To discuss the effects of apatinib (APa) on proliferation, apoptosis, and immune escape of gastric cancer cells by adjusting the high mobility group box 1 (HMGB1)/receptor for advanced glycosylation end products (RAGE) pathway.

SGC-7901 cells were randomly separated into blank control group, low-dose experimental group (intervention with 20 μmol·L^-1 Apa for 48 hours), medium-dose experimental group (intervention with 40 μmol·L^-1 Apa for 48 hours), high-dose experimental group (intervention with 60 μmol·L^-1 Apa for 48 hours) and HMGB1 group (intervention with 60 μmol·L^-1 Apa combined with 100 ng·mL^-1 HMGB1 recombinant factor for 48 hours). After intervention with APa and human HMGB1 recombinant factor, cell counting kit-8 (CCK-8) method, 5-Ethynyl-2’- deoxyuridine (Edu) staining, and immunofluorescence staining Ki67 were used to measure the proliferation of SGC-7901 cells in each group. Flow cytometry, Hoechst 33342/PI double staining, and immunofluorescence were performed to measure apoptosis of SGC-7901 cells in each group. Western blot was performed to detect the expression of HMGB1/RAGE signaling pathway proteins of SGC-7901 cells in various groups. A co-culture system of activated peripheral blood mononuclear cells (PBMCs) or NK cells with SGC-7901 cells was constructed. After grouping and drug intervention, the CCK-8 method was performed to detect the killing rates of T cells and NK cells against SGC-7901 cells in each group. Flow cytometry was used to measure the proportion of activated CD8⁺T cells in the co culture system of PBMCs and SGC-7901 cells in each group. Immunofluorescence staining was performed to measure the expression of programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1) in the co culture system of PBMC and SGC-7901 cells in various groups. In addition, enzyme linked immunosorbent assay (ELISA) method was used to measure the levels of immune cytokines interleukin (IL)-6, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and IL-2 production in the co culture system of PBMC and SGC-7901 cells.

The Edu positive rates in blank control group, the low-dose experimental group, medium-dose experimental group, high-dose experimental group and HMGB1 group were (86.23±5.30)%, (65.81±4.65)%, (43.16±4.52)%, (20.19±3.79)% and (82.45±5.27)%, respectively; the apoptosis rates were (4.37±1.19)%, (23.05±2.14)%, (41.87±2.69)%, (62.04±3.12)% and (5.91±1.28)%, respectively; the relative expression levels of HMGB1 protein were 1.15±0.07, 0.79±0.05, 0.43±0.04, 0.10±0.02 and 1.13±0.06, respectively; the RAGE protein expression levels were 1.23±0.08, 0.85±0.06, 0.47±0.05, 0.14±0.03 and 1.21±0.07, respectively; the PD-1 positive expression rates were (58.13±3.70)%, (45.37±2.84)%, (32.06±3.01)%, (21.47±2.31)% and (54.87±3.53)%, respectively; the T cell killing rates were (10.12±1.34)%, (23.45±1.62)%, (37.06±2.08)%, (51.29±2.73)% and (12.01±1.61)%, respectively; the proportions of activated CD8⁺T cells were (7.21±0.53)%, (12.42±0.81)%, (17.93±0.75)%, (23.07±0.64)% and (7.93±0.56)%, respectively; the IL-6 production levels were (28.31±3.26), (46.02±4.18), (65.43±3.70), (86.15±4.39) and (31.04±3.48) ng·L^-1, respectively. Compared the blank control group with the low-dose experimental group, medium-dose experimental group and high-dose experimental group, compared the HMGB1 group with the high-dose experimental group, the differences of above indexes were all statistically significant (all P<0.05).

APa can inhibit the proliferation and immune escape of gastric cancer cells, promote their apoptosis, possibly by blocking the activation of the HMGB1/RAGE signaling pathway.