Recently, with the development of RNA research techniques, a wide variety of circular RNAs (circRNAs) have been discovered and some of them are confirmed to have crucial biological functions. CircRNAs arise from exons (i.e. exonic circRNAs) or introns (i.e. intronic circRNAs). Acting as microRNA sponges or combining with proteins, circRNAs participate in the regulation of gene expression and influence the activity of some proteins. In addition, some circRNAs even encode proteins. More importantly, several circRNAs play a key role in the occurrence and progression of some tumors, including stomach, liver, colon, breast, cervical, and ovarian cancers. Therefore, circRNAs may be a novel type of diagnostic marker and therapeutic target of cancers.
近年来，随着RNA 研究技术的进步，研究者们在多种生物中发现了数量众多的环状RNA，且发现它们具有重要的生物学功能。环状RNA 来源于内含子或外显子，可以充当微小RNA 海绵，还能与蛋白质相结合，从而参与基因表达调控并影响蛋白质的功能，此外，个别环状RNA 甚至能编码蛋白质。更重要的是，环状RNA 在肿瘤 (如：胃癌、肝癌、结直肠癌、乳腺癌、宫颈癌和卵巢癌等) 的发生和发展过程中起着重要的调控作用。因此，环状RNA 有希望成为肿瘤诊断的标志物和治疗的新靶点。.
Keywords: circular RNA; microRNA sponge; occurrence; tumor.