Respiratory Department, Chinese People's Liberation Army (PLA) General Hospital, Beijing, China (mainland).
School of Medicine, Nankai University, Beijing, China (mainland).
Med Sci Monit. 2020 Apr 18;26:e921430. doi: 10.12659/MSM.921430.
BACKGROUND Squamous cell lung cancer is the main cause of cancer-associated mortality. The discovery of promising prognostic biomarkers for predicting the survival of patients with squamous cell lung cancer remains a challenge. MATERIAL AND METHODS Gene expression profiles of GSE33479 and GSE51855, including 42 squamous cell lung cancer tissues and 17 normal tissues, from the GEO database were assessed to find common differentially expressed genes (DEGs) via the GEO2R online tool and Venn diagram software. Then, gene ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analyses were conducted. The key protein-protein interaction (PPI) network within those common DEGs was subsequently illustrated through a combination of Search Tool for Retrieval of Interacting Genes (STRING) and Cytoscape software. Finally, core genes associated with survival and levels of immune infiltration were demonstrated by the Kaplan-Meier plotter and Tumor Immune Estimation Resource (TIMER) online database, respectively. RESULTS In total, 483 DEGs were involved, including 216 upregulated genes enriched in "cell division", "DNA replication", and "DNA repair pathway" and 267 downregulated genes enriched in "cell adhesion", "oxidation-reduction process", and "cell-cell signaling". The 75 core genes were selected by Molecular Complex Detection applied in Cytoscape. Four genes - MND1, FOXM1, CDC6, and POLE2 - were found to be significantly associated with survival. Further analysis of the KEEG pathway and TIMER database revealed that only POLE2 was enriched in "DNA replication" and its higher expression was negatively associated with survival and immune infiltration. CONCLUSIONS Higher expression of POLE2 is a prognosis-related biomarker for worse survival and is negatively associated with immune infiltration in squamous cell lung cancer.
鳞状细胞肺癌是癌症相关死亡的主要原因。发现有前途的预后生物标志物来预测鳞状细胞肺癌患者的生存仍然是一个挑战。
从 GEO 数据库中评估了 GSE33479 和 GSE51855 中包括 42 个鳞状细胞肺癌组织和 17 个正常组织的基因表达谱，通过 GEO2R 在线工具和 Venn 图软件来寻找共同差异表达基因（DEGs）。然后进行基因本体论（GO）和京都基因与基因组百科全书（KEGG）途径分析。随后，通过结合 Search Tool for Retrieval of Interacting Genes（STRING）和 Cytoscape 软件，展示了这些共同 DEGs 中的关键蛋白-蛋白相互作用（PPI）网络。最后，通过 Kaplan-Meier plotter 和 Tumor Immune Estimation Resource（TIMER）在线数据库分别显示与生存和免疫浸润水平相关的核心基因。
共涉及 483 个 DEGs，其中 216 个上调基因富集在“细胞分裂”、“DNA 复制”和“DNA 修复途径”，267 个下调基因富集在“细胞黏附”、“氧化还原过程”和“细胞-细胞信号转导”。通过 Cytoscape 中的分子复合物检测，选择了 75 个核心基因。发现 4 个基因-MND1、FOXM1、CDC6 和 POLE2-与生存显著相关。进一步对 KEEG 途径和 TIMER 数据库的分析表明，只有 POLE2 富集在“DNA 复制”中，其高表达与生存和免疫浸润呈负相关。
POLE2 的高表达是与预后相关的生物标志物，与鳞状细胞肺癌的生存较差和免疫浸润呈负相关。
