circ5615 functions as a ceRNA to promote colorectal cancer progression by upregulating TNKS

• Published in: Cell death & disease Vol. 11; no. 5; p. 356
• Main Authors: Ma, Zhifei, Han, Chencheng, Xia, Wenjia, wang, Siwei, Li, Xiang, Fang, Panqi, Yin, Rong, Xu, Lin, Yang, Liu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.05.2020; Springer Nature B.V
• Subjects: 13/51; 13/89; 14/105; 14/19; 14/32; 38/47; 38/71; 631/67/1504/1885; 692/308/2056; 96/31; Animals; Antibodies; beta Catenin - genetics; beta Catenin - metabolism; Biochemistry; Bioinformatics; Biomedical and Life Sciences; Biotin; Cancer; Cell Biology; Cell Culture; Cell Cycle; Cell Proliferation; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - enzymology; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; Cyclin D1; Cyclin D1 - genetics; Cyclin D1 - metabolism; Disease Progression; Exons; Gene Expression Regulation, Neoplastic; HCT116 Cells; HT29 Cells; Humans; Immunology; Immunoprecipitation; Life Sciences; Male; Mice, Inbred BALB C; Mice, Nude; MicroRNAs - genetics; MicroRNAs - metabolism; mRNA; Non-coding RNA; Phenotypes; RNA probes; RNA, Circular - genetics; RNA, Circular - metabolism; Splicing; Tankyrases - genetics; Tankyrases - metabolism; Tumor Burden; Up-Regulation; Wnt protein; Wnt Signaling Pathway; β-Catenin
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-020-2514-0

Circular RNAs (circRNAs), non-coding RNAs generated by precursor mRNA back-splicing of exons, have been reported to fulfill multiple roles in cancer. However, the role of quite a lot circRNAs in colorectal cancer (CRC) remains mostly unknown. Herein, we explored the expression profiles of circRNAs in 5 paired samples of CRC patients by microarray and noted a circRNA, hsa_circ_0005615 (circ5615), was significantly upregulated in CRC tissues. Circ5615 was derived from exon 2 of NFATC3 and its upregulation was tightly correlated with higher T stage and poor prognosis in CRC patients. Studies in vitro and in vivo demonstrated that knockdown of circ5615 in cancer cells inhibited proliferation and cell cycle acceleration, while overexpression promoted malignant phenotypes. Mechanistically, RNA immunoprecipitation, biotin-coupled probe pull-down and luciferase reporter assays revealed circ5615 effectively bound to miR-149-5p and might play a role like miR-149-5p sponge. Additionally, tankyrase (TNKS), regulator of β-catenin stabilization, was identified as circ5615 downstream and the potential miR-149-5p targets by RNA-seq and bioinformatics analysis. We further verified the upregulation of β-catenin and cyclin D1 induced by circ5615. Our results indicated that circ5615 exerted oncogenic function as competing endogenous RNA (ceRNA) of miR-149-5p to release TNKS and activated Wnt/β-catenin pathway.