scholarly journals Activation of LncRNA HOTAIR by STAT3 Promotes Gefitinib Resistance and Tumourigenesis by Targeting MicroRNA-216a in NSCLC

Author(s):  
Hongge Zhu ◽  
Xiuli Wang ◽  
Xin Zhou ◽  
Suqiong Lu ◽  
Guomin Gu ◽  
...  

Abstract Background: Gefitinib resistance has become a major obstacle for cancer therapy of non-small cell lung cancer (NSCLC). Exosome-mediated transfer of long noncoding RNAs (lncRNAs) is associated with the drug-resistance in various tumors. However, the role of NSCLC-specific exosomal lncRNAs remains largely unknown. The aim of this study is to explore the role of exosomal Hox transcript antisense intergenic RNA (HOTAIR) on gefitinib resistance in NSCLC. Methods: We investigated the expression of lncRNAs in 5 paired gefitinib-sensitive and gefitinib-resistant tissues of NSCLC by microarray analysis. The qRT-PCR analysis was to investigate the expression pattern of HOTAIR in gefitinib-resistant NSCLC patient tissues and cell lines. Then, we investigated the effects of HOTAIR on gefitinib resistance in vitro and in vivo. Results: In this study, we found HOTAIR was evidently up-regulated in both tissues and serum exosome of gefitinib-resistant NSCLC patients. Moreover, by knocking down HOTAIR, we found that HOTAIR promoted the proliferation of NSCLC cells in vitro, as well as inhibited cell apoptosis and cell sensitivity to gefitinib. Extracellular HOTAIR could be incorporated into exosomes and transmitted to sensitive cells, thus disseminated gefitinib resistance. The expression level of HOTAIR from circulating exosomes is significantly higher in NSCLC patients with gefitinib resistance than those without gefitinib resistance. Mechanistically, bioinformatic analysis coupled with dual luciferase assay revealed that HOTAIR served as miR-216a sponge, and MAP1S was identified as a functional target of miR-216a. Conclusions: In conclusion, these data suggest that exosomal HOTAIR serves as an oncogenic role in gefitinib resistance of NSCLC cells CRC through activating miR-216a/MAP1S signaling pathway, providing a novel avenue for the treatment of NSCLC.

2018 ◽  
Vol 51 (6) ◽  
pp. 2872-2886 ◽  
Author(s):  
Yuxin Dai ◽  
Yongkun Wan ◽  
Mingke Qiu ◽  
Shuqing Wang ◽  
Chang Pan ◽  
...  

Background/Aims: Dysregulation of long noncoding RNAs (lncRNAs) is associated with the proliferation and metastasis in a variety of cancers, of which lncRNA maternally expressed gene 3 (MEG3) has been indicated as a tumor suppressor in multiple malignancies. However, the underlying mechanisms by which MEG3 contributes to human hemangiomas (HAs) remain undetermined. Methods: qRT-PCR analysis was performed to examine the expression levels of MEG3 and VEGF in proliferating or involuting phase HAs. MTT, colony formation assay, flow cytometry analysis and a subcutaneous xenograft tumor model were conducted to assess the effects of MEG3 on the HAs tumorigenesis. The interaction between MEG3 and miRNAs or their downstream pathways was evidenced by bioinformatic analysis, luciferase report assays, RNA immunoprecipitation (RIP) assay. and Western blot analysis. Results: The expression of MEG3 was substantially decreased and had a negative correlation with VEGF expression in proliferating phase HAs, as compared with the involuting phase HAs and normal skin tissues. Ectopic expression of MEG3 suppressed cell proliferation, colony formation and induced cycle arrest in vitro and in vivo, followed by the downregulation of VEGF and cyclinD1, but knockdown of MEG3 reversed these effects. Furthermore, MEG3 was verified to act as a sponge of miR-494 in HAs cells, and miR-494 counteracted MEG3-caused anti-proliferative effects by regulating PTEN/PI3K/AKT pathway, and exhibited the negative correlation with MEG3 and PTEN expression in proliferating phase HAs. Conclusion: Our findings suggested that lncRNA MEG3 inhibited HAs tumorigenesis by sponging miR-494 and regulating PTEN/PI3K/AKT pathway.


2010 ◽  
Vol 78 (6) ◽  
pp. 2370-2376 ◽  
Author(s):  
Louise M. Temple ◽  
David M. Miyamoto ◽  
Manju Mehta ◽  
Christian M. Capitini ◽  
Stephen Von Stetina ◽  
...  

ABSTRACT Bordetella avium causes bordetellosis in birds, a disease similar to whooping cough caused by Bordetella pertussis in children. B. avium agglutinates guinea pig erythrocytes via an unknown mechanism. Loss of hemagglutination ability results in attenuation. We report the use of transposon mutagenesis to identify two genes required for hemagglutination. The genes (hagA and hagB) were adjacent and divergently oriented and had no orthologs in the genomes of other Bordetella species. Construction of in-frame, unmarked mutations in each gene allowed examination of the role of each in conferring erythrocyte agglutination, explanted tracheal cell adherence, and turkey poult tracheal colonization. In all of the in vitro and in vivo assays, the requirement for the trans-acting products of hagA and hagB (HagA and HagB) was readily shown. Western blotting, using antibodies to purified HagA and HagB, revealed proteins of the predicted sizes of HagA and HagB in an outer membrane-enriched fraction. Antiserum to HagB, but not HagA, blocked B. avium erythrocyte agglutination and explanted turkey tracheal ring binding. Bioinformatic analysis indicated the similarity of HagA and HagB to several two-component secretory apparatuses in which one product facilitates the exposition of the other. HagB has the potential to serve as a useful immunogen to protect turkeys against colonization and subsequent disease.


2021 ◽  
Vol 11 ◽  
Author(s):  
Jiawei Xiao ◽  
Lian Gong ◽  
Mengqing Xiao ◽  
Dong He ◽  
Liang Xiang ◽  
...  

PurposeLong non-coding RNAs (lncRNAs) play an important role in the occurrence and development of bladder cancer, but the underlying molecular mechanisms remain largely unknown. In this study, we found that LINC00467 was significantly highly expressed in bladder cancer through bioinformatic analysis. The present study aimed to explore the role of LINC00467 in bladder cancer and its possible underlying molecular mechanisms.MethodsThe expression of LINC00467 was obtained from GEO (GSE31189), the TCGA database, and qRT-PCR. The role of LINC00467 in bladder cancer was assessed both in vitro and in vivo. RIP, RNA pulldown, and CO-IP were used to demonstrate the potential mechanism by which LINC00467 regulates the progression of bladder cancer.ResultsThrough the analysis of GEO (GSE133624) and the TCGA database, it was found that LINC00467 was highly expressed in bladder cancer tissues and that the expression of LINC00467 was significantly negatively correlated with patient prognosis. Cell and animal experiments suggest that LINC00467 promotes the proliferation and invasion of bladder cancer cells. On the one hand, LINC00467 can directly bind to NF-kb-p65 mRNA to stabilize its expression. On the other hand, LINC00467 can directly bind to NF-kb-p65 to promote its translocation into the nucleus to activate the NF-κB signaling pathway, which promotes the progression of bladder cancer.ConclusionsLINC00467 is highly expressed in bladder cancer and can promote the progression of bladder cancer by regulating the NF-κB signaling pathway. Therefore, targeting LINC00467 is very likely to provide a new strategy for the treatment of bladder cancer and for improving patient prognosis.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jingjie Liang ◽  
Kui Li ◽  
Kaiyu Chen ◽  
Junyong Liang ◽  
Ti Qin ◽  
...  

Abstract Background The establishment of uterine receptivity is essential for embryo implantation initiation and involves a significant morphological transformation in the endometrial epithelial cells (EECs). The remodeling of junctional complexes and membrane-associated cytoskeleton is crucial for epithelial transformation. However, little is known about how this process is regulated in EECs during the receptive phase. ARHGAP19 is a Rho GTPase-activating protein that participates in various cytoskeletal-related events, including epithelial morphogenesis. Here, we investigated the role of ARHGAP19 in endometrial epithelial transformation during the establishment of uterine receptivity. The upstream regulator of ARHGAP19 was also investigated. Methods ARHGAP19 expression was examined in mouse uteri during early pregnancy and in human EEC lines. The role of ARHGAP19 was investigated by manipulating its expression in EECs. The effect of ARHGAP19 on junctional proteins in EECs was examined by western blotting and immunofluorescence. The effect of ARHGAP19 on microvilli was examined by scanning electron microscopy. The upstream microRNA (miRNA) was predicted using online databases and validated by the dual-luciferase assay. The in vivo and in vitro effect of miRNA on endogenous ARHGAP19 was examined by uterine injection of miRNA agomirs and transfection of miRNA mimics or inhibitors. Results ARHGAP19 was upregulated in the receptive mouse uteri and human EECs. Overexpression of ARHGAP19 in non-receptive EECs downregulated the expression of junctional proteins and resulted in their redistribution. Meanwhile, upregulating ARHGAP19 reorganized the cytoskeletal structure of EECs, leading to a decline of microvilli and changes in cell configuration. These changes weakened epithelial cell polarity and promoted the transition of non-receptive EECs to a receptive phenotype. Besides, miR-192-5p, a miRNA that plays a key role in maintaining epithelial properties, was validated as an upstream regulator of ARHGAP19. Conclusion These results suggested that ARHGAP19 may contribute to the transition of EECs from a non-receptive to a receptive state by regulating the remodeling of junctional proteins and membrane-associated cytoskeleton.


2020 ◽  
Author(s):  
Lei Zhuang ◽  
Wenzheng Xia ◽  
Didi Chen ◽  
Yijia Ye ◽  
Tingting Hu ◽  
...  

Abstract AIMS: The chemotherapy drug doxorubicin (Dox) is widely used for treating a variety of cancers. However, its high cardiotoxicity hampered its clinical use. Exosomes derived from stem cells showed a therapeutic effect against Dox-induced cardiomyopathy (DIC). Previous studies reported that exosomes derived from mesenchymal stem cells (MSCs) pretreated with macrophage migration inhibitory factor (MIF) (exosomeMIF) showed a cardioprotective effect through modulating long noncoding RNAs/microRNAs (lncRNAs/miRs). This study aimed to investigate the role of exosomeMIF in the treatment of DIC. METHODS AND RESULTS: Exosomes were isolated from control MSCs (exosome) and MIF-pretreated MSCs (exosomeMIF). Regulatory lncRNAs activated by MIF pretreatment were explored using genomics approaches. Fluorescence-labeled exosomes were tracked in vitro by fluorescence imaging. In vivo and in vitro, miR-221-3p mimic transfection enforced miR-221-3p overexpression, and senescence-associated β-galactosidase assay was applied to test cellular senescence. Exosomal delivering LncRNA-NEAT1 induced therapeutic effect in vivo was confirmed by echocardiography. It demonstrated that exosomesMIF recovered the cardiac function and exerted the anti-senescent effect through LncRNA–NEAT1 transfer against Dox. TargetScan and luciferase assay showed that miR-221-3p targeted the Sirt2 3'-untranslated region. Silencing LncRNA–NEAT1 in MSCs, miR-221-3p overexpression or Sirt2 silencing in cardiomyocytes ruined the exosomeMIF-induced anti-senescent effect against Dox. CONCLUSIONS: The results indicated exosomeMIF serving as a promising anti-senescent effector against Dox-induced cardiotoxicity through LncRNA–NEAT1 transfer, thus sponging miR-221-3p and leading to Sirt2 activation. The study proposed that exosomeMIF might have the potential to serve as a cardioprotective therapeutic agent during cancer chemotherapy.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Lei Zhuang ◽  
Wenzheng Xia ◽  
Didi Chen ◽  
Yijia Ye ◽  
Tingting Hu ◽  
...  

Abstract Background The chemotherapy drug doxorubicin (Dox) is widely used for treating a variety of cancers. However, its high cardiotoxicity hampered its clinical use. Exosomes derived from stem cells showed a therapeutic effect against Dox-induced cardiomyopathy (DIC). Previous studies reported that exosomes derived from mesenchymal stem cells (MSCs) pretreated with macrophage migration inhibitory factor (MIF) (exosomeMIF) showed a cardioprotective effect through modulating long noncoding RNAs/microRNAs (lncRNAs/miRs). This study aimed to investigate the role of exosomeMIF in the treatment of DIC. Results Exosomes were isolated from control MSCs (exosome) and MIF-pretreated MSCs (exosomeMIF). Regulatory lncRNAs activated by MIF pretreatment were explored using genomics approaches. Fluorescence-labeled exosomes were tracked in vitro by fluorescence imaging. In vivo and in vitro, miR-221-3p mimic transfection enforced miR-221-3p overexpression, and senescence-associated β-galactosidase assay was applied to test cellular senescence. Exosomal delivering LncRNA-NEAT1 induced therapeutic effect in vivo was confirmed by echocardiography. It demonstrated that exosomesMIF recovered the cardiac function and exerted the anti-senescent effect through LncRNA–NEAT1 transfer against Dox. TargetScan and luciferase assay showed that miR-221-3p targeted the Sirt2 3′-untranslated region. Silencing LncRNA–NEAT1 in MSCs, miR-221-3p overexpression or Sirt2 silencing in cardiomyocytes decreased the exosomeMIF-induced anti-senescent effect against Dox. Conclusions The results indicated exosomeMIF serving as a promising anti-senescent effector against Dox-induced cardiotoxicity through LncRNA–NEAT1 transfer, thus inhibiting miR-221-3p and leading to Sirt2 activation. The study proposed that exosomeMIF might have the potential to serve as a cardioprotective therapeutic agent during cancer chemotherapy.


2018 ◽  
Vol 48 (2) ◽  
pp. 528-539 ◽  
Author(s):  
Hongxue Sun ◽  
Di Zhong ◽  
Cheng Wang ◽  
Yilei Sun ◽  
Jiaying Zhao ◽  
...  

Background/Aims: This study investigated the role of the microRNA miR-298 and its target Act1 in ischemic stroke. Methods: Cell viability was assessed with the 3-(4,5-dimethythiazol-2- yl)-2,5-diphenyl tetrazolium bromide assay. Apoptotic cells were detected by flow cytometry, and mRNA and protein expression were assessed by quantitative real-time PCR and western blotting, respectively. The regulatory relationship between miR-298 and Act1 was evaluated with the luciferase assay. To clarify the role of Act1 following ischemic stroke, the transcript was knocked down by short interfering RNA. The in vitro findings were validated in a mouse model of middle cerebral artery occlusion by administration of miR-298 mimic. Results: Act1 was upregulated whereas miR-298 was downregulated in ischemic stroke. miR-298 overexpression by transfection of a mimic suppressed Act1 protein levels in vitro and in vivo, and the luciferase assay showed that miR-298 directly binds to the 3’ untranslated region of the Act1 transcript. miR-298 overexpression enhanced cell apoptosis and autophagy and exacerbated ischemic infarction and neurological deficits, effects that were exerted via negative regulation of Act1/c-Jun N-terminal kinase (JNK)/nuclear factor (NF)-κB signaling and downstream autophagy pathways. Conclusions: Upregulation of miR-298 following ischemic stroke promotes brain injury in vitro and vivo by inhibiting the Act1/JNK/NF-κB signaling cascade and the downstream autophagy pathway. Therapeutic strategies that target miR-298 could be beneficial for the treatment of ischemic stroke.


Endocrinology ◽  
2013 ◽  
Vol 154 (8) ◽  
pp. 2900-2911 ◽  
Author(s):  
Xiangbo Xu ◽  
Xihua Chen ◽  
Yunfeng Li ◽  
Huizi Cao ◽  
Cuige Shi ◽  
...  

Abstract The role of prostaglandins (PGs) in menstruation has long been proposed. Although evidence from studies on human and nonhuman primates supports the involvement of PGs in menstruation, whether PGs play an obligatory role in the process remains unclear. Although cyclooxygenase (COX) inhibitors have been used in the treatment of irregular uterine bleeding, the mechanism involved has not been elucidated. In this study, we used a recently established mouse menstrual-like model for investigating the role of COX in endometrial breakdown and its regulation. Administration of the nonspecific COX inhibitor indomethacin and the COX-2 selective inhibitor DuP-697 led to inhibition of the menstrual-like process. Furthermore, immunostaining analysis showed that the nuclear factor (NF)κB proteins P50, P65, and COX-2 colocalized in the outer decidual stroma at 12 to 16 hours after progesterone withdrawal. Chromatin immunoprecipitation analysis showed that NFκB binding to the Cox-2 promoter increased at 12 hours after progesterone withdrawal in vivo, and real-time PCR analysis showed that the NFκB inhibitors pyrrolidine dithiocarbamate and MG-132 inhibited Cox-2 mRNA expression in vivo and in vitro, respectively. Furthermore, COX-2 and NFκB inhibitors similarly reduced endometrial breakdown, suggesting that NFκB/COX-2-derived PGs play a critical role in this process. In addition, the CD45+ leukocyte numbers were sharply reduced following indomethacin (COX-1 and COX-2 inhibitor), DuP-697 (COX-2 inhibitor), and pyrrolidine dithiocarbamate (NFκB inhibitor) treatment. Collectively, these data indicate that NFκB/COX-2-induced PGs regulate leukocyte influx, leading to endometrial breakdown.


Author(s):  
Caiqiang Huang ◽  
Runguang Li ◽  
Changsheng Yang ◽  
Rui Ding ◽  
Qingchu Li ◽  
...  

AbstractOsteoporosis (OP) is the most common systematic bone disorder among elderly individuals worldwide. Long noncoding RNAs (lncRNAs) are involved in biological processes in various human diseases. It has been previously revealed that PAX8 antisense RNA 1 (PAX8-AS1) is upregulated in OP. However, its molecular mechanism in OP remains unclear. Therefore, we specifically designed this study to determine the specific role of PAX8-AS1 in OP. We first established a rat model of OP and then detected PAX8-AS1 expression in the rats with RT-qPCR. Next, to explore the biological function of PAX8-AS1 in osteoblasts, in vitro experiments, such as Cell Counting Kit-8 (CCK-8) assays, flow cytometry, western blotting and immunofluorescence (IF) staining, were conducted. Subsequently, we performed bioinformatic analysis and luciferase reporter assays to predict and identify the relationships between microRNA 1252-5p (miR-1252-5p) and both PAX8-AS1 and G protein subunit beta 1 (GNB1). Additionally, rescue assays in osteoblasts clarified the regulatory network of the PAX8-AS1/miR-1252-5p/GNB1 axis. Finally, in vivo loss-of-function studies verified the role of PAX8-AS1 in OP progression. The results illustrated that PAX8-AS1 was upregulated in the proximal tibia of OP rats. PAX8-AS1 silencing promoted the viability and inhibited the apoptosis and autophagy of osteoblasts. PAX8-AS1 interacted with miR-1252-5p. GNB1 was negatively regulated by miR-1252-5p. In addition, the impacts of PAX8-AS1 knockdown on osteoblasts were counteracted by GNB1 overexpression. PAX8-AS1 depletion suppressed OP progression by inhibiting apoptosis and autophagy in osteoblasts. In summary, PAX8-AS1 suppressed the viability and activated the autophagy of osteoblasts via the miR-1252-5p/GNB1 axis in OP.


2020 ◽  
Author(s):  
Hande Topel ◽  
Ezgi Bagirsakci ◽  
Dehan Comez ◽  
Gulsun Bagci ◽  
Gulcin Cakan-Akdogan ◽  
...  

Abstract Background: Epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) are both reversible processes, and regulation of phenotypical transition is very important for progression of several cancers including hepatocellular carcinoma (HCC). Recently, it is defined that cancer cells can attain a hybrid epithelial/mesenchymal (hybrid E/M) phenotype. Cells with hybrid E/M phenotype comprise mixed epithelial and mesenchymal properties, they can be more resistant to therapeutics and also more capable of initiating metastatic lesions. However, the mechanisms regulating hybrid E/M in HCC are not well described yet. In this study, we investigated the role of the potential crosstalk between lncRNA HOTAIR and c-Met receptor tyrosine kinase, which are two essential regulators of EMT and MET, in acquiring of hybrid E/M phenotype in HCC. Methods: Expression of c-Met and HOTAIR were defined in HCC cell lines and patient tissues through HCC progression. lncRNA HOTAIR was overexpressed in SNU-449 cells and its effects on c-Met signaling were analyzed. c-Met was overexpressed in SNU-398 cells and its effect on HOTAIR expression was analyzed. Biological significance of HOTAIR/c-Met interplay was defined in means of adhesion, proliferation, motility behavior, invasion, spheroid formation and metastatic ability. Effect of ectopic HOTAIR expression on phenotype was defined with investigation of molecular epithelial and mesenchymal traits. Results: In vitro and in vivo experiments verified the pivotal role of lncRNA HOTAIR in acquisition of hybrid E/M phenotype through modulating expression and activation of c-Met and its membrane co-localizing partner Caveolin-1, and membrane organization to cope with the rate limiting steps of metastasis such as survival in adhesion independent microenvironment, escaping from anoikis and resisting to fluidic shear stress (FSS) in HCC. Conclusions: Our work provides the first evidence suggesting a role for lncRNA HOTAIR in the modulation of c-Met to promote hybrid E/M phenotype. The balance between lncRNA HOTAIR and c-Met might be critical for cell fate decision and metastatic potential of HCC cells.


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