miR-208a-3p promotes NSCLC proliferation and migration by suppressing lncRNA-MEG3 expression

Background: The disordered expression of maternally expressed gene 3 (MEG3) has been observed in non-small-cell lung cancer (NSCLC). However, the molecular mechanism accounting for this abnormal expression is not fully understood. Methods: MEG3 expression was detected by qRT-PCR in 51 cases of NSCLC and adjacent normal tissues. Then, the relationship between MEG3 and miR-208a-3p was assessed in vitro by cell viability assay, cell migration assay, protein extraction and western blot analysis. Resoults We observed that MEG3 expression was decreased in NSCLC tissues. And MEG3 expression was negatively related to lymph node metastasis and differentiation. Moreover, MEG3 expression is regulated by miR-208a-3p expression by overexpression and knockout experiments. Furthermore, we focused on the underlying mechanism of MEG3 downregulation. We found that the overexpression of miR-208a-3p reduced the level of MEG3 expression based on computational predictions and in vitro assays. Using CCK-8 and transwell migration assays, we found that the overexpression of miR-208a-3p can increased proliferation and apoptosis in NSCLC cells. Moreover, the depletion of MEG3 rescued the proliferation and migration induced by miR-208a-3p knockdown. Conclusion: Taken together, the results of this study reveal that miR-208a-3p promotes NSCLC tumorigenesis by negatively regulating MEG3 expression and functions as an oncogenic miRNA in NSCLC.