B7-H4表达对胃癌患者预后的影响及机制

Effect and mechanism of B7-H4 expression on the prognosis of gastric cancer patients

目的探讨B7-H4表达对胃癌患者预后的影响及其可能机制。方法利用UALCAN、Kaplan-Meier Plotter数据库及GEPIA在线分析工具分析胃癌组织中B7-H4的表达及其与患者预后的关系。采用免疫组化染色检测胃癌组织中B7-H4的表达,分析其与临床病理特征、细胞周期调控蛋白、微血管密度(MVD)、干性相关蛋白及PI3K/Akt/NF-κB信号通路蛋白的关系。采用免疫荧光和Western blotting检测胃癌细胞中B7-H4及干性相关蛋白的表达。采用Oncomine数据库分析胃癌组织中B7-H4与PI3K、Akt mRNA表达的相关性。结果B7-H4在胃癌组织中的表达水平高于正常组织(P<0.001),其表达与肿瘤分化程度、pT分期、淋巴结转移、远处转移和临床分期明显相关(P<0.05),并预示胃癌患者预后不良。胃癌组织中B7-H4与细胞周期调控蛋白p16及干性相关蛋白LSD1、SOX9、CD133的表达呈正相关(r=0.250,P<0.001;r=0.331,P<0.001;r=0.176,P=0.018;r=0.434,P<0.001)。B7-H4阳性组织标本的MVD明显高于B7-H4阴性组织标本(P=0.019)。在胃癌细胞系中B7-H4与干性相关蛋白LSD1、SOX9、CD133共表达。B7-H4在胃癌组织中与p-PI3K-p85、p-Akt-Thr308、p-Akt-Ser473和NF-κB p65的表达呈正相关(r=0.269,P<0.001;r=0.282,P<0.01;r=0.214,P=0.005;r=0.157,P=0.034)。胃癌组织中B7-H4与PI3K、Akt mRNA的表达呈正相关(r=0.403,P<0.001;r=0.351,P<0.001)。结论B7-H4能够促进胃癌进展且与患者的预后不良密切相关,其机制可能与B7-H4通过PI3K/Akt/NF-κB通路调节胃癌干性特征相关。

Objective To investigate the effect and mechanism of B7-H4 expression on the prognosis of patients with gastric cancer.Methods The databases of Gene Expression Profiling Interactive Analysis(GEPIA),UALCAN and Kaplan-Meier Plotter were used to analyze the expression of B7-H4 in gastric cancer tissues and its relationship with the prognosis of gastric cancer patients.Immunohistochemistry staining was performed to observe the expression of B7-H4 protein in gastric cancer tissues and analyze its correlation with clinicopathological characteristics,cell cycle regulatory proteins,microvessel density(MVD),stemness-related proteins,and PI3K/Akt/NF-κB signaling pathway proteins.Immunofluorescence and Western blotting were used to detect the expressions of B7-H4 and stemness-related proteins in gastric cancer cells.Oncomine database was employed to analyze the correlation between B7-H4 and the expressions of PI3K and Akt mRNA in gastric cancer tissues.Results The expression level of B7-H4 was higher in gastric cancer tissues than in normal tissues,and its expression was significantly related to tumor differentiation,pT staging,lymph node metastasis,distant metastasis and clinical staging(P<0.05),and indicated a poor prognosis in gastric cancer.The expression of B7-H4 was positively correlated with the expressions of cell cycle regulatory protein p16(r=0.250,P<0.001)and stemness-related proteins LSD1(r=0.331,P<0.001),SOX9(r=0.176,P=0.018)and CD133(r=0.434,P<0.001).The MVD was significantly higher in B7-H4 positive tissue than in B7-H4 negative tissue(P=0.019).Furthermore,B7-H4 was co-expressed with stemness-related proteins LSD1,SOX9,and CD133 in gastric cancer cell lines,and the expression of B7-H4 was positively correlated with the expressions of p-PI3K-p85(r=0.269,P<0.001),p-Akt-Ser473(r=0.282,P<0.01),p-Akt-Thr308(r=0.214,P=0.005)andNF-κB p65(r=0.157,P=0.034).The expression of B7-H4 in gastric cancer tissue was positively correlated with the expressions of PI3K mRNA(r=0.403,P<0.001)and Akt mRNA(r=0.351,P<0.001).Conclusion B7-H4 can promote gastric cancer progression and is closely related to poor prognosis,and the mechanism may be related to the regulation of gastric cancer stemness via PI3K/Akt/NF-κB.