Dihydroartemisinin broke immune evasion through YAP1/JAK1/STAT1, 3 pathways to enhance anti-PD-1 therapy in hepatocellular carcinoma

Abstract

The efficacy of anti-PD-1 therapy is not as expected in patients with hepatocellular carcinoma (HCC). Yes-associated protein 1 (YAP1) was overexpressed and activated in HCC. This study aimed to investigate the potential mechanism and inhibitor of YAP1 on immune evasion, and promote anti-PD-1 therapy in HCC. Here, we showed that dihydroartemisinin (DHA), an FDA approved drug, directly suppressed YAP1 expression, leading to break immune evasion in liver tumor niche, characterized by decreased PD-L1 in liver tumor cells and increased CD8+ T cell infiltration. Mechanismly, YAP1 is not only directly related to PD-L1, but also involved in activating the JAK1/STAT1, 3 pathways. Moreover, Yap1 knockout elevated CD4+ and CD8+ T cells in liver tumor niche of Yap1LKO mice. Consistently, verteporfin, YAP1 inhibitor, decreased TGF-{beta} in liver tumor niche and exhausted CD8+ T cells in spleen. Furthermore, DHA combined with anti-PD-1 treatment promoted CD4+ T cell infiltration in the spleen and CD8+ T cells in tumor tissues. Thus, we provide a new combined therapeutic strategy for anti-PD-1 with DHA, a potent YAP1 inhibitor, in HCC.