Long non-coding RNA CCAT1 promotes colorectal cancer cell migration, invasiveness and viability by upregulating VEGF via negative modulation of microRNA-218

Increasing evidence has demonstrated that long non-coding (lnc) RNA is aberrantly expressed in numerous types of cancer. Colorectal cancer is a common malignancy; however, the role and mechanism underlying the influence of lncRNA-colon cancer associated transcript 1 (CCAT1) in colorectal cancer is yet to be elucidated. The present study revealed that CCAT1 is highly expressed in colorectal cancer tissues. Bioinformatics analysis and a dual-luciferase reporter gene assay indicated that CCAT1 and microRNA (miR)-218 had complementary binding sites. Furthermore, reverse transcription-quantitative PCR revealed that miR-218 was downregulated in colorectal cancer tissues compared with paired adjacent healthy tissues. To investigate the biological effects of CCAT1 on colorectal cancer cells, MTT and Transwell assays were performed. The results revealed that when compared with the control group, CCAT1-short hairpin (sh)RNA significantly inhibited colorectal cancer cell (SW480) viability and decreased migration and invasiveness. In addition, CCAT1-shRNA significantly reduced vascular endothelial growth factor (VEGF) expression in SW480 cells; however, these effects were partially rescued by an miR-218 inhibitor. Furthermore, it was revealed that the CCAT1-plasmid significantly promoted the viability of SW480 cells, increased cell migration and invasiveness, and significantly increased VEGF expression. However, these effects were also partially rescued by with a miR-218 mimic. Taken together, the present results identified that the CCAT1/miR-218 axis serves a key role in the regulation of colorectal cancer progression, which may be used as potential therapeutic target for the treatment of colorectal cancer.