Circular RNA circDENND4C facilitates proliferation, migration and glycolysis of colorectal cancer cells through miR-760/GLUT1 axis.

OBJECTIVE: Colorectal cancer is a common malignant tumor of the digestive tract, and its incidence is closely related to lifestyle inheritance and colorectal adenoma. Circular RNA (circRNA) has been proved to participate in the progression of colorectal cancer cells. Our study aimed to investigate the function and the underlying mechanism of circRNA circDENND4C in colorectal cancer cells. PATIENTS AND METHODS: The expression of circDENND4C, glucose transporter 1 (GLUT1), and miR-760 was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Western blot was used to measure the protein levels of GLUT1, the proliferation-related protein (Cyclin D1) and matrix metallopeptidase 9 ( MMP-9). Cell Counting Kit-8 (CCK- 8) assay and transwell assay were performed to evaluate cell proliferation and migration. The glucose uptake and lactate production were detected by the corresponding kits. The targets between circDENND4C and miR-760 and miR-760 and GLUT1 were predicted by starBase 3.0 and TargetScan, and then confirmed by Dual- Luciferase reporter assay. Animal experiment revealed the effect of circDENND4C on colorectal cancer cells in vivo. RESULTS: The expression of circDENND4C and GLUT1 was upregulated in colorectal cancer tissues and cells. Functionally, the knockdown of circDENND4C suppressed proliferation, migration, and glycolysis of colorectal cancer cells. Similarly, silence of GLUT1 also inhibited cell proliferation, migration, and glycolysis. Notably, the overexpression of GLUT1 reversed the functional effects of circDENND4C knockdown on colorectal cancer cells. More importantly, miR-760 acted as a direct target of circDENND4C, and miR-760 could bind to GLUT1, and circDENND4C regulated GLUT1 by sponging miR-760. Finally, circDENND4C knockdown decreased the growth of colorectal cancer cells in vivo. CONCLUSIONS: CircRNA circDENND4C accelerated proliferation, migration, and glycolysis of colorectal cancer cells through regulating GLUT1 by sponging miR-760.