STARD5对胃癌的预后影响及机制研究

Effect and mechanism of STARD5 on the prognosis of gastric cancer

目的采用人类肿瘤基因表达汇编(GEO)及癌症基因组图谱(TCGA)数据分析类固醇敏感性调节蛋白相关脂类转运结构域蛋白5(STARD5)对胃癌预后的影响,通过细胞实验和分子实验验证并探索其相关机制。方法采用GEO胃癌数据集GSE62254及TCGA胃癌数据集进行单因素和多因素Cox回归分析,筛选STARD家族中的胃癌独立预后因素,并建立基于STARD家族的列线图模型;分析STARD5表达与临床病理特征的关系;使用基因集富集分析(GSEA)预测STARD5影响胃癌预后的相关通路;瞬时沉默STARD5后检测胃癌细胞的迁移、侵袭及黏附能力和胃癌细胞中相关蛋白表达的变化;采用加州大学圣克鲁兹分校(UCSC)gnome browser预测转录因子与靶基因结合位点。生存分析使用Kaplan-Meier和log-rank检验,STARD5与临床病理特征的关系使用χ^(2)检验,组间比较使用Dunnett’s t检验。结果GSE62254及TCGA胃癌数据集均显示STARD5为胃癌的独立保护因素,均P<0.05;纳入STARD5表达与TNM分期所绘制的列线图预测胃癌患者1、3、5年生存率的性能良好,一致性指数及其95%CI为0.701(0.659~0.744);STARD5表达与胃癌肝转移呈负相关,P=0.020。GSEA提示STARD5低表达与Focal adhesion、PI3K/AKT等通路密切相关,均P<0.05。敲减STARD5后,胃癌细胞迁移、侵袭及黏附能力增加,且AKT磷酸化水平升高,Integrinβ1、XBP-1s、ATF4和ATF6α表达上调;经预测XBP-1与ITGB1(Integrinβ1)启动子区域存在6个结合位点。结论STARD5是胃癌的预后保护因素。STARD5在发生肝转移的胃癌患者中表达降低。STARD5下调可通过上调XBP-1来促进Integrinβ1的转录表达并激活PI3K/AKT信号通路,促进胃癌细胞转移。

Objective To assess the impact of steroid sensitivity regulatory protein-related lipid transport domain 5(STARD5)on the prognosis of gastric cancer by using data from the human tumor Gene Expression Omnibus(GEO)and the Cancer Genome Atlas(TCGA)and then to verify above correlation and explore the underlying mechanism associated with STARD5 by cellular and molecular experiment.Methods We analyzed the influence of the STARD family and clinicopathological features on the prognosis of gastric cancer using the GEO gastric cancer dataset GSE62254 and the TCGA gastric cancer dataset.Additionally,we developed a nomogram model and examined the relationship between STARD5 and clinicopathological features.To predict the relevant pathways involved in the impact of STARD5 on gastric cancer prognosis,we performed the GSEA enrichment analysis.Furthermore,we assessed gastric cancer cells'migration,invasion and adhesion abilities,and evaluated changes in the expression of related proteins following STARD5 silencing.We utilized the UCSC Genome Browser to predict the binding sites of transcription factors to target genes.Kaplan-Meier and log-rank tests were used for survival analysis,and Chi-square test was used to analyze the association between STARD5 and clinicopathological features.Comparisons between groups were statistically analyzed using Dunnett's t test.Results GSE62254 and TCGA gastric cancer datasets indicated that STARD5 was an independent protective factor for gastric cancer(P<0.05).The nomogram,incorporating STARD5 and TNM stages,demonstrated good performance in predicting gastric cancer patients'1-,3-,and 5-year survival rates.Concordance index(C-index)and its 95%confidence interval was 0.701(0.659-0.744).Notably,the expression of STARD5was negatively correlated with liver metastasis(P=0.020).GSEA analysis revealed that low STARD5expression was closely associated with Focal adhesion,PI3K-AKT and other pathways(P<0.05).Upon STARD5knockdown,we observed increased migration,invasion,and adhesion abilities in gastric cancer cells,as well as elevated phosphorylation levels of AKT,up-regulation of integrinβ1expression,and up-regulation of XBP-1s,ATF4and ATF6αexpression(P<0.05).Predictions suggested the presence of six binding sites between XBP-1and the promoter region of integrinβ1.Conclusions STARD5is a protective factor for the prognosis of gastric cancer.Decreased expression of STARD5is observed in gastric cancer patients with liver metastasis.Down-regulation of STARD5promotes the migration of gastric cancer cells by activating XBP-1,leading to increased expression of integrinβ1protein and activation of the PI3K/AKT signaling pathway.