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1.
Proc Natl Acad Sci U S A ; 113(7): 1937-42, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26831088

RESUMO

Cell-type-specific G protein-coupled receptor (GPCR) signaling regulates distinct neuronal responses to various stimuli and is essential for axon guidance and targeting during development. However, its function in axonal regeneration in the mature CNS remains elusive. We found that subtypes of intrinsically photosensitive retinal ganglion cells (ipRGCs) in mice maintained high mammalian target of rapamycin (mTOR) levels after axotomy and that the light-sensitive GPCR melanopsin mediated this sustained expression. Melanopsin overexpression in the RGCs stimulated axonal regeneration after optic nerve crush by up-regulating mTOR complex 1 (mTORC1). The extent of the regeneration was comparable to that observed after phosphatase and tensin homolog (Pten) knockdown. Both the axon regeneration and mTOR activity that were enhanced by melanopsin required light stimulation and Gq/11 signaling. Specifically, activating Gq in RGCs elevated mTOR activation and promoted axonal regeneration. Melanopsin overexpression in RGCs enhanced the amplitude and duration of their light response, and silencing them with Kir2.1 significantly suppressed the increased mTOR signaling and axon regeneration that were induced by melanopsin. Thus, our results provide a strategy to promote axon regeneration after CNS injury by modulating neuronal activity through GPCR signaling.


Assuntos
Axônios , Sistema Nervoso Central/metabolismo , Regeneração Nervosa , Receptores Acoplados a Proteínas G/metabolismo , Opsinas de Bastonetes/metabolismo , Transdução de Sinais , Animais , Camundongos , Camundongos Mutantes , PTEN Fosfo-Hidrolase/antagonistas & inibidores
2.
Br J Cancer ; 116(1): 66-76, 2017 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-27875524

RESUMO

BACKGROUND: microRNAs (miRNAs) have regulatory roles in various cellular processes, including apoptosis. Recently, X-linked inhibitor of apoptosis protein (XIAP) has been reported to be dysregulated in epithelial ovarian cancer (EOC). However, the mechanism underlying this dysregulation is largely unknown. METHODS: Using bioinformatics and a literature analysis, a panel of miRNAs dysregulated in EOC was chosen for further experimental confirmation from hundreds of miRNAs that were predicted to interact with the XIAP 3'UTR. A dual-luciferase reporter assay was employed to detect the interaction by cellular co-transfection of an miRNA expression vector and a reporter vector with the XIAP 3'UTR fused to a Renilla luciferase reporter. DAPI and TUNEL approaches were used to further determine the effects of an miR-137 mimic and inhibitor on cisplatin-induced apoptosis in ovarian cancer cells. RESULTS: We identified eight miRNAs by screening a panel of dysregulated miRNAs that may target the XIAP 3'UTR. The strongest inhibitory miRNA, miR-137, suppressed the activity of a luciferase reporter gene fused with the XIAP 3'UTR and decreased the levels of XIAP protein in SKOV3 ovarian cancer cells. Furthermore, forced expression of miR-137 increased cisplatin-induced apoptosis, and the depressed expression of miR-137 decreased cisplatin-induced apoptosis in SKOV3 and primary EOC cells. Consistently, the disruption of miR-137 via CRISPR/Cas9 inhibited apoptosis and upregulated XIAP in A2780 cells. Furthermore, the effect of miR-137 on apoptosis could be rescued by XIAP in SKOV3 cells. In addition, miR-137 expression is inversely correlated with the level of XIAP protein in both ovarian cancer tissues and cell lines. CONCLUSIONS: Our data suggest that multiple miRNAs can regulate XIAP via its 3'UTR. miR-137 can sensitise ovarian cancer cells to cisplatin-induced apoptosis, providing new insight into overcoming drug resistance in ovarian cancer.


Assuntos
Apoptose/genética , MicroRNAs/fisiologia , Neoplasias Ovarianas/patologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética , Regiões 3' não Traduzidas , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Neoplasias Ovarianas/genética
3.
Tumour Biol ; 37(7): 9289-99, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26779627

RESUMO

MicroRNAs (miRNAs) are a large group of small non-coding RNAs that can negatively regulate gene expression at the post-transcriptional level. The deregulation of miRNAs has been associated with tumorigenesis, drug resistance, and prognosis in cancers. Deregulated miR-155 has been reported in numerous cancers; however, its function remains unclear. 4',6-Diamidino-2-phenylindole (DAPI) staining and terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) techniques were used to determine the effects of a miR-155 mimic or inhibitor on the apoptotic ratio of ovarian cancer cells induced by cisplatin. Bioinformatic predictions, the dual-luciferase reporter assay, and western blot analysis were used to detect how miR-155 regulates X-linked inhibitor of apoptosis protein (XIAP). We demonstrated that a miR-155 mimic could decrease the IC50 value of cisplatin in SKOV3 ovarian cancer cells. Subsequently, gain- and loss-of-function analyses with a miR-155 mimic and inhibitor showed that miR-155 sensitizes ovarian cancer cells to cisplatin. Furthermore, the results from the luciferase assays and western blot analysis identified XIAP as the direct target of miR-155. In addition, introducing XIAP cDNA without a three prime untranslated region (3'-UTR) rescued the miR-155 promotion of apoptosis. These results indicate that miR-155 mediates cisplatin-induced apoptosis by targeting XIAP in ovarian cancer cells and that miR-155 could be a potential therapeutic target to increase the efficiency of ovarian cancer interventions.


Assuntos
Apoptose , Biomarcadores Tumorais/metabolismo , MicroRNAs/genética , Neoplasias Ovarianas/patologia , Ovário/patologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Western Blotting , Proliferação de Células , Cisplatino/farmacologia , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Ovário/efeitos dos fármacos , Ovário/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética
4.
Eur Heart J ; 35(11): 733-42, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23798577

RESUMO

AIMS: Elevated homocysteine levels are known to be a risk factor for congenital heart disease (CHD), but the mechanism underlying this effect is unknown. During early embryonic development, homocysteine removal is dictated exclusively by the MTR activity. To examine the role of MTR in CHD risk, we identified genetic variants in MTR and investigated the mechanisms that affect its expression levels and that increase the risk of CHD in Chinese populations. METHODS AND RESULTS: The association between regulatory variants of the MTR gene and CHD was examined in three independent case-control studies in a total of 2340 patients with CHD and 2270 controls. The functional consequences of these variants were demonstrated using dual-luciferase assays, real-time polymerase chain reaction (PCR), electrophoretic mobility shift assays, surface plasma resonance, chromatin immunoprecipitation, and bisulfite sequencing, as well as by a group of predicted microRNAs using a gene reporter system. Two regulatory variants of MTR, -186T>G and +905G>A, were associated with an increased risk of CHD in both the separate and combined case-control studies (-186GG P = 1.32 × 10(-9); +905AA P = 6.35 × 10(-14)). Compared with the major allele, the -186G allele exhibited significantly lower promoter activity, decreased hnRNA and mRNA levels, reduced transcription factor binding affinity, and a more highly methylated promoter. The +905A allele exhibited a statistically stronger binding affinity to functional microRNAs that down regulate MTR expression at the translational level. Both of the minor alleles were correlated with elevated plasma homocysteine concentrations, indicating a genetic component for hyperhomocysteinaemia. CONCLUSIONS: Regulatory variants of the MTR gene increase CHD risk by reducing MTR expression and inducing the homocysteine accumulation and elevation.


Assuntos
5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/genética , Cardiopatias Congênitas/genética , Povo Asiático/genética , Estudos de Casos e Controles , Metilação de DNA/genética , Ferredoxina-NADP Redutase/genética , Expressão Gênica/genética , Predisposição Genética para Doença/genética , Genótipo , Homocisteína/metabolismo , Humanos , Hiper-Homocisteinemia/genética , MicroRNAs/genética , Fatores de Risco , Transcrição Gênica/genética
5.
J Biol Chem ; 288(25): 18121-33, 2013 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-23649631

RESUMO

Emerging evidence indicates that the miR-23a/24-2/27a cluster may possess a causal role in mammary tumorigenesis and function as a novel class of oncogenes. However, the regulatory mechanism of the miR-23a/24-2/27a cluster in mammary carcinoma cell invasion and migration is still largely unknown. We observed that the expression levels of miR-23a, miR-24-2 and miR-27a were significantly higher in breast cancer with lymph node metastasis, compared with that from patients without lymph node metastasis or normal tissue. Forced expression of the miR-23a/24-2/27a cluster promoted mammary carcinoma cell migration, invasion, and hepatic metastasis, through targeting Sprouty2 (SPRY2) and consequent activation of p44/42 MAPK. Epidermal growth factor induced the expression of the transcription factor c-MYC, which promoted the expression of mature miR-23a, miR-24-2, and miR-27a and subsequently decreased expression of SPRY2 and activated p44/42 MAPK to promote mammary carcinoma cell migration and invasion. We therefore suggest a novel link between epidermal growth factor and the miR-23a/24-2/27a cluster via the regulation of c-MYC, providing the potential for the miR-23a/24-2/27a cluster to be used as biomarker in the diagnosis and/or treatment of breast cancer.


Assuntos
Neoplasias da Mama/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Western Blotting , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Movimento Celular/genética , Fator de Crescimento Epidérmico/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/secundário , Células MCF-7 , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutação , Invasividade Neoplásica , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Heterólogo
6.
J Biol Chem ; 287(13): 9962-9971, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22253443

RESUMO

miR-124 is a brain-enriched microRNA that plays a crucial role in neural development and has been shown to be down-regulated in glioma and medulloblastoma, suggesting its possible involvement in brain tumor progression. Here, we show that miR-124 is down-regulated in a panel of different grades of glioma tissues and in all of the human glioma cell lines we examined. By integrated bioinformatics analysis and experimental confirmation, we identified SNAI2, which is often up-regulated in glioma, as a direct functional target of miR-124. Because SNAI2 has been shown to regulate stem cell functions, we examined the roles of miR-124 and SNAI2 in glioma cell stem-like traits. The results showed that overexpression of miR-124 and knockdown of SNAI2 reduced neurosphere formation, CD133(+) cell subpopulation, and stem cell marker (BMI1, Nanog, and Nestin) expression, and these effects could be rescued by re-expression of SNAI2. Furthermore, enhanced miR-124 expression significantly inhibited glioma cell invasion in vitro. Finally, stable overexpression of miR-124 and knockdown of SNAI2 inhibited the tumorigenicity and invasion of glioma cells in vivo. These findings reveal, for the first time, that the tumor suppressor activity of miR-124 could be partly due to its inhibitory effects on glioma stem-like traits and invasiveness through SNAI2.


Assuntos
Antígenos de Diferenciação/metabolismo , Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Glioma/metabolismo , MicroRNAs/biossíntese , Células-Tronco Neoplásicas/metabolismo , Animais , Antígenos de Diferenciação/genética , Biomarcadores Tumorais/genética , Neoplasias Encefálicas , Linhagem Celular Tumoral , Regulação para Baixo/genética , Glioma/genética , Glioma/patologia , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , Invasividade Neoplásica , Células-Tronco Neoplásicas/patologia , Fatores de Transcrição da Família Snail , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Regulação para Cima/genética
7.
Biochim Biophys Acta Mol Cell Res ; 1870(3): 119414, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36535371

RESUMO

Previous studies have shown that high levels of reactive oxygen species (ROS) and low tricarboxylic acid (TCA) activity in the brain promote pupal diapause, which is characterized by metabolic depression and lifespan extension. However, it is unclear whether ROS are associated with TCA activity. In this study, we demonstrate that ROS downregulate TCA activity and acetyl-CoA and pyruvate levels in the brains of diapause-destined pupae in the moth Helicoverpa armigera, as well as the protein levels of acetyl-CoA synthetase (ACS) and pyruvate kinase (PK), two proteins involved in the biosynthesis of acetyl-CoA and pyruvate, respectively. Interestingly, miR-34, which is highly expressed in the brains of diapause-destined pupae, can respond to ROS signaling. Furthermore, we show that miR-34 can reduce the expression of ACS and PK by directly targeting their mRNAs. Additionally, hypoxia-inducible factor (HIF), a transcription factor, can be activated by ROS and then promotes miR-34 transcription by binding a cis-element in its promoter. Moreover, we observed delayed pupal development after treatment with a ROS activator paraquat and a HIF activator dimethyloxallyl glycine. Taken together, these results suggest that a novel pathway ROS/HIF/miR-34/ACS-PK was found to negatively regulate TCA activity to promote insect diapause for lifespan extension.


Assuntos
MicroRNAs , Mariposas , Animais , Piruvato Quinase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Longevidade/genética , Acetilcoenzima A/metabolismo , Mariposas/genética , Metabolismo Energético , Piruvatos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo
8.
J Biol Chem ; 286(30): 26616-27, 2011 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-21642433

RESUMO

Heparin, which has been used as an anticoagulant drug for decades, inhibits angiogenesis, whereas thrombin promotes tumor-associated angiogenesis. However, the mechanisms underlying the regulation of angiogenesis by heparin and thrombin are not well understood. Here, we show that microRNA-10b (miR-10b) is down-regulated by heparin and up-regulated by thrombin in human microvascular endothelial cells (HMEC-1). Overexpression of miR-10b induces HMEC-1 cell migration, tube formation, and angiogenesis, and down-regulates homeobox D10 (HoxD10) expression via direct binding of miR-10b to the putative 3' UTR of HoxD10. In addition, HMEC-1 cell migration and tube formation are induced by HoxD10 knockdown, whereas angiogenesis is arrested when HoxD10 expression is increased after anti-miR-10b or heparin treatments. Furthermore, expression of miR-10b and its transcription factor Twist are up-regulated by thrombin, whereas HoxD10 expression is impaired by thrombin. Using quartz crystal microbalance analysis, we show that heparin binds to thrombin, thereby inhibiting thrombin-induced expression of Twist and miR-10b. However, the expression of miR-10b is not attenuated by heparin any more after thrombin expression is silenced by its siRNA. Interestingly, we find that heparin attenuates miR-10b expression and induces HoxD10 expression in vivo to inhibit angiogenesis and impair the growth of MDA-MB-231 tumor xenografts. These results provide insight into the molecular mechanism by which heparin and thrombin regulate angiogenesis.


Assuntos
Anticoagulantes/farmacologia , Células Endoteliais/metabolismo , Heparina/farmacologia , MicroRNAs/biossíntese , Neovascularização Patológica/metabolismo , Animais , Linhagem Celular Tumoral , Células Endoteliais/patologia , Feminino , Técnicas de Silenciamento de Genes , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , Transplante de Neoplasias , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transplante Heterólogo , Proteína 1 Relacionada a Twist/genética , Proteína 1 Relacionada a Twist/metabolismo
9.
J Biol Chem ; 285(47): 36995-7004, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-20826811

RESUMO

The emerging concept of generating cancer stem cells from epithelial-mesenchymal transition has attracted great interest; however, the factors and molecular mechanisms that govern this putative tumor-initiating process remain largely elusive. We report here that miR-200a not only regulates epithelial-mesenchymal transition but also stem-like transition in nasopharyngeal carcinoma cells. We first showed that stable knockdown of miR-200a promotes the transition of epithelium-like CNE-1 cells to the mesenchymal phenotype. More importantly, it also induced several stem cell-like traits, including CD133(+) side population, sphere formation capacity, in vivo tumorigenicity in nude mice, and stem cell marker expression. Consistently, stable overexpression of miR-200a switched mesenchyme-like C666-1 cells to the epithelial state, accompanied by a significant reduction of stem-like cell features. Furthermore, in vitro differentiation of the C666-1 tumor sphere resulted in diminished stem-like cell population and miR-200a induction. To investigate the molecular mechanism, we demonstrated that miR-200a controls epithelial-mesenchymal transition by targeting ZEB2, although it regulates the stem-like transition differentially and specifically by ß-catenin signaling. Our findings reveal for the first time the function of miR-200a in shifting nasopharyngeal carcinoma cell states via a reversible process coined as epithelial-mesenchymal to stem-like transition through differential and specific mechanisms.


Assuntos
Transição Epitelial-Mesenquimal , Proteínas de Homeodomínio/metabolismo , MicroRNAs/fisiologia , Neoplasias Nasofaríngeas/patologia , Células-Tronco Neoplásicas/patologia , Proteínas Repressoras/metabolismo , beta Catenina/metabolismo , Animais , Western Blotting , Diferenciação Celular , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Proteínas de Homeodomínio/antagonistas & inibidores , Proteínas de Homeodomínio/genética , Técnicas Imunoenzimáticas , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Nasofaríngeas/metabolismo , Células-Tronco Neoplásicas/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Homeobox 2 de Ligação a E-box com Dedos de Zinco , beta Catenina/antagonistas & inibidores , beta Catenina/genética
10.
Biochem Biophys Res Commun ; 391(1): 535-41, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19931509

RESUMO

Nasopharyngeal carcinoma (NPC), a highly metastatic and invasive malignant tumor originating from the nasopharynx, is widely prevalent in Southeast Asia, the Middle East and North Africa. Although viral, dietary and genetic factors have been implicated in NPC, the molecular basis of its pathogenesis is not well defined. Based on a recent microRNA (miRNA) microarray study showing miR-200 downregulation in NPC, we further investigated the role of miR-200a in NPC carcinogenesis. We found that the endogenous miR-200a expression level increases with the degree of differentiation in a panel of NPC cell lines, namely undifferentiated C666-1, high-differentiated CNE-1, and low-differentiated CNE-2 and HNE1 cells. By a series of gain-of-function and loss-of-function studies, we showed that over-expression of miR-200a inhibits C666-1 cell growth, migration and invasion, whereas its knock-down stimulates these processes in CNE-1 cells. In addition, we further identified ZEB2 and CTNNB1 as the functional downstream targets of miR-200a. Interestingly, knock-down of ZEB2 solely impeded NPC cell migration and invasion, whereas CTNNB1 suppression only inhibited NPC cell growth, suggesting that the inhibitory effects of miR-200a on NPC cell growth, migration and invasion are mediated by distinct targets and pathways. Our results reveal the important role of miR-200a as a regulatory factor of NPC carcinogenesis and a potential candidate for miRNA-based therapy against NPC.


Assuntos
Carcinoma/patologia , Transformação Celular Neoplásica/patologia , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , MicroRNAs/fisiologia , Neoplasias Nasofaríngeas/patologia , Proteínas Repressoras/genética , beta Catenina/genética , Sequência de Bases , Carcinoma/genética , Carcinoma/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Regulação para Baixo , Humanos , MicroRNAs/genética , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Invasividade Neoplásica , Homeobox 2 de Ligação a E-box com Dedos de Zinco
11.
Pharmacogenomics ; 21(3): 195-207, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31967512

RESUMO

Aim: miR-137 is downregulated in various cancers; however, its function in ovarian cancer remains unclear. Methods: The roles of miR-137 in apoptosis were accessed through IC50 values and DAPI assay. The regulation of MCL1 by miR-137 was investigated through luciferase reporter assay and immunoblot. Results: miR-137 mimic could decrease the IC50 value of cisplatin and promote apoptosis in OVCAR3 ovarian cancer cells. Using luciferase assay, results on a panel of anti-apoptotic proteins, we identified MCL1 as a target for miR-137 and the results were confirmed using immunoblot. Finally, the underlying pathway in which miR-137 may be involved was investigated by transcriptome sequencing. Conclusion: These results suggest that miR-137 downregulates MCL1 in ovarian cancer cells and mediates cisplatin-induced apoptosis.


Assuntos
Apoptose/genética , Carcinoma Epitelial do Ovário/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Neoplasias Ovarianas/patologia , Carcinoma Epitelial do Ovário/genética , Feminino , Células HEK293 , Humanos , Neoplasias Ovarianas/genética , Cultura Primária de Células , Células Tumorais Cultivadas
12.
Cancer Res ; 80(18): 3945-3958, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32680921

RESUMO

Malignant glioma constitutes one of the fatal primary brain tumors in adults. Such poor prognosis calls for a better understanding of cancer-related signaling pathways of this disease. Here we elucidate a MYC-miRNA-MXI1 feedback loop that regulates proliferation and tumorigenesis in glioma. MYC suppressed MXI1 expression via microRNA-155 (miR-155) and the microRNA-23a∼27a∼24-2 cluster (miR-23a cluster), whereas MXI1, in turn, inhibited MYC expression by binding to its promoter. Overexpression of miR-155 and the miR-23a cluster promoted tumorigenesis in U87 glioma cells. Furthermore, fat mass and obesity-associated protein (FTO), an N6-methyladenosine (m6A) RNA demethylase, regulated the loop by targeting MYC. The ethyl ester form of meclofenamic acid (MA2) inhibited FTO and enhanced the effect of the chemotherapy drug temozolomide on suppressing proliferation of glioma cells and negatively regulated the loop. These data collectively highlight a key regulatory circuit in glioma and provide potential targets for clinical treatment. SIGNIFICANCE: These findings elucidate a novel feedback loop that regulates proliferation in glioma and can be targeted via inhibition of FTO to enhance the efficacy of temozolomide.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/antagonistas & inibidores , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Antineoplásicos Alquilantes/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase/farmacologia , Sinergismo Farmacológico , Retroalimentação Fisiológica/efeitos dos fármacos , Retroalimentação Fisiológica/fisiologia , Feminino , Glioma/tratamento farmacológico , Glioma/patologia , Humanos , Ácido Meclofenâmico/farmacologia , Camundongos , Camundongos Nus , Transplante de Neoplasias , Temozolomida/farmacologia
13.
Biochem Pharmacol ; 180: 114116, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32579960

RESUMO

Runt-related transcription factor 1 (RUNX1), one subunit of core-binding factors in hematopoiesis and leukemia, was highly expressed in ovarian cancer (OC), but the role of RUNX1 in OC is largely unknown. Since we found that high expression of RUNX1 is correlated with poor survival in patients with OC through bioinformatic analysis of TCGA database, we developed RUNX1-knockout clones by CRISPR/Cas9 technique and discovered that RUNX1 depletion could promote cisplatin-induced apoptosis in OC cells, which was further confirmed by RUNX1 knockdown and overexpression. We also proved that RUNX1 could elevate the expression of BCL2. We then examined a total of 32 candidate miRNAs that might mediate the regulation between RUNX1 and BCL2, of which three miRNAs from the miR-17~92 cluster were found to be negatively regulated by RUNX1. Consistently, our analysis of data from TCGA database revealed the negative correlation between RUNX1 and the cluster. We further confirmed that miR-17~92 cluster could enhance cisplatin-induced apoptosis by directly targeting BCL2 3'UTR. Since rescue experiments proved that RUNX1 could repress cisplatin-induced apoptosis by up-regulating BCL2 via miR-17~92 cluster, combining RUNX1 inhibitor Ro5-3335 and cisplatin showed synergic effect in triggering OC cell apoptosis. Collectively, these findings show for the first time that combinational treatment of cisplatin and RUNX1 inhibitor could be used to potentiate apoptosis of ovarian cancer cells, and reveal the potential of targeting RUNX1 in ovarian cancer chemotherapy.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Subunidade alfa 2 de Fator de Ligação ao Core/antagonistas & inibidores , Neoplasias Ovarianas/metabolismo , Apoptose/genética , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Estimativa de Kaplan-Meier , MicroRNAs/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Longo não Codificante
14.
Data Brief ; 28: 104960, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31890801

RESUMO

The data in this article is the supplementary data of the research article entitled "Comparable magnetocaloric properties of melt-extracted Gd36Tb20Co20Al24 metallic glass microwires" (Yin et al., 2020). The data shows the circular cross section of Gd36Tb20Co20Al24 metallic glass microwires with a diameter of ∼55 µm. The data also shows that the chemical compositions of microwires are basically uniform on macro-scale and micro-scale.

15.
Pharmacogenomics ; 20(3): 155-165, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30543142

RESUMO

AIM: NF1 loss confers chemoresistance in multiple cancers. However, the etiology remains largely unknown. Our study aimed to scrutinize the role of NF1 in chemoresistant ovarian cancer and its underlying mechanism. MATERIALS & METHODS: 4',6-diamidino-2-phenylindole staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, luciferase reporter assay, chromatin immunoprecipitation, Western blot, quantitative real-time-PCR and rescue experiments were performed to illustrate the antiapoptotic role of NF1 loss and its underlying mechanism. RESULTS: NF1-knockdown ovarian cells showed resistance to cisplatin-induced apoptosis. Furthermore, NF1 regulated MCL1 expression at protein level. Further dissections suggested that miR-142-5p was regulated by NF1 via its promoter and targeted MCL1. Consistently, miR-142-5p mimic and si-MCL1 can attenuate the antiapoptotic effect of NF1 knockdown. CONCLUSION: NF1 knockdown endowed ovarian cells with resistance to cisplatin-induced apoptosis by targeting MCL1 via miR-142-5p.


Assuntos
MicroRNAs/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Neurofibromina 1/genética , Neoplasias Ovarianas/tratamento farmacológico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/efeitos adversos , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia
16.
Biochem Pharmacol ; 161: 98-112, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30639456

RESUMO

Chemotherapy is the preferred treatment for advanced ovarian cancer, but the 5-year survival rate remains low partly because of the development of drug resistance. Although it has been reported that X-linked inhibitor of apoptosis (XIAP) causes more severe chemoresistance in ovarian cancer cells and is highly expressed in chemoresistant ovarian cancer, the molecular mechanism underlying this dysregulation is unknown. The purpose of this study was to identify microRNAs (miRNAs) that bind to the 3' untranslated region (3'UTR) of XIAP and have a role in chemoresistance in ovarian cancer. Using in silico analysis and literature review, a panel of miRNAs dysregulated in chemoresistant ovarian cancer was generated from hundreds of miRNAs that were predicted to target the XIAP 3'UTR. Using a dual luciferase reporter assay and cellular co-transfection of a miRNA expression vector and a luciferase reporter fused to the XIAP 3'UTR cognate miRNA binding site, we identified three miRNAs of which miR-142-5p had the greatest inhibitory effect. We found that overexpression of miR-142-5p suppressed XIAP expression by binding to its 3'UTR in OVCAR3 and SKOV3 cells. Using a chemosensitivity assay, we found that in OVCAR3, SKOV3, and primary epithelial ovarian cancer (EOC) cells, overexpression or inhibition of miR-142-5p increased or suppressed their sensitivities to cisplatin respectively. In contrast, introducing XIAP without a 3'UTR counteracted the effect of overexpressed miR-142-5p on cisplatin-induced apoptosis in OVCAR3 ovarian cancer cells. Furthermore, we found a negative correlation between miR-142-5p expression and XIAP protein levels in clinical samples from patients with EOC. Using clinical and miRNA expression data of more than 200 ovarian cancer patients treated with platinum-based chemotherapy from The Cancer Genome Atlas (TCGA) database, we found ovarian cancer patients with higher expression levels of miR-142-5p had longer median progression-free survival as compared to patients with lower miR-142-5p levels. We demonstrated that miR-142-5p also targeted four other anti-apoptotic genes, baculoviral IAP repeat-containing 3 (BIRC3), B-cell lymphoma-2 (BCL2), BCL2 like 2 (BCL2L2), and myeloid cell leukemia sequence 1 (MCL1) specifically. Transcriptome sequencing shed light on the essential apoptosis-related pathway in which miR-142-5p may be involved. To conclude, our findings illustrate that miR-142-5p sensitizes ovarian cancer cells to cisplatin-induced apoptosis by targeting multiple anti-apoptotic genes including XIAP, and may also suggest the therapeutic potential of miR-142-5p in ovarian cancer treatment.


Assuntos
Antineoplásicos/metabolismo , Apoptose/fisiologia , Cisplatino/metabolismo , Marcação de Genes/métodos , MicroRNAs/metabolismo , Neoplasias Ovarianas/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Células HEK293 , Humanos , MicroRNAs/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética
17.
Oncol Lett ; 16(3): 4027-4032, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30128024

RESUMO

MicroRNA-137 (miR-137) has been reported to be abnormally expressed in a variety of types of cancer, including ovarian cancer. However, the roles served by miR-137 in cancer are not fully understood. In the present study, 3 single guide RNAs (sgRNAs) were designed, synthesized and inserted into pXPR001 plasmids. The pXPR001-sgRNA plasmids were verified using sequencing and integrated into the genome of the ovarian cancer cell line, A2780, through lentiviral transduction, puromycin selection and single-cell culture. PCR products amplified from single-cell cultures using primers covering miR-137 targeting sites were sequenced to identify clones with miR-137 gene disruption. Genome editing was detected in 72% of the clones derived from sgRNA2, 4% from sgRNA3 and 0% from sgRNA1. Of the clones from sgRNA2, 32% contained 1 edited miR-137 allele and 40% contained 2 edited miR-137 alleles. The expression of miR-137 in clones #2 and #3 could not be detected by reverse transcription-quantitative polymerase chain reaction. In addition, an MTT assay demonstrated that clones #2 and #3 exhibited enhanced proliferation. In conclusion, an miR-137-knockout cell model was successfully established in A2780 cells using CRISPR/Cas9 technology.

18.
Int J Oncol ; 51(1): 327-335, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28560455

RESUMO

MicroRNAs play a crucial role in gene expression regulation in various types of cancers. Previous studies show the expression level of miR­146a­5p is downregulated in epithelial ovarian cancer. Further investigations suggest this downregulation is responsible for apoptosis resistance in ovarian cancer cells. However, the mechanism of how miR­146a­5p promotes apoptosis remains unclear. In this study, the role of miR­146a­5p in cisplatin­induced apoptosis of ovarian cancer cells was assessed by DAPI staining, MTT assays, and monitoring expression of XIAP, BCL2L2, BIRC2 and BIRC5 through a dual­luciferase assay. Our results show that miR­146a­5p can regulate three important anti­apoptotic genes including XIAP, BCL2L2 and BIRC5 via their 3'UTRs. Not only can overexpression of miR­146a­5p downregulate the expression of XIAP in SKOV3 cells, but it also lowers the IC50 values of cisplatin in OVCAR3 and SKOV3 cells and enhances the susceptibility of OVCAR3, SKOV3 and primary ovarian cancer cells to cisplatin­induced apoptosis. The effect of XIAP rescuing cisplatin­induced apoptosis accelerated by miR­146a­5p further supports our conclusion. Our results suggest that the regulation of three anti­apoptotic genes by miR­146­5p enhances the therapeutic effects of cisplatin.


Assuntos
Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Cisplatino/farmacologia , Proteínas Inibidoras de Apoptose/metabolismo , MicroRNAs/genética , Neoplasias Ovarianas/patologia , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Apoptose , Proliferação de Células , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Survivina , Células Tumorais Cultivadas
19.
ACS Appl Mater Interfaces ; 9(46): 40281-40289, 2017 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29098849

RESUMO

Water electrolysis has been considered as one of the most efficient approaches to produce renewable energy, although efficient removal of gas bubbles during the process is still challenging, which has been proved to be critical and can further promote electrocatalytic water splitting. Herein, a novel strategy is developed to increase gas bubble escape rate for water splitting by using nonwoven stainless steel fabrics (NWSSFs) as the conductive substrate decorated with flakelike iron nickel-layered double hydroxide (FeNi LDH) nanostructures. The as-prepared FeNi LDH@NWSSF electrode shows a much faster escape rate of gas bubbles as compared to that of other commonly used three-dimensional porous catalytic electrodes, and the maximum dragging force for a bubble releasing between NWSSF channels is only one-seventh of the dragging force within nickel foam channels. As a result, it exhibits excellent electrocatalytic performance for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with low overpotentials of 210 and 110 mV at the current density of 10 mA cm-2 in 1 M KOH for OER and HER, respectively. There is almost no current drop after a long-time durability test. In addition, its performance for full water splitting is superior to that of the previously reported catalysts, with a voltage of 1.56 V at current density of 10 mA cm-2.

20.
Pharmacogenomics ; 18(18): 1671-1682, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29173002

RESUMO

AIM: Previous observations have implicated miR-509-3p's ability in regulating cisplatin-triggered apoptosis in ovarian cancer. However, the underlying mechanisms were not fully understood. MATERIALS & METHODS: The roles of miR-509-3p in cellular apoptosis were assessed through MTT and DAPI assays. The confirmation of the regulation of BCL2 family members by miR-509-3p was investigated by luciferase reporter assay, western blot, quantitative real-time PCR and rescue experiments. RESULTS: MiR-509-3p can decrease the IC50 values of cisplatin and promote apoptosis in ovarian cancer cells. Furthermore, on a panel of anti-apoptotic proteins, we identified that miR-509-3p could regulate BCL2, BCL2L2 and MCL1 via their 3'UTRs. CONCLUSION: Our study demonstrates that miR-509-3p could sensitize ovarian cancer cells to cisplatin treatment by targeting multiple anti-apoptosis genes including BCL2.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Cisplatino/farmacologia , MicroRNAs/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Regiões 3' não Traduzidas/genética , Antineoplásicos/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Células HEK293 , Humanos , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética
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