MiR-106b-5p Promotes Proliferation and Inhibits Apoptosis by Regulating BTG3 in Non-Small Cell Lung Cancer

Background/Aims: MicroRNAs have been validated to play a crucial role in tumorigenesis of non-small cell lung cancer (NSCLC). Although miR-106b-5p has been reported to play a vital role in various malignancies the physiological function of miR-106b-5p in NSCLC still remain unknown. In this study, we investigated the role of miR-106b-5p in NSCLC. Methods: Quantitative real-time polymerase chain reaction was conducted to estimate the expression of miR-106b-5p and BTG3 in both NSCLC tissues and cell lines. The effects of miR-106b5p on proliferation were determined in vitro using CCK-8 proliferation assays, 5-ethynyl-2'deoxyuridine (EdU) incorporation, colony formation assays and cell-cycle assays and the in vivo effects were evaluated by a mouse tumorigenicity model. Cell apoptosis and cell cycle was investigated by flow cytometric analysis in vitro. The molecular mechanism underlying the relevance between miR-106b-5p and BTG3 was confirmed by luciferase assay and western blot. Results: In current study, we found a relatively higher miR-106b-5p and lower BTG3 expression in NSCLC specimens and cell lines. BTG3 was verified as a direct target of miR106b- 5p by luciferase assay. In vitro, over-expression of miR-106b-5p promoted proliferation and inhibited apoptosis by down-regulating BTG3 expression. In vivo, miR-106b-5p promoted xenograft tumor formation. Conclusion: Our findings revealed for the first time that miR-106b5p plays a tumorigenesis role in NSCLC progression by down-regulating BTG3 expression, which may lead to a novel insight to the potential biomarker and novel therapeutic strategies for NSCLC patients. (C) 2017 The Author(s) Published by S. Karger AG, Basel