Hao Shuhong, Huo Sibo, Du Zhenwu, Yang Qiwei, Ren Ming, Liu Shui, Liu Tongjun, Zhang Guizhen
Department of Medical Research Center.
Department of Hematology and Oncology.
Medicine (Baltimore). 2019 Apr;98(15):e15158. doi: 10.1097/MD.0000000000015158.
Colorectal cancer (CRC) is an extremely common gastrointestinal malignancy. The present study aimed to identify microRNAs (miRNAs) and transcription factors (TFs) associated with tumor development.
Three miRNA profile datasets were integrated and analyzed to elucidate the potential key candidate miRNAs in CRC. The starBase database was used to identify the potential targets of common differentially expressed miRNAs (DEMs). Transcriptional Regulatory Element Database and Transcriptional Regulatory Relationships Unraveled by Sentence-based Text databases were used to identify cancer-related TFs and the TF-regulated target genes. Functional and pathway enrichment analyses were performed using the Database for Annotation, Visualization and Integration Discovery (DAVID) database, and the miRNA-TF-gene networks were constructed by Cytoscape. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression of genes and miRNAs.
In total, 14 DEMs were found in CRC. By bioinformatics analysis, 5 DEMs (miR-145, miR-497, miR-30a, miR-31, and miR-20a) and 8 TFs (ELK4 (ETS-family transcription factor), myeloblastosis proto-oncogene like (MYBL)1, MYBL2, CEBPA, PPARA, PPARD, PPARG, and endothelial PAS domain protein (EPAS1)) appeared to be associated with CRC and were therefore used to construct miRNA-TF-gene networks. From the networks, we found that miR-20a might play the most important role as an miRNA in the networks. By qRT-PCR, we demonstrated that miR-20a was significantly upregulated in CRC tissues. We also performed qRT-PCR to identify the expression of miR-20a-related TFs (PPARA, PPARD, PPARG, EPAS1). Three of them, PPARA, PPARG, and EPAS1, were downregulated in CRC tissues, with statistically significant differences, while the downregulation of PPARD in CRC tissues was not significantly different. Pathway enrichment analyses indicated that the phosphoinositide 3-kinase (PI3K)-Akt signaling pathway was the most significantly enriched pathway. Two main elements of the PI3K-Akt signaling pathway, phosphatase and tensin homolog deleted on chromosome 10 and B-cell lymphoma 2-associated agonist of cell death, were demonstrated to be downregulated in CRC.
The present study identified hub miRNAs and miRNA-related TF regulatory networks in CRC, which might be potential targets for the diagnosis and treatment of CRC.
结直肠癌（CRC）是一种极为常见的胃肠道恶性肿瘤。本研究旨在鉴定与肿瘤发生发展相关的微小RNA（miRNA）和转录因子（TF）。
整合并分析了三个miRNA表达谱数据集，以阐明CRC中潜在的关键候选miRNA。利用starBase数据库鉴定常见差异表达miRNA（DEM）的潜在靶标。使用转录调控元件数据库和基于句子的文本解析转录调控关系数据库来鉴定癌症相关的TF以及TF调控的靶基因。利用注释、可视化和整合发现数据库（DAVID）进行功能和通路富集分析，并通过Cytoscape构建miRNA-TF-基因网络。采用定量逆转录聚合酶链反应（qRT-PCR）检测基因和miRNA的表达。
在CRC中总共发现了14个DEM。通过生物信息学分析，5个DEM（miR-145、miR-497、miR-30a、miR-31和miR-20a）和8个TF（ELK4（ETS家族转录因子）、成髓细胞瘤原癌基因样（MYBL）1、MYBL2、CEBPA、PPARA、PPARD、PPARG和内皮PAS结构域蛋白（EPAS1））似乎与CRC相关，因此用于构建miRNA-TF-基因网络。从这些网络中，我们发现miR-20a可能是网络中最重要的miRNA。通过qRT-PCR，我们证明miR-20a在CRC组织中显著上调。我们还进行了qRT-PCR以鉴定miR-20a相关TF（PPARA、PPARD、PPARG、EPAS1）的表达。其中三个，PPARA、PPARG和EPAS1，在CRC组织中下调，具有统计学显著差异，而PPARD在CRC组织中的下调无显著差异。通路富集分析表明磷脂酰肌醇3激酶（PI3K）-Akt信号通路是最显著富集的通路。PI3K-Akt信号通路的两个主要元件，10号染色体上缺失的磷酸酶和张力蛋白同源物以及细胞死亡相关的B细胞淋巴瘤2激动剂，在CRC中被证明下调。
本研究鉴定了CRC中的关键miRNA和与miRNA相关的TF调控网络，这可能是CRC诊断和治疗的潜在靶点。
