Recent progress in study of circRNAs and its role in leukemia

Circular RNAs (circRNAs) are a class of newly identified noncoding RNA and are considered as a new feature of eukaryotic gene expression. Hundreds of thousands of endogenous circRNAs have been found in mammalian cells, which we knew little before. CircRNAs are covalently closed, circular RNA molecules that typically comprise exonic sequences and are spliced at canonical splice sites. Researchers with RNA-Seq technology have identified that the expression of circRNAs is developmentally regulated, tissue- and cell-type specific. Like long noncoding RNAs (lncRNAs), circRNAs are becoming a new research hotspot in the RNA field, and aberrant expression of circRNAs could contribute to carcinogenesis. Recent studies have demonstrated that circRNAs play important roles in the development, maintenance, and progression of leukemia. Herein, we describe the biologic characteristics and functions of circRNAs, with a focus on circRNAs that play essential roles in leukemia.