In order to determine the influence of intracellular signaling pathways on the expression of PD-L1 in NBM, we first developed an integrated network of protein kinase cascades.
From an evaluation of patient neuroblastoma tumors, we found that the inflammatory environment of the mouse neuroblastoma mimicked human disease in which PD-L1 expression was associated directly with TILs and lower-risk tumors.
MYC and MYCN control the expression of PD-L1 in neuroblastoma cells both <i>in vitro</i> and <i>in vivo</i> Consistently, abundance of PD-L1 transcript correlates with MYC expression in primary neuroblastoma.<b>Conclusions:</b> The combination of PD-L1 and HLA class I represents a novel prognostic biomarker for neuroblastoma.
Here we show that mono-therapy with anti-PD-1/PD-L1 mAbs had no effect on systemic NB progression in vivo, and also their combination with IL-21, POM-1 or anti-CD25 mAb was ineffective.