Long non-coding RNA NEAT1 promotes colorectal cancer progression by regulating miR-205-5p/VEGFA axis

Long non-coding RNAs (lncRNAs) play key roles in tumorigenesis. It has been reported that the lncRNA nuclear-enriched abundant transcript 1 (NEAT1) may act as an oncogenic regulator in several cancers. However, the biological mechanism of action of NEAT1, particularly the miRNA sponge role in colorectal cancer (CRC), has not been fully elucidated. In our study, the expression of NEAT1, miR-205-5p, and vascular endothelial growth factor A (VEGFA) in CRC cell lines were assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. Cell proliferation was detected by Cell Counting Kit-8 (CCK-8) assay. Cell migration and invasion were examined by wound healing and transwell assays, respectively. RNA-binding protein immunoprecipitation (RIP), and dual-luciferase and RNA pull-down assays were conducted to determine the correlation between miR-205-5p and NEAT1 or VEGFA. VEGFA, matrix metalloproteinase (MMP)2, and MMP9 protein and mRNA expression were measured by western blotting and RT-qPCR analysis, respectively. Our results demonstrated high expression of NEAT1 and VEGFA and low expression of miR-205-5p in CRC cell lines. The RIP and dual-luciferase assays confirmed miR-205-5p as a target of NEAT1. In addition, VEGFA was identified as a direct target of miR-205-5p. Inhibition of NEAT1 or overexpression of miR-205-5p was able to repress VEGFA expression. Moreover, downregulation of NEAT1 and VEGFA inhibited cell proliferation, migration, and invasion. NEAT1 overexpression facilitated tumor growth by modulating miR-205-5p. Taken together, lncRNA NEAT1 was found to be upregulated in CRC cell lines, promoting CRC cell proliferation, migration, and invasion through regulating the miR-205-5p/VEGFA signaling pathway. These findings suggest that NEAT1 may be a promising biomarker in CRC diagnosis and treatment.