Mwangi Joseph N, Chiu Norman H L
Department of Chemistry and Biochemistry, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27412, USA.
Noncoding RNA. 2016 Dec 2;2(4):13. doi: 10.3390/ncrna2040013.
MicroRNA (miR) are short non-coding RNAs known to post-transcriptionally regulate gene expression, and have been reported as biomarkers for various diseases. miR have also been served as potential drug targets. The identity, functions and detection of a specific miR are determined by its RNA sequence, whose composition is made up of only 4 canonical ribonucleotides. Hence, among over two thousand human miR, their nucleotide compositions are expected to be similar but the extent of similarity has not been reported. In this study, the sequences of mature human miR were downloaded from miRBase, and collated using different tools to determine and compare their nucleotide compositions and sequences. 55% of all human miR were found to be structural isomers. The structural isomers of miR (SimiR) are defined as having the same size and identical nucleotide composition. A number of SimiR were also found to have high sequence similarities. To investigate the extent of SimiR in biological samples, three disease models were chosen, and disease-associated miR were identified from miR2Disease. Among the disease models, as high as 73% of miR were found to be SimiR. This report provides the missing information about human miR and highlights the challenges on the detection of SimiR.
微小RNA（miR）是短链非编码RNA，已知可在转录后调节基因表达，并且已被报道为多种疾病的生物标志物。miR也已被用作潜在的药物靶点。特定miR的身份、功能和检测由其RNA序列决定，其组成仅由4种标准核糖核苷酸构成。因此，在两千多种人类miR中，预计它们的核苷酸组成相似，但相似程度尚未见报道。在本研究中，从miRBase下载了成熟人类miR的序列，并使用不同工具进行整理，以确定和比较它们的核苷酸组成和序列。发现所有人类miR中有55%是结构异构体。miR的结构异构体（SimiR）被定义为具有相同大小和相同核苷酸组成。还发现许多SimiR具有高度的序列相似性。为了研究生物样品中SimiR的程度，选择了三种疾病模型，并从miR2Disease中鉴定出与疾病相关的miR。在这些疾病模型中，发现高达73%的miR是SimiR。本报告提供了关于人类miR缺失的信息，并突出了检测SimiR的挑战。
