Song Zikun, Zhang Yinjiang, Chen Zheren, Zhang Bicheng
Department of Intensive Care Medicine, The People's Second Hospital of Liaocheng, Linqing, Shandong 252601, P.R. China.
School of Pharmacy, Minzu University of China, Beijing 100081, P.R. China.
Oncol Lett. 2021 Jan;21(1):60. doi: 10.3892/ol.2020.12322. Epub 2020 Nov 19.
Lung adenocarcinoma (LUAD) is the most commonly diagnosed type of lung cancer and exhibits a high morbidity. The present study aimed to investigate the long non-coding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) mechanisms in LUAD. The receptor activity modifying protein 2-antisense RNA 1 (RAMP2-AS1) was identified using GSE113852 and GSE130779 datasets downloaded from the Gene Expression Omnibus database, and the downregulation of RAMP2-AS1 was the most significant in LUAD. In addition, microRNA (miR)-296-5p was identified to bind to RAMP2-AS1 via bioinformatics analysis. Subsequently, CD44, cyclin D3 (CCND3), neurocalcin δ (NCALD), microtubule actin crosslinking factor 1 (MACF1) and potassium channel tetramerization domain containing 15 were obtained by intersecting the predicted target genes of miR-296-5p and 368 differentially expressed mRNAs in LUAD. According to the Gene Expression Profiling Interactive Analysis and UALCAN databases, these five mRNAs were downregulated in LUAD, and their expression levels were positively correlated with those of RAMP2-AS1. CD44, CCND3, NCALD and MACF1 were selected as key mRNAs in LUAD based on prognostic analyses. Furthermore, functional enrichment analyses were performed and an interaction network was constructed to reveal the functions of the RAMP2-AS1-associated ceRNA in LUAD. The results indicated that the functions were mainly enriched in generic transcription pathways, cyclin D-associated events in G and epithelial stromal transformation. Reverse transcription-quantitative PCR assays revealed that RAMP2-AS1, CD44, CCND3, NCALD and MACF1 expression was lower in tumor tissues than in normal tissues, while miR-296-5p expression was higher in tumor tissues compared with in normal tissues. The association between RAMP2-AS1 and MACF1 was further confirmed using experiments. Overall, the present results indicated that RAMP2-AS1, miR-296-5p, CD44, CCND3, NCALD and MACF1 may be involved in LUAD progression and may therefore serve as potential biomarkers and provide a theoretical basis for the study of the pathogenesis of LUAD.
肺腺癌（LUAD）是最常被诊断出的肺癌类型，发病率很高。本研究旨在探讨LUAD中长链非编码RNA（lncRNA）相关的竞争性内源RNA（ceRNA）机制。利用从基因表达综合数据库下载的GSE113852和GSE130779数据集鉴定出受体活性修饰蛋白2反义RNA1（RAMP2-AS1），且RAMP2-AS1的下调在LUAD中最为显著。此外，通过生物信息学分析鉴定出微小RNA（miR）-296-5p与RAMP2-AS1结合。随后，通过将miR-296-5p的预测靶基因与LUAD中368个差异表达的mRNA进行交叉分析，获得了CD44、细胞周期蛋白D3（CCND3）、神经钙蛋白δ（NCALD）、微管肌动蛋白交联因子1（MACF1）和含钾通道四聚化结构域15。根据基因表达谱交互式分析和UALCAN数据库，这5种mRNA在LUAD中表达下调，且它们的表达水平与RAMP2-AS1的表达水平呈正相关。基于预后分析，选择CD44、CCND3、NCALD和MACF1作为LUAD中的关键mRNA。此外，进行了功能富集分析并构建了相互作用网络，以揭示LUAD中RAMP2-AS1相关ceRNA的功能。结果表明，这些功能主要富集在通用转录途径、G期细胞周期蛋白D相关事件和上皮间质转化中。逆转录定量PCR分析显示，肿瘤组织中RAMP2-AS1、CD44、CCND3、NCALD和MACF1的表达低于正常组织，而miR-296-5p在肿瘤组织中的表达高于正常组织。通过实验进一步证实了RAMP2-AS1与MACF1之间的关联。总体而言，目前的结果表明，RAMP2-AS1、miR-296-5p、CD44、CCND3、NCALD和MACF1可能参与LUAD的进展，因此可能作为潜在的生物标志物，并为LUAD发病机制的研究提供理论依据。
