The MAP2K2 Knockout Raji Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Raji B lymphocyte line, with targeted disruption of the MAP2K2 gene encoding MEK2. This loss-of-function model provides a heterogeneous pool of cells lacking functional MEK2, suitable for elucidating MAPK/ERK signaling in a lymphoblastoid context. The polyclonal format avoids clonal selection, reflecting diverse editing events and minimizing clone-specific artifacts.
Raji cells originate from an EBV-positive Burkitt lymphoma and exhibit a lymphoblastoid phenotype with robust proliferation and continuous growth in suspension. As B lymphocytes, they perform antibody production and antigen presentation, making them a relevant model for adaptive immunity and B-cell malignancies. EBV-driven latent gene expression activates multiple prosurvival pathways, including MAPK, creating a background where MAP2K2-dependent signaling is pathophysiologically meaningful.
MAP2K2 encodes the dual-specificity kinase MEK2, a key component of the RAS-RAF-MEK-ERK cascade. Upon activation by RAS (KRAS, NRAS, HRAS) through RAF kinases (BRAF, CRAF) in response to upstream receptor tyrosine kinases (EGFR, FGFR) and cytokines (IL-2), MEK2 phosphorylates ERK1/2 (MAPK3/MAPK1). Activated ERK translocates to the nucleus and regulates transcription factors including ELK1, MYC, and ETS, driving proliferation, differentiation, and survival. MEK2 function is modulated by the scaffold KSR1 and phosphatase PP2A, and is targeted by clinical inhibitors trametinib and cobimetinib. Knockout of MAP2K2 abolishes this phosphorylation event, disrupting downstream ERK1/2-mediated transcriptional programs.
Within Raji cells, MAPK/ERK hyperactivation resulting from EBV latency and oncogenic alterations renders them dependent on this pathway. Disrupting MAP2K2 impairs ERK phosphorylation, thereby attenuating proliferative signals and survival mechanisms. This model enables dissection of MEK2-specific contributions to lymphoma cell growth, differentiation, and drug response, while also allowing investigation of compensatory signaling through PI3K/AKT and other cascades. Additionally, it serves as a tool for studying mechanisms of resistance to MAPK pathway inhibitors and for exploring context-specific vulnerabilities in RASopathies.
Research applications of the MAP2K2 Knockout Raji Polyclonal Cells span functional evaluation of MEK2 in B-cell lymphoma, modeling of acquired resistance to MEK inhibitors, and examination of cytokine signaling in immune cells. Standard assays include immunoblotting for phospho-ERK1/2 and total ERK1/2, RT-qPCR analysis of downstream target genes, flow cytometry for proliferation and apoptosis, and drug sensitivity screens using trametinib and cobimetinib. Phospho-signaling profiling and RNA-seq can further characterize pathway alterations. This product is a valuable resource for mechanistic studies and preclinical therapeutic development. For technical inquiries, contact Ascent Research.
