Fig. 2

Interaction of NPC cells with the tumor microenvironment. EBV-encoded proteins promote tumor development by interacting with tumor-associated cells while limiting the immune infiltration of T cells and NK cells. Immune cells including nature killer (NK) cells, cytotoxic CD8⁺ T cells, M1 macrophage can inhibit NPC tumor growth. In contrast, regulatory T cells (Treg), M2 macrophage, and B cells can promote tumor cell proliferation by inhibiting the activity of CD8⁺ T cells and promote metastasis. Tumor endothelial cells (TEC) and cancer-associated fibroblasts (CAF) can promote tumor proliferation and metastasis by activating survival signaling pathways and producing pro-tumorigenic cytokines. Extracellular matrix acts as a cytokine reservoir at both primary tumor site and metastasis site to support tumor growth