Objective: The aim of this study was to investigate the microRNA-200b-3p expression in lung adenocarcinoma and the possible functional associations of microRNA-200b-3p with cell proliferation, migration, and invasion.
Methods: Quantitative real-time polymerase chain reaction was used to detect the expression of microRNA-200b-3p in lung adenocarcinoma samples and in the human lung adenocarcinoma cell lines A549 and H1299. A549 and H1299 cells were transfected with either a microRNA-200b-3p mimic or a negative control microRNA or either an empty vector or an adenosine triphosphate-binding cassette transporter A-1 overexpression vector. A Cell Counting Kit-8 assay was employed to assess the ability of cell proliferation. Transwell assays and transwell-Matrigel invasion assay were, respectively, utilized to assess the capacity of migration and invasion in A549 and H1299 cells.
Results: The results showed that microRNA-200b-3p expression was significantly upregulated in tumor tissues compared with that in adjacent normal tissues. Overexpression of microRNA-200b-3p promoted lung adenocarcinoma cell proliferation and metastasis. Furthermore, adenosine triphosphate-binding cassette transporter A-1 was a direct target of microRNA-200b-3p, and this binding was verified by luciferase reporter analysis. Overexpression of adenosine triphosphate-binding cassette transporter A-1 obviously suppressed lung adenocarcinoma cell proliferation, migration, and invasion. Lung adenocarcinoma cell phenotypes induced by microRNA-200b-3p overexpression could be partially remitted by the co-overexpression of microRNA-200b-3p and adenosine triphosphate-binding cassette transporter A-1.
Conclusion: This study first identified that microRNA-200b-3p is upregulated in lung adenocarcinoma cells and associated with cell proliferation and metastasis. MicroRNA-200b-3p promoted lung adenocarcinoma cell proliferation and metastasis by suppressing adenosine triphosphate-binding cassette transporter A-1. MicroRNA-200b-3p may function as a novel molecular marker and therapeutic target for lung adenocarcinoma treatment.
Keywords: ATP-binding cassette transporter A-1 (ABCA1); lung adenocarcinoma (LUAD); metastasis; miR-200b-3p; proliferation.