The NNMT Knockout Raji Polyclonal Cells product comprises a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Raji B lymphocyte suspension line, engineered to disrupt the nicotinamide N-methyltransferase (NNMT) gene. This heterogeneous population arises from a bulk gene-editing approach, yielding a loss-of-function model without clonal isolation, and is intended for advanced studies in cancer metabolism and epigenetics. The knockout abolishes NNMT enzymatic activity, thereby eliminating the methylation of nicotinamide to 1-methylnicotinamide and providing a valuable tool for dissecting methyl donor homeostasis and NAD+ biosynthesis in a B cell lymphoma context. Researchers can employ this model to investigate how NNMT deficiency reshapes the metabolome and chromatin landscape in EBV-positive lymphoma cells.
The parental Raji cell line is an Epstein-Barr virus (EBV)-positive Burkitt lymphoma-derived B lymphoblastoid line that grows in suspension and expresses canonical B cell surface markers such as CD19 and CD20. Raji cells are extensively used to study B cell biology, apoptosis mechanisms, and EBV latency programs. Their malignant phenotype, coupled with viral-driven proliferative signals, makes them a relevant host for examining metabolic vulnerabilities in aggressive lymphomas. The NNMT knockout extends the utility of Raji cells by introducing a defined metabolic perturbation that intersects with one-carbon metabolism and epigenetic regulation.
NNMT functions as a key enzyme at the intersection of nicotinate/nicotinamide metabolism and the S-adenosylmethionine (SAM) cycle. It catalyzes the transfer of a methyl group from SAM to nicotinamide, producing 1-methylnicotinamide and S-adenosylhomocysteine (SAH). This reaction consumes methyl donors and thereby influences the SAM/SAH ratio, a critical determinant of DNA and histone methyltransferase activity. NNMT is transcriptionally regulated by upstream factors including STAT3, HIF1A, TGFB1, PPARGC1A, and glucocorticoids, and its activity modulates downstream effectors such as SIRT1, DNMTs, and histone methyltransferases. The enzyme interacts with one-carbon metabolism components like MTHFR and AHCY, and its product 1-methylnicotinamide can accumulate to affect sirtuin activity and global DNA hypomethylation patterns. Consequently, NNMT integrates metabolic and epigenetic signals, and its disruption leads to SAM accumulation, DNA/histone hypermethylation, and altered NAD+ pools.
In the Raji B lymphoblastoid context, NNMT knockout severely impairs nicotinamide clearance, leading to a buildup of SAM and a rise in the SAM/SAH ratio, which drives promiscuous methyltransferase activity and aberrant gene silencing. This epigenetic remodeling likely cooperates with EBV latency programs to alter apoptosis susceptibility and proliferative capacity. NAD+ biosynthesis is diverted, reducing SIRT1 deacetylase activity and affecting metabolic gene expression. The model thus provides a platform to study how metabolic reprogramming and epigenetic dysregulation jointly contribute to lymphomagenesis and treatment resistance, particularly under conditions where NNMT is overexpressed, as observed in several cancers.
This polyclonal knockout cell product is ideally suited for a broad landscape of research applications, including investigation of epigenetic control mechanisms, validation of NNMT as a therapeutic target in B cell malignancies, and dissection of one-carbon metabolism in cancer. Typical experimental readouts encompass Western blotting to confirm NNMT loss, LC-MS quantification of 1-methylnicotinamide and SAM/SAH ratios, global DNA methylation ELISA, RNA-seq for transcriptome-wide changes, MTS proliferation assays, Annexin V apoptosis assays, NAD+/NADH measurements, and SIRT1 activity assays. The model enables systematic analysis of how NNMT ablation influences the molecular circuitry linking STAT3, HIF1A, and TGFB1 signaling to DNMT-dependent silencing and sirtuin-mediated metabolic adaptation. For additional information or assay-specific support, please contact Ascent Research.
