Androgen receptor affects the response to immune checkpoint therapy by suppressing PD-L1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy with gender-related differences in onset and course. Androgen receptor (AR), a male hormone receptor, is critical in the initiation and progression of HCC. The role of AR in HCC has been mechanistically characterized and anti-AR therapies have been developed, showing limited efficacy. Immunotherapy targeting immune checkpoint proteins may substantially improve the clinical management of HCC. The mechanism by which AR influences HCC immune state remains unclear. In this study, we demonstrated that AR negatively regulated PD-L1, by acting as a transcriptional repressor of PD-L1. Notably, AR over-expression in HCC cells enhanced CD8(+)T function in vitro. We then verified the AR/PD-L1 correlation in patients. In animal experiment we found that lower AR expressed tumor achieved better response to PD-L1 inhibitor. Thus, AR suppressed PD-L1 expression, possibly contributing to gender disparity in HCC. Better understanding of the roles of AR during HCC initiation and progression will provide a novel angle to develop potential HCC immunotherapies.