SF-9-2 is a PD-L1/PD-1 binding inhibitor with an IC50 of 24.9 nM. It suppresses epithelial-mesenchymal transition, migration, invasion, and proliferation of SK-N-SH cells, while also inducing apoptosis and causing cell cycle arrest. SF-9-2 blocks PD-L1-induced growth of SK-N-SH cells via the MAPK signaling pathway. It restores GSK-3beta activity and enhances PD-L1 degradation through the ubiquitin-proteasome pathway. In the SK-N-SH NOG mouse model, SF-9-2 inhibits tumor growth without notable toxicity. Additionally, SF-9-2 acts as an immune checkpoint inhibitor, blocking PD-L1 to restore T cell function and is applicable to neuroblastoma research.
