The CERS4 Knockout Raji Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human Raji B-lymphoblast cell line, engineered to achieve targeted disruption of the CERS4 gene. This loss-of-function model is designed for the systematic interrogation of ceramide synthase 4 function in B-cell biology, sphingolipid metabolism, and apoptotic signaling networks. The polyclonal format preserves population-level heterogeneity while eliminating functional CERS4 expression, enabling robust genotype-phenotype correlation studies without clonal artifacts. Researchers can employ these cells to dissect the role of very long-chain ceramide synthesis in lymphoma pathogenesis, stress responses, and therapeutic sensitivity, utilizing standard culture conditions compatible with downstream molecular and lipidomic analyses.
The parental Raji cell line is an extensively characterized human Burkitt lymphoma model derived from an Epstein-Barr virus (EBV)-positive B lymphocyte. As a lymphoblastoid cell line, Raji cells retain key features of antigen-presenting cells and are widely employed in immunology, cancer biology, and drug development. Their B-cell heritage renders them particularly suitable for investigating antibody production, cell-mediated immunity, and oncogenic signaling in hematopoietic malignancies. The EBV-positive status of Raji cells provides a context for studying viral interactions with cellular sphingolipid pathways, as EBV has been shown to modulate ceramide metabolism to promote survival and proliferation. This cellular background offers a clinically relevant platform for evaluating the consequences of CERS4 loss in a transformed B-cell environment.
CERS4 encodes ceramide synthase 4, an integral endoplasmic reticulum enzyme that preferentially catalyzes the synthesis of C18-C20 very long-chain ceramides through N-acylation of sphinganine. These ceramide species serve as critical bioactive lipids that mediate apoptosis, differentiation, and stress signaling. CERS4 activity is modulated by upstream regulators including tumor protein p53 (TP53), tumor necrosis factor (TNF), Fas ligand (FASLG), ultraviolet irradiation, and chemotherapeutic agents such as doxorubicin. Downstream, C18- and C20-ceramides activate protein kinase C zeta (PRKCZ), protein phosphatase 2A (PP2A), and cathepsin D, leading to caspase-dependent cell death via CASP3, CASP8, and CASP9. Ceramide also triggers mitogen-activated protein kinase (MAPK) signaling through JNK phosphorylation and promotes mitochondrial outer membrane permeabilization through BCL2 family members BAX and BAD. The enzyme functionally interacts with serine palmitoyltransferase subunits SPTLC1 and SPTLC2, ceramidases such as ASAH1, sphingosine kinase 1 (SPHK1), and the ceramide transfer protein CERT, integrating de novo synthesis, salvage, and trafficking pathways.
Disruption of CERS4 in the Raji background specifically abrogates the production of very long-chain ceramides, thereby compromising ceramide-mediated apoptotic signaling and cellular stress responses. This knockout is predicted to alter the balance between pro-survival and pro-death sphingolipid species, potentially conferring resistance to apoptosis induced by DNA-damaging agents or death receptor ligands. The model enables precise dissection of how CERS4-dependent ceramide pools regulate proliferation, drug sensitivity, and endoplasmic reticulum stress in B-cell lymphoma. Given the central role of sphingolipid dysregulation in lymphomagenesis, these polyclonal knockout cells facilitate the identification of therapeutic vulnerabilities and resistance mechanisms, making them invaluable for translational research in hematologic malignancies.
The CERS4 Knockout Raji Polyclonal Cells support a diverse array of research applications, including functional characterization of ceramide synthase 4 in B-cell lymphoma, sphingolipid metabolism profiling, apoptosis signaling pathway mapping, and drug resistance screening. Representative assays include Western blotting for CERS4 and cleaved caspases, RT-qPCR quantification of CERS4 mRNA, immunofluorescence localization studies, flow cytometric assessment of apoptosis and cell cycle, ceramide mass spectrometry, and comprehensive sphingolipidomics. Additional applications involve caspase activity assays, proliferation measurements via MTT or BrdU incorporation, drug sensitivity testing with doxorubicin or etoposide, and phospho-JNK analysis. These cells are suited for genetic complementation experiments, co-culture immunology models, and high-throughput chemical library screens. For further technical inquiries, please contact Ascent Research.
