LncRNA OGFRP1 promotes angiogenesis and epithelial-mesenchymal transition in colorectal cancer cells through miR-423-5p/CTCF axis

To investigate the mechanism of lncRNA OGFRP1 affecting angiogenesis and epithelial-mesenchymal transition (EMT) in colorectal cancer (CRC) and provide a new target for the treatment of CRC. The expressions of OGFRP1, miR-423-5p, and CTCF were measured in CRC cell lines (HT29, LoVo, HCT116, SW620, and SW480) and normal colonic epithelial cells NCM460. Gain and loss of function experiments were performed on HCT116 and SW620 cells, after which the proliferation, apoptosis, EMT, invasion, and migration of the cells were measured using CCK-8 and colony formation assays, flow cytometry, Western blotting, Transwell, and scratch assay. The transfected cells were incubated with human umbilical vein endothelial cells (HUVECs) to assess angiogenesis using tube formation assay. ELISA was performed to detect VEGF in the conditioned medium of HCT116 and SW620 cells. The interactions among OGFRP1, CTCF and miR-423-5p were validated by dual-luciferase reporter assay. CRC cell lines had increased expression levels of OGFRP1 and CTCF and a suppressed expression level of miR-423-5p when compared with NCM460 cells. Suppression on OGFRP1 or CTCF and overexpression of miR-423-5p led to inhibited proliferation, EMT, invasion and migration and increased apoptosis of HCT116 and SW620 cells. HUVECs incubated with cells transfected with si-OGFRP1, si-CTCF or miR-423-5p mimic had suppressed angiogenesis ability. The effect of OGFRP1 suppression in CRC cells could be counteracted by miR-423-5p inhibition. Both CTCF and OGFRP1 could bind to miR-423-5p. OGFRP1 promotes proliferation, EMT, and angiogenesis in CRC through miR-423-5p/CTCF axis.