Impact of Hypoxia on Epstein-Barr Virus–Mediated B Cell Transformation
Epstein-Barr virus (EBV) contributes to over 200,000 cancers annually, predominantly aggressive lymphomas originating from hypoxic germinal centers (<1% O2). However, conventional models fail to recapitulate the physiologically relevant hypoxic microenvironment which profoundly influences B-cell metabolic remodeling during transformation. Here, we establish an ex vivo model of EBV-driven B-cell transformation under 1% O2, demonstrating robust transformation and super-enhancer activation of oncogenic regulators, including MYC. Multi-omic analyses reveal distinct metabolic adaptations to hypoxia. Unlike normoxic B-cells, which rely on stearyl desaturase 1 and fatty acid oxidation to mitigate lipotoxicity, hypoxically transformed B-cells suppress fatty acid synthesis while upregulating glycerophospholipid metabolism and lipid droplet formation to buffer excess saturated lipids. Consequently, these cells exhibit heightened dependence on extracellular unsaturated fatty acids to support membrane biogenesis for proliferation. Our findings provide the first physiologically relevant model of EBV-driven B-cell transformation under hypoxia, uncovering metabolic vulnerabilities that could inform targeted therapeutic strategies for EBV-associated malignancies. Overall design: Newly isolated human primary B cells were transformed by Epstein-Barr virus under either 21% O2 or 1% O2 conditions. After 28 days in culture, the infected B cells were fully transformed into lymphoblastoid cell lines (LCLs). These LCLs, generated under 21% O2 (referred to as 21% O2 LCLs) or 1% O2 (1% O2 LCLs), were subsequently used for RNA-seq and ChIP-seq analysis targeting H3K27ac and H3K4me3.