LncRNA PVT1 Facilitates Proliferation, Migration and Invasion of NSCLC Cells via miR-551b/FGFR1 Axis

BACKGROUND: Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) plays a crucial role in non-small cell lung cancer (NSCLC). Nonetheless, regulatory effects of PVT1 on functions of NSCLC cells remain blurry. METHODS: Relative expression levels of PVT1, miR-551b and FGFR1 mRNA in tumor tissues and cells were examined employing quantitative real-time polymerase chain reaction (qRT-PCR); CCK-8 and BrdU assays were utilized for measuring cell viability and proliferation of H1299 and A549 cells; cell migration and invasion were detected deploying Transwell assay; dual-luciferase assay was used for the validation of binding sequence between PVT1 and miR-551b. FGFR1 expression in protein level was quantified employing Western blot. RESULTS: PVT1 was highly expressed in NSCLC tissues and cell lines, whereas miR-551b expression was down-regulated. Overexpression of PVT1 potentiated viability, proliferation, migration and invasion of NSCLC cells while miR-551b inhibited the biological behaviors mentioned above. MiR-551b was predicted and then confirmed as a direct downstream target of PVT1. Meanwhile, a negative correlation was observed between PVT1 expression and miR-551b expression in NSCLC tissues. Besides, PVT1 could increase FGFR1 expression by repressing miR-551b expression. CONCLUSION: PVT1 promotes the proliferation, migration and invasion of NSCLC cells by indirectly mediating FGFR1 via targeting miR-551b.