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

Figures & data

Figure 1 let-7d expression was downregulated and AEG-1 level was up-regulated in meningioma tissues and cell lines.

Notes: (A and B) qRT-PCR analysis revealed reduced let-7d and elevated AEG-1 expressions in meningioma tissues. (C) Negative correlation between let-7d and AEG-1 levels existed in meningioma tissues. (D and E) qRT-PCR analysis displayed the expression level of let-7d and AEG-1 in different WHO grade meningioma tissues (6 WHO grade I, 5 WHO grade II and 6 grade III) and normal arachnoidal tissues. (F) qRT-PCR analysis indicated the let-7d levels in meningioma cell lines (IOMM-Lee, CH-157MN, BenMen1 and HBL52). ^*P<0.05 vs controls.
Abbreviations: AEG-1, astrocyte elevated gene-1; qRT-PCR, quantitative real-time polymerase chain reaction; WHO, World Health Organization.

Figure 2 let-7d inhibited cell viability and invasion and induced apoptosis in meningioma cells.

Notes: IOMM-Lee and CH-157MN cells were transfected with miR-control or let-7d mimics. (A) let-7d was upregulated in IOMM-Lee and CH-157MN cells transfected with let-7d mimics. (B) MTT assay determined the cell viability in IOMM-Lee and CH-157MN cells. (C) Transwell invasion assay detected the cell invasion in IOMM-Lee and CH-157MN cells. (D) Flow cytometry analysis showed the cell apoptosis in IOMM-Lee and CH-157MN cells. *P<0.05 vs miR-control.
Abbreviations: FITC, fluorescein isothiocyanate; PI, propidium iodide.

Figure 3 AEG-1 is a functional target of let-7d.

Notes: (A) The putative let-7d binding site in the 3′ UTR of AEG-1 is shown. (B) The relative luciferase activity was determined by luciferase reporter assay in IOMM-Lee and CH-157MN cells co-transfected with AEG-1-wt or AEG-1-mut and let-7d mimic or miR-control. (C and D) qRT-PCR and Western blot analyses revealed the mRNA and protein levels of AEG-1 in IOMM-Lee and CH-157MN cells transfected with let-7d mimics or inhibitor. ^*P<0.05 vs controls.
Abbreviations: AEG-1, astrocyte elevated gene-1; mut, mutation; NC, normal control; UTR, untranslated region; qRT-PCR, quantitative real-time polymerase chain reaction; wt, wild type.

Figure 4 let-7d inhibited cell viability and invasion and promoted apoptosis in meningioma cells by targeting AEG-1.

Notes: IOMM-Lee and CH-157MN cells were transfected with let-7d or co-transfected with let-7d and pcDNA-AEG-1. (A) MTT assay revealed that AEG-1 overexpression reversed the inhibitory effect of let-7d on the viability of IOMM-Lee and CH-157MN cells. (B) Transwell invasion assay suggested that pcDNA-AEG-1 eliminated let-7d-mediated inhibition of cell invasion in IOMM-Lee and CH-157MN cells. (C) Flow cytometry analysis indicated that restoration of AEG-1 expression hindered let-7d-induced apoptosis in IOMM-Lee and CH-157MN cells. ^*P<0.05 vs controls.
Abbreviation: AEG-1, astrocyte elevated gene-1.

Figure 5 AEG-1 overexpression increased cell viability and invasion and had no significant effect on the apoptosis in IOMM-Lee cells.

Notes: (A) IOMM-Lee cells were transfected with pcDNA-control or pcDNA-AEG-1. Western blot analysis was performed to detect the protein level of AEG-1. (B) MTT assay revealed that AEG-1 overexpression increased the viability of IOMM-Lee cells. (C) Transwell invasion assay suggested that pcDNA-AEG-1 promoted cell invasion in IOMM-Lee cells. (D) Flow cytometry analysis indicated AEG-1 overexpression had no significant effect on the apoptosis in IOMM-Lee cells. ^*P<0.05 vs controls.
Abbreviations: AEG-1, astrocyte elevated gene-1; FITC, fluorescein isothiocyanate; PI, propidium iodide.