Emerging roles of circRNA_001569 targeting miR-145 in the proliferation and invasion of colorectal cancer.

Circular RNAs (circRNAs), a large class of RNAs, have recently shown huge capabilities as gene regulators in mammals. Some of them bind with microRNAs (miRNAs) and act as natural miRNA sponges to inhibit related miRNAs' activities. Here we showed that hsa_circ_001569 acted as a positive regulator in cell proliferation and invasion of colorectal cancer (CRC). Moreover, hsa_circ_001569 was identified as a sponge of miR-145 and up-regulated miR-145 functional targets E2F5, BAG4 and FMNL2. In CRC tissues, circ_001569 negatively correlated with miR-145, and miR-145 correlated negatively with E2F5, BAG4 and FMNL2 expressions. Our study reveals a novel regulatory mechanism of circ_001569 in cell proliferation and invasion in CRC, provides a comprehensive landscape of circ_001569 that will facilitate further biomarker discoveries in the progression of CRC.