LncRNA-NEAT1 blocks the Wnt/ß-catenin signaling pathway by targeting miR-217 to inhibit trophoblast cell migration and invasion.

OBJECTIVE: This study aimed to study the correlation between preeclampsia (PE) and lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1), and to examine the molecular mechanisms behind the development of PE. METHODS: 30 PE and 30 normal pregnant women placental samples were assessed the levels of NEAT1 and miR-217 by quantitative real-time PCR (qRT-PCR). The trophoblast cell line HTR8/SVneo was used for silencing NEAT1 or miR-217 inhibitor in the absence or presence of an inhibitor and H2O2. Cell counting Kit 8 (CCK-8), flow cytometry, and Transwell were used to detect cell proliferation, apoptosis, migration, and invasion. Luciferase reporter gene assay was utilized to verify the binding between miR-217 and Wnt family member 3 (Wnt3), and between the miR-217 and NEAT1. Proteins related to the Wnt/ß-catenin signaling pathway were detected using western blotting. RESULTS: The PE group exhibited a significantly downregulated expression of miR-217 and a significantly upregulated expression of NEAT1. NEAT1 targeted miR-217, and Wnt is a miR-217 target gene. siRNA-NEAT1 inhibited the apoptosis of trophoblast cells, but promoted their invasion, migration, and proliferation. MiR-217 inhibitor could partially reverse the effects of siRNA-NEAT1. The expression of the Wnt/ß-catenin signaling pathway-related proteins, WNT signaling pathway inhibitor 1 (DKK1), cyclin-D1 and ß-catenin, was significantly increased after siRNA-NEAT1. CONCLUSIONS: NEAT1 could reduce trophoblast cell invasion and migration by suppressing miR-217/Wnt signaling pathway, leading to PE.

MicroRNA-217 aggravates breast cancer through activation of NF1-mediated HSF1/ATG7 axis and c-Jun/ATF3/MMP13 axis.

Application of microRNA-mediated mRNA expression in treatment of diverse cancers has been documented. The current study was explored to study the role of miR-217 in breast cancer (BC) progression and the related downstream factors. Clinical tissue samples, BC cell lines and the established xenograft models were prepared for ectopic expression and depletion experiments to discern the regulatory roles of miR-217-mediated NF1 in BC cell proliferation, metastasis and chemoresistance as well as tumorigenic ability of BC cells in nude mice. miR-217 was upregulated in BC, which was a predictor of poor prognosis of BC patients. NF1 could be targeted by miR-217. miR-217 promoted malignant characteristics of BC cells through enhancing ATF3-MMP13 interaction by inhibiting NF1. miR-217 repressed sensitivity against anti-cancer drugs by inducing autophagy of BC cells through the NF1/HSF1/ATG7 axis. Also, miR-217 could inhibit NF1 to facilitate tumorigenic ability of BC cells in vivo. Our study emphasized that miR-217 could potentially inhibit NF1 expression to activate the c-Jun, thus enhancing the expression and interaction of ATF3/MMP13 and promoting the malignant features of BC cells. Furthermore, miR-217 conferred chemoresistance on BC by enhancing BC cell autophagy, which was achieved by limiting NF1 expression to induce the HSF1/ATG7 pathway.

Extracellular vesicles derived from mesenchymal stem cells confer protection against intervertebral disc degeneration through a microRNA-217-dependent mechanism.

OBJECTIVE: Extracellular vesicles released by mesenchymal stem cells (MSC-EVs) can be applied to alleviate intervertebral disc degeneration (IVDD) by curbing apoptosis of nucleus pulposus cells (NPCs). The current study aims to evaluate the effect of MSC-EVs on NPC apoptosis and IVDD and the related regulatory mechanisms involving microRNA (miR)-217. METHOD: Expression of miR-217 was examined in tumor necrosis factor-α (TNF-α)-induced NPCs and MSC-EVs, followed by identification in the relationship between miR-217, enhancer of zeste homolog 2 (EZH2) and forkhead box O-3 (FOXO3). After isolation of EVs from MSCs and subsequent co-culture with NPCs, we assessed effects of miR-217 on NPC viability, autophagy, senescence and apoptosis along with extracellular matrix (ECM) degradation. Further in vivo experiments were conducted in rat models of IVDD to substantiate the effect of miR-217 on IVDD. RESULTS: Poor miR-217 expression was found in TNF-α-induced NPCs, while high miR-217 expression was identified in MSC-EVs (P < 0.05). MSC-EVs transferred miR-217 to NPCs and increased its expression, thus attenuating NPC apoptosis and ECM degradation (elevated collagen II and aggrecan but reduced MMP13 and ADAMTS5) (P < 0.05). miR-217 targeted EZH2, and EZH2 bound to the FOXO3 promoter and consequently downregulated its expression. FOXO3 restrained NPC apoptosis and ECM degradation by stimulating cell autophagy (P < 0.05). Furthermore, in vivo experimental results confirmed the suppressive role of miR-217 shuttled by MSC-EVs in IVDD. CONCLUSION: Overall, the delivery of miR-217 may be a novel mechanism underlying the effect of MSC-EVs on NPC apoptosis and ECM degradation following IVDD.

miR-217-5p suppresses epithelial-mesenchymal transition and the NF-κB signaling pathway in breast cancer via targeting of metadherin.

MicroRNAs (miRNAs) have been associated with a number of human malignancies, including breast cancer (BC). However, the expression, biological function and fundamental underlying mechanism of miR-217-5p in BC remain unclear. Therefore, in the present study, the expression levels of miR-217-5p and metadherin (MTDH) were examined in BC tissues and BC cell lines using reverse transcription-quantitative PCR. Cell Counting Kit-8 assays, cell proliferation, wound healing assays, Transwell assays and western blotting were used to examine the effects of miR-217-5p on cell proliferation, migration, the epithelial-mesenchymal transition (EMT) and NF-κB signaling pathway expression. The direct relationship between miR-217-5p and MTDH was assessed using a dual-luciferase reporter assay. The results demonstrated that significantly reduced expression levels of miR-217-5p but significantly increased mRNA expression levels of MTDH were observed in BC tissues from 35 patients with BC compared with non-tumor breast tissues. Furthermore, BC cell lines SK-BR3 and BT549 expressed miR-217-5p at markedly lower levels and MTDH at markedly higher levels compared with the breast epithelial MCF10A cell line. miR-217-5p overexpression significantly inhibited cell proliferation, invasion and migration and suppressed the EMT in BC cells. miR-217-5p overexpression also inhibited the NF-κB signaling pathway by markedly decreasing p65 mRNA and protein expression levels but significantly increasing IκBα expression levels. Furthermore, miR-217-5p knockdown markedly increased MTDH mRNA and protein expression levels. The expression levels of miR-217-5p were negatively correlated with those of MTDH in BC tissues. These results suggested that restoration of MTDH expression levels could potentially attenuate the inhibitory effects of miR-217-5p overexpression on BC cell proliferation. Therefore, in conclusion miR-217-5p overexpression may inhibit cell migration, invasion, the EMT and NF-κB signaling pathway in BC via targeting of MTDH. miR-217-5p may serve as an important potential target in BC therapy.

Knockdown of Circ_0000144 Suppresses Cell Proliferation, Migration and Invasion in Gastric Cancer Via Sponging MiR-217.

Previous studies have uncovered the role of circ_0000144 in various tumors. Here, we investigated the function and mechanism of circ_0000144 in gastric cancer (GC) progression. The expression of circ_0000144 in GC tissues and cells was detected through quantitative real-time polymerase chain reaction (qRT-PCR) method. Gain- and loss-of-function experiments including colony formation, wound healing and transwell assays were performed to examine the role of circ_0000144 in GC cells. Furthermore, western blot was conducted to determine the expressions of epithelial mesenchymal transition (EMT)-related proteins. The interaction between circ_0000144 and miR-217 was analyzed by bioinformatic analysis and luciferase reporter assays. The circ_0000144 expression was obviously upregulated in GC tissues and cells. Silencing of circ_0000144 inhibited cell proliferation, migration and invasion of GC cells, but ectopic expression of circ_0000144 showed the opposite results. Moreover, circ_0000144 sponged miR-217, and rescue assays revealed that silencing miR-217 expression reversed the inhibitory effect of circ_0000144 knockdown on the progress of GC. Our findings reveal that circ_0000144 inhibition suppresses GC cell proliferation, migration and invasion via absorbing miR-217, providing a new biomarker and potential therapeutic target for treatment of GC.

miR-217 through SIRT1 regulates the immunotoxicity of cadmium in Cyprinus carpio.

MicroRNAs (miRNAs) play a critical role in regulating the response of animals exposed to heavy metal stress. As a globally dispersed heavy metal in aquatic ecosystems, cadmium (Cd) is highly toxic to many aquatic species. However, little is known about the miRNA response to Cd stress in fish. To investigate the regulatory effect of miRNAs in response to Cd, common carp (Cyprinus carpio) were exposed to Cd2+-containing water (0.005 mg/L, 0.05 mg/L, 0.5 mg/L) for 30 days. After exposure, Cd2+ contents were significantly higher in the kidneys of C. carpio compared to other tissues, when exposed to 0.5 mg/L Cd2+. Hematoxylin and eosin staining images revealed that elevated Cd induced inflammatory damage in the kidneys of C.carpio. Further, miRNA sequencing revealed nine differentially expressed miRNAs (miR-217, miR-205 and seven novel miRNAs) in the kidneys, between 0.5 mg/L Cd2+ exposure and control groups. Potential target mRNAs of miRNAs suggest that miR-217 is involved in immunotoxicity. miR-217 agomir was intraperitoneally administered to C. carpio and RT-PCR revealed that the expression of IL-8 and SIRT1 decreased, while TLR-4, TRAF6, NF-kB, TNF-α, IL-1ß, and TGF-ß increased in the kidneys of C.carpio. Additionally, the expression of SIRT1 decreased, while the expression of other mRNAs increased in kidneys of C. carpio exposed to Cd. According to mRNAs expression in the agomir and Cd treatment, miRNAs inhibit the expressions of target mRNAs. These results demonstrate that miR-217 via SIRT1 plays a regulatory role in the immunotoxicity of Cd to C. carpio.

LINC00467 facilitates osteosarcoma progression by sponging miR­217 to regulate KPNA4 expression.

Osteosarcoma (OS) is a musculoskeletal malignancy that originates from interstitial cells. An increasing number of studies have verified that long non­coding RNAs (lncRNAs) participate in the progression of numerous types of cancer. It has been reported that LINC00467 is a cancer­promoting gene in some types of cancer; however, the regulatory mechanism of LINC00467 in OS remains unknown. In the present study, reverse transcription-quantitative PCR was used to determine LINC00467 expression in OS tissues and cells. Additionally, the impact of LINC00467­knockdown on OS cell proliferation, migration and invasion was analyzed using Cell Counting Kit­8, colony formation and Transwell assays, as well as western blot analysis. RNA pulldown and luciferase reporter assays were conducted to investigate the regulatory mechanism of LINC00467 in OS. The results delineated that LINC00467 expression was elevated in OS tissues and cells, and that high LINC00467 expression was associated with a poor prognosis in patients with OS. LINC00467 inhibition suppressed OS progression by inhibiting cell proliferation, migration, invasion and epithelial­mesenchymal transition. LINC00467 served as a molecular sponge for microRNA (miR)­217, while karyopherin subunit α4 (KPNA4) was a downstream target gene of miR­217. Moreover, the overexpression of KPNA4 reversed the inhibitory effects of LINC00467 inhibition on OS progression. Therefore, the present study elucidated the potential mechanism of LINC00467 in OS and indicated that LINC00467 exerted its carcinogenic effects on OS through the miR­217/KPNA4 axis, implying that LINC00467 may be a novel potential therapeutic target for OS.

CircRNA-100284 activates aurora kinase B by inducing methylation of HSP70 via microRNA-217 to promote proliferation of bladder cancer cells.

OBJECTIVE: The malignant transformation of normal bladder cells (SV-HUC-1) was induced by arsenite to explore the possible mechanism of circRNA-100284 influencing bladder cancer cell proliferation. METHODS: Normal bladder SV-HUC-1 cells were cultured with 2 µM arsenite to induce malignant transformation. After 0, 3, 6, 12, and 24 h of culture, the expression level of circRNA-100284 in cells was detected by quantitative real-time PCR. Western blotting assays were used to detect the expression levels of EZH2 and cyclin-D1 proteins in cells treated with different media. Cell cycle was analyzed by flow cytometry. In addition, through cell transfection and CCK-8 experiments, the effect and mechanism of circRNA-100284 targeting microRNA-217 on proliferation was determined. The interaction between HSP70 methylation and Aurora-B was determined by Western blotting and immunoprecipitation experiments. RESULTS: With prolonged contact time with arsenite, the expression level of circRNA-100284 in cells increased continuously (P < 0.05). Western blotting assays showed that the expression levels of EZH2 and cyclin-D1 proteins in arsenite-transformed cells increased. Flow cytometry and CCK-8 showed that circRNA-100284 accelerated cell cycle transition and cell proliferation through miR-217. Finally, after culturing human bladder cancer T24 cells, combined with immunoprecipitation and in vitro kinase experiments, it was found that K561- dimethyl HSP70 activated Aurora-B, thus promoting the proliferation of bladder cancer cells. CONCLUSION: CircRNA-100284 activates aurora kinase B by inducing methylation of HSP70 via microRNA-217 to promote the proliferation of bladder cancer cells.

Cullin 4B regulates cell survival and apoptosis in clear cell renal cell carcinoma as a target of microRNA-217.

Cullin 4B (CUL4B) was reported to be closely related to the progression of some tumors, but its function in clear cell renal cell carcinoma (ccRCC) has not been reported. Our present study found CUL4B was upregulated in ccRCC, and CUL4B knockdown markedly inhibited ccRCC cell growth and induced apoptosis. In addition, CUL4B knockdown markedly inhibited antiapoptotic proteins' expression in ccRCC cells, including Mcl-1 and Bcl-2, and silenced CUL4B also induced the cleavages of PARP, an important index of apoptosis. We also confirmed microRNA-217 (miR-217) was downregulated in ccRCC tumor tissues, and negatively correlated with CUL4B expression. Further investigations revealed miR-217 targeted CUL4B and markedly inhibited its expression in ccRCC cells. In addition, overexpression of miR-217 by mimics significantly suppressed ccRCC cell growth. In contrast, enforced expression of CUL4B significantly abolished miR-217-induced cell survival inhibition in ccRCC cells. In conclusion, our present results suggested targeting miR-217-CUL4B axis would be a promising strategy for ccRCC treatment.

MicroRNA-217 modulates inflammation, oxidative stress, and lung injury in septic mice via SIRT1.

Inflammation and oxidative stress contribute to the initiation and progression of septic lung injury. MicroRNA-217 (miR-217) is proved to be involved in controlling inflammatory response and oxidative stress, yet its role and underlying mechanism in the pathogenesis of septic lung injury remain elusive. Caecal ligation and puncture surgery were performed to generate sepsis in vivo and mice were kept for 12 h to imitate septic lung injury. Next, mice were administrated with miR-217 antagomir or agomir to decrease or increase the expression of miR-217 in lung tissue. Moreover, primary peritoneal macrophages were separated and incubated with lipopolysaccharide (LPS) to further verify the role of miR-217 in vitro. miR-217 was upregulated in septic lungs and primary macrophages. miR-217 antagomir alleviated, whereas miR-217 agomir aggravated inflammation and oxidative stress in septic mice and LPS-stimulated macrophages. Further detection identified SIRT1 was responsible for miR-217 antagomir-mediated anti-inflammatory and anti-oxidant effects, and SIRT1 inhibition abolished the beneficial effects of miR-217 antagomir in vivo and in vitro. Our data defined miR-217 as a therapeutic target for treating septic lung injury.

MicroRNA-217 ameliorates inflammatory damage of endothelial cells induced by oxidized LDL by targeting EGR1.

Oxidized low-density lipoprotein (ox-LDL) modulates gene transcription and expression and induces the development of endothelium inflammation and endothelial dysfunction, in which microRNAs (miRNAs) play a crucial role. However, the mechanism of ox-LDL in inflammatory damage of endothelial cells still remains elusive. Herein, we focused on the effect of hsa-miR-217-5p (miR-217) on endothelial dysfunction induced by ox-LDL by targeting early growth response protein-1 (EGR1). In the present study, 31 upregulated miRNAs and 59 downregulated miRNAs (Fold Change > 2, P value < 0.05) were identified after 6 h of 80 µg/mL ox-LDL exposure in human aortic endothelial cells (HAECs) by small RNA sequencing, including miR-217 that was significantly decreased (FC = 0.2787, P value = 5.22E-16). MiR-217 knockdown inhibited cell proliferation and increased level of IL-6, IL-1ß, ICAM-1 and TNF-α, while overexpression of miR-217 relieved the growth inhibition induced by ox-LDL and demonstrated anti-inflammatory effect in HAECs. EGR1 was predicted as a potential candidate target gene of miR-217 by TargetScan. The subsequent dual-luciferase reporter assay confirmed the direct binding of miR-217 to 3'UTR of EGR1. And EGR1 expression was negatively correlated with the level of miRNA-217 in HAECs after exposure to ox-LDL. Overexpression of EGR1 recapitulated the effects of miR-217 knockdown on cell proliferation inhibition and inflammation in HAECs, while knockdown EGR1 relieved the proliferative inhibition and demonstrated anti-inflammatory effect in ox-LDL-induced HAECs. The present study confirmed miR-217 ameliorates inflammatory damage of endothelial cells induced by oxidized LDL by targeting EGR1.

circRNA_100859 functions as an oncogene in colon cancer by sponging the miR-217-HIF-1α pathway.

Circular RNAs (circRNAs) play an important role in cancer development and progression by regulating gene expression. The present study aimed to investigate the function of circRNA_100859 in colon cancer. circRNA expression profiles from a human circRNAs chip were analyzed. The effects of circRNA_100859 on cell proliferation and apoptosis were assessed in vitro and interactions between circRNA_100859 and its micro (mi)RNA and target genes were analyzed. The diagnostic and prognostic significance of circRNA_100859 was also investigated. It was identified that circRNA_100859 was overexpressed in colon cancer tissues and promoted cell proliferation and inhibited cell apoptosis. Additionally, bioinformatics and a dual-luciferase reporter assay confirmed that circRNA_100859 acted as a miR-217 sponge, and miR-217 directly targeted hypoxia-inducible factor (HIF)-1α. Rescue assays demonstrated that HIF-1α protein and mRNA expression levels and cell proliferation were regulated by the circRNA_100859/miR-217 axis (P<0.05). Furthermore, statistical analysis showed that the circRNA_100859-miR-217-HIF-1α axis was associated with Tumor-Node-Metastasis (TNM) stage, histological grade, and KRAS mutations, and also showed high diagnostic and prognostic value for patients with colon cancer (P<0.05). Therefore, it was concluded that circRNA_100859 functions as an oncogene in colon cancer by sponging the miR-217-HIF-1α pathway. In addition, the circRNA_100859-miR-217-HIF-1α axis may serve as a novel diagnostic and prognostic biomarker for patients with colon cancer.

miR­217­5p regulates myogenesis in skeletal muscle stem cells by targeting FGFR2.

MicroRNA-217-5p (miR-217-5p) has been implicated in cell proliferation; however, its role in skeletal muscle stem cells (SkMSCs) remains unknown. The present study aimed to explore the roles of miR­217­5p in the biological characteristics of SkMSCs. SkMSCs were identified by cell surface markers using flow cytometry. The present study observed that miR­217­5p mimics accelerated the proliferation and suppressed the differentiation in SkMSCs. In addition, the results of the present study revealed that fibroblast growth factor receptor 2 (FGFR2) was a target of miR­217­5p, as miR­217­5p bound directly to the 3'­untranslated region of FGFR2 mRNA, resulting in increased FGFR2 mRNA and protein levels. In addition, the present study suppressed the expression of FGFR2 in SkMSCs using a selective FGFR inhibitor AZD4547 and detected the efficiency of inhibition by reverse transcription­quantitative PCR and western blotting. miR­217­5p levels were positively associated with FGFR2 expression, which was upregulated and accelerated the proliferation of SkMSCs compared with that of the miR­NC group. Collectively, these results demonstrated that miR­217­5p may act as a myogenesis promoter in SkMSCs by directly targeting FGFR2 and may regulate the myogenesis of these cells.

miR­217 and miR­543 downregulation mitigates inflammatory response and myocardial injury in children with viral myocarditis by regulating the SIRT1/AMPK/NF­κB signaling pathway.

The aim of the present study was to investigate the expression levels and roles of microRNA (miR)­217 and miR­543 in viral myocarditis, and to examine their underlying mechanisms. Coxsackievirus B3 (CVB3) was used to establish in vivo and in vitro models of viral myocarditis. The levels of miR­217 and miR­543 were detected using reverse transcription­quantitative PCR. The association between miR­217 and miR­543 and sirtuin­1 (SIRT1) was predicted and confirmed by TargetScan and dual­luciferase reporter assay. Cell viability was detected using Cell Counting Kit­8 assay, and cell apoptosis was measured by analyzing the expression levels of Bcl­2 and Bax, and by flow cytometry. In addition, the synthesis of various pro­inflammatory factors was determined by ELISA. In addition, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were measured in cardiomyocytes following transfection and CVB infection. miR­217 and miR­543 were found to be highly expressed in the peripheral blood of pediatric patients with viral myocarditis, in the peripheral blood and myocardial tissues of viral myocarditis mice and in CVB3­infected cardiomyocytes. SIRT1 was found to be a target of both miR­217 and miR­543, and SIRT1 expression level was downregulated in viral myocarditis. Further analysis indicated that the reduced cell viability, increased cell apoptosis, enhanced synthesis of inflammatory factors, increased MDA content and decreased SOD activity associated with myocarditis were significantly reversed after inhibition of miR­217 or miR­543. Importantly, the present results showed that all the effects of miR­217 and miR­543 inhibition on cardiomyocytes were significantly suppressed following SIRT1 knockdown. Collectively, the present data indicated that miR­217 and miR­543 were significantly upregulated in viral myocarditis, and downregulation of miR­217 and miR­543 attenuated CVB3 infection­induced cardiomyocyte injury by targeting SIRT1. miR­217 and miR­543 may be potential therapeutic targets for developing novel viral myocarditis treatments in the future.

Baicalin augments the differentiation of osteoblasts via enhancement of microRNA-217.

Baicalin (BAI), a sort of flavonoid monomer, acquires from Scutellaria baicalensis Georgi, which was forcefully reported in diversified ailments due to the pleiotropic properties. But, the functions of BAI in osteoblast differentiation have not been addressed. The intentions of this study are to attest the influences of BAI in the differentiation of osteoblasts. MC3T3-E1 cells or rat primary osteoblasts were exposed to BAI, and then cell viability, ALP activity, mineralization process, and Runx2 and Ocn expression were appraised through implementing CCK-8, p-nitrophenyl phosphate (pNPP), Alizarin red staining, western blot, and RT-qPCR assays. The microRNA-217 (miR-217) expression was evaluated in MC3T3-E1 cells or rat primary osteoblasts after BAI disposition; meanwhile, the functions of miR-217 in BAI-administrated MC3T3-E1 cells were estimated after miR-217 inhibitor transfection. The impacts of BAI and miR-217 inhibition on Wnt/ß-catenin and MEK/ERK pathways were probed to verify the involvements in BAI-regulated the differentiation of osteoblasts. BAI accelerated cell viability, osteoblast activity, and Runx2 and Ocn expression in MC3T3-E1 cells or rat primary osteoblasts, and the phenomena were mediated via activations of Wnt/ß-catenin and MEK/ERK pathways. Elevation of miR-217 was observed in BAI-disposed MC3T3-E1 cells or rat primary osteoblasts, and miR-217 repression annulled the functions of BAI in MC3T3-E1 cell viability and differentiation. Additionally, the activations of Wnt/ß-catenin and MEK/ERK pathways evoked by BAI were both restrained by repression of miR-217. These explorations uncovered that BAI augmented the differentiation of osteoblasts via activations of Wnt/ß-catenin and MEK/ERK pathways by ascending miR-217 expression.

microRNA-217 suppressed epithelial-to-mesenchymal transition through targeting PTPN14 in gastric cancer.

BACKGROUND: Gastric cancer (GC) is the one of most common malignancies and its mechanism of metastasis remains unclear. The study was designed to investigate the effects of microRNA-217 on epithelial-to-mesenchymal transition. METHODS: The expression levels of miR-217 in GC were assayed by real-time qPCR. Metastasis and invasion of cancer cell were assayed by transwell chamber. Double luciferase reporter gene was used to verify the target regulatory relationship between microRNA-217 and tyrosine-protein phosphatase non-receptor type 14 (PTPN14) on gastric cell lines. Epithelial-to-mesenchymal transition (EMT) markers were assayed by Western blot. RESULTS: We found that miR-217 had a low level expression in gastric tumor tissues of 40 patients with GC, and a lower expression in the gastric tumor tissues of the patients with GC metastasis. Moreover, miR-217 markedly suppressed the metastasis and invasion of gastric cancer cell line in vitro. Furthermore, miR-217 inhibited the expression of PTPN14 by directly targeting its 3'UTR. Moreover, the down-regulation of PTPN14 reduced the metastasis and invasion, whereas up-regulation of PTPN14 led to the enhanced metastases and invasion of gastric cells. miR-217 induced the down-regulation of PTPN14 and inhibited the EMT in gastric cancer cells. CONCLUSION: miR-217 inhibited the EMT through directly targeting to the 3'UTR of PTPN14.

MicroRNA-217/138-5p downregulation inhibits inflammatory response, oxidative stress and the induction of neuronal apoptosis in MPP+-induced SH-SY5Y cells.

Parkinson's disease (PD) is a common neurodegenerative disease. Various microRNAs (miRNAs) have been reported to play important roles in cell growth regulation and inflammatory reaction. However, the detailed roles of miR-217 and miR-138-5p in PD progression remain to be investigated. In the present study, we explored the effects and underlying mechanisms of miR-217 and miR-138-5p on the inflammatory response, oxidative stress and the induction of neuronal apoptosis in an in vitro PD cell line model induced by 1-methyl-4-phenylpyridinium (MPP+). The results of the biological software analysis and luciferase reporter assays demonstrated that sirtuin 1 (SIRT1) was a direct target of miR-217 and miR-138-5p. MiR-217 and miR-138-5p exhibited a negative regulatory effect on the expression of SIRT1 in SH-SY5Y cells. In addition, the expression levels of miR-217 and miR-138-5p were increased, and SIRT1 expression was decreased in SH-SY5Y cells following MPP+ treatment. Loss-of-function experiments indicated that treatment of the cells with inhibitors against miR-217 and miR-138-5p promoted cell viability and superoxide dismutase (SOD) activity, while the induction of cell apoptosis, lactate dehydrogenase (LDH) activity, and the reactive oxygen species (ROS) release were inhibited in MPP+-induced SH-SY5Y cells. Moreover, the expression levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were reduced in MPP+-induced SH-SY5Y cells. Treatment of the cells with the miR-217 and the miR-138-5p inhibitors significantly inhibited the ratio of phosphorylated (p)-p65/p65 expression levels in MPP+-induced SH-SY5Y cells. In summary, the present study demonstrated that the miR-217/miR-138-5p/SIRT1 axis was involved in the progression of PD by regulating the inflammatory response and the induction of oxidative stress and neuronal apoptosis. The data provide new diagnostic and therapeutic strategies for PD patients.

Chemerin-induced angiogenesis and adipogenesis in 3 T3-L1 preadipocytes is mediated by lncRNA Meg3 through regulating Dickkopf-3 by sponging miR-217.

PURPOSE: Obesity is often caused by the excess adipogenesis and regulated by long non-coding RNAs (lncRNAs) and microRNAs (miRNAs). We performed this study to investigate the influence of Meg3 expression on adipogenesis and also the Meg3/miR-217/Dkk3 axis-mediated molecular mechanism in adipogenesis and angiogenesis. METHODS: 3 T3-L1 preadipocytes were incubated with chemerin and transfected with Meg3-overexpressing (OE-Meg3) and Dkk3-overexpressing (OE-Dkk3) plasmids, siRNAs, and miR-217 mimics, inhibitor and scrambled sequences for 48 h or 72 h. The changes in cell proliferation, adipogenesis and angiogenesis ability in 3 T3-L1 preadipocytes was detected by using the corresponding assay. The expressions of related proteins were detected via western blot. RESULTS: Chemerin decreased miR-217 expression and increased Meg3 expression, meanwhile promoted the proliferation, adipogenesis and angiogenesis in 3 T3-L1 preadipocytes. Besides, OE-Meg3 exerted the synergistic effect on 3 T3-L1 preadipocytes when co-treated with chemerin. The target interactions between Meg3 and miR-217 as well as between miR-217 and Dkk3 were validated using dual-luciferase reporter system. SiMeg3 antagonized chemerin-induced changes, while the addition of miR-217 inhibitor attenuated siMeg3-induced changes in 3 T3-L1 preadipocytes. The proliferation, adipogenesis and angiogenesis in 3 T3-L1 preadipocytes were suppressed by miR-217 mimics, while promoted by the OE-Dkk3 Chemerin promoted the expression of fatty acid binding protein 4 and vascular endothelial growth factor (VEGF) proteins, and decreased the expression of cyclin D1, c-Myc, and ß-catenin proteins. Meanwhile, these effects were further enhanced by OE-Meg3 or OE-Dkk3. However, the transfection of siMeg3, or miR-217 mimics, or siDkk3 reversed the previous changes. CONCLUSIONS: Meg3/miR-217/Dkk3 induced adipogenesis and angiogenesis in 3 T3-L1 preadipocytes via activating VEGF signaling pathway and inhibiting Wnt/ß-catenin signaling pathway.

Circular RNA hsa_circ_0023404 promotes proliferation, migration and invasion in non-small cell lung cancer by regulating miR-217/ZEB1 axis.

BACKGROUND: Circular RNAs (circRNAs) have been considered as key regulators of cancer biology. However, the functional role of hsa_circ_0023404 in non-small cell lung cancer (NSCLC) and its regulatory mechanism are still almost unknown. METHODS: The expression of hsa_circ_0023404, miR-217 and zinc finger E-box-binding homeobox 1 (ZEB1) was evaluated by quantitative real-time polymerase chain reaction. The role of hsa_circ_0023404 in NSCLC progression was determined using cell count kit-8 assay, transwell migration and invasion assay. Luciferase reporter assay was performed to assess the interaction of hsa_circ_0023404, miR-217 and ZEB1 in NSCLC cells. RESULTS: The expression of hsa_circ_0023404 was upregulated in NSCLC tissues, as well as in NSCLC cell lines. High hsa_circ_0023404 expression predicted short overall survival in NSCLC. Functionally, knockdown of hsa_circ_0023404 inhibited the proliferation, migration and invasion of NSCLC cells. In the further molecular mechanism study, hsa_circ_0023404 was shown to interact with miR-217/ZEB1 axis to contribute to the growth of NSCLC cells. CONCLUSION: hsa_circ_0023404 promotes the proliferation, migration and invasion of NSCLC cells by regulating miR-217/ZEB1 axis, providing a fresh perspective on circRNAs in NSCLC development.