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1.
Nat Commun ; 10(1): 4724, 2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624313

RESUMO

Acetylation of histone H3K23 has emerged as an essential posttranslational modification associated with cancer and learning and memory impairment, yet our understanding of this epigenetic mark remains insufficient. Here, we identify the native MORF complex as a histone H3K23-specific acetyltransferase and elucidate its mechanism of action. The acetyltransferase function of the catalytic MORF subunit is positively regulated by the DPF domain of MORF (MORFDPF). The crystal structure of MORFDPF in complex with crotonylated H3K14 peptide provides mechanistic insight into selectivity of this epigenetic reader and its ability to recognize both histone and DNA. ChIP data reveal the role of MORFDPF in MORF-dependent H3K23 acetylation of target genes. Mass spectrometry, biochemical and genomic analyses show co-existence of the H3K23ac and H3K14ac modifications in vitro and co-occupancy of the MORF complex, H3K23ac, and H3K14ac at specific loci in vivo. Our findings suggest a model in which interaction of MORFDPF with acylated H3K14 promotes acetylation of H3K23 by the native MORF complex to activate transcription.


Assuntos
Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Processamento de Proteína Pós-Traducional , Acetilação , Acilação , Sítios de Ligação/genética , Linhagem Celular Tumoral , Cristalografia por Raios X , Células HEK293 , Histona Acetiltransferases/química , Histona Acetiltransferases/genética , Histonas/química , Humanos , Células K562 , Simulação de Dinâmica Molecular , Ligação Proteica , Domínios Proteicos
2.
Nat Commun ; 10(1): 4541, 2019 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-31586052

RESUMO

High-throughput CRISPR-Cas9 knockout screens using a tiling-sgRNA design permit in situ evaluation of protein domain function. Here, to facilitate de novo identification of essential protein domains from such screens, we propose ProTiler, a computational method for the robust mapping of CRISPR knockout hyper-sensitive (CKHS) regions, which refer to the protein regions associated with a strong sgRNA dropout effect in the screens. Applied to a published CRISPR tiling screen dataset, ProTiler identifies 175 CKHS regions in 83 proteins. Of these CKHS regions, more than 80% overlap with annotated Pfam domains, including all of the 15 known drug targets in the dataset. ProTiler also reveals unannotated essential domains, including the N-terminus of the SWI/SNF subunit SMARCB1, which is validated experimentally. Surprisingly, the CKHS regions are negatively correlated with phosphorylation and acetylation sites, suggesting that protein domains and post-translational modification sites have distinct sensitivities to CRISPR-Cas9 mediated amino acids loss.

3.
J Asian Nat Prod Res ; : 1-14, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31345059

RESUMO

Xanthohumol (XN) exerts a specific cytotoxicity in B16-F10 melanoma cells with cytoplasmic vacuoles formation. Further investigation showed XN inhibited cell proliferation in a time- and dose-dependent manner along with down-regulation of mitogen-activated protein kinase and up-regulation of the endoplasmic reticulum (ER) stress marker Bip, CHOP and protein ubiquitination, which was relieved by the ER-stress inhibitor 4-PBA. Whereas no early apoptosis characteristics was identified during XN induced cell death.

4.
Nat Commun ; 10(1): 2314, 2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-31127101

RESUMO

Histone methyltransferase MLL4 is centrally involved in transcriptional regulation and is often mutated in human diseases, including cancer and developmental disorders. MLL4 contains a catalytic SET domain that mono-methylates histone H3K4 and seven PHD fingers of unclear function. Here, we identify the PHD6 finger of MLL4 (MLL4-PHD6) as a selective reader of the epigenetic modification H4K16ac. The solution NMR structure of MLL4-PHD6 in complex with a H4K16ac peptide along with binding and mutational analyses reveal unique mechanistic features underlying recognition of H4K16ac. Genomic studies show that one third of MLL4 chromatin binding sites overlap with H4K16ac-enriched regions in vivo and that MLL4 occupancy in a set of genomic targets depends on the acetyltransferase activity of MOF, a H4K16ac-specific acetyltransferase. The recognition of H4K16ac is conserved in the PHD7 finger of paralogous MLL3. Together, our findings reveal a previously uncharacterized acetyllysine reader and suggest that selective targeting of H4K16ac by MLL4 provides a direct functional link between MLL4, MOF and H4K16 acetylation.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Histona Acetiltransferases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Dedos de Zinco PHD/fisiologia , Acetilação , Animais , Sítios de Ligação , Cromatina/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/isolamento & purificação , Técnicas de Inativação de Genes , Células HEK293 , Histona Acetiltransferases/genética , Histona-Lisina N-Metiltransferase/química , Histonas/química , Humanos , Camundongos Transgênicos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Ressonância Magnética Nuclear Biomolecular , Processamento de Proteína Pós-Traducional/fisiologia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
5.
Nucleic Acids Res ; 47(10): 5038-5048, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-30916320

RESUMO

PRMT5 is an arginine methyltransferase that accounts for the vast majority of the symmetric methylation in cells. PRMT5 exerts its function when complexed with MEP50/WDR77. This activity is often elevated in cancer cells and correlates with poor prognosis, making PRMT5 a therapeutic target. To investigate the PRMT5 signaling pathway and to identify genes whose loss-of-function sensitizes cancer cells to PRMT5 inhibition, we performed a CRISPR/Cas9 genetic screen in the presence of a PRMT5 inhibitor. We identified known components of the PRMT5 writer/reader pathway including PRMT5 itself, MEP50/WDR77, PPP4C, SMNDC1 and SRSF3. Interestingly, loss of PRMT1, the major asymmetric arginine methyltransferase, also sensitizes cells to PRMT5 inhibition. We investigated the interplay between PRMT5 and PRMT1, and found that combinatorial inhibitor treatment of small cell lung cancer and pancreatic cancer cell models have a synergistic effect. Furthermore, MTAP-deleted cells, which harbor an attenuated PRMT5-MEP50 signaling pathway, are generally more sensitive to PRMT1 inhibition. Together, these findings demonstrate that there is a degree of redundancy between the PRMT5 and PRMT1 pathways, even though these two enzymes deposit different types of arginine methylation marks. Targeting this redundancy provides a vulnerability for tumors carrying a co-deletion of MTAP and the adjacent CDKN2A tumor suppressor gene.


Assuntos
Deleção de Genes , Neoplasias/enzimologia , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Repressoras/metabolismo , Células A549 , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Etilenodiaminas/farmacologia , Humanos , Isoquinolinas/farmacologia , Células MCF-7 , Camundongos Knockout , Neoplasias/genética , Neoplasias/patologia , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/genética , Pirimidinas/farmacologia , Pirróis/farmacologia , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
6.
Crit Rev Biochem Mol Biol ; 54(1): 1-10, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30691308

RESUMO

Although relatively small in size, the ZZ-type zinc finger (ZZ) domain is a versatile signaling module that is implicated in a diverse set of cell signaling events. Here, we highlight the most recent studies focused on the ZZ domain function as a histone reader and a sensor of protein degradation signals. We review and compare the molecular and structural mechanisms underlying targeting the amino-terminal sequences of histone H3 and arginylated substrates by the ZZ domain. We also discuss the ZZ domain sensitivity to histone PTMs and summarize biological outcomes associated with the recognition of histone and non-histone ligands by the ZZ domain-containing proteins and complexes.


Assuntos
Epigênese Genética , Dedos de Zinco , Acetilação , Animais , Autofagia , Cromatina/genética , Cromatina/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Processamento de Proteína Pós-Traducional
7.
Cancer Res ; 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31888886

RESUMO

Wnt/ß-catenin signaling activates the transcription of target genes to regulate stem cells and cancer development. However, the contribution of epigenetic regulation to this process is unknown. Here, we report that Wnt activation stabilizes the epigenetic regulator KDM4C that promotes tumorigenesis and survival of human glioblastoma cells by epigenetically activating the transcription of Wnt target genes. KDM4C protein expression was upregulated in human glioblastomas and its expression directly correlated with Wnt activity and Wnt target gene expression. KDM4C was essential for Wnt-induced gene expression and tumorigenesis of glioblastoma cells. In the absence of Wnt3a, protein kinase R phosphorylated KDM4C at Ser918, inducing KDM4C ubiquitination and degradation. Wnt3a stabilized KDM4C through inhibition of GSK3-dependent protein kinase R activity. Stabilized KDM4C accumulated in the nucleus and bound to and demethylated TCF4-associated histone H3K9 by interacting with ß-catenin, promoting HP1γ removal and transcriptional activation. These findings reveal that Wnt-KDM4C-ß-catenin signaling represents a novel mechanism for the transcription of Wnt target genes and regulation of tumorigenesis with important clinical implications.

8.
Nat Commun ; 9(1): 4574, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30385749

RESUMO

The YEATS domain has been identified as a reader of histone acylation and more recently emerged as a promising anti-cancer therapeutic target. Here, we detail the structural mechanisms for π-π-π stacking involving the YEATS domains of yeast Taf14 and human AF9 and acylated histone H3 peptides and explore DNA-binding activities of these domains. Taf14-YEATS selects for crotonyllysine, forming π stacking with both the crotonyl amide and the alkene moiety, whereas AF9-YEATS exhibits comparable affinities to saturated and unsaturated acyllysines, engaging them through π stacking with the acyl amide. Importantly, AF9-YEATS is capable of binding to DNA, whereas Taf14-YEATS is not. Using a structure-guided approach, we engineered a mutant of Taf14-YEATS that engages crotonyllysine through the aromatic-aliphatic-aromatic π stacking and shows high selectivity for the crotonyl H3K9 modification. Our findings shed light on the molecular principles underlying recognition of acyllysine marks and reveal a previously unidentified DNA-binding activity of AF9-YEATS.


Assuntos
DNA/metabolismo , Código das Histonas , Proteínas Nucleares/metabolismo , Domínios Proteicos , Proteínas de Saccharomyces cerevisiae/metabolismo , Fator de Transcrição TFIID/metabolismo , Acetilação , Acilação , Cristalografia por Raios X , DNA/ultraestrutura , Humanos , Lisina/metabolismo , Mutação , Proteínas Nucleares/química , Proteínas Nucleares/ultraestrutura , Ligação Proteica , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/ultraestrutura , Fator de Transcrição TFIID/química , Fator de Transcrição TFIID/genética , Fator de Transcrição TFIID/ultraestrutura
9.
ACS Appl Mater Interfaces ; 10(47): 40509-40522, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30372026

RESUMO

A series of samples with the precursor's molar ratio of {KMn8O16}/{CuFe2O4} = 0, 0.008, 0.010, 0.016, and 0.020 were successfully synthesized for selective catalytic reduction of NO by CO. The physicochemical properties of all samples were studied in detail by combining the means of X-ray photoelectron spectroscopy, H2-temperature-programmed reduction, scanning electron microscopy mapping, X-ray diffraction (XRD), N2 physisorption (Brunauer-Emmett-Teller), NO + CO model reaction, and in situ Fourier transform infrared spectroscopy techniques. The results show that three phases of γ-Fe2O3, CuFe2O4, and CuO, which have strong synergistic interaction, coexist in this catalyst system, and different phases play a leading role in different temperature ranges. Mn species are highly dispersed in the three-phase coexisting system in the form of Mn2+, Mn3+, and Mn4+. Because of the strong interaction between Mn2+ and Fe species, a small amount of Cu2+ precipitates from CuFe2O4 and grows along the CuO(110) plane, which has better catalytic performance. Mn3+ can inhibit the conversion of γ-Fe2O3 to α-Fe2O3 at high temperature and then increases the high-temperature activity. The synergistic effect between Mn4+ and the surfaces of three phases generates active oxygen species Cu2+-O-Mn4+ and Mn4+-O-Fe3+, which can be more easily reduced to some synergistic oxygen vacancies during the reaction. Furthermore, the formed synergistic oxygen vacancies can promote the dissociation of NO and are also propitious to the transfer of oxygen species. All of these factors make the appropriate manganese-modified three-phase coexisting system have better catalytic activity than the manganese-free catalyst, making NO conversion rate reach 100% at around 250 °C and maintain to 1000 °C. Combining comprehensive analysis of various characterization results and in situ infrared as well as XRD results in the equilibrium state, a new possible NO + CO model reaction mechanism was temporarily proposed to further understand the catalytic processes.

10.
Nat Chem Biol ; 14(12): 1140-1149, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30374167

RESUMO

Chemical probes of epigenetic 'readers' of histone post-translational modifications (PTMs) have become powerful tools for mechanistic and functional studies of their target proteins in normal physiology and disease pathogenesis. Here we report the development of the first class of chemical probes of YEATS domains, newly identified 'readers' of histone lysine acetylation (Kac) and crotonylation (Kcr). Guided by the structural analysis of a YEATS-Kcr complex, we developed a series of peptide-based inhibitors of YEATS domains by targeting a unique π-π-π stacking interaction at the proteins' Kcr recognition site. Further structure optimization resulted in the selective inhibitors preferentially binding to individual YEATS-containing proteins including AF9 and ENL with submicromolar affinities. We demonstrate that one of the ENL YEATS-selective inhibitors, XL-13m, engages with endogenous ENL, perturbs the recruitment of ENL onto chromatin, and synergizes the BET and DOT1L inhibition-induced downregulation of oncogenes in MLL-rearranged acute leukemia.


Assuntos
Desenho de Drogas , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/química , Peptídeos/farmacologia , Fatores de Elongação da Transcrição/antagonistas & inibidores , Azepinas/farmacologia , Linhagem Celular , Cromatina/metabolismo , Cristalografia por Raios X , Regulação da Expressão Gênica/efeitos dos fármacos , Histona-Lisina N-Metiltransferase , Humanos , Lisina/metabolismo , Metiltransferases/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Peptídeos/química , Domínios Proteicos , Processamento de Proteína Pós-Traducional , Relação Estrutura-Atividade , Fatores de Elongação da Transcrição/química , Fatores de Elongação da Transcrição/metabolismo , Triazóis/farmacologia
11.
Nat Commun ; 9(1): 4373, 2018 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-30349045

RESUMO

Autophagic receptor p62 is a critical mediator of cell detoxification, stress response, and metabolic programs and is commonly deregulated in human diseases. The diverse functions of p62 arise from its ability to interact with a large set of ligands, such as arginylated (Nt-R) substrates. Here, we describe the structural mechanism for selective recognition of Nt-R by the ZZ domain of p62 (p62ZZ). We show that binding of p62ZZ to Nt-R substrates stimulates p62 aggregation and macroautophagy and is required for autophagic targeting of p62. p62 is essential for mTORC1 activation in response to arginine, but it is not a direct sensor of free arginine in the mTORC1 pathway. We identified a regulatory linker (RL) region in p62 that binds p62ZZ in vitro and may modulate p62 function. Our findings shed new light on the mechanistic and functional significance of the major cytosolic adaptor protein p62 in two fundamental signaling pathways.


Assuntos
Autofagia/fisiologia , Proteína Sequestossoma-1/metabolismo , Autofagia/genética , Linhagem Celular , Cristalografia por Raios X , Citometria de Fluxo , Células HEK293 , Humanos , Imuno-Histoquímica , Espectroscopia de Ressonância Magnética , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Ligação Proteica , Proteína Sequestossoma-1/genética , Transdução de Sinais , Espectrometria de Fluorescência
12.
Nat Commun ; 9(1): 3759, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-30217978

RESUMO

Recognition of histones by epigenetic readers is a fundamental mechanism for the regulation of chromatin and transcription. Most reader modules target specific post-translational modifications on histones. Here, we report the identification of a reader of histone H3, the ZZ-type zinc finger (ZZ) domain of ZZZ3, a subunit of the Ada-two-A-containing (ATAC) histone acetyltransferase complex. The solution NMR structure of the ZZ in complex with the H3 peptide reveals a unique binding mechanism involving caging of the N-terminal Alanine 1 of histone H3 in an acidic cavity of the ZZ domain, indicating a specific recognition of H3 versus other histones. Depletion of ZZZ3 or disruption of the ZZ-H3 interaction dampens ATAC-dependent promoter histone H3K9 acetylation and target gene expression. Overall, our study identifies the ZZ domain of ZZZ3 as a histone H3 reader that is required for the ATAC complex-mediated maintenance of histone acetylation and gene activation.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Histona Acetiltransferases/genética , Código das Histonas/genética , Histonas/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional/genética , Acetilação , Proteínas de Ligação a DNA/genética , Epigênese Genética , Células HEK293 , Histona Acetiltransferases/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Processamento de Proteína Pós-Traducional , Espectrometria de Fluorescência , Fatores de Transcrição/genética , Dedos de Zinco
13.
Nat Struct Mol Biol ; 25(9): 841-849, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30150647

RESUMO

Human p300 is a transcriptional co-activator and a major acetyltransferase that acetylates histones and other proteins facilitating gene transcription. The activity of p300 relies on the fine-tuned interactome that involves a dozen p300 domains and hundreds of binding partners and links p300 to a wide range of vital signaling events. Here, we report a novel function of the ZZ-type zinc finger (ZZ) of p300 as a reader of histone H3. We show that the ZZ domain and acetyllysine-recognizing bromodomain of p300 play critical roles in modulating p300 enzymatic activity and its association with chromatin. The acetyllysine binding function of bromodomain is essential for acetylation of histones H3 and H4, whereas interaction of the ZZ domain with H3 promotes selective acetylation of the histone H3K27 and H3K18 sites.


Assuntos
Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Domínios Proteicos , Dedos de Zinco , Fatores de Transcrição de p300-CBP/metabolismo , Acetilação , Linhagem Celular , Ressonância Magnética Nuclear Biomolecular , Espectrometria de Fluorescência , Fatores de Transcrição de p300-CBP/química
14.
Cell Discov ; 4: 28, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29900004

RESUMO

The histone variant H2A.Z is essential for maintaining embryonic stem cell (ESC) identity in part by keeping developmental genes in a poised bivalent state. However, how H2A.Z is deposited into the bivalent domains remains unknown. In mammals, two chromatin remodeling complexes, Tip60/p400 and SRCAP, exchange the canonical histone H2A for H2A.Z in the chromatin. Here we show that Glioma Amplified Sequence 41 (Gas41), a shared subunit of the two H2A.Z-depositing complexes, functions as a reader of histone lysine acetylation and recruits Tip60/p400 and SRCAP to deposit H2A.Z into specific chromatin regions including bivalent domains. The YEATS domain of Gas41 bound to acetylated histone H3K27 and H3K14 both in vitro and in cells. The crystal structure of the Gas41 YEATS domain in complex with the H3K27ac peptide revealed that, similar to the AF9 and ENL YEATS domains, Gas41 YEATS forms a serine-lined aromatic cage for acetyllysine recognition. Consistently, mutations in the aromatic residues of the Gas41 YEATS domain abrogated the interaction. In mouse ESCs, knockdown of Gas41 led to flattened morphology of ESC colonies, as the result of derepression of differentiation genes. Importantly, the abnormal morphology was rescued by expressing wild-type Gas41, but not the YEATS domain mutated counterpart that does not recognize histone acetylation. Mechanically, we found that Gas41 depletion led to reduction of H2A.Z levels and a concomitant reduction of H3K27me3 levels on bivalent domains. Together, our study reveals an essential role of the Gas41 YEATS domain in linking histone acetylation to H2A.Z deposition and maintenance of ESC identity.

15.
J Mol Biol ; 430(11): 1562-1565, 2018 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-29689253

RESUMO

Histone H3 encoding genes, particularly H3F3A and H3F3B, the genes encoding the variant histone H3.3, are mutated at high frequency in pediatric brain and bone malignancies. Compared to the extensive studies on K27M and K36M mutations, little is known about the mechanism of G34 mutations found in pediatric glioblastoma or giant cell tumors of the bone. Here we report that unlike the K27M or K36M that affect global histone methylation, the giant cell tumors of the bone G34 mutations (G34L/W) only affect histone H3K36 and H3K27 methylation on the same mutated histone tails (in cis), a mechanism distinct from known histone mutations.


Assuntos
Neoplasias Ósseas/genética , Neoplasias Encefálicas/genética , Histonas/genética , Lisina/química , Mutação , Neoplasias Ósseas/metabolismo , Neoplasias Encefálicas/metabolismo , Criança , Epigênese Genética , Tumor de Células Gigantes do Osso/genética , Tumor de Células Gigantes do Osso/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Células HeLa , Histonas/química , Humanos , Metilação
16.
BMC Genomics ; 19(1): 150, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29458327

RESUMO

BACKGROUND: Epigenetic regulators are frequently mutated or aberrantly expressed in a variety of cancers, leading to altered transcription states that result in changes in cell identity, behavior, and response to therapy. RESULTS: To define alterations in epigenetic landscapes in breast cancers, we profiled the distributions of 8 key histone modifications by ChIP-Seq, as well as primary (GRO-seq) and steady state (RNA-Seq) transcriptomes, across 13 distinct cell lines that represent 5 molecular subtypes of breast cancer and immortalized human mammary epithelial cells. DISCUSSION: Using combinatorial patterns of distinct histone modification signals, we defined subtype-specific chromatin signatures to nominate potential biomarkers. This approach identified AFAP1-AS1 as a triple negative breast cancer-specific gene associated with cell proliferation and epithelial-mesenchymal-transition. In addition, our chromatin mapping data in basal TNBC cell lines are consistent with gene expression patterns in TCGA that indicate decreased activity of the androgen receptor pathway but increased activity of the vitamin D biosynthesis pathway. CONCLUSIONS: Together, these datasets provide a comprehensive resource for histone modification profiles that define epigenetic landscapes and reveal key chromatin signatures in breast cancer cell line subtypes with potential to identify novel and actionable targets for treatment.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Biomarcadores Tumorais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Cromatina/genética , Cromatina/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Transcriptoma
17.
Nat Commun ; 9(1): 500, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29402932

RESUMO

BMI1, a polycomb group (PcG) protein, plays a critical role in epigenetic regulation of cell differentiation and proliferation, and cancer stem cell self-renewal. BMI1 is upregulated in multiple types of cancer, including prostate cancer. As a key component of polycomb repressive complex 1 (PRC1), BMI1 exerts its oncogenic functions by enhancing the enzymatic activities of RING1B to ubiquitinate histone H2A at lysine 119 and repress gene transcription. Here, we report a PRC1-independent role of BMI1 that is critical for castration-resistant prostate cancer (CRPC) progression. BMI1 binds the androgen receptor (AR) and prevents MDM2-mediated AR protein degradation, resulting in sustained AR signaling in prostate cancer cells. More importantly, we demonstrate that targeting BMI1 effectively inhibits tumor growth of xenografts that have developed resistance to surgical castration and enzalutamide treatment. These results suggest that blocking BMI1 alone or in combination with anti-AR therapy can be more efficient to suppress prostate tumor growth.


Assuntos
Adenocarcinoma/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/metabolismo , Animais , Antineoplásicos Hormonais/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Progressão da Doença , Histonas/metabolismo , Humanos , Masculino , Camundongos , Camundongos SCID , Transplante de Neoplasias , Orquiectomia , Feniltioidantoína/análogos & derivados , Feniltioidantoína/farmacologia , Complexo Repressor Polycomb 1/genética , Neoplasias da Próstata/metabolismo , Proteólise , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Transdução de Sinais , Ubiquitinação , Regulação para Cima
18.
Pharmazie ; 73(2): 98-103, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442012

RESUMO

The dried seeds of Iris lactea Pall. var. chinensis (Fisch.) Koidz, an important traditional Chinese medicine, are regarded to have effects of clearing heat, eliminating dampness and pharyngitis and so on. It has been used in the treatment of jaundice, diarrhea, leucorrhea and carbuncles. Previous phytochemical studies of Iris species showed the presence of flavones, isoflavones, triterpenes and stilbenes. In our previous research, we isolated five known oligostilbenes, vitisin A, vitisin B, vitisin C, vitisin D, and cis-vitisin A were successfully isolated from Iris lactea for the first time. The aim of this study was to assess the effects of these oligostilbenes on the differentiation and adipogenes in 3T3-L1 cells. Our results showed that vitisin A, vitisin B, cis-vitisin A significantly inhibited adipocytes differentiation and reduced lipid accumulation in 3T3-L1 cells. In addition, vitisin A, vitisin B, cis-vitisin A strongly suppressed the expression levels of adipocyte-specific genes including peroxisome proliferator activated receptor-γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα) and adipocyte fatty acid binding protein 4 (FABP4). In contrast, vitisin C and vitisin D significantly promoted adipogenesis and increased intracellular lipid accumulation, while the two oligostilbenes markedly increased the expression of adipocyte marker genes. In the present study, we found that vitisin A, vitisin B and cis-vitisin A inhibit the adipogenesis and adipocytes differentiation by their influence on the expression of PPARγ, which leads to subsequenet downregulation of PPARγ mediated adipocyte-specific gene during adipogenesis.


Assuntos
Adipócitos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Iris (Planta)/química , Estilbenos/farmacologia , Células 3T3-L1 , Adipogenia/efeitos dos fármacos , Animais , Benzofuranos/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , PPAR gama/metabolismo , Fenóis/farmacologia , Sementes/química
19.
Genes Dev ; 32(1): 58-69, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29437725

RESUMO

Histone acetylation is associated with active transcription in eukaryotic cells. It helps to open up the chromatin by neutralizing the positive charge of histone lysine residues and providing binding platforms for "reader" proteins. The bromodomain (BRD) has long been thought to be the sole protein module that recognizes acetylated histones. Recently, we identified the YEATS domain of AF9 (ALL1 fused gene from chromosome 9) as a novel acetyl-lysine-binding module and showed that the ENL (eleven-nineteen leukemia) YEATS domain is an essential acetyl-histone reader in acute myeloid leukemias. The human genome encodes four YEATS domain proteins, including GAS41, a component of chromatin remodelers responsible for H2A.Z deposition onto chromatin; however, the importance of the GAS41 YEATS domain in human cancer remains largely unknown. Here we report that GAS41 is frequently amplified in human non-small cell lung cancer (NSCLC) and is required for cancer cell proliferation, survival, and transformation. Biochemical and crystal structural studies demonstrate that GAS41 binds to histone H3 acetylated on H3K27 and H3K14, a specificity that is distinct from that of AF9 or ENL. ChIP-seq (chromatin immunoprecipitation [ChIP] followed by high-throughput sequencing) analyses in lung cancer cells reveal that GAS41 colocalizes with H3K27ac and H3K14ac on the promoters of actively transcribed genes. Depletion of GAS41 or disruption of the interaction between its YEATS domain and acetylated histones impairs the association of histone variant H2A.Z with chromatin and consequently suppresses cancer cell growth and survival both in vitro and in vivo. Overall, our study identifies GAS41 as a histone acetylation reader that promotes histone H2A.Z deposition in NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Histonas/metabolismo , Neoplasias Pulmonares/metabolismo , Fatores de Transcrição/metabolismo , Acetilação , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Amplificação de Genes , Genes cdc , Histonas/fisiologia , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Regiões Promotoras Genéticas , Domínios e Motivos de Interação entre Proteínas , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia
20.
Genome Res ; 28(2): 159-170, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29273624

RESUMO

Noncoding transcription is a defining feature of active enhancers, linking transcription factor (TF) binding to the molecular mechanisms controlling gene expression. To determine the relationship between enhancer activity and biological outcomes in breast cancers, we profiled the transcriptomes (using GRO-seq and RNA-seq) and epigenomes (using ChIP-seq) of 11 different human breast cancer cell lines representing five major molecular subtypes of breast cancer, as well as two immortalized ("normal") human breast cell lines. In addition, we developed a robust and unbiased computational pipeline that simultaneously identifies putative subtype-specific enhancers and their cognate TFs by integrating the magnitude of enhancer transcription, TF mRNA expression levels, TF motif P-values, and enrichment of H3K4me1 and H3K27ac. When applied across the 13 different cell lines noted above, the Total Functional Score of Enhancer Elements (TFSEE) identified key breast cancer subtype-specific TFs that act at transcribed enhancers to dictate gene expression patterns determining growth outcomes, including Forkhead TFs, FOSL1, and PLAG1. FOSL1, a Fos family TF, (1) is highly enriched at the enhancers of triple negative breast cancer (TNBC) cells, (2) acts as a key regulator of the proliferation and viability of TNBC cells, but not Luminal A cells, and (3) is associated with a poor prognosis in TNBC breast cancer patients. Taken together, our results validate our enhancer identification pipeline and reveal that enhancers transcribed in breast cancer cells direct critical gene regulatory networks that promote pathogenesis.


Assuntos
Carcinogênese/genética , Elementos Facilitadores Genéticos/genética , Transcriptoma/genética , Neoplasias de Mama Triplo Negativas/genética , Adulto , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Redes Reguladoras de Genes/genética , Histonas/genética , Humanos , Pessoa de Meia-Idade , RNA Mensageiro/genética , Fatores de Transcrição/genética , Neoplasias de Mama Triplo Negativas/classificação , Neoplasias de Mama Triplo Negativas/patologia
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