Direct Target Of miR-206 Research Articles

MicroRNA-183 promotes the proliferation and metastasis of renal cell carcinoma through targeting Dickkopf-related protein 3.

Renal cell carcinoma (RCC) is insensitive to conventional chemotherapy and radiotherapy, and its prognosis remains poor. Targeted therapy is a novel technique for the treatment of RCC. The present study aimed to determine the precise effects of microRNA-183 (miR-183) on RCC. Reverse transcription-quantitative polymerase chain reaction analysis was conducted in order to analyze the expression level of miR-183 in RCC cell lines. Cell transfection, viability assays and invasion assays were also performed, followed by western blot analysis and a luciferase reporter assay, in order to examine the effects of miR-183. The expression of miR-183 was upregulated in all four RCC cell lines compared with the immortalized normal proximal tubule epithelial HK-2 cell line. The cell viability and invasion assays demonstrated that decreased expression of miR-183 suppressed RCC cell proliferation and invasion in vitro. Furthermore, the present study identified that Dickkopf-related protein-3 (DKK-3) was a direct target of miR-183 in RCC. The results demonstrated that miR-183 functioned as an oncogene by downregulating DKK-3 expression and that it provided a potential diagnostic, prognostic and therapeutic target for RCC.

MiR-183 inhibits osteosarcoma cell growth and invasion by regulating LRP6-Wnt/β-catenin signaling pathway

Recent studies have demonstrated that microRNA-183 (miR-183) deregulates and plays major roles in many tumors. However, the role of miR-183 in osteosarcoma (OS) pathogenesis is still largely unknown. In this study, we first over-expressed and knocked down miR-183 in MG63 and U20S cells, respectively. Functional analyses showed that ectopic expression of miR-183 suppressed MG63 cell growth, migration, and invasion in vitro and in vivo, whereas knockdown of endogenous miR-183 in U20S cells significantly enhanced these abilities. Next, we characterized low density lipoprotein receptor-related protein 6 (LRP6) as a direct target of miR-183 that interacted with the 3′-untranslated region of LRP6. Furthermore, ectopic expression of LRP6 significantly abrogated the tumor-suppressive effect induced by miR-183. Finally, miR-183 regulated the tumor-suppressive functions in MG63 cells by suppressing the LRP6-Wnt/β-catenin signaling pathway. Therefore, our study demonstrates that miR-183 is a tumor suppressor microRNA that plays a major role in OS.

Novel Therapy for Glioblastoma Multiforme by Restoring LRRC4 in Tumor Cells: LRRC4 Inhibits Tumor-Infitrating Regulatory T Cells by Cytokine and Programmed Cell Death 1-Containing Exosomes.

Glioblastoma multiforme (GBM) is a heterogeneous malignant brain tumor, the pathological incidence of which induces the accumulation of tumor-infiltrating lymphocytes (TILs). As a tumor suppressor gene, LRRC4 is absent in GBM cells. Here, we report that the recovery of LRRC4 in GBM cells inhibited the infiltration of tumor-infiltrating regulatory T cells (Ti-Treg), promoted the expansion of tumor-infiltrating effector T (Ti-Teff) cells and CD4+CCR4+ T cells, and enhanced the chemotaxis of CD4+CCR4+ T cells in the GBM immune microenvironment. LRRC4 was not transferred into TILs from GBM cells through exosomes but mainly exerted its inhibiting function on Ti-Treg cell expansion by directly promoting cytokine secretion. GBM cell-derived exosomes (cytokine-free and programmed cell death 1 containing) also contributed to the modulation of LRRC4 on Ti-Treg, Ti-Teff, and CD4+CCR4+ T cells. In GBM cells, LRRC4 directly bound to phosphoinositide-dependent protein kinase 1 (PDPK1), phosphorylated IKKβser181, facilitated NF-κB activation, and promoted the secretion of interleukin-6 (IL-6), CCL2, and interferon gamma. In addition, HSP90 was required to maintain the interaction between LRRC4 and PDPK1. However, the inhibition of Ti-Treg cell expansion and promotion of CD4+CCR4+ T cell chemotaxis by LRRC4 could be blocked by anti-IL-6 antibody or anti-CCL2 antibody, respectively. miR-101 is a suppressor gene in GBM. Our previous studies have shown that EZH2, EED, and DNMT3A are direct targets of miR-101. Here, we showed that miR-101 reversed the hypermethylation of the LRRC4 promoter and induced the re-expression of LRRC4 in GBM cells by directly targeting EZH2, EED, and DNMT3A. Our results reveal a novel mechanism underlying GBM microenvironment and provide a new therapeutic strategy using re-expression of LRRC4 in GBM cells to create a permissive intratumoral environment.

MicroRNA-126 Regulates Inflammatory Cytokine Secretion in Human Gingival Fibroblasts Under High Glucose via Targeting Tumor Necrosis Factor Receptor Associated Factor 6.

MicroRNAs (miRs) play a crucial role in inflammatory diseases, including periodontitis. Meanwhile, miRs act as biomarkers for predicting diabetes mellitus (DM). However, the regulatory mechanism of miR-126 on development of periodontitis in patients with DM still remains unclear. Human gingival fibroblasts were cultured with low (5.5 mmol/L), medium (15 mmol/L), and high (25 mmol/L) glucose, respectively. Expressions of miR-126, tumor necrosis factor (TNF) receptor associated factor (TRAF) 6, and related cytokines were analyzed by real-time polymerase chain reaction (PCR). After transfection with miR-126 mimic, PCR and western blot were performed to detect level of TRAF6, and luciferase reporter assay confirmed if TRAF6 is the direct target of miR-126. Production of cytokines was measured using enzyme-linked immunosorbent assay. Increased glucose significantly suppressed miR-126 expression in human gingival fibroblasts (P <0.05). Also, high glucose increased TRAF6, interleukin (IL)-6, TNF-α, and chemical chemokine ligand (CCL) 2 levels, whereas it decreased IL-10 level. MiR-126 mimic significantly decreased TRAF6 mRNA and protein levels under high glucose (P <0.05). Also, miR-126 directly targeted TRAF6 through binding to its 3' untranslated region in human gingival fibroblasts. Overexpression of miR-126 significantly abrogated high glucose-induced secretion of proinflammatory cytokines such as IL-6, TNF-α, and CCL2 and promoted production of IL-10. These data suggest that miR-126 inhibits inflammation of human gingival fibroblasts under high glucose through targeting TRAF6, which may be a potential therapeutic target for periodontitis concomitant with DM.

MiR-101 alleviates chemoresistance of gastric cancer cells by targeting ANXA2

BackgroundChemoresistance remains a main clinical obstacle in the treatment of gastric cancer (GC). microRNAs have been revealed to participate in the regulation of drug resistance in a variety of cancers. However, little is known about the function and detailed molecular mechanism of miR-101 in GC chemoresistance. MethodsThe expressions of miR-101 and Annexin A2 (ANXA2) in GC tissues and cells were detected by qRT-PCR and western blot. The effects of miR-101 overexpression on P-glycoprotein (P-gp) at mRNA and protein levels, cell viability, and apoptosis in drug-resistant GC cells were examined by qRT-PCR, western blot, MTT and flow cytometry analysis, respectively. Luciferase reporter assay, RNA immunoprecipitation (RIP) and qRT-PCR were applied to confirm whether miR-101 could target ANXA2 and regulate its expression. Rescue experiment was performed to verify the mechanism by which miR-101 involved in chemoresistance. ResultsmiR-101 was downregulated in GC tissues and drug-resistant GC cells. A negative correlation between miR-101 and ANXA2 expression was observed in GC tissues. Forced expression of miR-101 significantly reduced P-gp expression at mRNA and protein levels in drug-resistant GC cells. Overexpression of miR-101 enhanced sensitivity to cisplatin (DDP) or vincristine (VCR) via viability inhibition and apoptosis promotion. ANXA2 was identified as a direct target of miR-101 and miR-101 negatively regulated ANXA2 expression. Moreover, ectopic expression of ANXA2 reversed the effect of miR-101 on P-gp expression, cell viability and apoptosis. ConclusionmiR-101 alleviated chemoresistance of gastric cancer cells by targeting ANXA2. Therefore, targeting miR-101 may be a potential therapeutic approach for drug-resistant GC.

MicroRNA-206 regulates vascular smooth muscle cell phenotypic switch and vascular neointimal formation.

MiR-206 has been found to play a critical role in skeletal muscle proliferation, differentiation, and regeneration. However, little is known about the function of miR-206 in vascular smooth muscle cells (VSMCs) biology. In this study, we will investigate its roles in phenotypic switching of VSMCs and neointimal lesion formation. First, we identified the expression of miR-206 in VSMCs treated with various concentrations of TGFβ1 and in rat carotid arteries after angioplasty by using qPCR. TGFβ1 inhibited the expression of miR-206 and TGFβ1 inhibitor induced miR-206 expression. In VSMCs of injured vascular walls, miR-206 expression was upregulated. Then, we overexpressed miR-206 using lentivirus Lv-rno-mir-206 and knocked down miR-206 using LV-rno-mir-206-inhibitor in rat carotid arteries after angioplasty. Overexpression of miR-206 resulted in decreasing SM22α expression in VSMCs in vitro and knockdown of miR-206 suppressed neointimal lesion formation in vivo. Finally, ZFP580 (zinc finger protein 580) was identified as the direct target of miR-206 in VSMCs by using luciferase report assay. The results indicate that miR-206 is involved in phenotypic switching of VSMCs and neointimal lesion formation after angioplasty through targeting ZFP580. These findings may provide a novel therapeutic target in post-angioplasty restenosis.

MiR-183 overexpression inhibits tumorigenesis and enhances DDP-induced cytotoxicity by targeting MTA1 in nasopharyngeal carcinoma.

MicroRNA 183 (miR-183) was identified to be downregulated in nasopharyngeal carcinoma spheroids and served as a tumor suppressor in nasopharyngeal carcinoma. However, the regulatory mechanism of miR-183 and its role in cisplatin (DDP) resistance in nasopharyngeal carcinoma cells are still unclear. The expression of miR-183 and metastasis-associated protein 1 at messenger RNA and protein levels in nasopharyngeal carcinoma tissues and cells was evaluated using quantitative reverse transcription real-time polymerase chain reaction and western blotting, respectively. CNE1 and CNE2 cells were transfected with miR-183 mimic, miR-183 inhibitor, pcDNA-metastasis-associated protein 1, or respective controls. The effects of miR-183 and metastasis-associated protein 1 overexpression on cell proliferation, invasion, and DDP-induced apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Transwell invasion assay, and flow cytometry analysis, respectively. Luciferase reporter assay was performed to explore whether miR-183 directly targeted metastasis-associated protein 1. Xenograft tumor experiment was applied to confirm the biological function of miR-183 in vivo. MiR-183 was downregulated in nasopharyngeal carcinoma tissues and cells and negatively correlated with metastasis-associated protein 1 expression. Ectopic expression of miR-183 markedly suppressed cell proliferation and invasion and strikingly enhanced DDP-induced apoptosis in nasopharyngeal carcinoma cells, whereas metastasis-associated protein 1 overexpression partially reversed these effects. Luciferase reporter assay demonstrated that metastasis-associated protein 1 was a direct target of miR-183. MiR-183 negatively regulated the expression of metastasis-associated protein 1 at both the messenger RNA and protein levels. Xenograft tumor experiment indicated that miR-183 overexpression repressed tumor growth and improved DDP-induced cytotoxicity in nasopharyngeal carcinoma cells in vivo. MiR-183 overexpression inhibited tumorigenesis and enhanced DDP-induced cytotoxicity by targeting metastasis-associated protein 1 in nasopharyngeal carcinoma, contributing to the development of novel therapeutic approaches for the treatment of clinical nasopharyngeal carcinoma patients.

LincRNA-p21 inhibits invasion and metastasis of hepatocellular carcinoma through miR-9/E-cadherin cascade signaling pathway molecular mechanism.

In the previous study, it was found that long intergenic noncoding RNA-p21 (lincRNA-p21) was downregulated in hepatocellular carcinoma (HCC) and lincRNA-p21 overexpression inhibited tumor invasion through inducing epithelial–mesenchymal transition. However, the underlying mechanism was not fully elaborated. In this study, lincRNA-p21 expression was measured in 12 paired HCC and nontumor adjacent normal tissues by quantitative real-time polymerase chain reaction. The effects of lincRNA-p21 on HCC cells were studied using lentivirus expressing lincRNA-p21 vector in vitro. The association between lincRNA-p21 level and miR-9 level was tested with the Spearman rank correlation. The effects of miR-9 on HCC cells were studied by using miR-9 inhibitor in vitro. Luciferase assay was used to validate the target of miR-9. The results showed that lincRNA-p21 was downregulated in human HCC tissues and cell lines. LincRNA-p21 overexpression significantly inhibited HCC cell migration and invasion in vitro. Besides, lincRNA-p21 negatively regulated miR-9 expression level, and miR-9 was upregulated in human HCC tissues and cells. MiR-9 knockdown inhibited HCC cell migration and invasion in vitro. Finally, the luciferase assay results showed that E-cadherin was a direct target of miR-9. The expression level of E-cadherin was found to be regulated by lincRNA-p21 and miR-9. Altogether, the results suggested that lincRNA-p21 inhibits migration and invasion of HCC cells through regulating miR-9-mediated E-cadherin cascade signaling pathway.

Regulation of actin-binding protein ANLN by antitumor miR-217 inhibits cancer cell aggressiveness in pancreatic ductal adenocarcinoma.

Analysis of our microRNA (miRNA) expression signature of pancreatic ductal adenocarcinoma (PDAC) revealed that microRNA-217 (miR-217) was significantly reduced in cancer tissues. The aim of this study was to investigate the antitumor roles of miR-217 in PDAC cells and to identify miR-217-mediated molecular pathways involved in PDAC aggressiveness. The expression levels of miR-217 were significantly reduced in PDAC clinical specimens. Ectopic expression of miR-217 significantly suppressed cancer cell migration and invasion. Transcription of actin-binding protein Anillin (coded by ANLN) was detected by our in silico and gene expression analyses. Moreover, luciferase reporter assays showed that ANLN was a direct target of miR-217 in PDAC cells. Overexpression of ANLN was detected in PDAC clinical specimens by real-time PCR methods and immunohistochemistry. Interestingly, Kaplan–Meier survival curves showed that high expression of ANLN predicted shorter survival in patients with PDAC by TCGA database analysis. Silencing ANLN expression markedly inhibited cancer cell migration and invasion capabilities of PDAC cell lines. We further investigated ANLN-mediated downstream pathways in PDAC cells. “Focal adhesion” and “Regulation of actin binding protein” were identified as ANLN-modulated downstream pathways in PDAC cells. Identification of antitumor miR-217/ANLN-mediated PDAC pathways will provide new insights into the potential mechanisms underlying the aggressive course of PDAC.

WBP2 modulates G1/S transition in ER+ breast cancer cells and is a direct target of miR-206.

The mechanisms underlying the oncogenic properties of WW domain binding protein 2 (WBP2) in breast cancer have not been fully understood. In this study, we explored the role of WBP2 in cell cycle regulation in ER+ breast cancer cells and how it is regulated in the cancer cells. The association between WBP2 expression and prognosis in ER+ breast cancer was assessed by data mining in Breast Cancer Gene-Expression Miner v4.0. Cell cycle was assessed by PI staining and flow cytometry. EdU staining was applied to visualize cells in S phase. The binding between miR-206 and WBP2 were verified by dual luciferase assay. CCK-8 assay and flow cytometric analysis were applied to assess the functional role of WBP2 and miR-206 in the cancer cells. High WBP2 expression correlates with higher risk of any events (AE) and metastatic relapse (MR) and also indicates shorter AE-free survival and MR-free survival in ER+ breast cancer patients. In both MCF-7 and BT474 cells, WBP can influence the expression of G1/S-related cell cycle proteins, including p21, CDK4, and cyclin D1. In addition, WBP2 overexpression resulted in facilitated G1/S transition, while WBP2 knockdown impaired the transition. The 3'UTR of WBP2 has a conserved miR-206 binding site. Functionally, miR-206 knockdown decreased tamoxifen sensitivity in tamoxifen-sensitive (TamS) MCF-7 cells, while miR-206 overexpression and WBP2 knockdown enhanced the sensitivity in tamoxifen-resistant (TamR) MCF-7 cells. Based on these findings, we infer that the miR-206/WBP2 axis can modulate tamoxifen sensitivity via regulating G1/S progression in ER+ breast cancer.

MiR-101 Enhances Cisplatin-Induced DNA Damage Through Decreasing Nicotinamide Adenine Dinucleotide Phosphate Levels by Directly Repressing Tp53-Induced Glycolysis and Apoptosis Regulator Expression in Prostate Cancer Cells.

Tp53-induced glycolysis and apoptosis regulator (TIGAR) enhances the pentose phosphate pathway, thereby contributing directly to DNA repair due to generation of nicotinamide adenine dinucleotide phosphate (NADPH) and ribose-5-phosphate, two key precursors of DNA synthesis and repair. Targetscan database showed that miR-101 was predicted to potentially target TIGAR. Therefore, we speculated that miR-101 could enhance cisplatin-induced DNA damage by directly repressing TIGAR expression in prostate cancer cells. We found that upregulation of miR-101 inhibited viability, induced apoptosis, increased glycolysis rate and fructose-2,6-bisphosphate levels, decreased glucose-6-phosphate dehydrogenase expression and NADPH levels, and enhanced cisplatin-induced DNA damage in prostate cancer cells. We also demonstrated that TIGAR was a direct target of miR-101 by using luciferase activity assay. Furthermore, this study revealed that the roles of knockdown of TIGAR were similar to miR-101 upregulation in prostate cancer cells. Taken together, miR-101 inhibited viability, induced apoptosis, reprogramed glucose metabolism, and enhanced cisplatin-induced DNA damage through decreasing NADPH levels by directly suppressing the expression of TIGAR in prostate cancer cells.

MiR-126 impairs the intestinal barrier function via inhibiting S1PR2 mediated activation of PI3K/AKT signaling pathway

BackgroundAberrant expression of miRNAs was a critical element in the pathogenesis of inflammatory bowel disease (IBD). This study aimed to explore the involvement and mechanism of miR-126 in IBD. MethodsIn this study, the endogenous expressions of miR-126, S1PR2 and S1P in the pathological tissues of patients with IBD were detected using qRT-PCR and western blot assay, respectively. The luciferase reporter gene assay was performed to confirm the targeting regulatory relation between miR-126 and S1PR2. The transendothelial electrical resistance assay was used to measured the value of TEER. ResultsThe expressions of miR-126, S1PR2 and S1P in the pathological tissues of IBD patients were significantly higher than that of the control group. Moreover, miR-126 overexpression contributed to intestinal mucosal barrier dysfunction in vitro. S1PR2 was a direct target of miR-126, and S1PR2 expression was negatively regulated by miR-126 in Caco-2 cells. However, S1PR2 activated by S1P had the protection effect for the integrity and permeability of intestinal mucosal barrier via a PI3K/Akt dependent mechanism. MiR-126 silencing possessed obvious protective effects on the intestinal barrier function, but these effects could be reversed by JTE-013 or LY294002. ConclusionMiR-126 down-regulated S1PR2 and then prevented the activation of PI3K/AKT signaling pathway, which ultimately could damage intestinal mucosal barrier function.

The effects of microRNA-183 promots cell proliferation and invasion by targeting MMP-9 in endometrial cancer.

MiRNAs are known to play important roles in cancer cell development. However, the pattern and biological role of miR-183 in endometrial cancer (EC) have not been completely unexplored. Here, we found that miR-183 was upregulated in endometrial cancer cells. The purpose of the study was to evaluate the function of miR-183 in the endometrial cancer cell line and the mechanisms regulating its direct target protein in these processes. The mRNA and protein expressions were analyzed by quantitative RT-PCR and western blotting, respectively. The experiments about MTT assay, colony formation assay and transwell assay showed that miR-183 can positively regulate cell proliferation, migration and invasion in vitro. Furthermore, the in vivo experiments indicated that knockdown of miR-183 significantly attenuated EC cells growth. Mechanistically, luciferase reporter assay and western blotting assay was conducted to confirm target associations. The data analysis revealed that MMP-9 as a direct target of miR-183 in EC and there was a negatively relationship between miR-183 and MMP-9 expression in EC cells. Taken together, our results demonstrated that miR-183 plays a critical role in EC tumorigenesis and metastasis by suppressing MMP-9 expression, which may be an attractive therapeutic target for the treatment of endometrial cancer.

TTBK2 circular RNA promotes glioma malignancy by regulating miR-217/HNF1\u03b2/Derlin-1 pathway

BackgroundCircular RNAs are a subgroup of non-coding RNAs and generated by a mammalian genome. Herein, the expression and function of circular RNA circ-TTBK2 were investigated in human glioma cells.MethodsFluorescence in situ hybridization and quantitative real-time PCR were conducted to profile the cell distribution and expression of circ-TTBK2 and microRNA-217 (miR-217) in glioma tissues and cells. Immunohistochemical and western blot were used to determine the expression of HNF1β and Derlin-1 in glioma tissues and cells. Stable knockdown of circ-TTBK2 or overexpression of miR-217 glioma cell lines (U87 and U251) were established to explore the function of circ-TTBK2 and miR-217 in glioma cells. Further, luciferase reports and RNA immunoprecipitation were used to investigate the correlation between circ-TTBK2 and miR-217. Cell Counting Kit-8, transwell assays, and flow cytometry were used to investigate circ-TTBK2 and miR-217 function including cell proliferation, migration and invasion, and apoptosis, respectively. ChIP assays were used to ascertain the correlations between HNF1β and Derlin-1.ResultsWe found that circ-TTBK2 was upregulated in glioma tissues and cell lines, while linear TTBK2 was not dysregulated in glioma tissues and cells. Enhanced expression of circ-TTBK2 promoted cell proliferation, migration, and invasion, while inhibited apoptosis. MiR-217 was downregulated in glioma tissues and cell lines. We also found that circ-TTBK2, but not linear TTBK2, acted as miR-217 sponge in a sequence-specific manner. In addition, upregulated circ-TTBK2 decreased miR-217 expression and there was a reciprocal negative feedback between them in an Argonaute2-dependent manner. Moreover, reintroduction of miR-217 significantly reversed circ-TTBK2-mediated promotion of glioma progression. HNF1β was a direct target of miR-217, and played oncogenic role in glioma cells. Remarkably, circ-TTBK2 knockdown combined with miR-217 overexpression led to tumor regression in vivo.ConclusionsThese results demonstrated a novel role circ-TTBK2 in the glioma progression.

MiR-9 regulates the multidrug resistance of chronic myelogenous leukemia by targeting ABCB1.

Multidrug resistance(MDR) is commonly correlated with the poor prognosis of chronic myelogenous leukemia. Aberrant expression of microRNAs (miRNAs) plays an important role in the MDR of various types of cancers. MicroRNA-9 (miR-9) has been confirmed to be dysregulated in many types of cancers. However, the relationship between miR-9 and MDR in chronic myelogenous leukemia (CML) remains largely unknown. In the present study, we showed that miR‑9-3p (miR-9) was downregulated in adriamycin (ADR)‑resistant K562/ADR cells and CML/MDR patients. Overexpression of miR-9 was sufficient to reverse cancer cell resistance to multiple chemotherapeutics invitro and sensitized tumors to chemotherapy invivo. Furthermore, we found that ABCB1 is a direct target of miR-9. These findings suggest that miR-9 plays a critical role in MDR in CML by targeting ABCB1. These results provide new evidence of miR-9 as a biomarker for clinical diagnosis and as a potential therapeutic target for CML.

MicroRNA-183 Suppresses Neuropathic Pain and Expression of AMPA Receptors by Targeting mTOR/VEGF Signaling Pathway

Background: Neuropathic pain is a type of chronic pain that results from dysfunctions of the somatosensory nerve system. This study was aimed to investigate the effect of mTOR/VEGF signaling pathway on neuropathic pain and the regulation mechanisms of miR-183 on AMPA Receptors through mTOR/VEGF signaling pathway. Methods: Chronic compress injury (CCI) model was constructed in the current study, we used paw withdrawal mechanic threshold (PWMT) and paw withdrawal thermal latency (PWTL) to observe mTOR and VEGF receptors. Dual luciferase analysis, western blot and qRT-PCR were also applied to complete this experiment. Results: It was observed that the inhibition of mTOR and VEGF receptors could significantly relieve neuropathic pain in the CCI model. Moreover mTOR was confirmed as the direct target of miR-183. Furthermore, miR-183 could modulate VEGF through regulating mTOR expressions. We also found the expressions of AMPA receptors (i.e. GluR1 and GluR2), located in the downstream of mTOR/VEGF signaling pathway, were significantly upregulated when miR-183 was downregulated or when the mTOR/VEGF signaling pathway was activated. Conclusion: The inhibition of mTOR or VEGF receptors can significantly relieve neuropathic pain, and the upregulation of miR-183 can suppress AMPA receptors by inhibiting mTOR/VEGF pathway.

MicroRNA-126 suppresses inflammation in endothelial cells under hyperglycemic condition by targeting HMGB1

MicroRNA-126(miR-126) targets involved in inflammation need to be identified. In this study, we aim to investigate whether high-mobility group box 1(HMGB1), an inflammation-related gene, is the target of miR-126 in diabetic vascular endothelium. The diabetic apoE−/− mice model, a classical diabetic atherosclerosis model, was established. The aorta of diabetic apoE−/− mice showed decrease of miR-126 and elevation of HMGB1 and inflammation. Next, we employed several in vitro experiments to address the role of miRNA-126 on the regulation of HMGB1 in endothelial cells under hyperglycemic and inflammatory conditions. Manipulation of miRNA levels in human umbilical vein endothelial cells (HUVECs) was achieved by transfecting cells with miR-126 mimic and antagomir. Overexpression of miR-126 could decrease the expression of downstream components of HMGB1 including TNF-α, ROS, and NADPH oxidase activity in HUVECs under hyperglycemic condition. Nevertheless, such phenomenon was completely reversed by miR-126 antagomir. The expression of HMGB1 protein rather than HMGB1 mRNA was down-regulated after transfection with miR-126 mimic, which indicated the modulation of HMGB1 mediated by miR-126 was at the posttranslational level. Luciferase reporter assay confirmed the 3′-UTR of HMGB1 gene was a direct target of miR-126. Western blot analysis also indicated that overexpression of miR-126 contributed to the elevation of p-eNOS, eNOS and p-AKT expressions, respectively. In summary, our findings suggest that miR-126 may suppress inflammation and ROS production in endothelial cells treated by high glucose through modulating the expression of HMGB1. Our study provides a novel pathogenic link between dysregulated miRNA expression and inflammation in diabetic vascular endothelium.

Deregulation of miR-183 promotes melanoma development via lncRNA MALAT1 regulation and ITGB1 signal activation.

Dysregulation of miR-183 has been recently elucidated in several carcinomas. However, the expression patterns and mechanisms of miR-183 involved in malignant melanoma remain unidentified. Here, we found down-regulation of miR-183 in melanoma tissues and cells. Decreased level of miR-183 was relevant to poor overall survival, while miR-183 up-regulation resulted in a marked suppression of cell growth in vitro and in vivo. We further found that the expression and function of miR-183 were suppressed by MALAT1. Integrin β1 (ITGB1) was then speculated and confirmed as a direct target of miR-183. We also illustrated that MALAT1 may function as a sponge competitive endogenous RNA (ceRNA) for miR-183, and thus regulate the molecular expression of ITGB1. Collectively, we found a new signaling pathway promoting melanoma development by MALAT1-miR-183-ITGB1 axis, which may be clinically valuable as new targets for malignant melanoma therapy.

Long non-coding RNA XIST regulates gastric cancer progression by acting as a molecular sponge of miR-101 to modulate EZH2 expression.

BackgroundLong non-coding RNAs (lncRNAs) have emerged as critical regulators of tumor progression. However, the role and molecular mechanism of lncRNA XIST in gastric cancer is still unknown.MethodsReal-time PCR analysis was performed to measure the expression levels of lncRNA XIST in gastric cancer tissues and cell lines, the correlation between lncRNA XIST expression and clinicopathological characteristics and prognosis was analyzed in gastric cancer patients. The biological function of lncRNA XIST on gastric cancer cells were determined both in vitro and in vivo. The regulating relationship between lncRNA XIST and miR-101 was investigated in gastric cancer cells.ResultslncRNA XIST was significantly up-regulated in gastric cancer tissues and cell lines. Overexpression of lncRNA XIST was markedly associated with larger tumor size, lymph node invasion, distant metastasis and TNM stage in gastric cancer patients. Functionally, knockdown of lncRNA XIST exerted tumor-suppressive effects by inhibiting cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo. Furthermore, an inverse relationship between lncRNA XIST and miR-101 was found. Polycomb group protein enhancer of zeste homolog 2 (EZH2), a direct target of miR-101, could mediated the biological effects that lncRNA XIST exerted.ConclusionslncRNA XIST is up-regulated and is associated with aggressive tumor phenotypes and patient survival in gastric cancer, and the newly identified lncRNA XIST/miR-101/EZH2 axis could be a potential biomarkers or therapeutic targets for gastric cancer patients.

MicroRNA-126 increases chemosensitivity in drug-resistant gastric cancer cells by targeting EZH2

Chemotherapeutic insensitivity is a significant barrier for effective treatment of gastric cancer (GC). Recently, emerging evidence has demonstrated that microRNAs (miRNAs) are critically involved in drug resistance. Here, by a large-scale screen, we noticed low expression of miR-126 in the drug-resistant GC cell lines SGC7901/VCR and SGC7901/ADR compared with their parental cell line SGC7901. Ectopic expression of miR-126 increased sensitivity of SGC7901/VCR and SGC7901/ADR cells to vincristine (VCR) and adriamycin (ADR). Mechanistically, Enhancer of Zeste Homolog 2 (EZH2) was identified as a direct target of miR-126. Genetic silencing of EZH2 mirrored the effects of miR-126 in drug resistance, and restoration of EZH2 blocked the inhibitory effect of miR-126 on GC. Taken together, our results suggest that miR-126 is a tumor suppressor by sensitizing GC cells to chemotherapy and provide a potential therapeutic approach in cancer treatment.