Circ_0000799 promotes proliferation and invasion in colorectal cancer and epithelial-mesenchymal transition

Abstract

The current study aimed to investigate the effect of circ_0000799 on the biological function of colorectal cancer (CRC) cells and its mechanism. First, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was employed for detecting the expression of circ_0000799, miR-647, and miR-1243 in surgically resected specimens from hospitalized CRC patients, CRC-adjacent normal tissues (Normal group), human normal colon epithelial cells (FHC group), and CRC cell lines (HCT116, HT29, SW480, SW620). The cell proliferation, viability, and invasion were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation assay, transwell assay in HCT116 and SW480 cells with overexpression or inhibition of circ_0000799. The targeting relationship between circ_0000799 and miR-647 was verified by dual-luciferase reporter assay. The expression of epithelial-mesenchymal transition (EMT) proteins (E-cadherin, vimentin, and N-cadherin) was tested by western blot. The expression level of circ_0000799 was significantly increased in CRC tissues and cells. Overexpression of circ_0000799 significantly increased cell proliferation rate, viability, invasion, and the EMT process, whereas knockdown of circ_0000799 inhibited the biological performance of CRC cells. Bioinformatic analysis suggested that miR-647 was regulated by circ_0000799, and a dual-luciferase reporter assay further showed a targeting relationship between the two. In addition, circ_0000799 was negatively correlated with miR-647 expression in CRC. Our findings suggest that circ_0000799 promotes proliferation and invasion in CRC and EMT. These effects of circ_0000799 may be achieved by negatively regulating miR-62.