LncRNA ANRIL regulates cell proliferation and migration via sponging miR-339-5p and regulating FRS2 expression in atherosclerosis.

OBJECTIVE: Atherosclerosis (AS), with high risk of stroke or cerebrovascular disease, is one of the most common causes of death worldwide. Increasing evidence shows that long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) is related to atherothrombotic stroke susceptibility and contributes to AS progression. However, the underlying mechanism was not explained yet. PATIENTS AND METHODS: Human aorta vascular smooth muscle cells (HA-VSMCs) and human umbilical vein endothelial cells (HUVECs) were treated with oxidized Low Density Lipoprotein (ox-LDL) and considered as AS cell models. Quantitative reverse transcriptase PCR (qRT-PCR) and Western blotting were employed to investigate the mRNA and protein expression level, respectively. Microscopic examination through fluorescent in situ hybridization (FISH) was used to determine the location of ANRIL. Cell proliferation and migration assays were demonstrated to evaluate the functional role of ANRIL in AS. Potential target of ANRIL was determined using Luciferase reporter assay and RNA immunoprecipitation (RIP). RESULTS: ANRIL was upregulated and miR-399-5p was down-regulated in both human atherosclerotic plaques and ox-LDL-induced cells. ANRIL was located in cytoplasm and promoted cell proliferation and migration by sponging miR-399-5p. Further analysis identified fibroblast growth factor receptor substrate 2 (FRS2) as a direct target of miR-399-5p. Finally, RAS/RAF/ERK signal pathway was proved to be involved in the regulation of ANRIL on the progression of AS. CONCLUSIONS: These results revealed the underlying mechanism that ANRIL promoted AS progression by sponging miR-399-5p and regulating RAS/RAF/ERK signal pathway, suggesting that ANRIL might be a potential target for the therapeutic strategy of AS.