Fig 2: Immunohistochemistry was used to detect the expression levels of PD-L1, MGMT and STAT3 in para-carcinoma tissue and cancer tissues. Scale bar, 100 µm. Statistical analysis was conducted on the expression levels of PD-L1, MGMT and STAT3 in tissues. **P<0.001. PD-L1, programmed cell death 1 ligand 1; MGMT, 6-O-methylguanine-DNA methyltransferase.

Fig 3: BXXX regulates the sensitivity of drug-resistant cells of GC. The CCK-8 assay detected the viability of (A) AGS cells and (B) AGS/DDP cells. (C) Cell viability after the addition of 15% BXXX and DDP, as determined with a CCK-8 assay. (D) Flow cytometry was used to detect cell apoptosis. (E) Statistical analysis of apoptotic cells. (F) Western blotting was used to measure the expression levels of the signaling pathway-related proteins IL-6, JAK1, STAT3, IFNR and MGMT. *P<0.05, **P<0.01, ***P<0.001. CCK, Cell Counting Kit; PD-L1, programmed cell death 1 ligand 1; MGMT, 6-O-methylguanine-DNA methyltransferase; DDP, cisplatin; BXXX, Banxia xiexin decoction; IFNR, IFN receptor.

Fig 4: Expression levels of pathway-related proteins in the tumor tissue of tumor-bearing mice. *P<0.05, **P<0.01, ***P<0.001. PD-L1, programmed cell death 1 ligand 1; MGMT, 6-O-methylguanine-DNA methyltransferase; DDP, cisplatin; BXXX, Banxia xiexin decoction; IFNR, IFN receptor.

Fig 5: Expression levels of PD-L1, MGMT and STAT3. Reverse transcription-quantitative PCR were used to detect the expression levels of PD-L1, MGMT and STAT3 in (A) GC cell lines and (B) GC resistant cell lines AGS/DDP and NCI-N87/DDP. (C) A CCK-8 assay was used to assess the cell viability.*P<0.05, **P<0.01, ***P<0.001. CCK, Cell Counting Kit; PD-L1, programmed cell death 1 ligand 1; MGMT, 6-O-methylguanine-DNA methyltransferase; DDP, cisplatin.