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1.
Cell ; 178(4): 993-1003.e12, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31353218

RESUMO

Voltage-gated sodium (NaV) channels initiate action potentials in nerve, muscle, and other electrically excitable cells. The structural basis of voltage gating is uncertain because the resting state exists only at deeply negative membrane potentials. To stabilize the resting conformation, we inserted voltage-shifting mutations and introduced a disulfide crosslink in the VS of the ancestral bacterial sodium channel NaVAb. Here, we present a cryo-EM structure of the resting state and a complete voltage-dependent gating mechanism. The S4 segment of the VS is drawn intracellularly, with three gating charges passing through the transmembrane electric field. This movement forms an elbow connecting S4 to the S4-S5 linker, tightens the collar around the S6 activation gate, and prevents its opening. Our structure supports the classical "sliding helix" mechanism of voltage sensing and provides a complete gating mechanism for voltage sensor function, pore opening, and activation-gate closure based on high-resolution structures of a single sodium channel protein.


Assuntos
Potenciais de Ação/fisiologia , Membrana Externa Bacteriana/metabolismo , Escherichia coli/metabolismo , Ativação do Canal Iônico/fisiologia , Canais de Sódio Disparados por Voltagem/metabolismo , Animais , Linhagem Celular , Microscopia Crioeletrônica , Cristalografia por Raios X , Mutação , Conformação Proteica em alfa-Hélice , Sódio/metabolismo , Spodoptera/citologia , Canais de Sódio Disparados por Voltagem/química
2.
Cell ; 174(3): 576-589.e18, 2018 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-30033361

RESUMO

Genome-wide association studies (GWAS) have identified rs11672691 at 19q13 associated with aggressive prostate cancer (PCa). Here, we independently confirmed the finding in a cohort of 2,738 PCa patients and discovered the biological mechanism underlying this association. We found an association of the aggressive PCa-associated allele G of rs11672691 with elevated transcript levels of two biologically plausible candidate genes, PCAT19 and CEACAM21, implicated in PCa cell growth and tumor progression. Mechanistically, rs11672691 resides in an enhancer element and alters the binding site of HOXA2, a novel oncogenic transcription factor with prognostic potential in PCa. Remarkably, CRISPR/Cas9-mediated single-nucleotide editing showed the direct effect of rs11672691 on PCAT19 and CEACAM21 expression and PCa cellular aggressive phenotype. Clinical data demonstrated synergistic effects of rs11672691 genotype and PCAT19/CEACAM21 gene expression on PCa prognosis. These results provide a plausible mechanism for rs11672691 associated with aggressive PCa and thus lay the ground work for translating this finding to the clinic.


Assuntos
Neoplasias da Próstata/genética , RNA Longo não Codificante/genética , RNA não Traduzido/genética , Adulto , Alelos , Linhagem Celular Tumoral , Cromossomos Humanos Par 19/genética , Estudos de Coortes , Regulação Neoplásica da Expressão Gênica/genética , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Genótipo , Proteínas de Homeodomínio , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Prognóstico
3.
Mol Cell ; 83(15): 2692-2708.e7, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37478845

RESUMO

N6-methyladenosine (m6A) of mRNAs modulated by the METTL3-METTL14-WTAP-RBM15 methyltransferase complex and m6A demethylases such as FTO play important roles in regulating mRNA stability, splicing, and translation. Here, we demonstrate that FTO-IT1 long noncoding RNA (lncRNA) was upregulated and positively correlated with poor survival of patients with wild-type p53-expressing prostate cancer (PCa). m6A RIP-seq analysis revealed that FTO-IT1 knockout increased mRNA m6A methylation of a subset of p53 transcriptional target genes (e.g., FAS, TP53INP1, and SESN2) and induced PCa cell cycle arrest and apoptosis. We further showed that FTO-IT1 directly binds RBM15 and inhibits RBM15 binding, m6A methylation, and stability of p53 target mRNAs. Therapeutic depletion of FTO-IT1 restored mRNA m6A level and expression of p53 target genes and inhibited PCa growth in mice. Our study identifies FTO-IT1 lncRNA as a bona fide suppressor of the m6A methyltransferase complex and p53 tumor suppression signaling and nominates FTO-IT1 as a potential therapeutic target of cancer.


Assuntos
Neoplasias , RNA Longo não Codificante , Masculino , Camundongos , Animais , RNA Longo não Codificante/genética , Proteína Supressora de Tumor p53/genética , Adenosina/metabolismo , RNA Mensageiro/genética , Metiltransferases/genética , Metiltransferases/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo
4.
Nature ; 629(8011): 481-488, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38632411

RESUMO

The human calcium-sensing receptor (CaSR) detects fluctuations in the extracellular Ca2+ concentration and maintains Ca2+ homeostasis1,2. It also mediates diverse cellular processes not associated with Ca2+ balance3-5. The functional pleiotropy of CaSR arises in part from its ability to signal through several G-protein subtypes6. We determined structures of CaSR in complex with G proteins from three different subfamilies: Gq, Gi and Gs. We found that the homodimeric CaSR of each complex couples to a single G protein through a common mode. This involves the C-terminal helix of each Gα subunit binding to a shallow pocket that is formed in one CaSR subunit by all three intracellular loops (ICL1-ICL3), an extended transmembrane helix 3 and an ordered C-terminal region. G-protein binding expands the transmembrane dimer interface, which is further stabilized by phospholipid. The restraint imposed by the receptor dimer, in combination with ICL2, enables G-protein activation by facilitating conformational transition of Gα. We identified a single Gα residue that determines Gq and Gs versus Gi selectivity. The length and flexibility of ICL2 allows CaSR to bind all three Gα subtypes, thereby conferring capacity for promiscuous G-protein coupling.


Assuntos
Proteínas Heterotriméricas de Ligação ao GTP , Receptores de Detecção de Cálcio , Humanos , Cálcio/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/química , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/química , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/química , Modelos Moleculares , Ligação Proteica , Multimerização Proteica , Receptores de Detecção de Cálcio/metabolismo , Receptores de Detecção de Cálcio/química , Proteínas Heterotriméricas de Ligação ao GTP/química , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Sítios de Ligação , Estrutura Secundária de Proteína , Especificidade por Substrato
5.
Annu Rev Biochem ; 81: 615-35, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22443933

RESUMO

There are three kinds of membrane potentials: the surface potentials, resulting from the accumulation of charges at the membrane surfaces; the transmembrane potential, determined by imbalance of charge in the aqueous solutions; and the dipole potential, a membrane-internal potential from the dipolar components of the phospholipids and interface water. The absolute value of the dipole potential has been very difficult to measure, although its value has been estimated to be in the range of 200-1,000 mV from ion translocation rates (determined by the planar lipid bilayer method), the surface potential of lipid monolayers (determined by the lipid monolayer method), molecular-dynamics calculations, and electron scattering using cryoelectron microscopy (cryo-EM). Spectroscopy methods have also been used to monitor the dipole potential changes on the basis of the observed fluorescence changes of voltage-sensitive probes. The dipole potential accounts for the much larger permeability of a bare phospholipid membrane to anions than cations and affects the conformation and function of membrane proteins.


Assuntos
Bioquímica/métodos , Membrana Celular/química , Potenciais da Membrana , Animais , Microscopia Crioeletrônica/métodos , Humanos , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Fosfolipídeos/química , Água/química
6.
Mol Cell ; 73(1): 22-35.e6, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30527665

RESUMO

Aberrant expression of programmed death ligand-1 (PD-L1) in tumor cells promotes cancer progression by suppressing cancer immunity. The retinoblastoma protein RB is a tumor suppressor known to regulate the cell cycle, DNA damage response, and differentiation. Here, we demonstrate that RB interacts with nuclear factor κB (NF-κB) protein p65 and that their interaction is primarily dependent on CDK4/6-mediated serine-249/threonine-252 (S249/T252) phosphorylation of RB. RNA-seq analysis shows a subset of NF-κB pathway genes including PD-L1 are selectively upregulated by RB knockdown or CDK4/6 inhibitor. S249/T252-phosphorylated RB inversely correlates with PD-L1 expression in patient samples. Expression of a RB-derived S249/T252 phosphorylation-mimetic peptide suppresses radiotherapy-induced upregulation of PD-L1 and augments therapeutic efficacy of radiation in vivo. Our findings reveal a previously unrecognized tumor suppressor function of hyperphosphorylated RB in suppressing NF-κB activity and PD-L1 expression and suggest that the RB-NF-κB axis can be exploited to overcome cancer immune evasion triggered by conventional or targeted therapies.


Assuntos
Antígeno B7-H1/metabolismo , Neoplasias da Próstata/metabolismo , Proteína do Retinoblastoma/metabolismo , Fator de Transcrição RelA/metabolismo , Evasão Tumoral , Animais , Antineoplásicos Imunológicos/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Quimiorradioterapia/métodos , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Células PC-3 , Fosforilação , Neoplasias da Próstata/genética , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/terapia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Tolerância a Radiação , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/imunologia , Transdução de Sinais , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Brief Bioinform ; 25(4)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38860738

RESUMO

Picking protein particles in cryo-electron microscopy (cryo-EM) micrographs is a crucial step in the cryo-EM-based structure determination. However, existing methods trained on a limited amount of cryo-EM data still cannot accurately pick protein particles from noisy cryo-EM images. The general foundational artificial intelligence-based image segmentation model such as Meta's Segment Anything Model (SAM) cannot segment protein particles well because their training data do not include cryo-EM images. Here, we present a novel approach (CryoSegNet) of integrating an attention-gated U-shape network (U-Net) specially designed and trained for cryo-EM particle picking and the SAM. The U-Net is first trained on a large cryo-EM image dataset and then used to generate input from original cryo-EM images for SAM to make particle pickings. CryoSegNet shows both high precision and recall in segmenting protein particles from cryo-EM micrographs, irrespective of protein type, shape and size. On several independent datasets of various protein types, CryoSegNet outperforms two top machine learning particle pickers crYOLO and Topaz as well as SAM itself. The average resolution of density maps reconstructed from the particles picked by CryoSegNet is 3.33 Å, 7% better than 3.58 Å of Topaz and 14% better than 3.87 Å of crYOLO. It is publicly available at https://github.com/jianlin-cheng/CryoSegNet.


Assuntos
Microscopia Crioeletrônica , Processamento de Imagem Assistida por Computador , Microscopia Crioeletrônica/métodos , Processamento de Imagem Assistida por Computador/métodos , Proteínas/química , Inteligência Artificial , Algoritmos , Bases de Dados de Proteínas
8.
Mol Cell ; 71(4): 592-605.e4, 2018 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-30057199

RESUMO

The bromodomain and extra-terminal domain (BET) protein BRD4 is emerging as a promising anticancer therapeutic target. However, resistance to BET inhibitors often occurs, and it has been linked to aberrant degradation of BRD4 protein in cancer. Here, we demonstrate that the deubiquitinase DUB3 binds to BRD4 and promotes its deubiquitination and stabilization. Expression of DUB3 is transcriptionally repressed by the NCOR2-HDAC10 complex. The NCOR2 gene is frequently deleted in castration-resistant prostate cancer patient specimens, and loss of NCOR2 induces elevation of DUB3 and BRD4 proteins in cancer cells. DUB3-proficient prostate cancer cells are resistant to the BET inhibitor JQ1 in vitro and in mice, but this effect is diminished by DUB3 inhibitory agents such as CDK4/6 inhibitor in a RB-independent manner. Our findings identify a previously unrecognized mechanism causing BRD4 upregulation and drug resistance, suggesting that DUB3 is a viable therapeutic target to overcome BET inhibitor resistance in cancer.


Assuntos
Quinase 4 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/genética , Endopeptidases/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Nucleares/genética , Neoplasias de Próstata Resistentes à Castração/genética , Fatores de Transcrição/genética , Animais , Antineoplásicos/farmacologia , Azepinas/farmacologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/metabolismo , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Endopeptidases/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Masculino , Camundongos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Correpressor 2 de Receptor Nuclear/deficiência , Correpressor 2 de Receptor Nuclear/genética , Piperazinas/farmacologia , Próstata/efeitos dos fármacos , Próstata/enzimologia , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/enzimologia , Neoplasias de Próstata Resistentes à Castração/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteólise , Piridinas/farmacologia , Transdução de Sinais , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Transcrição Gênica , Triazóis/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Bioinformatics ; 40(3)2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38407301

RESUMO

MOTIVATION: Cryo-electron microscopy (cryo-EM) is a powerful technique for determining the structures of large protein complexes. Picking single protein particles from cryo-EM micrographs (images) is a crucial step in reconstructing protein structures from them. However, the widely used template-based particle picking process requires some manual particle picking and is labor-intensive and time-consuming. Though machine learning and artificial intelligence (AI) can potentially automate particle picking, the current AI methods pick particles with low precision or low recall. The erroneously picked particles can severely reduce the quality of reconstructed protein structures, especially for the micrographs with low signal-to-noise ratio. RESULTS: To address these shortcomings, we devised CryoTransformer based on transformers, residual networks, and image processing techniques to accurately pick protein particles from cryo-EM micrographs. CryoTransformer was trained and tested on the largest labeled cryo-EM protein particle dataset-CryoPPP. It outperforms the current state-of-the-art machine learning methods of particle picking in terms of the resolution of 3D density maps reconstructed from the picked particles as well as F1-score, and is poised to facilitate the automation of the cryo-EM protein particle picking. AVAILABILITY AND IMPLEMENTATION: The source code and data for CryoTransformer are openly available at: https://github.com/jianlin-cheng/CryoTransformer.


Assuntos
Inteligência Artificial , Software , Microscopia Crioeletrônica/métodos , Aprendizado de Máquina , Processamento de Imagem Assistida por Computador/métodos , Proteínas
10.
Hepatology ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39028883

RESUMO

Disruption of the epigenome is a hallmark of human disease including liver cirrhosis and hepatocellular carcinoma (HCC). While genetic heterogeneity is an established effector of pathologic phenotypes, epigenetic heterogeneity is less well understood. Environmental exposures alter the liver-specific DNA methylation landscape and influence the onset of liver cancer. Given that currently available treatments are unable to target frequently mutated genes in HCC, there is an unmet need for novel therapeutics to prevent or reverse liver damage leading to hepatic tumorigenesis, which the epigenome may provide. We performed genome-wide profiling of DNA methylation, copy number, and gene expression from multiple liver regions from 31 patients with liver disease to examine their crosstalk and define the individual and combinatorial contribution of these processes to liver disease progression. We identify epigenetic heterogeneity hotspots that are conserved across patients. Elevated epigenetic heterogeneity associates with increased gene expression heterogeneity. Cirrhotic regions comprise two distinct cohorts, one exclusively epigenetic, and a second where epigenetic and copy number variations collaborate. Epigenetic heterogeneity hotspots are enriched for genes central to liver function (e.g., HNF1A) and known tumor suppressors (e.g., RASSF1A). These hotspots encompass genes including ACSL1, ACSL5, MAT1A, and ELFN1, which have phenotypic effects in functional screens, supporting their relevance to hepatocarcinogenesis. Moreover, epigenetic heterogeneity hotspots are linked to clinical measures of outcome. CONCLUSION: Substantial epigenetic heterogeneity arises early in liver disease development, targeting key pathways in the progression and initiation of both cirrhosis and HCC. Integration of epigenetic and transcriptional heterogeneity unveils putative epigenetic regulators of hepatocarcinogenesis.

11.
Proc Natl Acad Sci U S A ; 119(39): e2205509119, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-36129942

RESUMO

Androgen receptor (AR) messenger RNA (mRNA) alternative splicing variants (AR-Vs) are implicated in castration-resistant progression of prostate cancer (PCa), although the molecular mechanism underlying the genesis of AR-Vs remains poorly understood. The CDK12 gene is often deleted or mutated in PCa and CDK12 deficiency is known to cause homologous recombination repair gene alteration or BRCAness via alternative polyadenylation (APA). Here, we demonstrate that pharmacological inhibition or genetic inactivation of CDK12 induces AR gene intronic (intron 3) polyadenylation (IPA) usage, AR-V expression, and PCa cell resistance to the antiandrogen enzalutamide (ENZ). We further show that AR binds to the CCNK gene promoter and up-regulates CYCLIN K expression. In contrast, ENZ decreases AR occupancy at the CCNK gene promoter and suppresses CYCLIN K expression. Similar to the effect of the CDK12 inhibitor, CYCLIN K degrader or ENZ treatment promotes AR gene IPA usage, AR-V expression, and ENZ-resistant growth of PCa cells. Importantly, we show that targeting BRCAness induced by CYCLIN K down-regulation with the PARP inhibitor overcomes ENZ resistance. Our findings identify CYCLIN K down-regulation as a key driver of IPA usage, hormonal therapy-induced AR-V expression, and castration resistance in PCa. These results suggest that hormonal therapy-induced AR-V expression and therapy resistance are vulnerable to PARP inhibitor treatment.


Assuntos
Antineoplásicos , Ciclinas , Inibidores de Poli(ADP-Ribose) Polimerases , Neoplasias de Próstata Resistentes à Castração , Receptores Androgênicos , Antagonistas de Androgênios/farmacologia , Antineoplásicos/farmacologia , Benzamidas/farmacologia , Linhagem Celular Tumoral , Ciclinas/genética , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Íntrons , Masculino , Nitrilas/farmacologia , Feniltioidantoína/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poliadenilação/genética , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , RNA Mensageiro/genética , Receptores Androgênicos/genética
12.
Nat Methods ; 18(2): 156-164, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33542514

RESUMO

This paper describes outcomes of the 2019 Cryo-EM Model Challenge. The goals were to (1) assess the quality of models that can be produced from cryogenic electron microscopy (cryo-EM) maps using current modeling software, (2) evaluate reproducibility of modeling results from different software developers and users and (3) compare performance of current metrics used for model evaluation, particularly Fit-to-Map metrics, with focus on near-atomic resolution. Our findings demonstrate the relatively high accuracy and reproducibility of cryo-EM models derived by 13 participating teams from four benchmark maps, including three forming a resolution series (1.8 to 3.1 Å). The results permit specific recommendations to be made about validating near-atomic cryo-EM structures both in the context of individual experiments and structure data archives such as the Protein Data Bank. We recommend the adoption of multiple scoring parameters to provide full and objective annotation and assessment of the model, reflective of the observed cryo-EM map density.


Assuntos
Microscopia Crioeletrônica/métodos , Modelos Moleculares , Cristalografia por Raios X , Conformação Proteica , Proteínas/química
13.
Macromol Rapid Commun ; 45(13): e2400022, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38704741

RESUMO

The preparation of self-healing polyurethane elastomers (PUEs) incorporating dynamic bonds is of considerable practical significance. However, developing a PUE with outstanding mechanical properties and high self-healing efficiency poses a significant challenge. Herein, this work has successfully developed a series of self-healing PUEs with various outstanding properties through rational molecular design. These PUEs incorporate m-xylylene diisocyanate and reversible dimethylglyoxime as hard segment, along with polytetramethylene ether glycol as soft segment. A significant amount of dynamic oxime-carbamate and hydrogen bonds are formed in hard segment. The microphase separated structure of the PUEs enables them to be colorless with a transparency of >90%. Owing to the chemical composition and multiple dynamic interactions, the PUEs are endowed with ultra-high tensile strength of 34.5 MPa, satisfactory toughness of 53.9 MJ m-3, and great elastic recovery both at low and high strains. The movement of polymer molecular chains and the dynamic reversible interactions render a self-healing efficiency of 101% at 70 °C. In addition, this self-healing polyurethane could still maintain high mechanical properties after recycling. This study provides a design strategy for the preparation of a comprehensive polyurethane with superior overall performance, which holds wide application prospects in the fields of flexible displays and solar cells.


Assuntos
Carbamatos , Elastômeros , Ligação de Hidrogênio , Oximas , Poliuretanos , Resistência à Tração , Poliuretanos/química , Oximas/química , Elastômeros/química , Carbamatos/química , Estrutura Molecular , Elasticidade
14.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33593912

RESUMO

Both gene repressor (Polycomb-dependent) and activator (Polycomb-independent) functions of the Polycomb protein enhancer of zeste homolog 2 (EZH2) are implicated in cancer progression. EZH2 protein can be phosphorylated at various residues, such as threonine 487 (T487), by CDK1 kinase, and such phosphorylation acts as a Polycomb repressive complex 2 (PRC2) suppression "code" to mediate the gene repressor-to-activator switch of EZH2 functions. Here we demonstrate that the histone reader protein ZMYND8 is overexpressed in human clear cell renal cell carcinoma (ccRCC). ZMYND8 binds to EZH2, and their interaction is largely enhanced by CDK1 phosphorylation of EZH2 at T487. ZMYND8 depletion not only enhances Polycomb-dependent function of EZH2 in hypoxia-exposed breast cancer cells or von Hippel-Lindau (VHL)-deficient ccRCC cells, but also suppresses the FOXM1 transcription program. We further show that ZMYND8 is required for EZH2-FOXM1 interaction and is important for FOXM1-dependent matrix metalloproteinase (MMP) gene expression and EZH2-mediated migration and invasion of VHL-deficient ccRCC cells. Our results identify a previously uncharacterized role of the chromatin reader ZMYND8 in recognizing the PRC2-inhibitory phosphorylation "code" essential for the Polycomb-dependent to -independent switch of EZH2 functions. They also reveal an oncogenic pathway driving cell migration and invasion in hypoxia-inducible factor-activated (hypoxia or VHL-deficient) cancer.


Assuntos
Carcinoma de Células Renais/patologia , Movimento Celular , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Hipóxia/fisiopatologia , Neoplasias Renais/patologia , Complexo Repressor Polycomb 2/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Proliferação de Células , Cromatina/genética , Cromatina/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Fosforilação , Complexo Repressor Polycomb 2/genética , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/genética
15.
Hum Mol Genet ; 30(11): 1045-1056, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-33615373

RESUMO

Craniofacial microsomia (CFM, OMIM%164 210) is one of the most common congenital facial abnormalities worldwide, but it's genetic risk factors and environmental threats are poorly investigated, as well as their interaction, making the diagnosis and prenatal screening of CFM impossible. We perform a comprehensive association study on the largest CFM cohort of 6074 samples. We identify 15 significant (P < 5 × 10-8) associated genomic loci (including eight previously reported) and decipher 107 candidates based on multi-omics data. Gene Ontology term enrichment found that these candidates are mainly enriched in neural crest cell (NCC) development and hypoxic environment. Single-cell RNA-seq data of mouse embryo demonstrate that nine of them show dramatic expression change during early cranial NCC development whose dysplasia is involved in pathogeny of CFM. Furthermore, we construct a well-performed CFM risk-predicting model based on polygenic risk score (PRS) method and estimate seven environmental risk factors that interacting with PRS. Single-nucleotide polymorphism-based PRS is significantly associated with CFM [P = 7.22 × 10-58, odds ratio = 3.15, 95% confidence interval (CI) 2.74-3.63], and the top fifth percentile has a 6.8-fold CFM risk comparing with the 10th percentile. Father's smoking increases CFM risk as evidenced by interaction parameter of -0.324 (95% CI -0.578 to -0.070, P = 0.011) with PRS. In conclusion, the newly identified risk loci will significantly improve our understandings of genetics contribution to CFM. The risk prediction model is promising for CFM prediction, and father's smoking is a key environmental risk factor for CFM through interacting with genetic factors.


Assuntos
Loci Gênicos/genética , Predisposição Genética para Doença , Síndrome de Goldenhar/diagnóstico , Patologia Molecular , Adulto , Animais , Desenvolvimento Embrionário/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Estudo de Associação Genômica Ampla , Síndrome de Goldenhar/genética , Síndrome de Goldenhar/patologia , Humanos , Masculino , Camundongos , Herança Multifatorial/genética , Polimorfismo de Nucleotídeo Único/genética , Gravidez , Diagnóstico Pré-Natal , RNA-Seq , Fatores de Risco , Análise de Célula Única
16.
EMBO J ; 38(5)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30723117

RESUMO

In light of the increasing number of identified cancer-driven gain-of-function (GOF) mutants of p53, it is important to define a common mechanism to systematically target several mutants, rather than developing strategies tailored to inhibit each mutant individually. Here, using RNA immunoprecipitation-sequencing (RIP-seq), we identified the Polycomb-group histone methyltransferase EZH2 as a p53 mRNA-binding protein. EZH2 bound to an internal ribosome entry site (IRES) in the 5'UTR of p53 mRNA and enhanced p53 protein translation in a methyltransferase-independent manner. EZH2 augmented p53 GOF mutant-mediated cancer growth and metastasis by increasing protein levels of mutant p53. EZH2 overexpression was associated with worsened outcome selectively in patients with p53-mutated cancer. Depletion of EZH2 by antisense oligonucleotides inhibited p53 GOF mutant-mediated cancer growth. Our findings reveal a non-methyltransferase function of EZH2 that controls protein translation of p53 GOF mutants, inhibition of which causes synthetic lethality in cancer cells expressing p53 GOF mutants.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Mutação com Ganho de Função , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/patologia , RNA Mensageiro/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose , Proliferação de Células , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Humanos , Sítios Internos de Entrada Ribossomal , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Metástase Neoplásica , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Estabilidade Proteica , RNA Mensageiro/genética , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Hepatology ; 76(5): 1466-1481, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35102596

RESUMO

BACKGROUND AND AIMS: NASH is associated with high levels of cholesterol and triglyceride (TG) in the liver; however, there is still no approved pharmacological therapy. Synthesis of cholesterol and TG is controlled by sterol regulatory element-binding protein (SREBP), which is found to be abnormally activated in NASH patients. We aim to discover small molecules for treating NASH by inhibiting the SREBP pathway. APPROACH AND RESULTS: Here, we identify a potent SREBP inhibitor, 25-hydroxylanosterol (25-HL). 25-HL binds to insulin-induced gene (INSIG) proteins, stimulates the interaction between INSIG and SCAP, and retains them in the endoplasmic reticulum, thereby suppressing SREBP activation and inhibiting lipogenesis. In NASH mouse models, 25-HL lowers levels of cholesterol and TG in serum and the liver, enhances energy expenditure to prevent obesity, and improves insulin sensitivity. 25-HL dramatically ameliorates hepatic steatosis, inflammation, ballooning, and fibrosis through down-regulating the expression of lipogenic genes. Furthermore, 25-HL exhibits both prophylactic and therapeutic efficacies of alleviating NASH and atherosclerosis in amylin liver NASH model diet-treated Ldlr-/- mice, and reduces the formation of cholesterol crystals and associated crown-like structures of Kupffer cells. Notably, 25-HL lowers lipid contents in serum and the liver to a greater extent than lovastatin or obeticholic acid. 25-HL shows a good safety and pharmacokinetics profile. CONCLUSIONS: This study provides the proof of concept that inhibiting SREBP activation by targeting INSIG to lower lipids could be a promising strategy for treating NASH. It suggests the translational potential of 25-HL in human NASH and demonstrates the critical role of SREBP-controlled lipogenesis in the progression of NASH by pharmacological inhibition.


Assuntos
Insulinas , Hepatopatia Gordurosa não Alcoólica , Humanos , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Lipogênese/fisiologia , Proteínas de Ligação a Elemento Regulador de Esterol , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Fígado/metabolismo , Triglicerídeos/metabolismo , Colesterol/metabolismo , Lovastatina/metabolismo , Insulinas/metabolismo , Camundongos Endogâmicos C57BL
18.
Nat Chem Biol ; 17(5): 567-575, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33664520

RESUMO

The discovery of effective therapeutic treatments for cancer via cell differentiation instead of antiproliferation remains a great challenge. Cyclin-dependent kinase 2 (CDK2) inactivation, which overcomes the differentiation arrest of acute myeloid leukemia (AML) cells, may be a promising method for AML treatment. However, there is no available selective CDK2 inhibitor. More importantly, the inhibition of only the enzymatic function of CDK2 would be insufficient to promote notable AML differentiation. To further validate the role and druggability of CDK2 involved in AML differentiation, a suitable chemical tool is needed. Therefore, we developed first-in-class CDK2-targeted proteolysis-targeting chimeras (PROTACs), which promoted rapid and potent CDK2 degradation in different cell lines without comparable degradation of other targets, and induced remarkable differentiation of AML cell lines and primary patient cells. These data clearly demonstrated the practicality and importance of PROTACs as alternative tools for verifying CDK2 protein functions.


Assuntos
Antineoplásicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Células Progenitoras Mieloides/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Triazóis/farmacologia , Antineoplásicos/síntese química , Aurora Quinase A/genética , Aurora Quinase A/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Quinase 2 Dependente de Ciclina/genética , Quinase 2 Dependente de Ciclina/metabolismo , Desenho de Fármacos , Descoberta de Drogas , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/metabolismo , Concentração Inibidora 50 , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Células Progenitoras Mieloides/enzimologia , Células Progenitoras Mieloides/patologia , Piperazinas/farmacologia , Cultura Primária de Células , Piridinas/farmacologia , Pirimidinas/farmacologia , Quinazolinas/farmacologia , Transdução de Sinais , Relação Estrutura-Atividade , Transcriptoma , Triazóis/síntese química
19.
Mol Cell ; 59(6): 904-16, 2015 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-26344096

RESUMO

SPOP mutations and TMPRSS2-ERG rearrangements occur collectively in up to 65% of human prostate cancers. Although the two events are mutually exclusive, it is unclear whether they are functionally interrelated. Here, we demonstrate that SPOP, functioning as an E3 ubiquitin ligase substrate-binding protein, promotes ubiquitination and proteasome degradation of wild-type ERG by recognizing a degron motif at the N terminus of ERG. Prostate cancer-associated SPOP mutations abrogate the SPOP-mediated degradation function on the ERG oncoprotein. Conversely, the majority of TMPRSS2-ERG fusions encode N-terminal-truncated ERG proteins that are resistant to the SPOP-mediated degradation because of degron impairment. Our findings reveal degradation resistance as a previously uncharacterized mechanism that contributes to elevation of truncated ERG proteins in prostate cancer. They also suggest that overcoming ERG resistance to SPOP-mediated degradation represents a viable strategy for treatment of prostate cancers expressing either mutated SPOP or truncated ERG.


Assuntos
Proteínas Nucleares/fisiologia , Proteínas de Fusão Oncogênica/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Repressoras/fisiologia , Transativadores/fisiologia , Sequência de Aminoácidos , Proliferação de Células , Pontos de Quebra do Cromossomo , Células HEK293 , Humanos , Masculino , Fragmentos de Peptídeos/fisiologia , Neoplasias da Próstata/metabolismo , Ligação Proteica , Proteólise , Regulador Transcricional ERG , Ubiquitinação
20.
Phytother Res ; 37(2): 515-526, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36281060

RESUMO

The treatments currently used for prostate cancer (PC) do not meet clinical needs, and thus, new therapies with greater effectiveness are urgently required. Metabolic reprogramming of tumor cells is emerging as an exciting field for cancer therapy. Although the Warburg effect is a common feature of glucose metabolism in many cancers, PC cells have a unique metabolic phenotype. Non-neoplastic prostate cells show reduced oxidative phosphorylation (OXPHOS) because large, accumulated zinc inhibits citrate oxidation. During transformation, there are low levels of zinc in PC cells, and the tricarboxylic acid (TCA) cycle is reactivated. However, metastatic PC exhibits the Warburg effect. Due to metabolic differences in prostate tissue, targeting metabolic alterations in PC cells is an attractive therapeutic strategy. In this study, we investigated the effect of juglone on energy metabolism in PC cells. We found that juglone inhibited cell proliferation and induced apoptosis. Mechanistically, we demonstrated that juglone suppressed OXPHOS and glycolysis due to its inhibition of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK) activity. Furthermore, downregulation of PFK and PK, but not HK contributed to the inhibition of these enzyme activities. The current study indicates that further development of juglone for PC treatment would be beneficial.


Assuntos
Fosforilação Oxidativa , Neoplasias da Próstata , Humanos , Masculino , Glicólise/fisiologia , Metabolismo Energético , Neoplasias da Próstata/tratamento farmacológico , Hexoquinase/metabolismo , Linhagem Celular Tumoral
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