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

// Huijun Xie 1, 2, 3, * , Xiaoli Ren 1, 2, 3, * , Sainan Xin 1, 2, 3, * , Xiaoliang Lan 4 , Guifeng Lu 1, 2, 3 , Yuan Lin 1, 2, 3 , Shaoshan Yang 1, 2, 3 , Zhicheng Zeng 1, 2, 3 , Wenting Liao 1, 2, 3 , Yan-Qing Ding 1, 2, 3 , Li Liang 1, 2, 3 1 Department of Pathology, Nanfang Hospital, Guangzhou, Guangdong, China 2 Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China 3 Guangdong Province Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China 4 Department of General Surgery, Nanfang Hospital, Guangzhou, Guangdong, China * These authors contributed equally to this work Correspondence to: Li Liang, email: redsnow007@hotmail.com Yan-Qing Ding, email: dyq@fimmu.com Keywords: hsa_circ_001569, miR-145, colorectal cancer, FMNL2, BAG4 Received: December 08, 2015 Accepted: March 07, 2016 Published: April 05, 2016 ABSTRACT 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.