锌指蛋白基因ZMYM2来源环状RNA hsa_circ_0029625的 特征分析和功能预测

Feature analysis and function prediction of circular RNA hsa_circ_0029625 transcribed from zinc finger protein gene ZMYM2 and its potential function

目的环状RNA(circRNA)在多种生理病理过程中均发挥重要作用,但仍有许多circRNAs的功能尚待发掘,文章旨在研究锌指蛋白基因ZMYM2转录形成的环状RNA hsa_circ_0029625的主要特征,并对其进行功能预测和初步探究。方法从反向剪接位点及全长测序验证、核糖核酸酶R(RNase R)抵抗实验(细胞样本分为RNase R组和对照组)、细胞核质RNA分离实验、翻译蛋白潜能四个方面探究该circRNA的基本特征。利用荧光实时定量PCR实验初步探究该circRNA在胃癌中的表达。通过生物信息学预测circRNA上潜在结合的微小RNA(miRNA),并应用基因本体论(GO)对下游靶基因进行功能注释,初步验证下游靶基因,筛选和分析下游关键基因。结果hsa_circ_0029625是由ZMYM2转录本NM_003453反向剪接形成,全长测序比对结果符合预期。hsa_circ_0029625可耐受RNase R,主要位于细胞质。蛋白翻译分析显示:hsa_circ_0029625可能编码多肽。RNA定量分析显示:该circRNA在胃癌组织中较癌旁组织明显下调。荧光实时定量PCR实验验证5个下游靶基因在胃癌组织中表达下调。GO功能注释显示:靶基因主要涉及转录等生物过程以及转录调节活性等分子功能。结论锌指蛋白基因ZMYM2来源环状RNA hsa_circ_0029625具有环状RNA的基本特征,有编码多肽潜能,可能通过海绵miRNAs参与多种生物学过程及功能,在胃癌样本中低表达及生物信息学预测提示其可作为胃癌潜在靶点。

Objective Though circular RNAs(circRNAs)exhibit potent effects under physiological and pathological conditions,a majority of circular RNAs are waiting to be explored.Our study aims to investigate the major features and make the function prediction and initial exploration of circular RNA hsa_circ_0029625 transcribed from zinc finger protein Gene ZMYM2.Methods The basic characteristics of the circular RNA were explored from four aspects:verification of the backsplicing junction and the full-length sequence,isolation and quantification of the cytoplasmic and nuclear RNA and analysis of the protein-coding ability.We detected the expression of hsa_circ_0029625 in gastric cancer tissue by real-time quantitative PCR.The potential microRNAs(miRNAs)binding to circRNAs were predicted by bioinformatics methods.The preliminary verification of potential downstream target genes and the downstream hub genes screening were then performed.Gene Oncology(GO)analysis was used for annotating the downstream target genes.Results circBase annotation shows that hsa_circ_0029625 was generated through backsplcing of the transcript from ZMYM2.The backsplcing site was verified and the results of full-length sequencing were in line with expectations.Hsa_circ_0029625 was proved to be resistant to RNase R treatment and expressed significantly in the nucleus.Protein-coding ability analysis indicated that hsa_circ_0029625 had the potential ability of encoding peptides.Quantitative analysis assay of RNA expression revealed that the expression of hsa_circ_0029625 was significantly decreased in gastric cancer tissues than that in adjacent tissues.The expression of 5 downstream target genes were observed to be down-regulated in gastric cancer tissue in real-time PCR analysis.The GO function annotation showed that the target genes related to miRNA were involved in the biological process(BP)such as transcription and in molecular function(MF)such as transcription regulator activity.Conclusion The novel circRNA hsa_circ_0029625 derived from zinc finger protein gene ZMYM2 possesses the basic feature of circRNAs.It has the potential ability of encoding polypeptides and sponging miRNAs,which may serve for many biological process and molecular function.Hsa_circ_0029625 is low-expressed in gastric cancer tissue samples,together with bioinformatics prediction result,implying hsa_circ_0029625 can serve as a potential target of the treatment of gastric cancer.