| Objective To study the effects of Xiaoshui powder on the B7/CD28/cytotoxic T lymphocyte associated antigen-4 (CTLA4) costimulatory pathway and ascites microenvironment in a mouse peritoneal transplantation model of human gastric cancer.Methods This study was conducted in the Animal Central Laboratory of Hunan Academy of Traditional Chinese Medicine from April 2019 toMay 2020. In this study, MGC803 human gastric cancer cells were injected intraperitoneally to establish a mouse peritoneal transplan tation model of human gastric cancer. The mice were divided into the model group and the low-dose, medium-dose and high-dose Xiaoshui powder groups, and normal mice were used as the control group, with 10 mice in each group. The model quality was evaluatedby behavioral observation and determination of serum adrenocorticotropic hormone (ACTH), cortisol (CORT), triiodothyronine (T3), thy roxine (T4), and thyroid-stimulating hormone (TSH). The condition of malignant ascites was evaluated by imaging. The expression lev els of B7-1, B7-2, CD28 and CTLA-4 and their mRNA expression levels were detected by flow cytometry and real-time quantitative PCR (RT-qPCR), respectively. The expression levels of transforming growth factor-β1 (TGF-β1) and interleukin-10 (IL-10) were detect ed by enzyme-linked immunosorbent assay (ELISA).Results The score of Yang deficiency symptoms in normal mice was (0.00±0.00)points, the serum ACTH level was (103.46±10.13) ng/L, the CORT level was (81.34±9.21) mg/L, and the T3 content was (178.52±15.86) ng/L, the T4 content was (213.59±16.97) mg/L, and the TSH content was (10.84±1.15) mIU/mL. Compared with the controlgroup, the scores of Yang deficiency symptoms [(7.84±1.59) points] in model mice increased significantly (P < 0.05), and the contentsof ACTH [(71.09±6.42) ng/L], CORT [(43.42±7.14) μg/L], T3 [(103.77±13.24) ng/L], T4 [(127.64±13.25) μg/L] and TSH [(8.14±1.02)mIU/mL] in serum were significantly lower (P < 0.05). The ascites volume, tumor volume and tumor weight of mice in the model group were (5.18±0.46)mL, (1.23±0.12)cm3, and (1.73±0.15)g, respectively; the B7-1 mRNA level was (1.06±0.10); the B7-2 mRNA level was (1.04±0.11); the CD28 mRNA level was (0.97±0.08); the CTLA-4 mRNA level was (1.03±0.09); the TGF-β1 content was (181.73± 15.26)pg/g; and the IL-10 level was (68.74±6.03)pg/g. Compared with the model group, the ascites volume [(4.03±0.41), (3.24±0.25),(2.33±0.27) mL], tumor volume [(0.93±0.09), (0.49±0.05), (0.16±0.02) cm3], tumor weight [(1.42±0.13), (0.79±0.11), (0.27±0.08) g], CT LA-4 mRNA level [(0.83±0.07), (0.42±0.05), (0.16±0.02)], TGF-β1 content [(152.69±12.39), (131.45±11.68), (107.26±10.52) pg/g], and IL-10 level [(51.65±5.38), (34.28±2.73), (27.13±2.64) pg/g] decreased in a dose-dependent manner (P < 0.05) in Xiaoshui Powder low-dose, medium-dose and high-dose groups, while the miRNA levels of B7-1[(2.13±0.22), (4.56±0.51), (7.29±0.68)], B7-2[(1.95± 0.14), (4.32±0.41), (6.83±0.63)] and CD28[(2.02±0.15), (3.94±0.28), (7.11±0 .84)] were increased gradually (P < 0.05).Conclusion Xiaoshui powder can resist malignant ascites of human gastric cancer xenografts, which may be related to inhibiting the expression of CTLA-4, promoting T-cell activation, and improving immune suppression and the peritoneal immune microenvironment. |
