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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.
Anticancer Res ; 39(8): 4179-4184, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366503

RESUMO

BACKGROUND/AIM: Enhancer of zeste homolog 2 (EZH2), the catalytic subunit of polycomb repressive complex 2 (PRC2), possesses histone N-methyltransferase (HMT) activity and plays an essential role in cancer initiation and development. The aim of the present study was to investigate the potential of Wedelolactone (WL) to inhibit the methylation activity of EZH2. MATERIALS AND METHODS: The mantle cell lymphoma (MCL) cell line, Mino, was treated with WL, while untreated cells were used as control. HMT activity and EZH2 amount were measured in nuclear extracts from WL-treated and control Mino cells. RESULTS: WL was found to target EZH2-mediated histone H3K27 methylation. Along with the inhibition of H3K27 methylation in vitro (IC50=0.3 µM), WL suppressed HMT activity in Mino cells with an IC50 value of 3.2 µM. We detected a reduced amount of EZH2 in Mino cells treated with WL, compared to untreated control cells. CONCLUSION: This is the first study to show that WL induces inhibition of H3K27 methylation via EZH2 modulation and decreases cell proliferation in MCL, in vitro. WL is proposed as a promising agent and a novel epigenetic approach in MCL investigation and treatment.


Assuntos
Cumarínicos/farmacologia , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Código das Histonas/genética , Linfoma de Célula do Manto/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Código das Histonas/efeitos dos fármacos , Histona Metiltransferases/genética , Histona Metiltransferases/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Metilação/efeitos dos fármacos , Complexo Repressor Polycomb 2/genética
3.
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
4.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(3): 820-826, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31204938

RESUMO

OBJECTIVE: To investigate the expression of miR-101 and EZH2 in patients with mantle cell lymphoma(MCL) and to analyze its correlation with clinical prognosis of MCL patients. METHODS: RQ-PCR and S-P immunohistochemistry were used to detect the expressions of miR-101 and EZH2 in tissue of MCL patients. CCK-8 was used to assay the effect of miR-100 minics on the proliferation of Jeko-1 and Mino cells; the flow cytometry with Annexin V/PI double staining was used to assay the apoptosis; Western blot was used to assay the effect of miR-101 minics on the expression of EZH2 protein in Jeko-1 and Mino cells. RESULTS: Compared with control group, miR-101 lowly expressed, and EZH2 protein highly expressed in MCL group, with very statistically significant difference(P<0.01).There was negative correlation between miR-101 and EZH2 expression(r=-0.638,P<0.05). The expression of miR-101 and EZH2 significantly correlated with B symptoms, International Prognostic Index(IPI) and Ann Arbor stage, respectively. Survival analysis showed that the overall survival(OS) rate of patients with low expression of miR-101 were significantly lower than that of patients with high miR-101 expression (P=0.0014), the OS rate of patients with EZH2 high expression were significantly lower than that of patients with EZH2 low expression (P=0.0093). The miR-100 minics could inhibit the proliferation of Jeko-1 and Mino cells, and increase the apoptotic rate. The expression of EZH2 protein was markedly suppressed by the miR-100 minics. CONCLUSION: The expression of miR-101 and EZH2 is different in MCL patients with different clinical stage and prognosis. The miR-101 can inhibit the cell proliferation and induce cell apoptosis of mantle cell lymphoma by targeting EZH2.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Linfoma de Célula do Manto , MicroRNAs/genética , Apoptose , Proliferação de Células , Humanos , Linfoma de Célula do Manto/genética , Prognóstico
5.
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
6.
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
7.
Pathobiology ; 86(2-3): 152-161, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31096221

RESUMO

INTRODUCTION: The interaction of K27M mutation in histone H3 (H3K27M mutation) with polycomb repressive complex 2 (PRC2) is facilitated by the enhancer of zeste homolog 2 (EZH2). Subsequently, this interaction leads to the global reduction level of H3K27me3. We analyzed the EZH2 expression level in H3K27M mutation-positive tumors and revealed the association of high EZH2 expression with poor survival. METHODS: Our study included 12 patients, with an age range of 6-56 years and treated between 2007 and 2016. All patients underwent MRI study for nonenhanced T1, T2, diffusion, gadolinium-enhanced T1-weighted imaging, and fluid-attenuated inversion recovery (FLAIR). Immunohistochemical staining was performed against H3K27M, H3K27me3, EZH2, EED, mutant isocitrate dehydrogenase 1 (IDH1), α-thalassemia X-linked intellectual disability (ATRX), p53, O6-methylguanine-DNA methyltransferase (MGMT), and Ki-67 antibodies. RESULTS: All patients were negative for IDH1R132H and H3K27me3, but H3K27M-positive. Staining against EZH2 was negative in all histological features of grade II cases (3/12) and positive in grade III and IV cases; EZH2 positivity is associated with poor prognosis (p = 0.0082). EZH2 positivity was not associated with EED positivity. Retained ATRX staining was found mostly in grade III and IV cases (6/12). P53 was predominantly positive in cases of astrocytoma and glioblastoma (8/12). The labeling index of Ki-67 was 1.2-31.4% for grade II and III histological features and 11.2-24.8% for grade IV. CONCLUSION: We suggest that the expression of EZH2 is not associated with the PRC2 pathway and increases in patients with H3K27M-mutant diffuse midline glioma and a poor prognosis. Further studies are necessary to understand the mechanism involved.


Assuntos
Neoplasias Encefálicas/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Glioma/genética , Mutação , Adolescente , Adulto , Neoplasias Encefálicas/diagnóstico , Criança , Feminino , Glioma/diagnóstico , Histonas/genética , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Complexo Repressor Polycomb 2/genética , Prognóstico , Coloração e Rotulagem , Análise de Sobrevida , Adulto Jovem
8.
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
9.
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
10.
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
11.
J Biol Regul Homeost Agents ; 33(2): 331-343, 2019 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30972996

RESUMO

LncRNA MALAT1 is reported to play a potential role in human cancers. Hence, we investigated the effects of MALAT1 on colorectal cancer in vitro and in vivo, and further validated whether MALAT1 affected colorectal cancer development and EZH2 expression via regulating miR-363-3p. The fresh colorectal cancer tissues, adjacent non-tumor tissues, FHC, LOVO, SW620, CL40 and HCT116 cells were analyzed in this study. MALAT1, miR-363-3p and EZH2 expression levels were assessed using qRT-PCR and Western blot. Cell proliferation, migration and invasion were also measured. Binding effects between MALAT1 and miR-363-3p, or miR-363-3p and EZH2 3'UTR were detected by dual luciferase assay. We observed that MALAT1 was highly expressed in colorectal cancer tissues and cells, and MALAT1 knockdown inhibited cell proliferation as well as expression levels of EZH2 by upregulated miR-363-3p in cell models and in vivo. Moreover, miR-363-3p functions as a downstream target of MALAT1, meanwhile EZH2 was a target of miR-363-3p, suggesting MALAT1 might regulate miR-363-3p and/or EZH2 expression. Collectively, we concluded that MALAT1 functioned as a ceRNA to promote colorectal cancer development and EZH2 expression through sponging miR-363-3p in vitro and in vivo.


Assuntos
Neoplasias Colorretais/patologia , Proteína Potenciadora do Homólogo 2 de Zeste/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Humanos
12.
Cancer Discov ; 9(4): 472-475, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30936220

RESUMO

Even in diffuse large B-cell lymphoma (DLBCL), a cancer of professional antigen-presenting cells, response rates to immune checkpoint blockade therapy have been limited. One reason for DLBCL immune evasion is epigenetic repression instead of activation of the antigen-presenting MHC-a dissection of mechanisms underlying this repression suggests an opening for restoring B-cell maturation and, along the way, MHC expression as a novel modality of cytoreducing DLBCL and simultaneously augmenting possibilities for immunotherapy.See related article by Ennishi et al., p. 546.


Assuntos
Linfoma Difuso de Grandes Células B , Adulto , Criança , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Humanos , Imunoterapia
13.
In Vivo ; 33(3): 737-742, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31028191

RESUMO

BACKGROUND/AIM: Nine genetic loci have been associated with abdominal aortic aneurysm (AAA) susceptibility, including DAB2IP. This gene is playing a role in apoptosis, cell proliferation and epithelial-to-mesenchymal transition in cancers. This study aimed to elucidate the differential expression levels of DAB2IP in AAA tissues and investigate whether mir-363-3p and EZH2 can be considered as potential mediators of its expression. MATERIALS AND METHODS: 18 AAA samples and 15 non-aneurysmatic controls were collected. Relative mRNA expression levels of DAB2IP, EZH2 and mir-363-3p were measured using qPCR. RESULTS: DAB2IP was significant up-regulated (~2.29 fold) in AAA tissues, while EZH2 and mir-363-3p were down-regulated (3.28 and 3.62-fold, respectively). A limited negative correlation was found between the DAB2IP and EZH2 expression and between DAB2IP and the mir-363-3p. CONCLUSION: An increased expression of DAB2IP in AAA tissues was shown. We suggest 2 potential mediators of DAB2IP expression in abdominal aortic aneurysm, EZH2 and mir-363-3p.


Assuntos
Aneurisma da Aorta Abdominal/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Expressão Gênica , MicroRNAs/genética , Proteínas Ativadoras de ras GTPase/genética , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/patologia , Biomarcadores , Comorbidade , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Interferência de RNA , Proteínas Ativadoras de ras GTPase/metabolismo
14.
Proc Natl Acad Sci U S A ; 116(13): 6075-6080, 2019 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-30867289

RESUMO

Genetic mutations affecting chromatin modifiers are widespread in cancers. In malignant peripheral nerve sheath tumors (MPNSTs), Polycomb repressive complex 2 (PRC2), which plays a crucial role in gene silencing, is inactivated through recurrent mutations in core subunits embryonic ectoderm development (EED) and suppressor of zeste 12 homolog (SUZ12), but mutations in PRC2's main catalytic subunit enhancer of zeste homolog 2 (EZH2) have never been found. This is in contrast to myeloid and lymphoid malignancies, which harbor frequent loss-of-function mutations in EZH2. Here, we investigated whether the absence of EZH2 mutations in MPNST is due to a PRC2-independent (i.e., noncanonical) function of the enzyme or to redundancy with EZH1. We show that, in the absence of SUZ12, EZH2 remains bound to EED but loses its interaction with all other core and accessory PRC2 subunits. Through genetic and pharmacological analyses, we unambiguously establish that EZH2 is functionally inert in this context, thereby excluding a PRC2-independent function. Instead, we show that EZH1 and EZH2 are functionally redundant in the slowly proliferating MPNST precursors. We provide evidence that the compensatory function of EZH1 is alleviated upon higher proliferation. This work reveals how context-dependent redundancies can shape tumor-type specific mutation patterns in chromatin regulators.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Neoplasias/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Cromatina/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Mutação/genética , Neoplasias/genética , Neurofibroma/genética , Neurofibroma/metabolismo , Complexo Repressor Polycomb 2/genética
15.
Neoplasma ; 66(4): 507-515, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-30868890

RESUMO

Laryngeal carcinoma is the second commonest head and neck carcinoma globally. MicroRNA-101 (miR-101) has been reported as a tumor suppressor in multiple malignancies including laryngeal squamous cell carcinoma (LSCC). However, the roles and molecular mechanisms of miR-101 in the development of LSCC have not been fully elucidated. In present study, RT-qPCR assay was performed to detect the expression of miR-101 and enhancer of zeste homolog 2 (EZH2) mRNA. Western blot assay was conducted to determine protein expression of LC3-Ⅰ, LC3-Ⅱ, p62 and EZH2. Cell proliferative capacity was evaluated by MTS assay. The effect of miR-101 alone or along with EZH2 on cell apoptosis was assessed by apoptotic index and caspase-3 activity. Bioinformatic analysis, luciferase assay and RNA immunoprecipitation (RIP) assay were carried out to investigate the interaction between miR-101 and EZH2. Results revealed that miR-101 expression was strikingly down-regulated in LSCC cell lines. Functional analyses showed that ectopic expression of miR-101 suppressed cell autophagy and proliferation and facilitated cell apoptosis in LSCC. Further investigations revealed that miR-101 inhibited EZH2 expression by direct interaction and EZH2 was highly expressed in LSCC cells. Also, EZH2 knockdown reduced the autophagic activity of LSCC cells. Moreover, restoration experiments showed that EZH2 up-regulation weakened miR-101-mediated anti-autophagy, anti-proliferation and pro-apoptosis effects in LSCC cells. In conclusion, our findings suggested that miR-101 inhibited autophagy and proliferation and promoted apoptosis via targeting EZH2 in LSCC, providing a deep insight into the pathogenesis of LSCC and hinting the pivotal roles of epigenetic modifications especially histone methylation in the development of LSCC.


Assuntos
Apoptose , Autofagia , Carcinoma de Células Escamosas/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Neoplasias Laríngeas/genética , MicroRNAs/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Laríngeas/patologia
16.
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
17.
J Hum Genet ; 64(6): 561-572, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30858506

RESUMO

Variants have been identified in the embryonic ectoderm development (EED) gene in seven patients with syndromic overgrowth similar to that observed in Weaver syndrome. Here, we present three additional patients with missense variants in the EED gene. All the missense variants reported to date (including the three presented here) have localized to one of seven WD40 domains of the EED protein, which are necessary for interaction with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). In addition, among the seven patients reported in the literature and the three new patients presented here, all of the reported pathogenic variants except one occurred at one of four amino acid residues in the EED protein. The recurrence of pathogenic variation at these loci suggests that these residues are functionally important (mutation hotspots). In silico modeling and calculations of the free energy changes resulting from these variants suggested that they not only destabilize the EED protein structure but also adversely affect interactions between EED, EZH2, and/or H3K27me3. These cases help demonstrate the mechanism(s) by which apparently deleterious variants in the EED gene might cause overgrowth and lend further support that amino acid residues in the WD40 domain region may be mutation hotspots.


Assuntos
Anormalidades Múltiplas/genética , Hipotireoidismo Congênito/genética , Anormalidades Craniofaciais/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Deformidades Congênitas da Mão/genética , Histona-Lisina N-Metiltransferase/genética , Complexo Repressor Polycomb 2/genética , Anormalidades Múltiplas/etiologia , Anormalidades Múltiplas/fisiopatologia , Adolescente , Criança , Simulação por Computador , Hipotireoidismo Congênito/etiologia , Hipotireoidismo Congênito/fisiopatologia , Anormalidades Craniofaciais/etiologia , Anormalidades Craniofaciais/fisiopatologia , Proteína Potenciadora do Homólogo 2 de Zeste/química , Feminino , Deformidades Congênitas da Mão/etiologia , Deformidades Congênitas da Mão/fisiopatologia , Histona-Lisina N-Metiltransferase/química , Humanos , Masculino , Simulação de Dinâmica Molecular , Taxa de Mutação , Mutação de Sentido Incorreto/genética , Complexo Repressor Polycomb 2/química , Conformação Proteica , Repetições WD40/genética , Sequenciamento Completo do Exoma
18.
Oncogene ; 38(22): 4384-4396, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30710146

RESUMO

Discovery of new actionable targets and functional networks in melanoma is an urgent need as only a fraction of metastatic patients achieves durable clinical benefit by targeted therapy or immunotherapy approaches. Here we show that NFATc2 expression is associated with an EMT-like transcriptional program and with an invasive melanoma phenotype, as shown by analysis of melanoma cell lines at the mRNA and protein levels, interrogation of the TCGA melanoma dataset and characterization of melanoma lesions by immunohistochemistry. Gene silencing or pharmacological inhibition of NFATc2 downregulated EMT-related genes and AXL, and suppressed c-Myc, FOXM1, and EZH2. Targeting of c-Myc suppressed FOXM1 and EZH2, while targeting of FOXM1 suppressed EZH2. Inhibition of c-Myc, or FOXM1, or EZH2 downregulated EMT-related gene expression, upregulated MITF and suppressed migratory and invasive activity of neoplastic cells. Stable silencing of NFATc2 impaired melanoma cell proliferation in vitro and tumor growth in vivo in SCID mice. In NFATc2+ EZH2+ melanoma cell lines pharmacological co-targeting of NFATc2 and EZH2 exerted strong anti-proliferative and pro-apoptotic activity, irrespective of BRAF or NRAS mutations and of BRAF inhibitor resistance. These results provide preclinical evidence for a role of NFATc2 in shaping the EMT-like melanoma phenotype and reveal a targetable vulnerability associated with NFATc2 and EZH2 expression in melanoma cells belonging to different mutational subsets.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Transição Epitelial-Mesenquimal/genética , Melanoma/genética , Fatores de Transcrição NFATC/genética , Animais , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação para Baixo/genética , Feminino , Proteína Forkhead Box M1/genética , GTP Fosfo-Hidrolases/genética , Regulação Neoplásica da Expressão Gênica/genética , Inativação Gênica/fisiologia , Humanos , Melanoma/patologia , Camundongos , Camundongos SCID , Mutação/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-myc/genética , Regulação para Cima/genética
19.
J Exp Clin Cancer Res ; 38(1): 92, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30786928

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) with stemness features are pivotal for tumorigenesis, chemoresistance, and progression. Long non-coding RNAs have been implicated in the regulation of HCC stemness features; however, their mechanisms remain largely unknown. Here, we found that Lnc-PDZD7 is a potential oncogene. We systematically analyzed the clinical significance and mechanism of Lnc-PDZD7 in stemness and chemosensitivity regulation. METHODS: We analyzed the Lnc-PDZD7 expression levels in liver cancer tissues and cell line by qRT-PCR and In situ hybridization. Gain- and loss-of-function experiments were conducted to investigate the biological functions of Lnc-PDZD7 in stemness and chemosensitivity regulation. Bioinformatics analysis, dual-luciferase reporter assays were performed to validate that Lnc-PDZD7 competitively regulates EZH2, Moreover, chromatin immunoprecipitation assays, bisulfite genomic sequencing and Western blot were performed to evaluate the mechanisms of EZH2 repressing ATOH8. RESULTS: Lnc-PDZD7 is frequently upregulated in HCC tissues. Patients with high Lnc-PDZD7 expression had poorer prognoses and a poor response to adjuvant TACE therapy. Lnc-PDZD7 could promote stemness features and suppress the sensitivity of HCC cells to anticancer drugs in vitro and in vivo. Mechanistically, Lnc-PDZD7 functioned as a molecular sponge for miR-101, antagonizing its ability to repress EZH2 expression. Subsequently, EZH2 can further inhibit the expression of the stemness regulator ATOH8 via elevating its H3K27 trimethylation and DNA methylation. CONCLUSION: Lnc-PDZD7 promotes stemness properties and suppresses chemosensitivity though the miR-101/EZH2/ATOH8 pathway, providing new biomarkers for diagnosis and potential drug targets for HCC.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carcinoma Hepatocelular/genética , Proteínas de Transporte/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Repressão Epigenética , Neoplasias Hepáticas/genética , Adulto , Idoso , Animais , Carcinogênese/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Metilação de DNA/genética , Progressão da Doença , Feminino , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Pessoa de Meia-Idade , Transcrição Genética , Regulação para Cima
20.
Mol Cell ; 73(5): 930-945.e4, 2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30709709

RESUMO

R-loops are three-stranded nucleic acid structures that form during transcription, especially over unmethylated CpG-rich promoters of active genes. In mouse embryonic stem cells (mESCs), CpG-rich developmental regulator genes are repressed by the Polycomb complexes PRC1 and PRC2. Here, we show that R-loops form at a subset of Polycomb target genes, and we investigate their contribution to Polycomb repression. At R-loop-positive genes, R-loop removal leads to decreased PRC1 and PRC2 recruitment and Pol II activation into a productive elongation state, accompanied by gene derepression at nascent and processed transcript levels. Stable removal of PRC2 derepresses R-loop-negative genes, as expected, but does not affect R-loops, PRC1 recruitment, or transcriptional repression of R-loop-positive genes. Our results highlight that Polycomb repression does not occur via one mechanism but consists of different layers of repression, some of which are gene specific. We uncover that one such mechanism is mediated by an interplay between R-loops and RING1B recruitment.


Assuntos
Ilhas de CpG , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Embrionárias Murinas/fisiologia , Complexo Repressor Polycomb 1/metabolismo , Regiões Promotoras Genéticas , Transcrição Genética , Ubiquitina-Proteína Ligases/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Regulação para Baixo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Conformação de Ácido Nucleico , Complexo Repressor Polycomb 1/genética , Ligação Proteica , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Relação Estrutura-Atividade , Ubiquitina-Proteína Ligases/genética
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