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1.
Sci Adv ; 7(41): eabi7511, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34613776

RESUMO

Colorectal cancer (CRC) is a leading cause of cancer mortality. Creatine metabolism was previously shown to critically regulate colon cancer progression. We report that RGX-202, an oral small-molecule SLC6A8 transporter inhibitor, robustly inhibits creatine import in vitro and in vivo, reduces intracellular phosphocreatine and ATP levels, and induces tumor apoptosis. RGX-202 suppressed CRC growth across KRAS wild-type and KRAS mutant xenograft, syngeneic, and patient-derived xenograft (PDX) tumors. Antitumor efficacy correlated with tumoral expression of creatine kinase B. Combining RGX-202 with 5-fluorouracil or the DHODH inhibitor leflunomide caused regressions of multiple colorectal xenograft and PDX tumors of distinct mutational backgrounds. RGX-202 also perturbed creatine metabolism in patients with metastatic CRC in a phase 1 trial, mirroring pharmacodynamic effects on creatine metabolism observed in mice. This is, to our knowledge, the first demonstration of preclinical and human pharmacodynamic activity for creatine metabolism targeting in oncology, thus revealing a critical therapeutic target.


Assuntos
Antineoplásicos , Neoplasias do Colo , Neoplasias Colorretais , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Neoplasias Colorretais/patologia , Creatina/metabolismo , Creatina/farmacologia , Creatina/uso terapêutico , Humanos , Proteínas de Membrana Transportadoras , Camundongos , Camundongos Nus , Mutação , Proteínas do Tecido Nervoso/metabolismo , Proteínas da Membrana Plasmática de Transporte de Neurotransmissores/genética , Proteínas da Membrana Plasmática de Transporte de Neurotransmissores/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo
2.
Development ; 147(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969356

RESUMO

Neural development is controlled at multiple levels to orchestrate appropriate choices of cell fate and differentiation. Although more attention has been paid to the roles of neural-restricted factors, broadly expressed factors can have compelling impacts on tissue-specific development. Here, we describe in vivo conditional knockout analyses of murine Ars2, which has mostly been studied as a general RNA-processing factor in yeast and cultured cells. Ars2 protein expression is regulated during neural lineage progression, and is required for embryonic neural stem cell (NSC) proliferation. In addition, Ars2 null NSCs can still transition into post-mitotic neurons, but fail to undergo terminal differentiation. Similarly, adult-specific deletion of Ars2 compromises hippocampal neurogenesis and results in specific behavioral defects. To broaden evidence for Ars2 as a chromatin regulator in neural development, we generated Ars2 ChIP-seq data. Notably, Ars2 preferentially occupies DNA enhancers in NSCs, where it colocalizes broadly with NSC regulator SOX2. Ars2 association with chromatin is markedly reduced following NSC differentiation. Altogether, Ars2 is an essential neural regulator that interacts dynamically with DNA and controls neural lineage development.


Assuntos
Envelhecimento , Proteínas de Ligação a DNA/metabolismo , Embrião de Mamíferos/metabolismo , Neurogênese , Fatores de Transcrição/metabolismo , Envelhecimento/genética , Animais , Comportamento Animal , Encéfalo/embriologia , Encéfalo/metabolismo , Linhagem da Célula/genética , Proliferação de Células , Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos/genética , Deleção de Genes , Genoma , Hidrocefalia/embriologia , Hidrocefalia/genética , Camundongos Endogâmicos C57BL , Mosaicismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição/genética
3.
Cell ; 172(4): 825-840.e18, 2018 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-29336888

RESUMO

Therapeutic harnessing of adaptive immunity via checkpoint inhibition has transformed the treatment of many cancers. Despite unprecedented long-term responses, most patients do not respond to these therapies. Immunotherapy non-responders often harbor high levels of circulating myeloid-derived suppressor cells (MDSCs)-an immunosuppressive innate cell population. Through genetic and pharmacological approaches, we uncovered a pathway governing MDSC abundance in multiple cancer types. Therapeutic liver-X nuclear receptor (LXR) agonism reduced MDSC abundance in murine models and in patients treated in a first-in-human dose escalation phase 1 trial. MDSC depletion was associated with activation of cytotoxic T lymphocyte (CTL) responses in mice and patients. The LXR transcriptional target ApoE mediated these effects in mice, where LXR/ApoE activation therapy elicited robust anti-tumor responses and also enhanced T cell activation during various immune-based therapies. We implicate the LXR/ApoE axis in the regulation of innate immune suppression and as a target for enhancing the efficacy of cancer immunotherapy in patients.


Assuntos
Apolipoproteínas E/imunologia , Imunidade Inata , Receptores X do Fígado/imunologia , Células Supressoras Mieloides/imunologia , Neoplasias Experimentais/imunologia , Animais , Apolipoproteínas E/genética , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Linhagem Celular Tumoral , Feminino , Receptores X do Fígado/genética , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Células Supressoras Mieloides/patologia , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Nat Neurosci ; 16(11): 1567-75, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24097040

RESUMO

Relative quiescence and self renewal are defining features of adult stem cells, but their potential coordination remains unclear. Subependymal neural stem cells (NSCs) lacking cyclin-dependent kinase (CDK) inhibitor (CKI) 1a (p21) exhibit rapid expansion that is followed by their permanent loss later in life. Here we demonstrate that transcription of the gene encoding bone morphogenetic protein 2 (Bmp2) in NSCs is under the direct negative control of p21 through actions that are independent of CDK. Loss of p21 in NSCs results in increased levels of secreted BMP2, which induce premature terminal differentiation of multipotent NSCs into mature non-neurogenic astrocytes in an autocrine and/or paracrine manner. We also show that the cell-nonautonomous p21-null phenotype is modulated by the Noggin-rich environment of the subependymal niche. The dual function that we describe here provides a physiological example of combined cell-autonomous and cell-nonautonomous functions of p21 with implications in self renewal, linking the relative quiescence of adult stem cells to their longevity and potentiality.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Regulação da Expressão Gênica/genética , Células-Tronco Neurais/fisiologia , Fatores Etários , Animais , Bromodesoxiuridina , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Ciclo Celular/genética , Diferenciação Celular/genética , Linhagem Celular Transformada , Meios de Cultivo Condicionados/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/deficiência , Antígeno Ki-67/metabolismo , Camundongos , Camundongos Knockout , Mutagênese , Células-Tronco Neoplásicas , Proteínas do Tecido Nervoso/metabolismo , Frações Subcelulares/metabolismo , Fatores de Tempo , Transdução Genética , Transfecção
5.
Development ; 140(9): 1892-902, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23571214

RESUMO

The activity of the Notch pathway revolves around a CSL-class transcription factor, which recruits distinct complexes that activate or repress target gene expression. The co-activator complex is deeply conserved and includes the cleaved Notch intracellular domain (NICD) and Mastermind. By contrast, numerous CSL co-repressor proteins have been identified, and these are mostly different between invertebrate and vertebrate systems. In this study, we demonstrate that mammalian BEND6 is a neural BEN-solo factor that shares many functional attributes with Drosophila Insensitive, a co-repressor for the Drosophila CSL factor. BEND6 binds the mammalian CSL protein CBF1 and antagonizes Notch-dependent target activation. In addition, its association with Notch- and CBF1-regulated enhancers is promoted by CBF1 and antagonized by activated Notch. In utero electroporation experiments showed that ectopic BEND6 inhibited Notch-mediated self-renewal of neocortical neural stem cells and promoted neurogenesis. Conversely, knockdown of BEND6 increased NSC self-renewal in wild-type neocortex, and exhibited genetic interactions with gain and loss of Notch pathway activity. We recapitulated all of these findings in cultured neurospheres, in which overexpression and depletion of BEND6 caused reciprocal effects on neural stem cell renewal and neurogenesis. These data reveal a novel mammalian CSL co-repressor in the nervous system, and show that the Notch-inhibitory activity of certain BEN-solo proteins is conserved between flies and mammals.


Assuntos
Células-Tronco Neurais/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Animais , Núcleo Celular/genética , Núcleo Celular/metabolismo , Clonagem Molecular , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Eletroporação , Feminino , Células HEK293 , Células HeLa , Humanos , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/metabolismo , Camundongos , Neocórtex/citologia , Neocórtex/metabolismo , Células-Tronco Neurais/citologia , Neurogênese , Neurônios/citologia , Neurônios/metabolismo , Gravidez , Ligação Proteica , Mapeamento de Interação de Proteínas , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores Notch/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transfecção
6.
Genome Res ; 23(5): 812-25, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23520388

RESUMO

Remarkable advances in techniques for gene expression profiling have radically changed our knowledge of the transcriptome. Recently, the mammalian brain was reported to express many long intergenic noncoding (lincRNAs) from loci downstream from protein-coding genes. Our experimental tests failed to validate specific accumulation of lincRNA transcripts, and instead revealed strongly distal 3' UTRs generated by alternative cleavage and polyadenylation (APA). With this perspective in mind, we analyzed deep mammalian RNA-seq data using conservative criteria, and identified 2035 mouse and 1847 human genes that utilize substantially distal novel 3' UTRs. Each of these extends at least 500 bases past the most distal 3' termini available in Ensembl v65, and collectively they add 6.6 Mb and 5.1 Mb to the mRNA space of mouse and human, respectively. Extensive Northern analyses validated stable accumulation of distal APA isoforms, including transcripts bearing exceptionally long 3' UTRs (many >10 kb and some >18 kb in length). The Northern data further illustrate that the extensions we annotated were not due to unprocessed transcriptional run-off events. Global tissue comparisons revealed that APA events yielding these extensions were most prevalent in the mouse and human brain. Finally, these extensions collectively contain thousands of conserved miRNA binding sites, and these are strongly enriched for many well-studied neural miRNAs. Altogether, these new 3' UTR annotations greatly expand the scope of post-transcriptional regulatory networks in mammals, and have particular impact on the central nervous system.


Assuntos
Regiões 3' não Traduzidas/genética , Encéfalo/metabolismo , Perfilação da Expressão Gênica , Poliadenilação/genética , RNA Longo não Codificante/genética , Animais , Sequência de Bases , Regulação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Camundongos , Anotação de Sequência Molecular , Fases de Leitura Aberta/genética , Análise de Sequência de RNA
8.
Nature ; 481(7380): 195-8, 2011 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-22198669

RESUMO

Fundamental questions remain unanswered about the transcriptional networks that control the identity and self-renewal of neural stem cells (NSCs), a specialized subset of astroglial cells that are endowed with stem properties and neurogenic capacity. Here we report that the zinc finger protein Ars2 (arsenite-resistance protein 2; also known as Srrt) is expressed by adult NSCs from the subventricular zone (SVZ) of mice, and that selective knockdown of Ars2 in cells expressing glial fibrillary acidic protein within the adult SVZ depletes the number of NSCs and their neurogenic capacity. These phenotypes are recapitulated in the postnatal SVZ of hGFAP-cre::Ars2(fl/fl) conditional knockout mice, but are more severe. Ex vivo assays show that Ars2 is necessary and sufficient to promote NSC self-renewal, and that it does so by positively regulating the expression of Sox2. Although plant and animal orthologues of Ars2 are known for their conserved roles in microRNA biogenesis, we unexpectedly observed that Ars2 retains its capacity to promote self-renewal in Drosha and Dicer1 knockout NSCs. Instead, chromatin immunoprecipitation revealed that Ars2 binds a specific region within the 6-kilobase NSC enhancer of Sox2. This association is RNA-independent, and the region that is bound is required for Ars2-mediated activation of Sox2. We used gel-shift analysis to refine the Sox2 region bound by Ars2 to a specific conserved DNA sequence. The importance of Sox2 as a critical downstream effector is shown by its ability to restore the self-renewal and multipotency defects of Ars2 knockout NSCs. Our findings reveal Ars2 as a new transcription factor that controls the multipotent progenitor state of NSCs through direct activation of the pluripotency factor Sox2.


Assuntos
Encéfalo/citologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional , Animais , Proliferação de Células , Células Cultivadas , Imunoprecipitação da Cromatina , Sequência Conservada/genética , RNA Helicases DEAD-box/deficiência , Proteínas de Ligação a DNA , Ensaio de Desvio de Mobilidade Eletroforética , Elementos Facilitadores Genéticos/genética , Proteína Glial Fibrilar Ácida/metabolismo , Camundongos , Camundongos Knockout , Neurogênese/genética , Proteínas Nucleares/química , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Bulbo Olfatório/citologia , Ribonuclease III/deficiência , Fatores de Transcrição/química , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Dedos de Zinco
9.
Nat Neurosci ; 12(12): 1514-23, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19898467

RESUMO

We sought to address the fundamental question of how stem cell microenvironments can regulate self-renewal. We found that Notch was active in astroglia-like neural stem cells (NSCs), but not in transit-amplifying progenitors of the murine subependymal zone, and that the level of Notch transcriptional activity correlated with self-renewal and multipotency. Moreover, dividing NSCs appeared to balance renewal with commitment via controlled segregation of Notch activity, leading to biased expression of known (Hes1) and previously unknown (Egfr) Notch target genes in daughter cells. Pigment epithelium-derived factor (PEDF) enhanced Notch-dependent transcription in cells with low Notch signaling, thereby subverting the output of an asymmetrical division to the production of two highly self-renewing cells. Mechanistically, PEDF induced a non-canonical activation of the NF-kappaB pathway, leading to the dismissal of the transcriptional co-repressor N-CoR from specific Notch-responsive promoters. Our data provide a basis for stemness regulation in vascular niches and indicate that Notch and PEDF cooperate to regulate self-renewal.


Assuntos
Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Epêndima/citologia , Proteínas do Olho/metabolismo , Fatores de Crescimento Neural/metabolismo , Neurônios/citologia , Receptor Notch1/metabolismo , Serpinas/metabolismo , Fatores Etários , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Receptores ErbB/genética , Proteínas do Olho/genética , Expressão Gênica/fisiologia , Proteínas de Homeodomínio/genética , Camundongos , Fatores de Crescimento Neural/genética , Correpressor 1 de Receptor Nuclear/metabolismo , Receptor Notch1/genética , Serpinas/genética , Transdução de Sinais/fisiologia , Fatores de Transcrição HES-1 , Fator de Transcrição RelA/metabolismo , Transcrição Gênica/fisiologia
10.
Nat Protoc ; 2(4): 849-859, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17474182

RESUMO

We describe a protocol developed/modified by our group for the ex vivo and in vivo assessment of the response to a soluble factor of murine neural stem cells from the adult sub-ventricular zone (SVZ). The procedure includes several experimental options that can be used either independently or in combination. Potential factor effects on self-renewal, survival and proliferation are assayed by means of neurosphere cultures, with the factor administered directly in vitro to the culture plates (Step 1) or infused in vivo immediately before tissue dissociation (Step 3). We also use bromodeoxiuridine (BrdU) retention to label slowly dividing cells in vivo and subsequently perform two different types of experiments. In one set of experiments, the factor is added to primary cultures of stem cells obtained from the BrdU-pulsed animals and effects are tested on label-retaining cells after immunocytochemistry (Step 2). In another set, prolonged intraventricular infusion of the factor in BrdU-pulsed animals is followed by immunohistochemical analysis of BrdU labeling in the intact SVZ (Step 4). The minimum estimated time for the full combined procedure is 45 d.


Assuntos
Ventrículos Cerebrais/citologia , Imuno-Histoquímica/métodos , Neurônios/citologia , Células-Tronco/citologia , Animais , Bromodesoxiuridina , Células Cultivadas , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Camundongos , Neurônios/efeitos dos fármacos , Coloração e Rotulagem/métodos , Células-Tronco/efeitos dos fármacos
11.
Nat Neurosci ; 9(3): 331-9, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16491078

RESUMO

Adult stem cells are characterized by self-renewal and multilineage differentiation, and these properties seem to be regulated by signals from adjacent differentiated cell types and by extracellular matrix molecules, which collectively define the stem cell "niche." Self-renewal is essential for the lifelong persistence of stem cells, but its regulation is poorly understood. In the mammalian brain, neurogenesis persists in two germinal areas, the subventricular zone (SVZ) and the hippocampus, where continuous postnatal neuronal production seems to be supported by neural stem cells (NSCs). Here we show that pigment epithelium-derived factor (PEDF) is secreted by components of the murine SVZ and promotes self-renewal of adult NSCs in vitro. In addition, intraventricular PEDF infusion activated slowly dividing stem cells, whereas a blockade of endogenous PEDF decreased their cycling. These data demonstrate that PEDF is a niche-derived regulator of adult NSCs and provide evidence for a role for PEDF protein in NSC maintenance.


Assuntos
Proliferação de Células/efeitos dos fármacos , Proteínas do Olho/metabolismo , Fatores de Crescimento Neural/metabolismo , Plasticidade Neuronal/fisiologia , Neurônios/metabolismo , Serpinas/metabolismo , Células-Tronco/metabolismo , Telencéfalo/metabolismo , Animais , Células COS , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Células Cultivadas , Chlorocebus aethiops , Endotélio Vascular/metabolismo , Epêndima/citologia , Epêndima/efeitos dos fármacos , Epêndima/metabolismo , Proteínas do Olho/farmacologia , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Injeções Intraventriculares , Ventrículos Laterais/citologia , Ventrículos Laterais/metabolismo , Camundongos , Fatores de Crescimento Neural/farmacologia , Plasticidade Neuronal/efeitos dos fármacos , Neurônios/citologia , Serpinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Células-Tronco/efeitos dos fármacos , Telencéfalo/citologia , Telencéfalo/efeitos dos fármacos
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