Lai Huan, Hu Nan, Zhang Miao, Jiang Weiwei, Han Yiqian, Mao Chenxi, Zhou Kangjie, Zhang Jingzhou, Hong Yidong, Wu Fenglei
Department of Oncology, The Affiliated Lianyungang Hospital of Xuzhou Medical University/The First People's Hospital of Lianyungang, Lianyungang, China.
Department of Oncology, Lianyungang Clinical College of Nanjing Medical University/The First People's Hospital of Lianyungang, Lianyungang, China.
Comb Chem High Throughput Screen. 2024 Jun 14. doi: 10.2174/0113862073299882240530051559.
This study aimed to examine the associations of FTO expression with prognosis, tumor microenvironment (TME), immune cell infiltration, immune checkpoint genes, and relevant signaling pathways in GC. Furthermore, the relationship between FTO and TGF-β was studied in GC.
The mRNA expression and clinical survival data of GC samples were obtained from The Cancer Genome Atlas Stomach Adenocarcinoma (TCGA-STAD). TIMER2, TNM plot, and GEPIA database were used to analyze FTO expression. The associations of FTO with prognosis and clinicopathologic features were assessed using the Kaplan-Meier plotter and UALCAN database, respectively. The R software was employed to analyze its related signaling pathways and the associations with TME, immune cell infiltration, and immune checkpoint genes. GEPIA and ENCORI were used to examine the association of FTO with TGF-β expression. The SRAMP website was utilized to predict m6A modification of TGF-β. IHC, Western blot, and qPCR were used to analyze the expression levels of FTO and TGF-β in clinical gastric cancer tissue samples or gastric cancer cell lines. In addition, a m6A RNA methylation assay kit was used to determine m6A levels in gastric cancer cells.
FTO mRNA and protein levels were significantly elevated in GC compared to normal gastric tissues. Kaplan-Meier survival analysis suggested that upregulated FTO was associated with a worse prognosis in GC. Upregulated FTO was markedly correlated with differentiation degree, lymph node metastasis, and clinical TNM stage. GO and KEGG pathway analyses revealed that FTO-associated molecules were enriched in neuroactive ligand-receptor interaction, calcium signaling, PI3k-Akt signaling, cAMP signaling pathways, and TGF-β signaling pathways, among others. The TME score was remarkably higher in the high-FTO group than in the low-FTO group. Furthermore, FTO expression had positive correlations with different types of immune cells and immune checkpoint genes. Moreover, FTO may regulate TGF-β in an m6A RNA modification manner in GC.
FTO may become an independent predictive prognostic biomarker correlating with TME, immune cell infiltration, and immune checkpoint genes in gastric cancer and might influence GC progression by regulating TGF-β expression.
本研究旨在探讨FTO表达与胃癌预后、肿瘤微环境（TME）、免疫细胞浸润、免疫检查点基因及相关信号通路之间的关联。此外，还研究了胃癌中FTO与转化生长因子-β（TGF-β）之间的关系。
从癌症基因组图谱胃腺癌（TCGA-STAD）获取胃癌样本的mRNA表达和临床生存数据。使用TIMER2、TNM plot和GEPIA数据库分析FTO表达。分别使用Kaplan-Meier绘图仪和UALCAN数据库评估FTO与预后及临床病理特征的关联。采用R软件分析其相关信号通路以及与TME、免疫细胞浸润和免疫检查点基因的关联。使用GEPIA和ENCORI检测FTO与TGF-β表达的关联。利用SRAMP网站预测TGF-β的m6A修饰。采用免疫组化（IHC）、蛋白质免疫印迹法（Western blot）和定量聚合酶链反应（qPCR）分析临床胃癌组织样本或胃癌细胞系中FTO和TGF-β的表达水平。此外，使用m6A RNA甲基化检测试剂盒测定胃癌细胞中的m6A水平。
与正常胃组织相比，胃癌中FTO的mRNA和蛋白质水平显著升高。Kaplan-Meier生存分析表明，FTO上调与胃癌预后较差相关。FTO上调与分化程度、淋巴结转移及临床TNM分期显著相关。基因本体（GO）和京都基因与基因组百科全书（KEGG）通路分析显示，FTO相关分子富集于神经活性配体-受体相互作用、钙信号传导、磷脂酰肌醇-3激酶-蛋白激酶B（PI3k-Akt）信号传导、环磷酸腺苷（cAMP）信号通路以及TGF-β信号通路等。高FTO组的TME评分显著高于低FTO组。此外，FTO表达与不同类型的免疫细胞和免疫检查点基因呈正相关。而且，在胃癌中FTO可能以m6A RNA修饰的方式调节TGF-β。
FTO可能成为与胃癌TME、免疫细胞浸润和免疫检查点基因相关的独立预测预后生物标志物，并可能通过调节TGF-β表达影响胃癌进展。
