CircMTO1: a novel regulator of hepatocellular carcinoma progression

Circular RNAs (circRNAs), a unique class of RNA, were transcribed from protein-coding genes or non-coding genes by RNA polymerase II and engendered by backsplicing (1,2). CircRNAs are characterized by forming a covalently closed continuous loop which have no 5’–3’ polarity and polyA tail (3,4). Compared to linear RNAs, circRNAs were stable, abundant and showed a cell-type-specific, tissue-specific and stage-specific expression pattern (5,6). Previous studies had showed that circRNAs played important roles in many biological processes in different types of cancers, such as prostate (7), and gastric (8) cancer.