摘要： 目的·筛选胰腺癌进展相关的核心基因和关键通路。方法·通过GEO（Gene Expression Omnibus）数据库检索筛选得到包含45例胰腺癌组织和45例癌旁正常组织的基因芯片数据集GSE28735。采用GEO2R在线分析工具提取癌组织及癌旁正常组织的基因，联合RStudio软件筛选差异表达基因（differentially expressed genes，DEGs）并对其进行可视化处理。通过基因功能注释在线工具DAVID对差异表达显著的基因进行基因本体（gene ontology，GO）功能富集和京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes，KEGG）通路富集分析。利用交互基因检索工具STRING及Cytoscape软件构建蛋白质-蛋白质相互作用（protein-protein interaction，PPI）网络，结合节点度值进一步筛选核心基因。通过基因表达谱分析数据库GEPIA对179例胰腺癌中核心基因的表达水平与患者总生存期（overall survival，OS）、无病生存期（disease free survival，DFS）及肿瘤分期的关系进行分析。结果·从GSE28735芯片中筛选得到131个DEGs，其中表达上调的基因115个，表达下调的基因16个。GO功能富集分析显示DEGs主要在细胞黏附、质膜、蛋白质结合方面富集。KEGG通路富集提示磷脂酰肌醇-3激酶（phosphatidylinositol 3-kinase，PI3K）/蛋白激酶B（protein kinase B，AKT）是DEGs富集的主要信号通路。通过PPI网络筛选得到5个核心基因，分别为纤维连接蛋白1（fibronectin 1，
FN1）、间质表皮转化因子（mesenchymal to epithelial transition factor，
MET）、层粘连蛋白β3（polyclonal antibody to laminin β3，
LAMB3）、层粘连蛋白α3（laminin subunit α3，
LAMA3）、整合素亚单位α3（integrin subunit α3，
ITGA3）。
MET、LAMA3、LAMB3和
ITGA3的表达水平均与胰腺癌患者OS有关，仅
MET、
LAMB3和
ITGA3的表达水平与胰腺癌患者DFS有关，且基因低表达组的预后明显优于基因高表达组。
FN1、
MET、
LAMA3和
LAMB3的表达水平在不同分期胰腺癌组织中的差异存在统计学意义。结论·胰腺癌中异常表达的
FN1、
MET、
LAMB3、
LAMA3、
ITGA3与细胞黏附、质膜组分、蛋白质结合功能的改变和PI3K/AKT通路相关，
MET和
LAMB3的表达升高可能预示胰腺癌患者的不良预后。
关键词: 胰腺癌, 生物信息学, 差异表达基因, 肿瘤发生 Abstract: Objective·To select pancreatic cancer progression-related core genes and key pathways.
Methods·The dataset GSE28735 for pancreatic cancer was obtained by searching and screening in the Gene Expression Omnibus (GEO) database. Genes in 45 cases of cancer tissues and 45 cases of normal tissues adjacent to cancer were extracted by GEO2R and combined with RStudio to screen and visualize differentially expressed genes (DEGs). Genes with significant differential expression were analyzed by gene ontology (GO) function enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis through the gene utilization function annotation online tool DAVID. The protein-protein interaction (PPI) network was constructed by using the interactive gene retrieval tool, STRING and Cytoscape, to further screen core genes based on the node degree value. The relationship between the expression levels of core genes and overall survival (OS), disease-free survival (DFS) and tumor stage of 179 cases of patients was analyzed through the gene expression profile analysis database GEPIA.
Results·A total of 131 DEGs were screened from the dataset GSE28735, including 115 up-regulated genes and 16 down-regulated genes. GO function enrichment analysis showed that DEGs were mainly enriched in cell adhesion, plasma membrane, and protein binding. KEGG pathway enrichment suggested that phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) was the main signaling pathway for DEG enrichment. Five core genes, fibronectin1 (FN1), mesenchymal to epithelial transition factor (MET), polyclonal antibody to laminin β3 (LAMB3), laminin subunit α3 (LAMA3), and integrin subunit α3 (ITGA3),were obtained through PPI network screening. The expression levels of MET, LAMA3, LAMB3 and ITGA3 were associated with OS of patients, and the expression levels of MET, LAMB3 and ITGA3 were associated with DFS. The prognosis of low gene expression group was significantly better than that of high gene expression group. There were significant differences in the expression levels of FN1, MET, LAMA3 and LAMB3 in the different stages of pancreatic cancer.
Conclusion·The abnormal expression of FN1, MET, LAMB3, LAMA3 and ITGA3 is related to the changes of cell adhesion, plasma membrane component, protein binding function and PI3K/Akt pathway. The increased expression of MET and LAMB3 may predict poor prognosis of patients with pancreatic cancer.
Key words: pancreatic cancer, bioinformatics, differentially expressed gene, tumorigenesis PDF全文下载地址:
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