scholarly journals Long Non-Coding RNA MALAT1 Protects Human Osteoblasts from Dexamethasone-Induced Injury via Activation of PPM1E-AMPK Signaling

2018 ◽  
Vol 51 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Jian-bo Fan ◽  
Yingzi Zhang ◽  
Wei Liu ◽  
Xin-hui Zhu ◽  
Da-wei Xu ◽  
...  

Background/Aims: Dexamethasone (Dex) induces injuries to human osteoblasts. In this study, we tested the potential role of the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (Lnc-MALAT1) in this process. Materials: Two established human osteoblastic cell lines (OB-6 and hFOB1.19) and primary human osteoblasts were treated with Dex. Lnc-MALAT1 expression was analyzed by quantitative real-time polymerase chain reaction assay. Cell viability, apoptosis, and death were tested by the MTT assay, histone-DNA assay, and trypan blue staining assay, respectively. AMP-activated protein kinase (AMPK) signaling was evaluated by western blotting and AMPK activity assay. Results: Lnc-MALAT1 expression was downregulated by Dex treatment in the established osteoblastic cell lines (OB-6 and hFOB1.19) and primary human osteoblasts. The level of Lnc-MALAT1 was decreased in the necrotic femoral head tissues of Dex-administered patients. In osteoblastic cells and primary human osteoblasts, forced overexpression of Lnc-MALAT1 using a lentiviral vector (LV-MALAT1) inhibited Dex-induced cell viability reduction, cell death, and apoptosis. Conversely, transfection with Lnc-MALAT1 small interfering RNA aggravated Dex-induced cytotoxicity. Transfection with LV-MALAT1 downregulated Ppm1e (protein phosphatase, Mg2+/ Mn2+-dependent 1e) expression to activate AMPK signaling. Treatment of osteoblasts with AMPKα1 short hairpin RNA or dominant negative mutation (T172A) abolished LV-MALAT1-induced protection against Dex-induced cytotoxicity. Furthermore, LV-MALAT1 induced an increase in nicotinamide adenine dinucleotide phosphate activity and activation of Nrf2 signaling. Dex-induced reactive oxygen species production was significantly attenuated by LV-MALAT1 transfection in osteoblastic cells and primary osteoblasts. Conclusion: Lnc-MALAT1 protects human osteoblasts from Dex-induced injuries, possibly via activation of Ppm1e-AMPK signaling.

2017 ◽  
Vol 42 (3) ◽  
pp. 1192-1201 ◽  
Author(s):  
Hongwei Li ◽  
Xiaoli Yuan ◽  
Dongming Yan ◽  
Dongpeng Li ◽  
Fangxia Guan ◽  
...  

Background/Aim: Multidrug resistance (MDR) is largely responsible for the failure of chemotherapy. The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript (MALAT1) has been reported to be closely related to tumor biology. In the present study, whether MALAT1 contributes to the resistance of glioblastoma cell lines to temozolomide (TMZ) was investigated. Methods: The glioblastoma cell lines U251 and U87 were exposed to increasing concentrations of TMZ to generate TMZ-resistant colonies (the U251/TMZ and U87/TMZ cell lines). The expression levels of MALAT1 and proteins related to epithelial-mesenchymal transition (EMT) were detected by real-time PCR and western blot, respectively. After the transfection of si-MALAT1 or pcDNA-MALAT1, cell viability, mRNA expression of MDR-associated proteins (MDR1, MRP5 and LRP1), and protein expression of EMT related proteins (ZEB1, Snail and SLUG) were evaluated. Results: The expression of MALAT1 was upregulated in the U251/TMZ and U87/TMZ cell lines compared to that in U251 and U87 cell lines, respectively. The treatment of si-MALAT1 decreased MDR1, MRP5, and LRP1 expression, enhanced cell sensitivity to TMZ, and downregulated ZEB1 protein expression, whereas pcDNA-MALAT1 had the opposite effects. However, the effects of si-MALAT1 on MDR -associated protein expression, cell viability, and EMT status were reversed by the transfection of pcDNA-ZEB1, and the effects of pcDNA-MALAT1 were reversed by the transfection of si-ZEB1. In vivo, MALAT1 overexpression enhanced tumors’ TMZ resistance and upregulated ZEB1 expression. Conclusion: MALAT1 decreased the sensitivity of resistant glioma cell lines to TMZ by regulating ZEB1.


2017 ◽  
Vol 313 (2) ◽  
pp. G150-G156 ◽  
Author(s):  
Luo Fang ◽  
Jiao Sun ◽  
Zongfu Pan ◽  
Yu Song ◽  
Like Zhong ◽  
...  

Long non-coding RNA nuclear-enriched abundant transcript 1 (NEAT1) plays an important role in the pathogenesis and development of several types of cancer. However, the functional mechanism of NEAT1 in hepatocellular carcinoma (HCC) remains unclear. NEAT1 and microRNA (miR)-129-5p expression in HCC tissues and cell lines was quantified by means of quantitative PCR. The effects of NEAT1 expression inhibition or upregulation in HCC cell lines were analyzed in terms of cell viability and apoptosis. Biological software was used to predict the binding sites of NEAT1 and miR-129-5p. The expression of the miR-129-5p target molecules valosin-containing protein (VCP) and IκB was detected using Western blotting. The effect of NEAT1 on tumor growth was observed in mouse models of transplanted hepatoma. In the present study, it was concluded that the expression of NEAT1 was significantly increased in the HCC tissues and cell lines. Meanwhile, after downregulating NEAT1 expression in HepG2/Huh7 cell lines, the cell viability was significantly lowered, whereas the corresponding rate of apoptosis was significantly increased. Additionally, it was found that the NEAT1 and miR-129-5p expression showed a negative correlation in HCC tissues. It was further proved that there was a certain negative regulatory mechanism between NEAT1 and miR-129-5p, which was related to the expression of VCP and IκB. The mouse model experiments confirmed that the interference with NEAT1 expression inhibited tumor growth. The study concluded that the overexpression of NEAT1 inhibited the expression of miR-129-5p by regulating VCP/IκB, thereby promoting the proliferation of HCC cells. This study provides new insights into the pathogenesis of HCC, as well as identifying new target genes for diagnosis and treatment. NEW & NOTEWORTHY The results provide strong evidence that upregulated NEAT1 promotes the proliferation of cancer cells in hepatocellular carcinoma (HCC) and this regulatory mechanism depends on the microRNA (miR)-129-5p-valosin-containing protein-IκB axis. The study also indicates that NEAT1 could be a potential therapeutic target for HCC.


2017 ◽  
Vol 45 (1) ◽  
pp. 131-147 ◽  
Author(s):  
Yana Gao ◽  
Hai Yu ◽  
Yunhui Liu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
...  

Background/Aims: Vasculogenic mimicry (VM) has been reported to be a novel glioma neovascularization process. Anti-VM therapy provides new insight into glioma clinical management. In this study, we revealed the role of the long non-coding RNA HOXA cluster antisense RNA 2 (HOXA-AS2) in malignant glioma behaviors and VM formation. Methods: Quantitative real-time PCR was performed to determine the expression levels of HOXA-AS2 in glioma samples and glioblastoma cell lines. CD34-periodic acid-Schiff dual-staining was performed to assess VM in glioma samples. CCK-8, transwell, and Matrigel tube formation assays were performed to measure the effects of HOXA-AS2 knockdown on cell viability, migration, invasion, and VM tube formation, respectively. RNA immunoprecipitation, dual-luciferase reporter and Western blot assays were performed to explore the molecular mechanisms underlying the functions of HOXS-AS2 in glioblastoma cells. A nude mouse xenograft model was used to investigate the role of HOXA-AS2 in xenograft glioma growth and VM density. Student’s t-tests, one-way ANOVAs followed by Bonferroni posthoc tests, and chi-square tests were used for the statistical analyses. Results: HOXA-AS2 was upregulated in glioma samples and cell lines and was positively correlated with VM. HOXA-AS2 knockdown attenuated cell viability, migration, invasion, and VM formation in glioma cells and inhibited the expression of vascular endothelial-cadherin (VE-cadherin), as well as the expression and activity of matrix metalloproteinase matrix metalloproteinase (MMP)-2 and MMP-9. miR-373 was downregulated in glioma samples and cell lines and suppressed malignancy in glioblastoma cells. HOXA-AS2 bound to miR-373 and negatively regulated its expression. Epidermal growth factor receptor (EGFR), a target of miR-373, increased the expression levels of VE-cadherin, as well as the expression and activity levels of MMP-2 and MMP-9, via activating phosphatidylinositol 3-kinase/serine/threonine kinase pathways. HOXA-AS2 knockdown combined with miR-373 overexpression yielded optimal tumor suppressive effects and the lowest VM density in vivo. Conclusion: HOXA-AS2 knockdown inhibited malignant glioma behaviors and VM formation via the miR-373/EGFR axis.


Author(s):  
Xiuming Liu ◽  
Xiaofeng Li ◽  
Jianchang Li

AbstractRetinoblastoma is the most common malignancy in children's eyes with high incidence. Long non-coding RNAs (lncRNAs) play important roles in the progression of retinoblastoma. LncRNA FEZF1 antisense RNA 1 (FEZF1-AS1) has been found to stimulate retinoblastoma. However, the mechanism of FEZF1-AS1 underlying progression of retinoblastoma is still unclear. In current study, FEZF1-AS1 was up-regulated in retinoblastoma tissues and cells. FEZF1-AS1 overexpression enhanced retinoblastoma cell viability, promoted cell cycle, and inhibited apoptosis. Conversely, FEZF1-AS1 knockdown reduced cell viability, cycle, and elevated apoptosis. The interaction between FEZF1-AS1 and microRNA-363-3p (miR-363-3p) was confirmed. FEZF1-AS1 down-regulated miR-363-3p and up-regulated PAX6. PAX6 was a target gene of miR-363-3p. EZF1-AS1 promoted retinoblastoma cell viability and suppressed apoptosis via PAX6. Further, we demonstrated that FEZF1-AS1 contribute to tumor formation in vivo. In conclusion, FEZF1-AS1 elevated growth and inhibited apoptosis by regulating miR-363-3p/PAX6 in retinoblastoma, which provide a new target for retinoblastoma treatment.


2017 ◽  
Vol 58 (5-6) ◽  
pp. 216-226
Author(s):  
Johannes Schauwecker ◽  
Mark Bock ◽  
Florian Pohlig ◽  
Heinz Mühlhofer ◽  
Jutta Tübel ◽  
...  

Background/Purpose: Polymethylmethacrylate (PMMA) and calcium phosphate (Ca-P) cements are widely used for arthroplasty surgery and augmentation of bone defects. However, aseptic implant loosening in absence of wear-induced osteolysis indicates an unfavourable interaction between the cement surface and human osteoblasts. Our underlying hypothesis is that cement surfaces directly modify cell viability, proliferation rate, and cell differentiation. Methods: To test this hypothesis, we examined primary human osteoblasts harvested from six individuals. These cells were pooled and subsequently seeded directly on cement pellets prepared from Palacos® R, Palacos® R+G, and Norian® Drillable cements. After incubation for 24 and 72 h, cell viability, proliferation rate, apoptosis rate, and cell differentiation were analysed. Results: Upon cultivation of human osteoblasts on cement surfaces, we observed a significantly reduced cell viability and DNA content compared to the control. Analysis of the apoptosis rate revealed an increase for cells on Palacos R and Norian Drillable, but a significant decrease on Palacos R+G compared to the control. Regarding osteogenic differentiation, significantly lower values of alkaline phosphatase enzyme activity were identified for all cement surfaces after 24 and 72 h compared to cultivation on tissue culture plastic, serving as control. Conclusions: In summary, these data suggest a limited biocompatibility of both PMMA and Ca-P cements, necessitating further research to reduce unfavourable cell-cement interactions and consequently extend implant survival.


2021 ◽  
Author(s):  
hafiza sobia ramzan ◽  
Kashif Aziz Ahmad

Background: Osteoarthritis (OA) is a common disease of the joints among old populace until today. The treatment possibilities and roles of miRNA and long non-coding RNA (lncRNA) in therapy of OA has previously been explored. However, the functional roles of Long noncoding RNA KCNQ1OT1 and miRNA let-7a-5p on Osteoarthritis development and progression remains unclear. This study aimed at investigating the influence of KCNQ1OT1 on let-7a-5p in moderation of OA development and advancement. Materials and Methods: RT-qPCR examined expression of KCNQ1OT1and let-7a-5p in cultured human primary chondrocyte cell lines. Cell transfection overexpressed or knocked down the genes and CCK-8 assay measured cell viability in the proliferation biomarkers Ki87 and PCNA. While caspase-8 and caspase-3 activity determined rate of apoptosis. Furthermore, luciferase assay analyzed the luciferase activity and western blotting analysis determined the protein expression of KCNQ1OT1 and let-7a-5p in proliferation and apoptosis biomarkers. Results: The results demonstrated that KCNQ1OT1 is upregulated in OA-mimic cells and promotes the cell viability. KCNQ1OT1 knockdown suppresses cell viability of OA cells. Furthermore KCNQ1OT1 directly binds the 3'-UTR of let-7a-5p to negatively regulate let-7a-5p expression and OA progression. While upregulated let-7a-5p abolishes the proliferation effect of KCNQ1OT1 in OA cells. Conclusion: In summary, our study provides further insights into the underlying molecular mechanisms of KCNQ1OT1 and let-7a-5p suggesting a novel therapeutic approach to OA


2020 ◽  
Author(s):  
Juanjuan Shi ◽  
Xijian Xu ◽  
Dan Zhang ◽  
Jiuyan Zhang ◽  
Hui Yang ◽  
...  

Abstract Background: Long non-coding RNA PTPRG antisense RNA 1 (PTPRG-AS1) deregulation has been reported in various human malignancies and identified as an important modulator of cancer development. Few reports have focused on the detailed role of PTPRG-AS1 in epithelial ovarian cancer (EOC) and its underlying mechanism. This study aimed to determine the physiological function of PTPRG-AS1 in EOC. A series of experiments were also performed to identify the mechanisms through which PTPRG-AS1 exerts its function in EOC.Methods: Reverse transcription-quantitative polymerase chain reaction was used to determine PTPRG-AS1 expression in EOC tissues and cell lines. PTPRG-AS1 was silenced in EOC cells and studied with respect to cell proliferation, apoptosis, migration, and invasion in vitro and tumor growth in vivo. The putative miRNAs that target PTPRG-AS1 were predicted using bioinformatics analysis and further confirmed in luciferase reporter and RNA immunoprecipitation assays.Results: Our data verified the upregulation of PTPRG-AS1 in EOC tissues and cell lines. High PTPRG-AS1 expression was associated with shorter overall survival in patients with EOC. Functionally, EOC cell proliferation, migration, invasion in vitro, and tumor growth in vivo were suppressed by PTPRG-AS1 silencing. In contrast, cell apoptosis was promoted by loss of PTPRG-AS1. Regarding the mechanism, PTPRG-AS1 could serve as a competing endogenous RNA in EOC cells by decoying microRNA-545-3p (miR-545-3p), thereby elevating histone deacetylase 4 (HDAC4) expression. Furthermore, rescue experiments revealed that PTPRG-AS1 knockdown-mediated effects on EOC cells were, in part, counteracted by the inhibition of miR-545-3p or restoration of HDAC4.Conclusions: PTPRG-AS1 functioned as an oncogenic lncRNA that aggravated the malignancy of EOC through the miR-545-3p/HDAC4 ceRNA network. Thus, targeting the PTPRG-AS1/miR-545-3p/HDAC4 pathway may be a novel strategy for EOC anticancer therapy.


2018 ◽  
Vol 49 (4) ◽  
pp. 1403-1419 ◽  
Author(s):  
Yunxiuxiu Xu ◽  
Xinxi Luo ◽  
Wenguang He ◽  
Guangcheng Chen ◽  
Yanshan Li ◽  
...  

Background/Aims: To investigate the biological roles and underlying molecular mechanisms of long non-coding RNA (lncRNA) PVT1 in Hepatocellular carcinoma (HCC). Methods: qRT-PCR was performed to measure the expression of miRNA and mRNA. Western blot was performed to measure the protein expression. CCK-8 assay was performed to determine cell proliferation. Flow cytometry was performed to detect cell apoptosis. Wounding-healing assay and Transwell assay was performed to detect cell migration and invasion. Dual luciferase reporter assay was performed to verify the target relationship. Quantichrom iron assay was performed to check uptake level of cellular iron. Results: PVT1 expression was up-regulated in HCC tissues and cell lines. Function studies revealed that PVT1 knockdown significantly suppressed cell proliferation, migration and invasion, and induced cell apoptosis in vitro. Furthermore, PVT1 could directly bind to microRNA (miR)-150 and down-regulate miR-150 expression. Hypoxia-inducible protein 2 (HIG2) was found to be one target gene of miR-150, and PVT1 knockdown could inhibit the expression of HIG2 through up-regulating miR-150 expression. In addition, the expression of miR-150 was down-regulated, while the expression of HIG2 was up-regulated in HCC tissues and cell lines. Moreover, inhibition of miR-150 could partly reverse the biological effects of PVT1 knockdown on proliferation, motility, apoptosis and iron metabolism in vitro, which might be associated with dysregulation of HIG2. In vivo results showed that PVT1 knockdown suppressed tumorigenesis and iron metabolism disorder by regulating the expression of miR-150 and HIG2. Conclusion: Taken together, the present study demonstrates that PVT1/miR-150/HIG2 axis may lead to a better understanding of HCC pathogenesis and provide potential therapeutic targets for HCC.


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