This CRISPR/Cas9-edited polyclonal knockout cell population targets the FBXW9 gene in Raji B lymphocytes. As a heterogeneous pool of knockout alleles, the polyclonal format provides a loss-of-function model free from single-clone selection artifacts, enabling robust functional studies. FBXW9 encodes the substrate recognition subunit of the SCF (SKP1-CUL1-F-box) E3 ubiquitin ligase, which directs specific proteins for ubiquitin-dependent proteasomal degradation. Ablation of FBXW9 expression allows researchers to examine substrate stabilization, protein turnover, and downstream signaling consequences in a well-defined lymphoma background.
The Raji cell line originates from an EBV-positive Burkitt lymphoma patient and exhibits B lymphocyte markers CD19 and CD20. Raji cells harbor a MYC-immunoglobulin enhancer juxtaposition, leading to constitutive MYC overexpression, a hallmark of Burkitt lymphoma. This genetic feature makes Raji an ideal model for studying B-cell signaling, oncogenic networks, viral latency, and lymphoma biology. The line is amenable to genetic manipulation and supports a wide range of downstream phenotypic and molecular assays.
FBXW9 functions as a molecular adaptor, recognizing phosphorylated degrons on substrate proteins and facilitating their ubiquitination by the SCF complex in conjunction with the E2 enzyme UBE2D. The SCF core consists of SKP1, CUL1, and RBX1, which together with FBXW9 form an active E3 ligase. Established targets include cell cycle regulators (cyclins), CDK inhibitors, and pro-apoptotic factors, whose 26S proteasome-mediated destruction balances proliferation and apoptosis. In the Raji background, overexpressed MYC may modulate SCF component expression and substrate recognition, positioning FBXW9 as a node that integrates oncogenic signals with proteolytic control.
FBXW9 knockout in Raji cells likely stabilizes substrates that promote growth arrest or apoptosis, potentially inducing synthetic vulnerabilities or compensatory pathway activation. This provides a valuable system to study how ubiquitin-mediated proteolysis influences B-cell malignancy, particularly in the context of MYC-driven transformation. The polyclonal knockout population reduces clonal bias and better reflects native functional heterogeneity, making it suitable for robust identification of FBXW9-dependent phenotypes and therapeutic targets in lymphoma.
This model supports diverse applications, including Western blot and RT-qPCR for monitoring protein and transcript levels, flow cytometry for cell cycle and apoptosis analysis, co-immunoprecipitation to assess SCF complex interactions, and RNA-seq for transcriptome profiling. Proteasome inhibitor sensitivity and proliferation assays help define the role of FBXW9 in drug response and lymphoma growth. For further information or to discuss custom applications, please contact Ascent Research.
