The MTHFS Knockout Raji Polyclonal Cells comprise a CRISPR/Cas9-edited polyclonal knockout population derived from the human Raji B lymphocyte suspension line. This model enables targeted disruption of the MTHFS gene, which encodes the folate-metabolizing enzyme 5-formyltetrahydrofolate cyclo-ligase, generating a heterogeneous pool of cells with loss-of-function mutations. By using a polyclonal strategy, the product avoids clonal selection bias and better represents the genetic diversity observed in tumor microenvironments, making it suitable for population-level metabolic studies.
The Raji host cell line was established from a Burkitt’s lymphoma patient and is characterized by EBV positivity and the hallmark MYC translocation t(8;14). As a suspension-growing B lymphocyte line, Raji cells are extensively employed in immunological and oncological research, particularly for investigating B cell biology, antigen presentation, and lymphoma pathogenesis. The constitutive MYC overexpression in these cells drives metabolic reprogramming and proliferation, providing a highly relevant context for studying folate-dependent one-carbon metabolism in aggressive B cell malignancies.
MTHFS catalyzes the irreversible ATP-dependent conversion of 5-formyltetrahydrofolate to 5,10-methenyltetrahydrofolate, committing folate cofactors to the one-carbon pool. As a homodimer, it interacts with serine hydroxymethyltransferase 1 (SHMT1), methylenetetrahydrofolate reductase (MTHFR), and the trifunctional enzyme MTHFD1. Its expression is influenced by folate availability and transcription factors MYC and NRF2, positioning MTHFS at a regulatory node that controls purine and thymidylate synthesis through TYMS and DHFR, as well as DNA methylation via S-adenosylmethionine (SAM). Disruption of MTHFS consequently impairs nucleotide biosynthesis and can perturb methylation-dependent gene regulation, with profound effects on cellular proliferation and survival.
In the Raji lymphoma context, constitutive MYC activation drives heightened reliance on one-carbon metabolism, making MTHFS a potentially critical vulnerability. The polyclonal knockout disrupts folate homeostasis, likely impeding purine and thymidylate synthesis and altering DNA methylation landscapes. These metabolic and epigenetic perturbations can affect proliferation, cell cycle progression, and sensitivity to antifolate agents such as methotrexate and pemetrexed. By using a heterogeneous knockout population, researchers can study how metabolic heterogeneity influences drug responses and compensatory pathway activation, without the limitations of clonal artifacts.
Researchers can apply these MTHFS knockout polyclonal Raji cells in diverse experimental settings, including cell proliferation and viability assays, flow cytometric cell cycle and apoptosis analyses, and drug sensitivity profiling with antifolates like methotrexate. Metabolite profiling by LC-MS and nucleotide quantification can directly assess impacts on the one-carbon pool, while bisulfite sequencing enables DNA methylation analysis. Folate rescue experiments can probe metabolic flexibility, and western blotting or RT-qPCR can evaluate expression changes in folate pathway components such as MTHFR, TYMS, and DHFR. These applications make the cells a valuable tool for investigating one-carbon metabolism in lymphoma, studying mechanisms of antifolate resistance, and identifying metabolic targets in B cell malignancies. For additional technical information, please contact Ascent Research.
