MiR-424 suppressed viability and invasion by targeting to the DCLK1 in neuroblastoma.

OBJECTIVE: Neuroblastoma is the most frequent tumor of sympathetic nervous system in infants. MiRNAs acted as oncogenes or tumor suppressors in the process of tumor development. We aim at exploring the functions of miRNA in neuroblastoma. PATIENTS AND METHODS: Cell viability and invasion were evaluated by Cell Counting Kit-8 (CCK-8) and transwell assays. Western blot was utilized to assess the protein expression associated with epithelial-mesenchymal transition (EMT) markers. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to calculate the mRNA levels of miRNA and gene. RESULTS: MiR-424 was downregulated while doublecortin like kinase 1 (DCLK1) was upregulated in neuroblastoma tissues and cells compared to adjacent non-tumor and normal spongiocyte cells. MiR-424 suppressed cell viability, invasion, and EMT by targeting DCLK1. MiR-424 regulated the expression of DCLK1 by directly binding to the 3'-untranslated region (UTR) of DCLK1 mRNA in SK-N-SH and Be2C cells. DCLK1 reversed partial functions of miR-424 in neuroblastoma. CONCLUSIONS: MiR-424 suppressed cell viability, invasion, and EMT by directly targeting the 3'-UTR of DCLK1 mRNA. The newly identified miR-424/DCLK1 axis provides novel insights into the pathogenesis of neuroblastoma.

Microvesicles containing microRNA-216a secreted by tubular epithelial cells participate in renal interstitial fibrosis through activating PTEN/AKT pathway.

OBJECTIVE: The aim of this study was to elucidate the role of microRNA-216a in microvesicles (MVs) during the process of renal interstitial fibrosis and to investigate its underlying mechanism. MATERIALS AND METHODS: Unilateral ureteral occlusion (UUO) model was first established in mice, and kidney tissues and urine in the obscured kidney were collected. NRK-52E cells were induced with 5 ng/mL transforming growth factor-ß1 (TGF-ß1) for constructing the renal interstitial fibrosis model in vitro. Subsequently, the expression levels of E-cadherin, α-smooth muscle actin (α-SMA) and fibronectin (FN) in NRK-52E cells induced with or without TGF-ß1 were determined, respectively. The culture medium was collected from NRK-52E cells of the control group (without TGF-ß1 induction) and the TGF-ß1 group (TGF-ß1 induction), and MVs were observed. Afterward, NRK-52E cells were treated with MVs isolated from the control group or the TGF-ß1 group, followed by detecting the expressions of E-cadherin, α-SMA and FN. Meanwhile, the expression levels of CD63, microRNA-216a, PTEN and p-AKT were determined as well. The microRNA-216 level in kidney tissues and urine of UUO mice were determined. Furthermore, the expressions of PTEN and p-AKT in mouse kidney tissues were accessed by Western blot and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). RESULTS: TGF-ß1 induction in NRK-52E cells gradually downregulated E-cadherin, whereas upregulated α-SMA and FN with the prolongation of induction time. MVs isolated from the culture medium of the TGF-ß1 group downregulated E-cadherin, and upregulated FN and α-SMA. The expression levels of CD63 and microRNA-216a were markedly higher in the TGF-ß1 group compared with the control group. Downregulated PTEN and upregulated p-AKT were observed in TGF-ß1-induced cells at both mRNA and protein levels. Besides, microRNA-216a expression in mouse kidney tissues and urine from obscured kidney was remarkably increased with the prolongation of UUO. Consistent with those in NRK-52E cells, the protein level of PTEN was significantly decreased, whereas p-AKT was markedly increased with the prolongation of UUO. CONCLUSIONS: MVs containing microRNA-216a secreted by injured proximal tubular epithelial cells participate in renal interstitial fibrosis by activating the PTEN/AKT pathway.