology.
CBL acts as a negative regulator of RTK pathways by ubiquitinating activated receptors and downstream effectors, targeting them for degradation. It is phosphorylated by upstream kinases such as SRC, SYK, and ZAP?70, and assembles into complexes with adaptor proteins including GRB2, SHC, and CRKL. Key substrates include EGFR, MET, and PDGFR, whose ubiquitination-dependent downregulation attenuates the RAS?CRAF?CMEK?CERK cascade and PI3K/AKT signaling. Additionally, CBL promotes degradation of SHC and inhibits GRB2 recruitment to activated receptors, further dampening signal propagation. CRISPR/Cas9-mediated disruption of CBL impairs this negative feedback, resulting in sustained activation of ERK and AKT.
In Raji cells, CBL knockout likely enhances B-cell receptor (BCR) signaling since CBL normally limits signal propagation through interactions with SYK and ZAP?70. Loss of CBL function may thus amplify MAPK/ERK and PI3K/AKT pathway output, mimicking oncogenic states associated with CBL mutations in myeloid and lymphoid neoplasms. This polyclonal knockout population therefore serves as a relevant platform for dissecting mechanisms of lymphomagenesis, evaluating targeted inhibitors, and exploring synthetic lethal interactions in B-cell malignancies.
Experimental applications include Western blotting and immunoprecipitation to examine ubiquitination of EGFR or MET, RT?qPCR and flow cytometry to measure transcriptional and phospho?protein changes (e.g., phospho?ERK, phospho?AKT), and functional assays such as proliferation, apoptosis, and calcium flux. Drug sensitivity testing with RTK or MAPK pathway inhibitors further facilitates drug target validation in lymphoid malignancies. Overall, this CBL knockout Raji model is an essential tool for preclinical studies on ubiquitin ligase regulation in hematopoietic cancers and for testing inhibitors of dysregulated RTK or BCR signaling. For more details, please contact Ascent Research.
