Figure S1. Alignments between full-length read to exon(s). Figure S2. CircRNAs validation in CRC. Figure S3. Sanger sequencing results for the backsplice junction. Figure S4. Hypoxia tunes the levels of linear and circular CCDC66 transcripts. Figure S5. CircCCDC66 reshapes the tumor transcriptome. Figure S6. CircCCDC66 regulates a subset of oncogenes. Figure S7. Levels of circCCDC66 from xenografted tumors.
Funding
Ministry of Science and Technology of Taiwan
National Health Research Institute
National Cheng Kung University
Cancer Prevention Research Institute of Texas
National Institutes of Health
ARTICLE ABSTRACT
Circular RNA (circRNA) is a class of noncoding RNA whose functions remain mostly unknown. Recent studies indicate circRNA may be involved in disease pathogenesis, but direct evidence is scarce. Here, we characterize the functional role of a novel circRNA, circCCDC66, in colorectal cancer. RNA-Seq data from matched normal and tumor colon tissue samples identified numerous circRNAs specifically elevated in cancer cells, several of which were verified by quantitative RT-PCR. CircCCDC66 expression was elevated in polyps and colon cancer and was associated with poor prognosis. Gain-of-function and loss-of-function studies in colorectal cancer cell lines demonstrated that circCCDC66 controlled multiple pathological processes, including cell proliferation, migration, invasion, and anchorage-independent growth. In-depth characterization revealed that circCCDC66 exerts its function via regulation of a subset of oncogenes, and knockdown of circCCDC66 inhibited tumor growth and cancer invasion in xenograft and orthotopic mouse models, respectively. Taken together, these findings highlight a novel oncogenic function of circRNA in cancer progression and metastasis. Cancer Res; 77(9); 2339–50. ©2017 AACR.
