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1.
Gene ; 720: 144099, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31479715

RESUMO

Emerging evidence demonstrates that circular RNA (circRNA) is a novel class of non-coding RNA that plays a pivotal role in cancer. Recently, circ-PRMT5 was identified as an oncogene in bladder cancer. Nevertheless, its contribution to non-small cell lung cancer (NSCLC) is unknown. Herein, we aimed to clarify the biological role of circ-PRMT5 in NSCLC. High circ-PRMT5 expression was identified in NSCLC tissues and cell lines and positively correlated with larger tumor size, advanced clinic stage, lymph node metastasis as well as worse prognosis. Stable knockdown of circ-PRMT5 dramatically weakened the proliferative capacities of NSCLC cells both in vitro and in vivo. Mechanically, circ-PRMT5 could simultaneously effectively sponge three miRNAs (miR-377, miR-382 and miR-498) and alleviate their repression on the well-known oncogenic EZH2, resulting in increased EZH2 expression, thereby facilitating NSCLC progression. Importantly, a strong positive correlation between circ-PRMT5 and EZH2 expression was observed in NSCLC tissues. Overall, our data indicate that circ-PRMT5 is an oncogenic circRNA in NSCLC that can promote the growth of NSCLC via regulation of miR-377/382/498-EZH2 axis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/secundário , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , MicroRNAs/genética , Proteína-Arginina N-Metiltransferases/genética , RNA/genética , Animais , Apoptose , Biomarcadores Tumorais/análise , Carcinogênese , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proliferação de Células , Progressão da Doença , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Metástase Linfática , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Prognóstico , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
2.
J Cancer Res Clin Oncol ; 145(11): 2835-2843, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31506740

RESUMO

PURPOSE: Molecular mechanisms of response to hypomethylating agents in patients with myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) still remain largely unknown. Therefore, the effects of 5-Azacytidine (Aza) on clonal architecture and DNA methylation were investigated in this study. METHODS: Using next-generation sequencing (NGS), 30 myeloid leukemia-associated genes were analyzed in 15 MDS/CMML patients with excellent response to Aza. Effects on methylation levels were analyzed by quantitative methylation analysis using pyrosequencing for the global methylation marker LINE-1 in patients and myeloid cell lines. Various myeloid cell lines and a healthy cohort were screened for methylation levels in 23 genes. Selected targets were verified on the MDS/CMML cohort. RESULTS: The study presented here showed a stable variant allele frequency and stable global methylation levels in responding patients. A significant demethylation of EZH2 and NOTCH1 was revealed in patients with Aza response. CONCLUSIONS: A response to Aza is not associated with eradication of malignant clones, but rather with a stabilization of the clonal architecture. We suggest changes in CpG methylation levels of EZH2 and NOTCH1 as potential targets of epigenetic response to Aza treatment which may also serve as useful biomarkers after clinical evaluation.


Assuntos
Azacitidina/farmacologia , Biomarcadores Tumorais/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Leucemia Mielomonocítica Crônica/genética , Síndromes Mielodisplásicas/genética , Receptor Notch1/genética , Idoso , Antimetabólitos Antineoplásicos/farmacologia , Estudos de Casos e Controles , Ilhas de CpG , Metilação de DNA , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Feminino , Seguimentos , Perfilação da Expressão Gênica , Humanos , Leucemia Mielomonocítica Crônica/tratamento farmacológico , Leucemia Mielomonocítica Crônica/patologia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/patologia , Prognóstico , Receptor Notch1/metabolismo , Células Tumorais Cultivadas
3.
Shanghai Kou Qiang Yi Xue ; 28(3): 241-245, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31489409

RESUMO

PURPOSE: To study the effects of curcumin on EZH2 mRNA expression in the mandible and femur of ovariectomized osteoporosis rats,and to investigate its protective effect and mechanism. METHODS: Thirty female 6-month old SD rats were randomly divided into sham group,OVX group and experimental group. The rats in the experimental groups were given curcumin (110 mg/kg) by intragastric administration after ovariectomy, while rats in the sham group and OVX group were given the same dosage of carboxymethylcellulose sodium solution, once a day for 12 weeks. All rats were sacrificed after the last intragastric administration. The serum samples were collected for detemination of biochemistrical parameters. Micro-CT was used for bone parameters and the morphology of the trabecular bone of the left mandibles and femurs. The expression level of EZH2mRNA in right mandible and femurs tissue was detected by reverse transcription polymerase chain reaction (RT-PCR). SPSS22.0 software package was used for statistical analysis. RESULTS: The expression of EZH2mRNA in the OVX group was significantly higher than the sham group (P<0.05). Compared with the OVX group,curcumin increased BMD and improved bone microstructure, decreased serum contents of alkaline phosphatase,and down-regulated the expression levels of EZH2mRNA in bone tissues of rats with osteoporosis (P<0.05). CONCLUSIONS: Curcumin can effectively prevent the lose of bone volume of ovariectomized rats, and repaire bone microstructure. Its mechanism is related with down -regulation of EZH2mRNA.


Assuntos
Curcumina , Proteína Potenciadora do Homólogo 2 de Zeste , Inibidores Enzimáticos , Osteoporose , Animais , Densidade Óssea , Curcumina/farmacologia , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Mandíbula , Osteoporose/tratamento farmacológico , Ovariectomia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley
4.
Nat Commun ; 10(1): 2901, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263101

RESUMO

Dysregulation of histone modifications promotes carcinogenesis by altering transcription. Breast cancers frequently overexpress the histone methyltransferase EZH2, the catalytic subunit of Polycomb Repressor Complex 2 (PRC2). However, the role of EZH2 in this setting is unclear due to the context-dependent functions of PRC2 and the heterogeneity of breast cancer. Moreover, the mechanisms underlying PRC2 overexpression in cancer are obscure. Here, using multiple models of breast cancer driven by the oncogene ErbB2, we show that the tyrosine kinase c-Src links energy sufficiency with PRC2 overexpression via control of mRNA translation. By stimulating mitochondrial ATP production, c-Src suppresses energy stress, permitting sustained activation of the mammalian/mechanistic target of rapamycin complex 1 (mTORC1), which increases the translation of mRNAs encoding the PRC2 subunits Ezh2 and Suz12. We show that Ezh2 overexpression and activity are pivotal in ErbB2-mediated mammary tumourigenesis. These results reveal the hitherto unknown c-Src/mTORC1/PRC2 axis, which is essential for ErbB2-driven carcinogenesis.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Epigênese Genética , Complexo Repressor Polycomb 2/genética , Receptor ErbB-2/metabolismo , Quinases da Família src/metabolismo , Trifosfato de Adenosina/metabolismo , Adulto , Animais , Neoplasias da Mama/patologia , Carcinogênese , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Feminino , Humanos , Glândulas Mamárias Humanas/metabolismo , Glândulas Mamárias Humanas/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Pessoa de Meia-Idade , Mitocôndrias/genética , Mitocôndrias/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Biossíntese de Proteínas , Receptor ErbB-2/genética , Quinases da Família src/genética
5.
Yonsei Med J ; 60(8): 751-759, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31347330

RESUMO

PURPOSE: This study aimed to explore the effects and mechanisms of long non-coding RNA (lncRNA) anti-differentiation non-coding RNA (ANCR) on the osteogenesis of osteoblast cells in postmenopausal osteoporosis (PMOP). MATERIALS AND METHODS: Mice models of PMOP were established. ANCR expression and intracellular calcium ions were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and laser confocal microscopy, respectively. ANCR was silenced in osteoblast cells from PMOP mice by the transfection of siRNA-ANCR (si-ANCR). The proliferation and apoptosis of osteoblast cells was analyzed by MTT and flow cytometry, respectively. Alkaline phosphatase (ALP) activity and calcium nodules were examined by ALP and alizarin red staining assay, respectively. The expression of enhancer of zeste homolog 2 (EZH2), runt related transcription factor 2 (RUNX2), and OSTERIX was detected by qRT-PCR and Western blot. Furthermore, an osteogenesis model was constructed in mice, and osteoid formation was observed by hematoxylin-eosin (HE) staining. The interaction between lncRNA-ANCR and EZH2 was further identified by RNA pull-down assay. RESULTS: ANCR expression and intracellular calcium ions were increased in PMOP mice. Si-ANCR significantly increased the proliferation, ALP activity, calcium deposition of osteoblast cells and decreased apoptosis. ANCR and EZH2 were down-regulated by si-ANCR, while RUNX2 and OSTERIX were upregulated. Si-ANCR also promoted osteoid formation in mice treated with hydroxyapatite-tricalcium phosphate. In addition, ANCR specifically bound to EZH2. CONCLUSION: Silencing ANCR promotes the osteogenesis of PMOP osteoblast cells. The specific binding of ANCR with EZH2 suppressed RUNX2, thereby inhibiting osteogenesis.


Assuntos
Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Inativação Gênica , Osteoblastos/metabolismo , Osteogênese , Osteoporose Pós-Menopausa/genética , Osteoporose Pós-Menopausa/patologia , RNA Longo não Codificante/genética , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Osteoblastos/patologia , Osteogênese/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Ratos , Fator de Transcrição Sp7/metabolismo
6.
Cancer Sci ; 110(10): 3089-3097, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325197

RESUMO

Delphinidin, one of the main anthocyanidins, has potent anti-cancer properties. In this study, we investigated the effect of delphinidin on 1-methyl-1-nitrosourea (MNU)-induced breast carcinogenesis on rats and the mechanism of delphinidin via negative regulation of the HOTAIR/microRNA-34a axis. We found administration of delphinidin could effectively suppress MNU-induced mammal breast carcinogenesis. Delphinidin downregulated the level of HOTAIR and upregulated miR-34a in breast carcinogenesis. Western blot analysis confirmed that delphinidin treatment can significantly decrease the expression of ß-catenin, glycogen synthase kinase-3ß (Gsk3ß), c-Myc, cyclin-D1, and matrix metalloproteinase-7(MMP-7) expression in breast cancer cells, and inhibition of miR-34a significantly reduced the effect of delphinidin on c-Myc, cyclin-D1, and MMP-7. HOTAIR overexpression also blocked the effect of delphinidin on miR-34a and the Wnt/ß-catenin signaling pathway in MDA-MB-231 cells. RNA immunoprecipitation (RIP) assay and chromatin immunoprecipitation (ChIP) assay results showed that delphinidin upregulated miR-34a by inhibiting HOTAIR, coupled with enhancement of the zeste homolog 2 (EZH2) and histone H3 Lys27 trimethylation (H3K27me3). This study indicated that delphinidin may potentially suppress breast carcinogenesis and exert its anti-cancer effect through the HOTAIR/miR-34a axis. These findings provided new evidence for the use of delphinidin in preventing breast carcinogenesis.


Assuntos
Antocianinas/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Metilnitrosoureia/toxicidade , MicroRNAs/genética , RNA Longo não Codificante/genética , Animais , Antocianinas/farmacologia , Neoplasias da Mama/induzido quimicamente , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histonas/metabolismo , Humanos , Ratos , Via de Sinalização Wnt/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
8.
J Cancer Res Clin Oncol ; 145(9): 2227-2240, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31317325

RESUMO

PURPOSE: Enhancer of zeste homolog 2 (EZH2) is associated with epigenetic gene silencing and aggressiveness in many tumor types. However, the prognostic impact of high EZH2 expression is controversially discussed for colorectal cancer. For this reason, we immunohistochemically analyzed EZH2 expression in 105 specimens from colon cancer patients separately for tumor center and invasion front. METHODS: All sections from tissue microarrays were evaluated manually and digitally using Definiens Tissue Studio software (TSS). To mirror-image the EZH2 status at the tumor invasion front, we treated HCT116 colon cancer cells with the EZH2 inhibitor 3-Deazaneplanocin A (DZNep) and studied the growth of in ovo xenografts in the chorioallantoic membrane (CAM) assay. RESULTS: We showed a significant decrease in EZH2 expression and the repressive H3K27me3 code at the tumor invasion front as supported by the TSS-constructed heatmaps. Loss of EZH2 at tumor invasion front, but not in tumor center was correlated with unfavorable prognosis and more advanced tumor stages. The observed cell cycle arrest in vitro and in vivo was associated with higher tumor aggressiveness. Xenografts formed by DZNep-treated HCT116 cells showed loosely packed tumor masses, infiltrative growth into the CAM, and high vessel density. CONCLUSION: The differences in EZH2 expression between tumor center and invasion front as well as different scoring and cutoff values can most likely explain controversial literature data concerning the prognostic value of EZH2. Epigenetic therapies using EZH2 inhibitors have to be carefully evaluated for each specific tumor type, since alterations in cell differentiation might lead to unfavorable results.


Assuntos
Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Margens de Excisão , Adenocarcinoma/diagnóstico , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Biomarcadores Tumorais/metabolismo , Embrião de Galinha , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/cirurgia , Regulação para Baixo , Feminino , Células HCT116 , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Estudos Retrospectivos , Análise Serial de Tecidos
9.
Genomics Proteomics Bioinformatics ; 17(2): 154-168, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31154015

RESUMO

N6-methyladenosine (m6A), catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14, is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However, the roles and precise mechanisms of m6A modification in regulating neuronal development and adult neurogenesis remain unclear. Here, we examined the function of Mettl3, the key component of the complex, in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced m6A levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neuronal development and skewed the differentiation of aNSCs more toward glial lineage, but also affected the morphological maturation of newborn neurons in the adult brain. m6A immunoprecipitation combined with deep sequencing (MeRIP-seq) revealed that m6A was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically, m6A was present on the transcripts of histone methyltransferase Ezh2, and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively, our results uncover a crosstalk between RNA and histone modifications and indicate that Mettl3-mediated m6A modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.


Assuntos
Adenosina/análogos & derivados , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Neurogênese , Neurônios/metabolismo , Adenosina/metabolismo , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Animais , Encéfalo/metabolismo , Diferenciação Celular/genética , Proliferação de Células , Regulação da Expressão Gênica , Metiltransferases/metabolismo , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Neurônios/citologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
10.
Cell Mol Life Sci ; 76(19): 3711-3722, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31222372

RESUMO

Studies over the past decades have elucidated the critical role of autophagy in human health and diseases. Although the processes of autophagy in the cytoplasm have been well studied, the posttranscriptional and epigenetic regulation mechanisms of autophagy are still poorly understood. Protein methylation, including histone methylation and non-histone protein methylation, is the most important type of posttranscriptional and epigenetic modification. Recent studies have shown that protein methylation is associated with effects on autophagosome formation, autophagy-related protein expression, and signaling pathway activation, but the details are still unclear. Thus, it is important to summarize the current status and discuss the future directions of research on protein methylation in the context of autophagy.


Assuntos
Autofagia , Processamento de Proteína Pós-Traducional , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histona Metiltransferases/metabolismo , Histonas/metabolismo , Metilação , Transdução de Sinais
11.
Nat Commun ; 10(1): 2571, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31189930

RESUMO

While the antiandrogen enzalutamide (Enz) extends the castration resistant prostate cancer (CRPC) patients' survival an extra 4.8 months, it might also result in some adverse effects via inducing the neuroendocrine differentiation (NED). Here we found that lncRNA-p21 is highly expressed in the NEPC patients derived xenograft tissues (NEPC-PDX). Results from cell lines and human clinical sample surveys also revealed that lncRNA-p21 expression is up-regulated in NEPC and Enz treatment could increase the lncRNA-p21 to induce the NED. Mechanism dissection revealed that Enz could promote the lncRNA-p21 transcription via altering the androgen receptor (AR) binding to different androgen-response-elements, which switch the EZH2 function from histone-methyltransferase to non-histone methyltransferase, consequently methylating the STAT3 to promote the NED. Preclinical studies using the PDX mouse model proved that EZH2 inhibitor could block the Enz-induced NED. Together, these results suggest targeting the Enz/AR/lncRNA-p21/EZH2/STAT3 signaling may help urologists to develop a treatment for better suppression of the human CRPC progression.


Assuntos
Antagonistas de Androgênios/efeitos adversos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Tumores Neuroendócrinos/patologia , Feniltioidantoína/análogos & derivados , Neoplasias de Próstata Resistentes à Castração/patologia , RNA Longo não Codificante/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Linhagem Celular Tumoral , Progressão da Doença , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Humanos , Masculino , Camundongos , Camundongos SCID , Células Neuroendócrinas/efeitos dos fármacos , Células Neuroendócrinas/patologia , Tumores Neuroendócrinos/tratamento farmacológico , Tumores Neuroendócrinos/genética , Feniltioidantoína/efeitos adversos , Próstata/citologia , Próstata/efeitos dos fármacos , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
12.
DNA Cell Biol ; 38(7): 651-659, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31140859

RESUMO

Breast cancer is the leading cause of death in women. Although numerous clinical regimens are used to treat breast cancer and manifest satisfied efficacy, drug resistance is emerging as the major obstacle to their long-term use. It is critically necessary to decipher the molecular mechanism underlying this process to obtain improved and long-term use of each regimen. In the present study, we showed the negative relationship between EZH2 and chemoresistance to taxol in breast cancer cells. EZH2 interference was capable of decreasing while overexpression increasing apoptosis of breast cancer cells challenged with taxol. Meanwhile, p21, the inhibitor of cell cycle entry, interference upregulated, while overexpression downregulated apoptosis induced by taxol. Mechanistically, EZH2 was recruited to the promoter of p21 accompanied with H3K27me3 enrichment and transcription silencing. Collectively, EZH2 attenuates chemoresistance of breast cancer cells to taxol by dampening p21 epigenetically.


Assuntos
Antineoplásicos Fitogênicos/toxicidade , Neoplasias da Mama/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética , Paclitaxel/toxicidade , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Resistencia a Medicamentos Antineoplásicos , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Feminino , Humanos , Células MCF-7
13.
Nat Microbiol ; 4(7): 1208-1220, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31036909

RESUMO

The protozoan parasite Toxoplasma gondii has co-evolved with its homeothermic hosts (humans included) strategies that drive its quasi-asymptomatic persistence in hosts, hence optimizing the chance of transmission to new hosts. Persistence, which starts with a small subset of parasites that escape host immune killing and colonize the so-called immune privileged tissues where they differentiate into a low replicating stage, is driven by the interleukin 12 (IL-12)-interferon-γ (IFN-γ) axis. Recent characterization of a family of Toxoplasma effectors that are delivered into the host cell, in which they rewire the host cell gene expression, has allowed the identification of regulators of the IL-12-IFN-γ axis, including repressors. We now report on the dense granule-resident effector, called TEEGR (Toxoplasma E2F4-associated EZH2-inducing gene regulator) that counteracts the nuclear factor-κB (NF-κB) signalling pathway. Once exported into the host cell, TEEGR ends up in the nucleus where it not only complexes with the E2F3 and E2F4 host transcription factors to induce gene expression, but also promotes shaping of a non-permissive chromatin through its capacity to switch on EZH2. Remarkably, EZH2 fosters the epigenetic silencing of a subset of NF-κB-regulated cytokines, thereby strongly contributing to the host immune equilibrium that influences the host immune response and promotes parasite persistence in mice.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , NF-kappa B/metabolismo , Proteínas de Protozoários/metabolismo , Transdução de Sinais/genética , Toxoplasma/fisiologia , Animais , Linhagem Celular , Núcleo Celular/metabolismo , Citocinas/metabolismo , Fatores de Transcrição E2F/genética , Fatores de Transcrição E2F/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Expressão Gênica , Regulação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Carga Parasitária , Regiões Promotoras Genéticas , Multimerização Proteica , Proteínas de Protozoários/genética , Toxoplasma/genética , Toxoplasma/imunologia , Toxoplasmose/metabolismo , Toxoplasmose/parasitologia
14.
RNA ; 25(8): 935-947, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31048495

RESUMO

Some neurological disorders, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), fragile X syndrome, Huntington's disease, myotonic dystrophy, and various ataxias, can be caused by expansions of short nucleic acid sequence repeats in specific genes. A possible disease mechanism involves the transcribed repeat RNA binding an RNA-binding protein (RBP), resulting in its sequestration and thus dysfunction. Polycomb repressive complex 2 (PRC2), the histone methyltransferase that deposits the H3K27me3 mark of epigenetically silenced chromatin, binds G-rich RNAs and has especially high affinity for G-quadruplex (G-Q) structures. Here, we find that PRC2 target genes are derepressed and the RNA binding subunit EZH2 largely insoluble in postmortem brain samples from ALS/FTD patients with C9ORF72 (C9) repeat expansions, leading to the hypothesis that the (G4C2)n repeat RNA might be sequestering PRC2. Contrary to this expectation, we found that C9 repeat RNAs (n = 6 or 10) bind weakly to purified PRC2, and studies with the G-Q specific BG4 antibody and circular dichroism studies both indicated that these C9 RNAs have little propensity to form G-Qs in vitro. Several GC-rich triplet-repeat expansion RNAs also have low affinity for PRC2 and do not appreciably form G-Qs in vitro. The results are consistent with these sequences forming hairpin structures that outcompete G-Q folding when the repeat length is sufficiently large. We suggest that binding of PRC2 to these GC-rich RNAs is fundamentally weak but may be modulated in vivo by protein factors that affect secondary structure, such as helicases and other RBPs.


Assuntos
Esclerose Amiotrófica Lateral/genética , Proteína C9orf72/química , Proteína C9orf72/genética , Demência Frontotemporal/genética , Complexo Repressor Polycomb 2/metabolismo , Repetições de Trinucleotídeos , Esclerose Amiotrófica Lateral/metabolismo , Autopsia , Dicroísmo Circular , Proteína Potenciadora do Homólogo 2 de Zeste/química , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética , Demência Frontotemporal/metabolismo , Quadruplex G , Humanos , Complexo Repressor Polycomb 2/química , Solubilidade
15.
BMC Cancer ; 19(1): 455, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31092221

RESUMO

BACKGROUND: Wolf-Hirschhorn syndrome candidate gene-1 (WHSC1), a histone methyltransferase, has been found to be upregulated and its expression to be correlated with expression of enhancer of zeste homolog 2 (EZH2) in several cancers. In this study, we evaluated the role of WHSC1 and its therapeutic significance in ovarian clear cell carcinoma (OCCC). METHODS: First, we analyzed WHSC1 expression by quantitative PCR and immunohistochemistry using 23 clinical OCCC specimens. Second, the involvement of WHSC1 in OCCC cell proliferation was evaluated by MTT assays after siRNA-mediated WHSC1 knockdown. We also performed flow cytometry (FACS) to address the effect of WHSC1 on cell cycle. To examine the functional relationship between EZH2 and WHSC1, we knocked down EZH2 using siRNAs and checked the expression levels of WHSC1 and its histone mark H3K36m2 in OCCC cell lines. Finally, we checked WHSC1 expression after treatment with the selective inhibitor, GSK126. RESULTS: Both quantitative PCR and immunohistochemical analysis revealed that WHSC1 was significantly overexpressed in OCCC tissues compared with that in normal ovarian tissues. MTT assay revealed that knockdown of WHSC1 suppressed cell proliferation, and H3K36me2 levels were found to be decreased in immunoblotting. FACS revealed that WHSC1 knockdown affected the cell cycle. We also confirmed that WHSC1 expression was suppressed by EZH2 knockdown or inhibition, indicating that EZH2 is upstream of WHSC1 in OCCC cells. CONCLUSIONS: WHSC1 overexpression induced cell growth and its expression is, at least in part, regulated by EZH2. Further functional analysis will reveal whether WHSC1 is a promising therapeutic target for OCCC.


Assuntos
Adenocarcinoma de Células Claras/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Histona-Lisina N-Metiltransferase/genética , Neoplasias Ovarianas/genética , Proteínas Repressoras/genética , Adenocarcinoma de Células Claras/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Neoplasias Ovarianas/metabolismo , Proteínas Repressoras/metabolismo , Regulação para Cima
16.
Int J Nanomedicine ; 14: 2637-2653, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31043779

RESUMO

Background: For the past few years, gene-therapy has recently shown considerable clinical benefit in cancer therapy, and the applications of gene therapies in cancer treatments continue to increase perennially. EZH2, an ideal candidate for tumor gene therapy, plays an important role in the tumorigenesis. Methods: In this study, we developed a novel gene delivery system with a self-assembly method by Methoxy polyethylene glycol-polycaprolactone (MPEG-PCL) and DOTAP(DMC). And EZH2si-DMC was used to research anti-glioma both in vitro and in vivo. Results: DMC with zeta-potential value of 36.7 mV and size of 35.6 nm showed good performance in the delivery siRNA to glioma cell in vitro with high 98% transfection efficiency. EZH2si-DMC showed good anti-glioma effect in vitro through inducing cell apoptosis and inhibiting cell growth. What's more, treatment of tumor-bearing mice with DMC-EZH2si complex had significantly inhibited tumor growth at the subcutaneous model in vivo by inhibiting EZH2 protein expression, promoting apoptosis and reducing proliferation. Conclusion: The EZH2 siRNA and DMC complex may be used to treat the glioma in clinical as a new drug.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Glioma/tratamento farmacológico , Terapia de Alvo Molecular , Nanopartículas/química , RNA Interferente Pequeno/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Ácidos Graxos Monoinsaturados/síntese química , Ácidos Graxos Monoinsaturados/química , Feminino , Glioma/patologia , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Micelas , Nanopartículas/ultraestrutura , Poliésteres/síntese química , Poliésteres/química , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Compostos de Amônio Quaternário/síntese química , Compostos de Amônio Quaternário/química , RNA Interferente Pequeno/administração & dosagem
17.
Biomed Pharmacother ; 112: 108719, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30970517

RESUMO

Long noncoding RNAs (lncRNAs) are a type of noncoding RNA transcript that are characterized by lack of protein-coding capacity. The vital role of lncRNAs in tongue squamous cell carcinoma (TSCC) is attracting increasing attention. In the present study, we identify a key lncRNA regulating TSCC metastasis and investigated the underlying mechanism. Our results indicate that the lncRNA ADAMTS9-AS2 is most significantly upregulated in TSCC tissues from patients with lymph node metastasis and is closely associated with poor prognosis. Furthermore, ADAMTS9-AS2 knockdown in TSCC cells leads to a inhibition of cell migration and invasion and reverses TGF-ß1 induced EMT. ADAMTS9-AS2 knockdown also inhibits TSCC cell growth in vitro and in vivo. In addition, we show that ADAMTS9-AS2 is a cytoplasmic lncRNA that shares the miRNA response elements (MREs) of miR-600 with EZH2, which is confirmed by a luciferase reporter assay and AGO2-dependent RNA immunoprecipitation (RIP). In summary, our results demonstrate an explicit oncogenic role of ADAMTS9-AS2 in TSCC tumorigenesis via competition with miR-600, suggesting a new regulatory mechanism of ADAMTS9-AS2 and providing a potential therapeutic target for TSCC patients.


Assuntos
Carcinoma de Células Escamosas/patologia , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , RNA Longo não Codificante/genética , Transdução de Sinais/genética , Neoplasias da Língua/patologia , Carcinoma de Células Escamosas/genética , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Humanos , Metástase Linfática , MicroRNAs/metabolismo , Neoplasias da Língua/genética , Regulação para Cima
18.
Nat Commun ; 10(1): 1679, 2019 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-30976011

RESUMO

The Polycomb repressive complexes PRC1 and PRC2 act non-redundantly at target genes to maintain transcriptional programs and ensure cellular identity. PRC2 methylates lysine 27 on histone H3 (H3K27me), while PRC1 mono-ubiquitinates histone H2A at lysine 119 (H2Aub1). Here we present engineered mouse embryonic stem cells (ESCs) targeting the PRC2 subunits EZH1 and EZH2 to discriminate between contributions of distinct H3K27 methylation states and the presence of PRC2/1 at chromatin. We generate catalytically inactive EZH2 mutant ESCs, demonstrating that H3K27 methylation, but not recruitment to the chromatin, is essential for proper ESC differentiation. We further show that EZH1 activity is sufficient to maintain repression of Polycomb targets by depositing H3K27me2/3 and preserving PRC1 recruitment. This occurs in the presence of altered H3K27me1 deposition at actively transcribed genes and by a diffused hyperacetylation of chromatin that compromises ESC developmental potential. Overall, this work provides insights for the contribution of diffuse chromatin invasion by acetyltransferases in PRC2-dependent loss of developmental control.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Histonas/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Acetilação , Animais , Diferenciação Celular/fisiologia , Cromatina/metabolismo , Metilação de DNA/fisiologia , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Técnicas de Inativação de Genes , Camundongos , Células-Tronco Embrionárias Murinas , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 2/genética
19.
Chem Biol Interact ; 307: 51-57, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31026422

RESUMO

Nasopharyngeal carcinoma (NPC) is a head and neck epithelial malignancy with high prevalence and represents a significant disease burden. Eudesmin is a natural lignin that has been reported to exhibit antitumor effect on lung cancer. However, the effect of eudesmin on NPC has not been investigated. The aim of the present study was to evaluate the role of eudesmin in NPC and to explore the underlying mechanism. The NPC cell lines CNE-1 and HONE-1 were treated with eudesmin for 48 h. Cell viability was measured using MTT assay. Cell apoptosis was detected using flow cytometry. The expression levels of enhancer of zeste homolog 2 (EZH2), Akt, and p-Akt were measured using Western blot analysis. We found that eudesmin inhibited cell viability and induced cell apoptosis of NPC cell lines in a dose-dependent manner. Eudesmin suppressed the expression of EZH2 and blocked the activation of Akt signaling pathway. Inhibition of Akt signaling pathway caused significant decrease in EZH2 expression. Moreover, knockdown of EZH2 attenuated the effects of Akt overexpression on cell viability and apoptosis in NPC cells. In conclusion, eudesmin exhibited antitumor activity via downregulating EZH2 expression through the inhibition of Akt signaling pathway. Eudesmin could be developed as a new pharmacologic approach for NPC treatment.


Assuntos
Antineoplásicos/farmacologia , Regulação para Baixo/efeitos dos fármacos , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Furanos/farmacologia , Lignanas/farmacologia , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Furanos/química , Humanos , Lignanas/química , Carcinoma Nasofaríngeo/metabolismo , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos
20.
Inflamm Res ; 68(4): 325-336, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30820607

RESUMO

OBJECTIVE AND DESIGN: Renal ischemia-reperfusion (IR)-induced acute kidney injury (AKI) remains a major challenge in clinic. The histone methyltransferases enhancer of zest homolog-2 (EZH2) is associated with the development of renal injury. However, the molecular mechanism has not been fully elucidated. MATERIALS: AKI in C57BL/6 mice was generated by renal IR. TREATMENTS: The 3-deazaneplanocin A (DZNeP), a selective EZH2 inhibitor, or vehicle was administrated in mice after IR. HK-2 cells were exposed to hypoxia-reoxygenation (H/R) stress. METHODS: Apoptosis was detected by TUNEL assay or flow cytometry. EZH2, caspase-3, p38, F4/80+ macrophages, and CD3+ T cells were examined by immunohistochemistry or Western blot. Tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, IL-6, and IL-18 were measured using RT-PCR. RESULTS: Mice treated with DZNeP exhibited less severe renal dysfunction and tubular injury following IR. EZH2 inhibition decreased apoptotic cells while reducing activation of caspase-3 in kidneys under IR condition. Moreover, EZH2 inhibition impaired the recruitment of CD3+ T cells and F4/80+ cells in kidneys with IR. Administration of DZNeP suppressed the production of TNF-α, MCP-1, IL-6, and IL-18 in IR-treated kidneys. Of note, EZH2 inhibition reduced p38 phosphorylation in kidneys after IR. In H/R-treated HK-2 cells, DZNeP treatment or EZH2 knockdown reduced apoptosis. EZH2 inhibition inactivated p38 resulting in reduction of active caspase-3 and proinflammatory molecules. By contrast, EZH2 overexpression induced p38 phosphorylation, caspase-3 activation, and production of proinflammatory molecules, which was reversed by SB203580. CONCLUSIONS: EZH2 plays a crucial role in IR-induced AKI via modulation of p38 signaling. Targeting EZH2/p38 signaling pathway may offer novel strategies to protect kidneys from acute kidney injury induced by ischemia-reperfusion.


Assuntos
Lesão Renal Aguda/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Traumatismo por Reperfusão/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Lesão Renal Aguda/etiologia , Lesão Renal Aguda/genética , Lesão Renal Aguda/patologia , Animais , Caspase 3/metabolismo , Linhagem Celular , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Humanos , Rim/metabolismo , Rim/patologia , Masculino , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologia , Transdução de Sinais
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