Ginsenoside Rh1 regulates the immune microenvironment of hepatocellular carcinoma via the glucocorticoid receptor.

Abstract

Objective: Ginsenoside Rh1 (G-Rh1) has been confirmed to inhibit the growth of breast cancer and colon cancer, but its therapeutic effect on hepatocellular carcinoma (HCC) is unclear. This study investigates the therapeutic effect of G-Rh1 on HCC as well as the underlying mechanism.

Methods: Bioinformatics methods were used to analyze glucocorticoid receptor (GR) expression and the tumor microenvironment in HCC tissues from HCC patients. The effect of G-Rh1 on HCC cells was investigated in vitro using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The therapeutic effect of G-Rh1 was investigated in vivo using subcutaneous transplantation models in C57BL/6J and nude mice. Additionally, the proportion of infiltrating immune cells in tumors was analyzed using flow cytometry, the GR and major histocompatibility complex class-I (MHC-I) expression of HCC cells after G-Rh1 treatment was analyzed using Western blotting, and G-Rh1-treated Hepa1-6 cells were cocultured with bone marrow-derived dendritic cells and B3Z T cells to further analyze the ability of G-Rh1 to induce dendritic cell (DC) maturation and CD8⁺ T cell activation.

Results: GR expression was upregulated in HCC tissues, and high GR expression was associated with a worsened immune microenvironment. In vitro studies showed that G-Rh1 had no significant effect on the proliferation of HCC cells, while in vivo studies showed that G-Rh1 exerted antitumor effects in C57BL/6J mice but not in nude mice. Further research revealed that G-Rh1 ameliorated the immunosuppressive tumor microenvironment, thereby enhancing the antitumor effects of lenvatinib by increasing the infiltration of CD8⁺ T cells, mature DCs, and MHC-I-positive cells. MHC-I was upregulated by G-Rh1 via GR suppression. Moreover, overexpression of GR abolished the G-Rh1-mediated promotion of MHC-I expression in Huh7 cells, as well as the maturation of DCs and the activation of CD8⁺ T cells.

Conclusion: G-Rh1 can regulate the immune microenvironment of HCC by targeting GR, thus increasing the antitumor effect of lenvatinib. Please cite this article as: Wang XH, Fu YL, Xu YN, Zhang PC, Zheng TX, Ling CQ, Feng YL. Ginsenoside Rh1 regulates the immune microenvironment of hepatocellular carcinoma via the glucocorticoid receptor. J Integr Med. 2024; Epub ahead of print.