In order to examine the underlying relationship between OS cells and EMT, we silenced ATG5, which is recognized to have an essential role in autophagosome formation

In order to examine the underlying relationship between OS cells and EMT, we silenced ATG5, which is recognized to have an essential role in autophagosome formation. transcription-polymerase chain reaction (RT-PCR), miR-210-5p was found to be upregulated in clinical OS specimens and cell lines. Further functional analysis demonstrated that miR-210-5p promoted epithelialCmesenchymal transition (EMT) and induced oncogenic autophagy. Luciferase reporter assay, RNA-ChIP, and western blot analysis confirmed that PIK3R5, an essential regulator in the AKT/mTOR signaling pathway, is a target downstream gene of miR-210-5p. Overexpression or knockdown of PIK3R5 reversed the functional role of overexpression or knockdown of miR-210-5p, respectively. Silencing autophagy-related gene 5 (ATG5) abolished the functional effects of miR-210-5p upregulation or PIK3R5 knockdown in OS cells. In vivo, miR-210-5p overexpression promoted OS tumor growth and pulmonary metastasis. Taken together, our results demonstrated that miR-210-5p promoted EMT and oncogenic autophagy by suppressing the expression of PIK3R5 and regulating the AKT/mTOR signaling pathway. Therefore, inhibition of miR-210-5p may represent a promising treatment for OS. test was used to compare two groups. Statistical analyses were performed using SPSS v. 22.0 (SPSS Inc., Chicago, IL, USA). em P /em ? ?0.05 was considered statistically significant. Results Upregulation of miR-210-5p in clinical OS specimens and cell lines First, we assessed the expression of miR-210-5p in 62 paired OS specimens and matched adjacent normal specimens. It was found the expression level of miR-210-5p was significantly upregulated in OS tissues compared with adjacent normal tissues (Fig. ?(Fig.1a).1a). FISH was then used to detect the miR-210-5p expression level, and the results shown in Fig. ?Fig.1b1b confirmed the above RT-PCR results. It was also found that miR-210-5p expression was higher in the metastasis group compared with the non-metastasis group (Fig. ?(Fig.1c).1c). The representative radiological images of OS patients with or without pulmonary metastasis are shown in Supplementary Fig. S1. In OS cell lines, including HOS, Saos-2, SW1353, U2OS, and MG63, the expression level of miR-210-5p was upregulated in OS cell lines when compared with the normal human osteoblast cell line hFOB 1.19 (Fig. ?(Fig.1d).1d). In addition, the expression level of miR-210-5p was obtained from the GEO online database and confirmed that the expression of miR-210-5p was higher in OS cell lines (Supplementary Fig. S2A). Furthermore, we analyzed the relationship between the expression level of miR-210-5p and the clinicopathological characteristics in Obatoclax mesylate (GX15-070) OS patients (Supplementary Table S1). The expression level of miR-210-5p was found to be significantly positively correlated with TNM stage, lung metastasis, and tumor size. Open in a separate window Fig. 1 miR-210-5p is upregulated in clinical OS specimens and cell lines.a The expression of miR-210-5p in 62 pairs of clinical OS specimens and matched adjacent normal tissues. b Representative FISH images of miR-210-5p in clinical OS specimens and matched adjacent normal tissues. Scale bar?=?50?m. c The expression of miR-210-5p in the metastasis group compared with the non-metastasis group. d The relative expression of miR-210-5p in OS cells Obatoclax mesylate (GX15-070) and the hFOB 1.19 cell line. e, f The expression of miR-210-5p in HOS and MG63 cells transfected with LV-miR-210-5p or ANTI-miR-210-5p. miR-210-5p promotes tumor invasion and migration in OS cells Based on the expression level of miR-210-5p in the OS cell lines, HOS and MG63 cell lines were transfected with LV-miR-210-5p or ANTI-miR-210-5p lentivirus, respectively. The expression level after transfection was assessed using miRNA RT-PCR (Fig. 1e, f). Gene set enrichment analysis (GSEA) was performed, and it was found that miR-210-5p expression was positively correlated with EMT-associated gene signatures, which means that miR-210-5p may have an impact on the EMT process in OS (Fig. ?(Fig.2a).2a). Staining of vimentin, a mesenchymal biomarker, showed that the expression level of vimentin was higher in the high miR-210-5p group (Fig. Obatoclax mesylate (GX15-070) ?(Fig.2b).2b). Furthermore, overexpression of miR-210-5p in HOS cells increased the expression levels of mesenchymal markers including N-cadherin, Vimentin, and MMP2, but decreased the expression of epithelial cell marker E-cadherin. In contrast, suppression of miR-210-5p in MG63 cells showed the opposite effects (Fig. ?(Fig.2c).2c). A transwell invasion assay was then conducted to investigate the impact of miR-210-5p on cell invasion and migration Mouse monoclonal to CD95(Biotin) ability in OS. As shown in Fig. ?Fig.2d,2d, overexpression of miR-210-5p significantly promoted HOS cell invasiveness, and silencing miR-210-5p attenuated MG63 cell invasiveness (Fig..