Background: It was previously reported that targeting vascular epithelial growth factor (VEGF)/VEGFR could modulate the antitumor immunity. VEGFR2 inhibitor YN968D1 is a highly selective VEGFR2 inhibitor and was approved for the treatment of late-stage gastric cancer in 2014, but its role in antitumor immunity remains unknown.
Materials and methods: In this study, we investigated the effects of YN968D1 on the function of T cells in vitro by testing the cytotoxicity and cytokine production. Next, we constructed peritoneal dissemination and subcutaneous gastric cancer mouse model to assess the cytotoxicity of YN968D1-treated T cells in vivo, respectively.
Results: We found that the use of YN968D1 in CD8⁺ T cells could reduce the expression levels of inhibitory checkpoints, such as Lag-3, PD-1, and Tim3, escalate the production of IFN-γ and IL-2 and promote the cytotoxicity of T cells dramatically in vitro. The transfer of YN968D1-treated T cells achieved better tumor control compared to DMSO-treated T cells or control in both peritoneal dissemination and subcutaneous gastric cancer mouse models.
Conclusion: Our results indicate that YN968D1 can enhance the T cell-mediated antitumor immunity.
Keywords: YN968D1, gastric cancer, T cells, cytotoxicity, anti-tumor immunity