复方蜥蜴散干预肿瘤细胞干性对胃癌顺铂耐药的增敏提效作用机制OA

Objective To investigate the mechanism by which Compound Xiyi San(CXS)enhances cisplatin sensitivity in gastric cancer by interfering with tumor stemness via the interferon-γ(IFN-γ)/nuclear factor-κB(NF-κB)/SNAIL axis.Methods(1)MKN45 cells and MKN45/DDP cisplatin-resistant cells in the logarithmic growth phase were treated with different concentrations(0,0.2,0.4,0.8,1.6,3.2 μg·mL-1)of cisplatin(DDP)for 48 hours.Cell proliferation capacity and the resistance index were measured using the CCK-8 assay.The cancer stem cell characteristics of MKN45 and MKN45/DDP cells were validated using the serum-free suspension sphere formation assay.(2)MKN45/DDP cells in the logarithmic growth phase were subcutaneously inoculated into the right anterior axilla of male BALB/c nude mice to establish a cisplatin-resistant gastric cancer xenograft model.Successfully modeled mice were randomly divided into four groups(n=8 per group):model group,cisplatin group,CXS group,and combination group.The model group received an equal volume of normal saline by gavage;the cisplatin group received intraperitoneal injections of 0.002 g·kg-1 cisplatin twice weekly;the CXS group received 2.8 g·kg-1 CXS aqueous extract by gavage twice daily;the combination group received both CXS aqueous extract(2.8 g·kg-1,twice daily)and cisplatin(0.002 g·kg-1,twice weekly).All interventions continued for 4 weeks.Tumor mass was weighed,and tumor volume was calculated.Pathological changes in tumor tissue were observed by HE staining;apoptosis was detected by TUNEL assay;protein expression of Ki67,EpCAM,and CD44 in tumor tissue was determined by immunohistochemistry;and protein expression levels of multidrug resistance-associated protein 1(MRP1),P-glycoprotein(P-gp),EpCAM,CD44,IFN-γ,p65,phosphorylated p65(p-p65),and SNAIL were measured by Western Blot.Results(1)Compared with MKN45 cells,the survival rates of MKN45/DDP cells in the 0.8,1.6,and 3.2 μg·mL-1 cisplatin groups were significantly increased(P＜0.05,P＜0.01).The IC50 for MKN45 cells was 0.96 μg·mL-1,and for MKN45/DDP cells it was 2.26 μg·mL-1,resulting in a resistance index of 2.36 for MKN45/DDP cells.Compared with MKN45 cells,MKN45/DDP cells exhibited a significantly enhanced sphere-forming ability(P＜0.01).(2)In the model group,tumor cells showed irregular morphology,tight arrangement,large nuclei,and pathological mitotic figures.Compared with the model group,all treatment groups showed significantly reduced tumor volume(P＜0.01)and tumor mass(P＜0.01)in MKN45/DDP xenograft nude mice;mitotic figures were reduced,cell density decreased,arrangement became looser,and necrotic cells were observed;tumor cell apoptosis rates were significantly increased(P＜0.01);Ki67 positive expression levels in tumor tissue were significantly decreased(P＜0.05,P＜0.01);protein expression levels of stemness markers EpCAM and CD44,and drug resistance-related proteins MRP1 and P-gp were significantly decreased(P＜0.05,P＜0.01);and protein expression levels of p-p65/p65,IFN-γ,and SNAIL in tumor tissue were significantly decreased(P＜0.01).Compared with the cisplatin group,the tumor volume and tumor mass of MKN45/DDP xenograft nude mice in the CXS group and the combination group were significantly reduced(P＜0.01);significantly increased apoptosis rates(P＜0.01);significantly decreased Ki67 positive expression(P＜0.05,P＜0.01),and significantly lower protein expression levels of CD44,MRP1,P-gp,IFN-γ,and SNAIL(P＜0.05,P＜0.01);the combination group also showed significantly decreased EpCAM and p-p65/p65 protein expression levels(P＜0.01).Conclusion Compound Xiyi San effectively inhibits tumor growth,suppresses cell proliferation,and promotes apoptosis in nude mice bearing cisplatin-resistant MKN45/DDP gastric cancer xenografts.This effect may be related to the suppression of tumor stemness and subsequent reduction of cisplatin resistance through regulation of the IFN-γ/NF-κB/SNAIL axis.