Banxia Xiexin Decoction Inhibits the Expression of PD-L1 Through Multi-Target and Multi-Pathway Regulation of Major Oncogenes in Gastric Cancer

PURPOSE: Banxia xiexin decoction (BXXX) is a classical Chinese herbal compound for the treatment of gastrointestinal diseases. Its ingredients are also considered helpful for cancer rehabilitation. Here, we will explore the regulatory mechanism of BXXX acting on PD-L1 in gastric cancer (GC). METHODS: GC samples and the general baseline data of the patients were collated. Immunohistochemical (IHC) detected the expression of programmed cell death-ligand 1(PD-L1), hypoxia-inducible factor-1 (HIF-1), epidermal growth factor receptor (EGFR), interferon-γ receptor (IFNGR) and Toll-like receptor 4 (TLR4). ELISA detected the expressions of EGF, IFNG and IL-6 in serum samples. Network tools were used to analyze the potential molecules of BXXX. In the cell experiment, CCK-8 detected the cell proliferation. Tunel detected the apoptosis. Western blot detected the expression of related proteins. In animal experiments, the tumor volume of GC-bearing mice was observed. Expression of EGF, IFNG and IL-6 in the serum of tumor-bearing GC mice were detected by ELISA. Western blot detected the expression of related proteins. RESULTS: The expressions of PD-L1, HIF-1, EGFR, IFNGR and TLR4 in the tissues of GC patients were significantly increased, and the expressions of EGF, IFNG and IL-6 in serum were increased. The molecular results of the network tools showed that BXXX and its main components have a targeting effect on the key molecules of each pathway in the PD-L1 regulatory network. Cell experiments showed that BXXX can inhibit the expression of PD-L1, HIF-1, EGFR and TLR4, but has no significant effect on the expression of IFNGR, thus inhibiting the proliferation and promoting the apoptosis of GC cells. The results were consistent with the animal experiments on tumor-bearing gastric cancer mice. CONCLUSION: BXXX inhibited the expression of PD-L1 through multi-target and multi-pathway regulation of major oncogenes in GC, thus effect cell proliferation and apoptosis.