The OSBPL8 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population derived from Raji B lymphocytes, designed to disrupt the OSBPL8 gene. This gene-edited pool provides a loss-of-function model to study ORP8 functions in sterol transport and growth signaling, avoiding clonal artifacts.
Raji cells, an EBV-positive Burkitt??s lymphoma line, express B-cell markers CD19 and CD20 and exhibit constitutive NF-??B activity. They are a well-established model for B-cell malignancies, allowing investigation of oncogenic signaling and metabolic reprogramming in lymphomas.
OSBPL8/ORP8 is an ER-anchored lipid transfer protein that exchanges cholesterol/oxysterols for PIP2/PIP3 at ER?CPM contacts. Regulated by SREBP2, LXR, and oxysterols, ORP8 interacts with VAPA/VAPB, PTEN, and Raptor to promote mTORC1 lysosomal recruitment and modulates PTEN stability, thereby linking sterol sensing to mTORC1/S6K/4E-BP1 and PI3K/AKT pathways. It also cooperates with NUP62 and controls SREBP2 targets LDLR and HMGCR. OSBPL8 loss disrupts cholesterol homeostasis and dampens mTORC1 signaling.
In B-cell lymphoma models, hyperactive mTORC1 and altered cholesterol metabolism drive oncogenesis. OSBPL8 knockout Raji cells allow precise dissection of how ORP8 loss affects constitutive NF-??B signaling, PI3K/AKT dynamics, and sensitivity to targeted agents, revealing metabolic dependencies specific to EBV-driven tumors.
Research applications include Western blot (pS6K, p4E-BP1, PTEN), RT-qPCR (LDLR, HMGCR), Filipin cholesterol staining, flow cytometry, co-IP with VAPA/PTEN, and drug sensitivity assays (rapamycin). These cells are ideal for mechanistic studies of membrane contact sites, lipid-regulated mTORC1 signaling, and identification of ORP8-dependent vulnerabilities in B-cell lymphoma. For further information, please contact Ascent Research.
