ginsenoside-rh4 and Breast-Neoplasms

High expression of histone deacetylase 2 (HDAC2) is recognized as a marker of invasive breast cancer (BC). HDAC2 is not only responsible for enhancing tumor cell growth, development, and anti-apoptosis, but also plays a significant role in regulating PD-L1 on the surface of tumor cells. Continuous expression of PD-L1 allows tumor cells to escape immune surveillance. There is not much research on how HDAC2 affects the immune system in breast cancer. Ginsenoside Rh4 (Rh4) is a major rare saponin in heat-treated ginseng, which is widely applied in treating and preventing various diseases because of its potent medicinal value and stable safety. However, it is unclear how Rh4 affects the tumor immune microenvironment in breast cancer. Therefore, this paper aims to investigate the effect of Rh4 on HDAC2 in breast cancer, specifically the effect of HDAC2 on apoptosis and the immune microenvironment to inhibit breast cancer growth. According to our study, ginsenoside Rh4 has been shown to significantly suppress breast cancer cell proliferation without any adverse effects. The molecular docking results of Rh4 and HDAC2 indicate a binding energy of -6.06 kcal/mol, suggesting the potential of Rh4 as a targeting modulator of HDAC2. Mechanistically, Rh4 induces apoptosis of breast cancer cells by the HDAC2-mediated caspase pathway and inhibits the HDAC2-mediated JAK/STAT pathway to regulate the immune microenvironment, which inhibits breast cancer growth. Specifically, Rh4 was shown for the first time to blockade immune checkpoints (PD-1/PD-L1) and increase levels of T-lymphocytes in the tumor. In a word, our study establishes a theoretical framework for applying Rh4 as an immune checkpoint inhibitor as part of breast cancer treatment.

Topics: B7-H1 Antigen; Breast Neoplasms; Cell Line, Tumor; Female; Histone Deacetylase 2; Humans; Janus Kinases; Molecular Docking Simulation; Signal Transduction; STAT Transcription Factors; Tumor Microenvironment

Breast cancer is a tremendous threat to humans in many countries, and thus we need to find safe and effective drugs for treatment. Ginsenoside Rh4 has been reported to be present in processed ginseng. However, few studies have focused on its anti-tumor activity. In this study, we investigated the inhibitory effects of ginsenoside Rh4 on MCF-7 breast cancer cells and the pathways that promote apoptosis in vitro. To study the effect of ginsenoside Rh4 in vivo, xenograft models were randomly divided into 3 groups (the control group, 10 mg/kg/d Rh4, 20 mg/kg/d Rh4, n = 10 per group), the ginsenoside Rh4 injection method was i.p. The results showed that ginsenoside Rh4 effectively inhibited proliferation, arrested the cell cycle in S phase and induced apoptosis in MCF-7 cells by flow cytometry. Morphological changes caused by ginsenoside Rh4-induced apoptosis were also observed by Hoechst 33342 staining. Western-blot analyses indicated that the apoptosis-inducing effects of ginsenoside Rh4 were associated with the external pathway by decreasing Bcl-2, increasing Bax, and activating caspase-8, -3 and PARP. Moreover, ginsenoside Rh4 significantly inhibited the growth of MCF-7 tumor cells in vivo. These results suggested that ginsenoside Rh4 could be a potentially effective anti-tumor drug for breast cancer.

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Breast Neoplasms; Cell Cycle; Cell Proliferation; Female; Ginsenosides; Humans; MCF-7 Cells; Mice, Inbred BALB C; Mice, Nude