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1.
Proc Natl Acad Sci U S A ; 117(37): 22880-22889, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32868440

RESUMO

Polycomb group proteins are essential regulators of developmental processes across animals. Despite their importance, studies on Polycomb are often restricted to classical model systems and, as such, little is known about the evolution of these important chromatin regulators. Here we focus on Polycomb Repressive Complex 1 (PRC1) and trace the evolution of core components of canonical and non-canonical PRC1 complexes in animals. Previous work suggested that a major expansion in the number of PRC1 complexes occurred in the vertebrate lineage. We show that the expansion of the Polycomb Group RING Finger (PCGF) protein family, an essential step for the establishment of the large diversity of PRC1 complexes found in vertebrates, predates the bilaterian-cnidarian ancestor. This means that the genetic repertoire necessary to form all major vertebrate PRC1 complexes emerged early in animal evolution, over 550 million years ago. We further show that PCGF5, a gene conserved in cnidarians and vertebrates but lost in all other studied groups, is expressed in the nervous system in the sea anemone Nematostella vectensis, similar to its mammalian counterpart. Together this work provides a framework for understanding the evolution of PRC1 complex diversity and it establishes Nematostella as a promising model system in which the functional ramifications of this diversification can be further explored.


Assuntos
Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Animais , Antozoários/genética , Núcleo Celular/metabolismo , Cromatina/genética , Bases de Dados Genéticas , Evolução Molecular , Inativação Gênica/fisiologia , Variação Genética/genética , Humanos , Proteínas do Grupo Polycomb/genética , Vertebrados/genética
2.
Nat Commun ; 11(1): 4782, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963223

RESUMO

Polycomb and Trithorax group proteins maintain stable epigenetic memory of gene expression states for some genes, but many targets show highly dynamic regulation. Here we combine experiment and theory to examine the mechanistic basis of these different modes of regulation. We present a mathematical model comprising a Polycomb/Trithorax response element (PRE/TRE) coupled to a promoter and including Drosophila developmental timing. The model accurately recapitulates published studies of PRE/TRE mediated epigenetic memory of both silencing and activation. With minimal parameter changes, the same model can also recapitulate experimental data for a different PRE/TRE that allows dynamic regulation of its target gene. The model predicts that both cell cycle length and PRE/TRE identity are critical for determining whether the system gives stable memory or dynamic regulation. Our work provides a simple unifying framework for a rich repertoire of PRE/TRE functions, and thus provides insights into  genome-wide Polycomb/Trithorax regulation.


Assuntos
Proteínas Cromossômicas não Histona/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Epigenômica , Regulação da Expressão Gênica no Desenvolvimento/genética , Modelos Teóricos , Complexo Repressor Polycomb 1/genética , Animais , Divisão Celular , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Epigênese Genética , Feminino , Inativação Gênica , Complexo Repressor Polycomb 1/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Regiões Promotoras Genéticas , Elementos de Resposta
3.
Environ Toxicol ; 35(11): 1234-1240, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32621571

RESUMO

As a natural compound, resveratrol (Res) is confirmed to be promising drug for the treatment of malignant tumors. Therefore, our study aimed to observe the impacts of Res on the proliferation and apoptosis of oral squamous cell carcinoma cells (HSC-3 cells) as well as the mechanism involving chromobox protein homolog 7 (CBX7) signal transduction. HSC-3 cells were treated with Res, Akt agonist (AL3818) and p16 inhibitor (SC79), and transfected with CBX7 mimics and inhibitor plasmids. The CCK-8 assay was used to detect cell proliferation, flow cytometry was performed to assess cell cycle and apoptosis, and cell colonies and histone DNA level were also measured. Western blot analysis was used to determine the expression levels of related proteins. HSC-3 cells showed decreased cell proliferation, colonies, BrdU-counled cells and increased apoptosis, histone DNA level, the activities of caspase-3 and caspase-9 when treated with Res. Western blot analysis revealed elevated Cle-PARP and Cle-caspase 3 expression and reduced t-PARP expression in HSC-3 cells treated with Res compared with control. AL3818 and SC79 could decrease the inhibitory effects of Res on the growth of HSC-3 cells. Furthermore, CBX7 overexpression could also partly reverse the roles of Res in the growth of HSC-3 cells, and Akt and p16 signal transduction. Our results demonstrate that Res suppresses the proliferation, and induces the apoptosis of oral squamous cell carcinoma cells through the inhibition of CBX7/Akt and the activation of p16 cascades.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Resveratrol/uso terapêutico , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3 , Caspase 9 , Ciclo Celular , Linhagem Celular Tumoral , Humanos , Neoplasias Bucais , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Resveratrol/farmacologia , Transdução de Sinais
4.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(3): 815-820, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-32552941

RESUMO

OBJECTIVE: To explore the molecular mechanism by which miR-218 targeting Bmi-1 inhibits the proliferation of acute promyelocytic leukemia (APL) cells. METHODS: APL cell line HL-60 was transfected by miR-218 and RNA-negative control sequences, respectively. The expression of miR-218 in cells was detected by real-time fluorescence quantitative PCR. The effect of transfected miR-218 on the proliferation of APL cells was detected by MTT assay. Cell apoptosis was detected by flow cytometry. The regulation effect of miR-218 on Bmi-1 expression was determined by Western blot. The correlation of miR-218 expressions with Bmi-1 was analyzed by Spearman test. The targeted relationship between miR-218 and Bmi-1 was verified by luciferase assay. RESULTS: MTT assay showed that the proliferation of HL-60 cells in vitro was inhibited by high expression miR-218 significantly. Flow cytometry showed that the G1 and G2 phase cells increased while the S phase cells decreased after transfected by miR-218. Western blot showed that the level of Bmi-1 protein in HL-60 cells decreased significantly after transfection of miR-218 (P<0.05). Spearman correlation analysis showed that the mRNA level of miR-218 negatively correlated with the protein content of Bmi-1 (r=-0.326, P<0.01). Luciferase assay indicated that Bmi-1 could targeted on miR-218 directly. CONCLUSION: miR-218 can inhibit the proliferation, metastasis and invasion of APL cells, which can be related with the down-regulated of Bmi-1.


Assuntos
Leucemia Promielocítica Aguda/genética , MicroRNAs/genética , Complexo Repressor Polycomb 1/genética , Apoptose , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Células HL-60 , Humanos
5.
Proc Natl Acad Sci U S A ; 117(27): 15673-15683, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571933

RESUMO

Stemness encompasses the capability of a cell for self-renewal and differentiation. The stem cell maintains a balance between proliferation, quiescence, and regeneration via interactions with the microenvironment. Previously, we showed that ectopic expression of the mitochondrial ribosomal protein S18-2 (MRPS18-2) led to immortalization of primary fibroblasts, accompanied by induction of an embryonic stem cell (ESC) phenotype. Moreover, we demonstrated interaction between S18-2 and the retinoblastoma-associated protein (RB) and hypothesized that the simultaneous expression of RB and S18-2 is essential for maintaining cell stemness. Here, we experimentally investigated the role of S18-2 in cell stemness and differentiation. Concurrent expression of RB and S18-2 resulted in immortalization of Rb1 -/- primary mouse embryonic fibroblasts and in aggressive tumor growth in severe combined immunodeficiency mice. These cells, which express both RB and S18-2 at high levels, exhibited the potential to differentiate into various lineages in vitro, including osteogenic, chondrogenic, and adipogenic lineages. Mechanistically, S18-2 formed a multimeric protein complex with prohibitin and the ring finger protein 2 (RNF2). This molecular complex increased the monoubiquitination of histone H2ALys119, a characteristic trait of ESCs, by enhanced E3-ligase activity of RNF2. Furthermore, we found enrichment of KLF4 at the S18-2 promoter region and that the S18-2 expression is positively correlated with KLF4 levels. Importantly, knockdown of S18-2 in zebrafish larvae led to embryonic lethality. Collectively, our findings suggest an important role for S18-2 in cell stemness and differentiation and potentially also in cancerogenesis.


Assuntos
Mitocôndrias/genética , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas de Ligação a Retinoblastoma/genética , Proteínas Ribossômicas/genética , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Autorrenovação Celular/genética , Fibroblastos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Histonas/genética , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Fatores de Transcrição Kruppel-Like/genética , Camundongos , Mitocôndrias/metabolismo , Complexo Repressor Polycomb 1/genética , Proteínas Ribossômicas/química , Microambiente Tumoral/genética , Ubiquitina-Proteína Ligases/genética
6.
Am J Physiol Renal Physiol ; 318(6): F1531-F1538, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32390514

RESUMO

Renal ischemia-reperfusion injury (I/R) usually occurs in renal transplantation and partial nephrectomy, which could lead to acute kidney injury. However, the effective treatment for renal I/R still remains limited. In the present study, we investigated whether inhibition of chromobox 7 (CBX7) could attenuate renal I/R injury in vivo and in vitro as well as the potential mechanisms. Adult male mice were subjected to right renal ischemia and reperfusion for different periods, both with and without the CBX7 inhibitor UNC3866. In addition, human kidney cells (HK-2) were subjected to a hypoxia/reoxygenation (H/R) process for different periods, both with or without the CBX7 inhibitor or siRNA for CBX7. The results showed that expression of CBX7, glucose regulator protein-78 (GRP78), phosphorylated eukaryotic translation initiation factor-2α (p-eIF2α), and C/EBP homologous protein (CHOP) were increased after extension of I/R and H/R periods. Moreover, overexpression of CBX7 could elevate the expression of CBX7, GRP78, p-eIF2α, and CHOP. However, CBX7 inhibition with either UNC3866 or genetic knockdown led to reduced expression of GRP78, p-eIF2α, and CHOP through nuclear factor-erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 activation in I/R and H/R injury. Furthermore, ML385, the Nrf2 inhibitor, could elevate endoplasmic reticulum stress levels, abrogating the protective effects of UNC3866 against renal I/R injury. In conclusion, our results demonstrated that CBX7 inhibition alleviated acute kidney injury by preventing endoplasmic reticulum stress via the Nrf2/HO-1 pathway, indicating that CBX7 inhibitor could be a potential therapeutic target for renal I/R injury.


Assuntos
Lesão Renal Aguda/prevenção & controle , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Rim/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Oligopeptídeos/farmacologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Traumatismo por Reperfusão/prevenção & controle , Lesão Renal Aguda/enzimologia , Lesão Renal Aguda/genética , Lesão Renal Aguda/patologia , Animais , Hipóxia Celular , Linhagem Celular , Heme Oxigenase-1/genética , Humanos , Rim/enzimologia , Rim/patologia , Masculino , Proteínas de Membrana/genética , Camundongos , Fator 2 Relacionado a NF-E2/genética , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologia , Transdução de Sinais
7.
Genes Dev ; 34(13-14): 931-949, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32439634

RESUMO

Polycomb group (PcG) proteins silence gene expression by chemically and physically modifying chromatin. A subset of PcG target loci are compacted and cluster in the nucleus; a conformation that is thought to contribute to gene silencing. However, how these interactions influence gross nuclear organization and their relationship with transcription remains poorly understood. Here we examine the role of Polycomb-repressive complex 1 (PRC1) in shaping 3D genome organization in mouse embryonic stem cells (mESCs). Using a combination of imaging and Hi-C analyses, we show that PRC1-mediated long-range interactions are independent of CTCF and can bridge sites at a megabase scale. Impairment of PRC1 enzymatic activity does not directly disrupt these interactions. We demonstrate that PcG targets coalesce in vivo, and that developmentally induced expression of one of the target loci disrupts this spatial arrangement. Finally, we show that transcriptional activation and the loss of PRC1-mediated interactions are separable events. These findings provide important insights into the function of PRC1, while highlighting the complexity of this regulatory system.


Assuntos
Núcleo Celular/genética , Genoma/genética , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Animais , Fator de Ligação a CCCTC/metabolismo , Embrião de Mamíferos , Camundongos , Células-Tronco Embrionárias Murinas , Proteínas do Grupo Polycomb/metabolismo , Ligação Proteica , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
8.
Cancer Res ; 80(11): 2243-2256, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32273282

RESUMO

Epigenetic regulation of gene transcription has been shown to coordinate with nutrient availability, yet the mechanisms underlying this coordination remain incompletely understood. Here, we show that glucose starvation suppresses histone 2A K119 monoubiquitination (H2Aub), a histone modification that correlates with gene repression. Glucose starvation suppressed H2Aub levels independently of energy stress-mediated AMP-activated protein kinase activation and possibly through NADPH depletion and subsequent inhibition of BMI1, an integral component of polycomb-repressive complex 1 (PRC1) that catalyzes H2Aub on chromatin. Integrated transcriptomic and epigenomic analyses linked glucose starvation-mediated H2Aub repression to the activation of genes involved in the endoplasmic reticulum (ER) stress response. We further showed that this epigenetic mechanism has a role in glucose starvation-induced cell death and that pharmacologic inhibition of glucose transporter 1 and PRC1 synergistically promoted ER stress and suppressed tumor growth in vivo. Together, these results reveal a hitherto unrecognized epigenetic mechanism coupling glucose availability to the ER stress response. SIGNIFICANCE: These findings link glucose deprivation and H2A ubiquitination to regulation of the ER stress response in tumor growth and demonstrate pharmacologic susceptibility to inhibition of polycomb and glucose transporters.


Assuntos
Estresse do Retículo Endoplasmático/genética , Glucose/metabolismo , Histonas/genética , Histonas/metabolismo , Neoplasias Renais/genética , Neoplasias Pulmonares/genética , Animais , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Morte Celular/fisiologia , Linhagem Celular Tumoral , Epigênese Genética , Feminino , Regulação Neoplásica da Expressão Gênica , Glucose/administração & dosagem , Glucose/deficiência , Transportador de Glucose Tipo 1/antagonistas & inibidores , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Células HEK293 , Xenoenxertos , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Fosforilação , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Ubiquitinação
9.
PLoS One ; 15(4): e0227592, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32343689

RESUMO

BMI1 is a core protein of the polycomb repressive complex 1 (PRC1) that is overexpressed in several cancer types, making it a promising target for cancer therapies. However, the underlying mechanisms and interactions associated with BMI1-induced tumorigenesis are often context-dependent and complex. Here, we performed a drug resistance screen on mutagenized human haploid HAP1 cells treated with BMI1 inhibitor PTC-318 to find new genetic and mechanistic features associated with BMI1-dependent cancer cell proliferation. Our screen identified NUMA1-mutations as the most significant inducer of PTC-318 cell death resistance. Independent validations on NUMA1-proficient HAP1 and non-small cell lung cancer cell lines exposed to BMI1 inhibition by PTC-318 or BMI1 knockdown resulted in cell death following mitotic arrest. Interestingly, cells with CRISPR-Cas9 derived NUMA1 knockout also showed a mitotic arrest phenotype following BMI1 inhibition but, contrary to cells with wildtype NUMA1, these cells were resistant to BMI1-dependent cell death. The current study brings new insights to BMI1 inhibition-induced mitotic lethality in cancer cells and presents a previously unknown role of NUMA1 in this process.


Assuntos
Antineoplásicos/farmacologia , Carcinogênese/genética , Proteínas de Ciclo Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias/genética , Complexo Repressor Polycomb 1/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Sistemas CRISPR-Cas/genética , Carcinogênese/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Técnicas de Inativação de Genes , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/genética , RNA Interferente Pequeno/metabolismo
10.
Nat Cell Biol ; 22(4): 439-452, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32203418

RESUMO

Stable propagation of epigenetic information is important for maintaining cell identity in multicellular organisms. However, it remains largely unknown how mono-ubiquitinated histone H2A on lysine 119 (H2AK119ub1) is established and stably propagated during cell division. In this study, we found that the proteins RYBP and YAF2 each specifically bind H2AK119ub1 to recruit the RYBP-PRC1 or YAF2-PRC1 complex to catalyse the ubiquitination of H2A on neighbouring nucleosomes through a positive-feedback model. Additionally, we demonstrated that histone H1-compacted chromatin enhances the distal propagation of H2AK119ub1, thereby reinforcing the inheritance of H2AK119ub1 during cell division. Moreover, we showed that either disruption of RYBP/YAF2-PRC1 activity or impairment of histone H1-dependent chromatin compaction resulted in a significant defect of the maintenance of H2AK119ub1. Therefore, our results suggest that histone H1-dependent chromatin compaction plays a critical role in the stable propagation of H2AK119ub1 by RYBP/YAF2-PRC1 during cell division.


Assuntos
Proteínas de Ciclo Celular/genética , Histonas/genética , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas Musculares/genética , Complexo Repressor Polycomb 1/genética , Processamento de Proteína Pós-Traducional , Proteínas Repressoras/genética , Animais , Sistemas CRISPR-Cas , Proteínas de Ciclo Celular/metabolismo , Divisão Celular , Epigênese Genética , Retroalimentação Fisiológica , Deleção de Genes , Edição de Genes , Células HEK293 , Histonas/metabolismo , Humanos , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Proteínas Musculares/metabolismo , Nucleossomos/química , Nucleossomos/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Ligação Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Repressoras/metabolismo , Ubiquitinação
11.
J Clin Pathol ; 73(6): 314-317, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32161069

RESUMO

BCL-6 transcriptional corepressor (BCOR) gene is located at Xp11.4 and encodes a protein which is involved in transcriptional repression in association with BCL-6 and epigenetic silencing through polycomb repressive complex 1 (PRC1). BCOR mutations are being identified in an increasing number of tumours which are diverse in their anatomical location and clinical setting. Interestingly, these tumours share similar and overlapping histological features, namely small round blue cell morphology and a myxoid background with delicate capillary channels. Clear cell sarcoma of the kidney, primitive myxoid mesenchymal tumour of infancy and central nervous system high-grade neuroepithelial tumour with BCOR alteration all share similar internal tandem duplications in the polycomb-group really interesting new gene (RING) finger homolog ubiquitin-likefold discriminator domain of BCOR Translocations resulting in BCOR fusion with CCNB3, MAML3 and ZC3H7B have been identified in undifferentiated round cell sarcoma. Subsets of high-grade endometrial stromal sarcoma and ossifying fibromyxoid tumour which have a more aggressive clinical course have been shown to harbour ZC3H7B-BCOR fusions. BCOR immunohistochemistry is an established marker with diagnostic utility.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Translocação Genética , Biomarcadores Tumorais/metabolismo , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Epigênese Genética , Duplicação Gênica , Fusão Gênica , Inativação Gênica , Humanos , Imuno-Histoquímica , Neoplasias/diagnóstico , Neoplasias/patologia , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Proteínas Repressoras/metabolismo
12.
Am J Pathol ; 190(6): 1343-1354, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32201260

RESUMO

Lung adenocarcinoma (LUAD) is a malignant tumor with poor patient survival and high patient mortality. Long noncoding RNA is profoundly involved in the tumorigenesis of LUAD. The present study explores the effect of small nucleolar RNA host gene 7 (SNHG7) on the progression of LUAD and its underlying mechanisms. SNHG7 was found to be down-regulated in LUAD tissues compared with normal tissues. Altered SNHG7 expression induced changes in cell proliferation and migration both in vitro and in vivo. Mechanistically, it was found that SNHG7 interacted with microRNA mir-181 and sequentially up-regulated cbx7. cbx7, which suppresses the Wnt/ß-catenin pathway in LUAD, was found to be a direct target of mir-181. Taken together, loss of SNHG7 in LUAD up-regulated mir-181 and then down-regulated the tumor suppressor cbx7.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Neoplasias Pulmonares/metabolismo , MicroRNAs/metabolismo , Complexo Repressor Polycomb 1/metabolismo , RNA Longo não Codificante/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Animais , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/genética , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Camundongos , MicroRNAs/genética , Complexo Repressor Polycomb 1/genética , RNA Longo não Codificante/genética , Transdução de Sinais/fisiologia
13.
PLoS Genet ; 16(3): e1008524, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32142505

RESUMO

Common fragile sites (CFSs) are breakage-prone genomic loci, and are considered to be hotspots for genomic rearrangements frequently observed in cancers. Understanding the underlying mechanisms for CFS instability will lead to better insight on cancer etiology. Here we show that Polycomb group proteins BMI1 and RNF2 are suppressors of transcription-replication conflicts (TRCs) and CFS instability. Cells depleted of BMI1 or RNF2 showed slower replication forks and elevated fork stalling. These phenotypes are associated with increase occupancy of RNA Pol II (RNAPII) at CFSs, suggesting that the BMI1-RNF2 complex regulate RNAPII elongation at these fragile regions. Using proximity ligase assays, we showed that depleting BMI1 or RNF2 causes increased associations between RNAPII with EdU-labeled nascent forks and replisomes, suggesting increased TRC incidences. Increased occupancy of a fork protective factor FANCD2 and R-loop resolvase RNH1 at CFSs are observed in RNF2 CRISPR-KO cells, which are consistent with increased transcription-associated replication stress in RNF2-deficient cells. Depleting FANCD2 or FANCI proteins further increased genomic instability and cell death of the RNF2-deficient cells, suggesting that in the absence of RNF2, cells depend on these fork-protective factors for survival. These data suggest that the Polycomb proteins have non-canonical roles in suppressing TRC and preserving genomic integrity.


Assuntos
Sítios Frágeis do Cromossomo/genética , Replicação do DNA/genética , Complexo Repressor Polycomb 1/genética , Transcrição Genética/genética , Linhagem Celular , Linhagem Celular Tumoral , Instabilidade Genômica/genética , Células HEK293 , Células HeLa , Humanos
14.
Int J Mol Sci ; 21(4)2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32075028

RESUMO

Chromobox homolog 2 (CBX2), a key member of the polycomb group (PcG) family, is essential for gonadal development in mammals. A functional deficiency or genetic mutation in cbx2 can lead to sex reversal in mice and humans. However, little is known about the function of cbx2 in gonadal development in fish. In this study, the cbx2 gene was identified in medaka, which is a model species for the study of gonadal development in fish. Transcription of cbx2 was abundant in the gonads, with testicular levels relatively higher than ovarian levels. In situ hybridization (ISH) revealed that cbx2 mRNA was predominately localized in spermatogonia and spermatocytes, and was also observed in oocytes at stages I, II, and III. Furthermore, cbx2 and vasa (a marker gene) were co-localized in germ cells by fluorescent in situ hybridization (FISH). After cbx2 knockdown in the gonads by RNA interference (RNAi), the sex-related genes, including sox9 and foxl2, were influenced. These results suggest that cbx2 not only plays a positive role in spermatogenesis and oogenesis but is also involved in gonadal differentiation through regulating the expression levels of sex-related genes in fish.


Assuntos
Proteínas de Peixes/genética , Gônadas/metabolismo , Oryzias/genética , Complexo Repressor Polycomb 1/genética , Sequência de Aminoácidos , Animais , Feminino , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/classificação , Proteínas de Peixes/metabolismo , Proteína Forkhead Box L2/antagonistas & inibidores , Proteína Forkhead Box L2/genética , Proteína Forkhead Box L2/metabolismo , Gônadas/crescimento & desenvolvimento , Masculino , Oryzias/crescimento & desenvolvimento , Filogenia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/classificação , Complexo Repressor Polycomb 1/metabolismo , Interferência de RNA , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição SOX9/antagonistas & inibidores , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Alinhamento de Sequência , Espermatócitos/metabolismo , Espermatogônias/metabolismo
15.
Life Sci ; 247: 117438, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070708

RESUMO

AIMS: This study intends to investigate the mechanisms of ubiqutin-specific protease 22 (USP22)/B cell-specific Moloney murine leukemia virus integration site 1 (BMI1) on the biological phenotypes of glioma stem cells (GSCs) under hypoxia. MAIN METHODS: Western blot, Cell Counting Kit-8, colony formation and flow cytometry assays were preformed to evaluate cells biological behaviors. Luciferase assay was utilized to identify the associations among USP22, HIF-1α and BMI1. KEY FINDINGS: Silencing USP22 reduced the stemness and proliferation of GSCs, and increased its apoptosis in response to hypoxia. Whilst, overexpression of BMI1 reversed these phenomena. Whilst, a significant decrease in proliferation and stemness of GSCs caused by HIF-1α exhaustion were inversed by overexpression of USP22 or BMI1. SIGNIFICANCE: Function of USP22-BMI1 on biological behaviors of GSCs was regulated by HIF-1α in response to hypoxia.


Assuntos
Glioma/terapia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Ubiquitina Tiolesterase/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/genética , Transdução de Sinais , Hipóxia Tumoral , Ubiquitina Tiolesterase/genética
16.
Science ; 367(6480): 870-874, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-32079766

RESUMO

Diapause is a state of suspended development that helps organisms survive extreme environments. How diapause protects living organisms is largely unknown. Using the African turquoise killifish (Nothobranchius furzeri), we show that diapause preserves complex organisms for extremely long periods of time without trade-offs for subsequent adult growth, fertility, and life span. Transcriptome analyses indicate that diapause is an active state, with dynamic regulation of metabolism and organ development genes. The most up-regulated genes in diapause include Polycomb complex members. The chromatin mark regulated by Polycomb, H3K27me3, is maintained at key developmental genes in diapause, and the Polycomb member CBX7 mediates repression of metabolism and muscle genes in diapause. CBX7 is functionally required for muscle preservation and diapause maintenance. Thus, vertebrate diapause is a state of suspended life that is actively maintained by specific chromatin regulators, and this has implications for long-term organism preservation.


Assuntos
Diapausa/fisiologia , Peixes Listrados/crescimento & desenvolvimento , Músculo Esquelético/crescimento & desenvolvimento , Complexo Repressor Polycomb 1/metabolismo , Animais , Diapausa/genética , Regulação da Expressão Gênica no Desenvolvimento , Histonas/metabolismo , Mutação , Complexo Repressor Polycomb 1/genética
17.
Cancer Genomics Proteomics ; 17(2): 169-174, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32108039

RESUMO

BACKGROUND/AIM: In this study, we aimed to investigate the prognostic role of a previously identified panel of 10 stem cell markers stratified against the catalytic subunit of telomerase (hTERT) in human breast cancer. MATERIALS AND METHODS: The mRNA copy numbers of these genes were determined using real time quantitative PCR in 124 breast cancer tissues and adjacent non-cancerous tissues. Relations between mRNA levels and survival were analysed using Kaplan-Meier plots and Cox regression analysis. RESULTS: Five genes (BMI1, NES, POU5F1, ALDH1A2 and CDKN1A) correlated with survival when stratified with hTERT and predicted overall (Wilcoxon: p=0.004; Cox: p=0.006) and disease-free (Wilcoxon: p<0.000; Cox: p=0.000) survival. CONCLUSION: This panel of genes stratified by hTERT could open new avenues for the development of new prognostic tools, as well as for the identification of new research directions regarding breast oncogenesis.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Telomerase/genética , Aldeído Desidrogenase 1/genética , Aldeído Desidrogenase 1/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Feminino , Humanos , Nestina/genética , Nestina/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Retinal Desidrogenase/genética , Retinal Desidrogenase/metabolismo , Análise de Sobrevida , Taxa de Sobrevida , Telomerase/metabolismo
18.
Anticancer Res ; 40(1): 133-141, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31892561

RESUMO

BACKGROUND/AIM: Aberrant expression of the BMI1 oncogene has been prevalently found in a variety of human cancers, including cervical cancer. Recent studies have shown that PTC209, a specific BMI1 inhibitor, exhibits high potency in inhibiting the growth of colon, breast, oral cancer cells and cancer-initiating cells, indicative of its chemotherapeutic potential. In the current study, we evaluated the inhibitory abilities of PTC209 in cervical cancer cells. MATERIALS AND METHODS: Three cervical cell lines, C33A, HeLa, and SiHa were treated with PTC209. The impacts of PTC209 on BMI1 were investigated using quantitative reverse-transcription PCR assay (qRT-PCR) and western blotting; changes in cell viability, cell cycle distribution, and apoptosis were assessed using cell viability testing, colony formation assay and flow cytometry analyses, respectively. RESULTS: PTC209 exhibited considerably high short-term and long-term cytotoxicities in all tested cervical cancer cell lines regardless of their HPV infection status, TP53 and pRb statuses. PTC209 significantly downregulated the expression of BMI1 in cervical cancer cell lines, and such downregulation led to G0/G1 arrest (p<0.05). Moreover, PTC209 drove more cells into apoptosis (p<0.05). CONCLUSION: PTC209 (BMI1-targeting agents, in general) represents a novel chemotherapeutic agent with potential in cervical cancer therapy.


Assuntos
Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia
19.
J Biosci ; 452020.
Artigo em Inglês | MEDLINE | ID: mdl-31965994

RESUMO

For mammals to develop properly, master regulatory genes must be repressed appropriately in a heritable manner. This review concerns the Polycomb Repressive Complex 1 (PRC1) family and the relationship between the establishment of repression and memory of the repressed state. The primary focus is on the CBX family of proteins in PRC1 complexes and their role in both chromatin compaction and phase separation. These two activities are linked and might contribute to both repression and memory.


Assuntos
Cromatina/genética , Proteínas Cromossômicas não Histona/genética , Epigênese Genética/genética , Complexo Repressor Polycomb 1/genética , Núcleo Celular/genética , Regulação da Expressão Gênica/genética , Humanos , Nucleossomos/genética
20.
Oncogene ; 39(1): 17-29, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31462713

RESUMO

B lymphoma Mo-MLV insertion region 1 (BMI1) has been reported to be an oncoprotein. BMI1 represses tumor suppressors to promote cell proliferation, epithelial-mesenchymal transition (EMT), and cancer progression. Although it is known that the expression of BMI1 is increased in many cancer types, the mechanism of BMI1 upregulation is not yet clear. We performed integrative analysis for 3 sets of prostate cancer (PCa) genomic data, and found that BMI1 and androgen receptor (AR) were positively correlated, suggesting that AR might regulate BMI1. Next, we showed that dihydrotestosterone (DHT) upregulated both mRNA and protein levels of BMI1 and that BMI1 was increased in castration-resistant prostate cancer (CRPC) from both human patients and a mouse xenograph model. We further identified an AR binding site in the promoter/enhancer region of BMI1, and confirmed BMI1 as the direct target of AR using gene-editing technology. We also demonstrated that high expression of BMI1 is critical for the development of castration-resistance. Our data also suggest that BMI1-specific inhibitors could be an effective treatment of CRPC.


Assuntos
Complexo Repressor Polycomb 1/genética , Neoplasias de Próstata Resistentes à Castração/genética , Receptores Androgênicos/genética , Animais , Sítios de Ligação/genética , Proliferação de Células/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Di-Hidrotestosterona/administração & dosagem , Elementos Facilitadores Genéticos/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Regiões Promotoras Genéticas/genética , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/patologia , RNA Mensageiro/genética , Análise Serial de Tecidos , Ensaios Antitumorais Modelo de Xenoenxerto
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