[HTML][HTML] EBV-driven LMP1 and IFN-γ up-regulate PD-L1 in nasopharyngeal carcinoma: Implications for oncotargeted therapy

W Fang, J Zhang, S Hong, J Zhan, N Chen, T Qin… - Oncotarget, 2014 - ncbi.nlm.nih.gov
W Fang, J Zhang, S Hong, J Zhan, N Chen, T Qin, Y Tang, Y Zhang, S Kang, T Zhou, X Wu…
Oncotarget, 2014ncbi.nlm.nih.gov
PD-L1 expression is a feature of Epstein-Barr virus (EBV) associated malignancies such as
nasopharyngeal carcinoma (NPC). Here, we found that EBV-induced latent membrane
protein 1 (LMP1) and IFN-γ pathways cooperate to regulate programmed cell death protein
1 ligand (PD-L1). Expression of PD-L1 was higher in EBV positive NPC cell lines compared
with EBV negative cell lines. PD-L1 expression could be increased by exogenous and
endogenous induction of LMP1 induced PD-L1. In agreement, expression of PD-L1 was …
Abstract
PD-L1 expression is a feature of Epstein-Barr virus (EBV) associated malignancies such as nasopharyngeal carcinoma (NPC). Here, we found that EBV-induced latent membrane protein 1 (LMP1) and IFN-γ pathways cooperate to regulate programmed cell death protein 1 ligand (PD-L1). Expression of PD-L1 was higher in EBV positive NPC cell lines compared with EBV negative cell lines. PD-L1 expression could be increased by exogenous and endogenous induction of LMP1 induced PD-L1. In agreement, expression of PD-L1 was suppressed by knocking down LMP1 in EBV positive cell lines. We further demonstrated that LMP1 up-regulated PD-L1 through STAT3, AP-1, and NF-κB pathways. Besides, IFN-γ was independent of but synergetic with LMP1 in up-regulating PD-L1 in NPC. Furthermore, we showed that PD-L1 was associated with worse disease-free survival in NPC patients. These results imply that blocking both the LMP1 oncogenic pathway and PD-1/PD-L1 checkpoints may be a promising therapeutic approach for EBV positive NPC patients.
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