The CYBRD1 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population with targeted disruption of the CYBRD1 gene in the human Raji B-lymphocyte line. This live pool provides a versatile loss-of-function model for investigating ferric reductase activity without single-cell cloning. It allows robust functional studies of iron metabolism in a lymphoma background.
Raji is an EBV-positive Burkitt??s lymphoma suspension cell line widely used to model B-cell malignancies and humoral immunity. The cells?? rapid proliferation and metabolic reprogramming make iron homeostasis a relevant research focus. EBV latency further influences host pathways, potentially intersecting with iron regulation.
CYBRD1 (duodenal cytochrome b) encodes a ferric reductase essential for converting dietary or extracellular Fe3+ to Fe2+, the substrate for DMT1-mediated import. This reaction is rate-limiting for iron absorption in the duodenum and for iron acquisition in other tissues. Transcription is induced by HIF-2?? under low oxygen, while IRP1 and IRP2 post-transcriptionally control CYBRD1 mRNA stability in response to iron levels. At the plasma membrane, CYBRD1 forms a complex with DMT1 and PDZK1 to facilitate efficient iron transport. Once internalized, iron is incorporated into heme, iron-sulfur clusters, or stored in ferritin. The broader regulatory network includes the transferrin receptor for alternative uptake, ferroportin for iron export, and hepcidin as the hormone governing systemic iron distribution. In this way, CYBRD1 sits at a critical junction between cellular iron uptake and systemic iron homeostasis.
In the Raji lymphoma model, CYBRD1 knockout offers a precise tool to study how ferric reductase activity supports malignant B-cell proliferation. Rapidly dividing lymphomas demand abundant iron, and CYBRD1 may be especially important when transferrin-bound iron is limiting. Loss of CYBRD1 can reveal vulnerabilities, potentially enhancing sensitivity to ferroptosis induced by agents like erastin or RSL3. This is clinically relevant, as ferroptosis induction is being explored as a therapeutic strategy in refractory lymphomas. Additionally, the knockout can be used to probe interactions between EBV latency programs and iron metabolism, since viral proteins often subvert host nutrient pathways. Such studies may uncover novel drug targets.
A range of assays can be applied to this polyclonal knockout. Ferric reductase activity can be measured using colorimetric substrates, and 59Fe uptake assays quantify transport capacity. Western blotting for ferritin, transferrin receptor, and ferroportin, combined with RT-qPCR for CYBRD1, verifies gene disruption. Flow cytometry with fluorescent metal sensors detects changes in the labile iron pool. Functional experiments using iron chelators (e.g., deferoxamine), iron sources (e.g., ferric ammonium citrate), or ferroptosis inducers (erastin, sorafenib) can assess phenotypic consequences. These applications facilitate research into iron-dependent cell death, mechanisms of anemia, and resistance to chemotherapeutics in B-cell cancers. For further details, contact Ascent Research.
