Yang Nuo, Coukos George, Zhang Lin
Center for Research on Early Detection and Cure of Ovarian Cancer, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Int J Cancer. 2008 Mar 1;122(5):963-8. doi: 10.1002/ijc.23325.
MicroRNAs (miRNAs) are approximately 22 nt non-coding RNAs, which regulate gene expression in a sequence-specific manner via translational inhibition or messenger RNA (mRNA) degradation. Since the discovery of their fundamental mechanisms of action, the field of miRNAs has opened a new era in the understanding of small noncoding RNAs. By molecular cloning and bioinformatic approaches, miRNAs have been identified in viruses, plants and animals. miRNAs are predicted to negatively target up to one-third of human mRNAs. Cancer is a complex genetic disease caused by abnormalities in gene structure and expression. Previous studies have heavily focused on protein-coding genes; however, accumulating evidence is revealing an important role of miRNAs in cancer. Epigenetics is defined as mitotically and/or meiotically heritable changes in gene expression that are not accompanied by changes in DNA sequence. Given the critical roles of miRNAs and epigenetics in cancer, characterizing the epigenetic regulation of miRNAs will provide novel opportunities for the development of cancer biomarkers and/or the identification of new therapeutic targets in the foreseeable future.
微小RNA（miRNA）是约22个核苷酸的非编码RNA，其通过翻译抑制或信使核糖核酸（mRNA）降解以序列特异性方式调节基因表达。自从发现其基本作用机制以来，miRNA领域开启了理解小型非编码RNA的新纪元。通过分子克隆和生物信息学方法，已在病毒、植物和动物中鉴定出miRNA。据预测，miRNA对多达三分之一的人类mRNA具有负向靶向作用。癌症是一种由基因结构和表达异常引起的复杂遗传疾病。以往的研究主要集中在蛋白质编码基因上；然而，越来越多的证据表明miRNA在癌症中发挥着重要作用。表观遗传学被定义为基因表达中可通过有丝分裂和/或减数分裂遗传的变化，且这些变化不伴有DNA序列的改变。鉴于miRNA和表观遗传学在癌症中的关键作用，在可预见的未来，表征miRNA的表观遗传调控将为癌症生物标志物的开发和/或新治疗靶点的鉴定提供新的机遇。
