let-7d suppresses proliferation and invasion and promotes apoptosis of meningioma by targeting AEG-1

BACKGROUND: let-7d has been indicated to act as a tumor suppressor in various cancers. However, the function and molecular mechanism of let-7d in meningioma progression have not been elucidated. MATERIALS AND METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression levels of let-7d and AEG-1 mRNA in meningioma tissues and cell lines. The protein level of AEG-1 was measured by Western blot analysis. MTT assay, Transwell invasion assay and flow cytometry analysis were carried out to determine the proliferation, invasion and apoptosis of IOMM-Lee and CH-157MN cells, respectively. Target gene of let-7d was verified by luciferase reporter analysis. RESULTS: let-7d expression was downregulated, and AEG-1 expression was upregulated in meningioma tumor tissues. let-7d overexpression suppressed proliferation and invasion and induced apoptosis in IOMM-Lee and CH-157MN cells. Moreover, AEG-1 was a direct target of let-7d. Restoration of AEG-1 expression reversed let-7d-mediated suppression of the proliferation and invasion and let-7d-induced apoptosis in IOMM-Lee and CH-157MN cells. CONCLUSION: let-7d repressed proliferation and invasion and promoted apoptosis of meningioma cells by targeting AEG-1. The present study provided a better understanding of the meningioma pathogenesis and a promising therapeutic target for meningioma patients.