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1.
Microb Cell ; 11: 69-78, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38414808

RESUMO

Saccharomyces cerevisiae (baker's yeast) has yielded relevant insights into some of the basic mechanisms of organismal aging. Among these are genomic instability, oxidative stress, caloric restriction and mitochondrial dysfunction. Several genes are known to have an impact on the aging process, with corresponding mutants exhibiting short- or long-lived phenotypes. Research dedicated to unraveling the underlying cellular mechanisms can support the identification of conserved mechanisms of aging in other species. One of the hitherto less studied fields in yeast aging is how the organism regulates its gene expression at the transcriptional level. To our knowledge, we present the first investigation into alternative splicing, particularly intron retention, during replicative aging of S. cerevisiae. This was achieved by utilizing the IRFinder algorithm on a previously published RNA-seq data set by Janssens et al. (2015). In the present work, 44 differentially retained introns in 43 genes were identified during replicative aging. We found that genes with altered intron retention do not display significant changes in overall transcript levels. It was possible to functionally assign distinct groups of these genes to the cellular processes of mRNA processing and export (e.g., YRA1) in early and middle-aged yeast, and protein ubiquitination (e.g., UBC5) in older cells. In summary, our work uncovers a previously unexplored layer of the transcriptional program of yeast aging and, more generally, expands the knowledge on the occurrence of alternative splicing in baker's yeast.

2.
Neuro Oncol ; 26(6): 1109-1123, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38334125

RESUMO

BACKGROUND: Cellular senescence can have positive and negative effects on the body, including aiding in damage repair and facilitating tumor growth. Adamantinomatous craniopharyngioma (ACP), the most common pediatric sellar/suprasellar brain tumor, poses significant treatment challenges. Recent studies suggest that senescent cells in ACP tumors may contribute to tumor growth and invasion by releasing a senesecence-associated secretory phenotype. However, a detailed analysis of these characteristics has yet to be completed. METHODS: We analyzed primary tissue samples from ACP patients using single-cell, single-nuclei, and spatial RNA sequencing. We performed various analyses, including gene expression clustering, inferred senescence cells from gene expression, and conducted cytokine signaling inference. We utilized LASSO to select essential gene expression pathways associated with senescence. Finally, we validated our findings through immunostaining. RESULTS: We observed significant diversity in gene expression and tissue structure. Key factors such as NFKB, RELA, and SP1 are essential in regulating gene expression, while senescence markers are present throughout the tissue. SPP1 is the most significant cytokine signaling network among ACP cells, while the Wnt signaling pathway predominantly occurs between epithelial and glial cells. Our research has identified links between senescence-associated features and pathways, such as PI3K/Akt/mTOR, MYC, FZD, and Hedgehog, with increased P53 expression associated with senescence in these cells. CONCLUSIONS: A complex interplay between cellular senescence, cytokine signaling, and gene expression pathways underlies ACP development. Further research is crucial to understand how these elements interact to create novel therapeutic approaches for patients with ACP.


Assuntos
Senescência Celular , Craniofaringioma , Aprendizado de Máquina , Neoplasias Hipofisárias , Humanos , Craniofaringioma/metabolismo , Craniofaringioma/patologia , Craniofaringioma/genética , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/genética , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/genética , Fenótipo , Regulação Neoplásica da Expressão Gênica , Criança , Masculino , Feminino
3.
EBioMedicine ; 99: 104905, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38043401

RESUMO

The long-standing view of senescent cells as passive and dysfunctional biological remnants has recently shifted into a new paradigm where they are main players in the development of many diseases, including cancer. The senescence programme represents a first line of defence that prevents tumour cell growth but also leads to the secretion of multiple pro-inflammatory and pro-tumourigenic factors that fuel tumour initiation, growth, and progression. Here, we review the main molecular features and biological functions of senescent cells in cancer, including the outcomes of inducing or targeting senescence. We discuss evidence on the role of cellular senescence in pituitary tumours, with an emphasis on adamantinomatous craniopharyngioma (ACP) and pituitary adenomas. Although senescence has been proposed to be a tumour-preventing mechanism in pituitary adenomas, research in ACP has shown that senescent cells are tumour-promoting in both murine models and human tumours. Future studies characterizing the impact of targeting senescent cells may result in novel therapies against pituitary tumours.


Assuntos
Craniofaringioma , Neoplasias Hipofisárias , Humanos , Camundongos , Criança , Animais , Neoplasias Hipofisárias/genética , Hipófise , Craniofaringioma/genética , Craniofaringioma/patologia , Carcinogênese/patologia , Transformação Celular Neoplásica/patologia , Senescência Celular
4.
Cancer Cell ; 41(7): 1242-1260.e6, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37267953

RESUMO

The accumulation of senescent cells in the tumor microenvironment can drive tumorigenesis in a paracrine manner through the senescence-associated secretory phenotype (SASP). Using a new p16-FDR mouse line, we show that macrophages and endothelial cells are the predominant senescent cell types in murine KRAS-driven lung tumors. Through single cell transcriptomics, we identify a population of tumor-associated macrophages that express a unique array of pro-tumorigenic SASP factors and surface proteins and are also present in normal aged lungs. Genetic or senolytic ablation of senescent cells, or macrophage depletion, result in a significant decrease in tumor burden and increased survival in KRAS-driven lung cancer models. Moreover, we reveal the presence of macrophages with senescent features in human lung pre-malignant lesions, but not in adenocarcinomas. Taken together, our results have uncovered the important role of senescent macrophages in the initiation and progression of lung cancer, highlighting potential therapeutic avenues and cancer preventative strategies.


Assuntos
Senescência Celular , Neoplasias Pulmonares , Idoso , Animais , Humanos , Camundongos , Carcinogênese/genética , Carcinogênese/metabolismo , Senescência Celular/genética , Células Endoteliais , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Macrófagos/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Microambiente Tumoral
5.
Nanomaterials (Basel) ; 13(10)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37242034

RESUMO

(-)-Epicatechin and quercetin have attracted considerable attention for their potential therapeutic application in non-communicable chronic diseases. A novel hybrid inulin-soy protein nanoparticle formulation was simultaneously loaded with (-)-epicatechin and quercetin (NEQs) to improve the bioavailability of these flavonoids in the human body, and NEQs were synthesized by spray drying. After process optimization, the physicochemical and functional properties of NEQs were characterized including in vitro release, in vitro gastrointestinal digestion, and cell viability assays. Results showed that NEQs are an average size of 280.17 ± 13.42 nm and have a zeta potential of -18.267 ± 0.83 mV in the organic phase. Encapsulation efficiency of (-)-epicatechin and quercetin reached 97.04 ± 0.01 and 92.05 ± 1.95%, respectively. A 3.5% soy protein content conferred controlled release characteristics to the delivery system. Furthermore, NEQs presented inhibitory effects in Caco-2, but not in HepG-2 and HDFa cell lines. These results contribute to the design and fabrication of inulin-soy protein nanoparticles for improving the bioavailability of multiple bioactive compounds with beneficial properties.

6.
PLoS One ; 18(2): e0280001, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36800350

RESUMO

The chemokine SDF-1 (CXCL12) and its receptor CXCR4 control several processes during embryonic development such as the regulation of stem cell proliferation, differentiation, and migration. However, the role of this pathway in the formation of the pituitary gland is not understood. We sought to characterise the expression patterns of CXCR4, SDF-1 and CXCR7 at different stages of pituitary gland development. Our expression profiling revealed that SDF-1 is expressed in progenitor-rich regions of the pituitary anterior lobe, that CXCR4 and CXCR7 have opposite expression domains and that CXCR4 expression is conserved between mice and human embryos. We then assessed the importance of this signalling pathway in the development and function of the murine pituitary gland through conditional deletion of CXCR4 in embryonic pituitary progenitors. Successful and specific ablation of CXCR4 expression in embryonic pituitary progenitors did not lead to observable embryonic nor postnatal defects but allowed the identification of stromal CXCR4+ cells not derived from HESX1+ progenitors. Further analysis of constitutive SDF-1, CXCR7 and CXCR4 mutants of the pathway indicates that CXCR4 expression in HESX1+ cells and their descendants is not essential for normal pituitary development in mice.


Assuntos
Receptores CXCR , Animais , Feminino , Humanos , Camundongos , Gravidez , Diferenciação Celular , Quimiocina CXCL12/metabolismo , Embrião de Mamíferos/metabolismo , Proteínas de Homeodomínio/metabolismo , Receptores CXCR/metabolismo , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais
7.
Cell Mol Life Sci ; 78(10): 4521-4544, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34019103

RESUMO

Cellular senescence is a process that can prevent tumour development in a cell autonomous manner by imposing a stable cell cycle arrest after oncogene activation. Paradoxically, senescence can also promote tumour growth cell non-autonomously by creating a permissive tumour microenvironment that fuels tumour initiation, progression to malignancy and metastasis. In a pituitary tumour known as adamantinomatous craniopharyngioma (ACP), cells that carry oncogenic ß-catenin mutations and overactivate the WNT signalling pathway form cell clusters that become senescent and activate a senescence-associated secretory phenotype (SASP). Research in mouse models of ACP has provided insights into the function of the senescent cell clusters and revealed a critical role for SASP-mediated activities in paracrine tumour initiation. In this review, we first discuss this research on ACP and subsequently explore the theme of paracrine tumourigenesis in other tumour models available in the literature. Evidence is accumulating supporting the notion that paracrine signalling brought about by senescent cells may underlie tumourigenesis across different tumours and cancer models.


Assuntos
Carcinogênese/patologia , Senescência Celular/fisiologia , Craniofaringioma/patologia , Comunicação Parácrina/fisiologia , Animais , Humanos , Transdução de Sinais/fisiologia , Microambiente Tumoral/fisiologia
8.
J Aging Health ; 32(7-8): 543-553, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30913945

RESUMO

Objectives: To assess the burden of disease and disability in older persons in Mexico from the Global Burden of Disease (GBD) 2016 study data. Methods: Analysis of the Mexican data from the GBD 2016 study is presented by state, sex, and stratified into four age groups: 60 to 69, 70 to 79, 80 to 89, and 90+ years. Results: The majority of disability-adjusted life-years (DALYs) attributable to disorders in persons 60+ in Mexico were due to premature mortality (68%). Diabetes mellitus, ischemic heart disease, and chronic kidney disease were the main causes of DALYs. With progressing age, sense organ diseases, dementias, and falls climbed to the top causes of years lived with disability (YLDs) in both sexes. Discussion: Most of the burden of disease in older Mexicans is due to premature mortality, underlining the need to strengthen the health system to respond better to health care needs of older persons with non-communicable diseases. This analysis provides information for the development of national health policies.


Assuntos
Envelhecimento , Efeitos Psicossociais da Doença , Mortalidade Prematura , Doenças não Transmissíveis/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Pessoas com Deficiência , Feminino , Recursos em Saúde , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida
9.
Mol Cell Oncol ; 5(3): e1435180, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29876518

RESUMO

Novel detrimental functions of senescent cells have been recently uncovered in the context of cancer development and progression, which they mainly exert through the secretion of several pro-tumorigenic factors. Here we discuss how cellular senescence and its secretory phenotype can be involved in the widely unexplored phenomenon of paracrine tumorigenesis.

10.
Br J Cancer ; 118(10): 1283-1288, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29670296

RESUMO

Senescent cells activate genetic programmes that irreversibly inhibit cellular proliferation, but also endow these cells with distinctive metabolic and signalling phenotypes. Although senescence has historically been considered a protective mechanism against tumourigenesis, the activities of senescent cells are increasingly being associated with age-related diseases, including cancer. An important feature of senescent cells is the secretion of a vast array of pro-inflammatory cytokines, chemokines, and growth factors collectively known as the senescence-associated secretory phenotype (SASP). Recent research has shown that SASP paracrine signalling can mediate several pro-tumourigenic effects, such as enhancing malignant phenotypes and promoting tumour initiation. In this review, we summarise the paracrine activities of senescent cells and their role in tumourigenesis through direct effects on growth and proliferation of tumour cells, tumour angiogenesis, invasion and metastasis, cellular reprogramming and emergence of tumour-initiating cells, and tumour interactions with the local immune environment. The evidence described here suggests cellular senescence acts as a double-edged sword in cancer pathogenesis, which demands further attention in order to support the use of senolytic or SASP-modulating compounds for cancer treatment.


Assuntos
Carcinogênese/genética , Senescência Celular/genética , Neoplasias/genética , Comunicação Parácrina/genética , Movimento Celular/genética , Proliferação de Células/genética , Reprogramação Celular/genética , Humanos , Invasividade Neoplásica/genética , Metástase Neoplásica , Neoplasias/patologia
11.
Acta Neuropathol ; 135(5): 757-777, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29541918

RESUMO

Adamantinomatous craniopharyngiomas (ACPs) are clinically challenging tumours, the majority of which have activating mutations in CTNNB1. They are histologically complex, showing cystic and solid components, the latter comprised of different morphological cell types (e.g. ß-catenin-accumulating cluster cells and palisading epithelium), surrounded by a florid glial reaction with immune cells. Here, we have carried out RNA sequencing on 18 ACP samples and integrated these data with an existing ACP transcriptomic dataset. No studies so far have examined the patterns of gene expression within the different cellular compartments of the tumour. To achieve this goal, we have combined laser capture microdissection with computational analyses to reveal groups of genes that are associated with either epithelial tumour cells (clusters and palisading epithelium), glial tissue or immune infiltrate. We use these human ACP molecular signatures and RNA-Seq data from two ACP mouse models to reveal that cell clusters are molecularly analogous to the enamel knot, a critical signalling centre controlling normal tooth morphogenesis. Supporting this finding, we show that human cluster cells express high levels of several members of the FGF, TGFB and BMP families of secreted factors, which signal to neighbouring cells as evidenced by immunostaining against the phosphorylated proteins pERK1/2, pSMAD3 and pSMAD1/5/9 in both human and mouse ACP. We reveal that inhibiting the MAPK/ERK pathway with trametinib, a clinically approved MEK inhibitor, results in reduced proliferation and increased apoptosis in explant cultures of human and mouse ACP. Finally, we analyse a prominent molecular signature in the glial reactive tissue to characterise the inflammatory microenvironment and uncover the activation of inflammasomes in human ACP. We validate these results by immunostaining against immune cell markers, cytokine ELISA and proteome analysis in both solid tumour and cystic fluid from ACP patients. Our data support a new molecular paradigm for understanding ACP tumorigenesis as an aberrant mimic of natural tooth development and opens new therapeutic opportunities by revealing the activation of the MAPK/ERK and inflammasome pathways in human ACP.


Assuntos
Craniofaringioma/metabolismo , Sistema de Sinalização das MAP Quinases , Neoplasias Hipofisárias/metabolismo , Transcriptoma , Microambiente Tumoral/fisiologia , Animais , Biologia Computacional , Craniofaringioma/patologia , Craniofaringioma/terapia , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Inflamação/metabolismo , Inflamação/terapia , Microdissecção e Captura a Laser , Camundongos , Neuroglia/metabolismo , Odontogênese/fisiologia , Hipófise/embriologia , Hipófise/patologia , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/terapia , Análise de Sequência de RNA , Técnicas de Cultura de Tecidos
12.
Nat Commun ; 8(1): 1819, 2017 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-29180744

RESUMO

Senescent cells may promote tumour progression through the activation of a senescence-associated secretory phenotype (SASP), whether these cells are capable of initiating tumourigenesis in vivo is not known. Expression of oncogenic ß-catenin in Sox2+ young adult pituitary stem cells leads to formation of clusters of stem cells and induction of tumours resembling human adamantinomatous craniopharyngioma (ACP), derived from Sox2- cells in a paracrine manner. Here, we uncover the mechanisms underlying this paracrine tumourigenesis. We show that expression of oncogenic ß-catenin in Hesx1+ embryonic precursors also results in stem cell clusters and paracrine tumours. We reveal that human and mouse clusters are analogous and share a common signature of senescence and SASP. Finally, we show that mice with reduced senescence and SASP responses exhibit decreased tumour-inducing potential. Together, we provide evidence that senescence and a stem cell-associated SASP drive cell transformation and tumour initiation in vivo in an age-dependent fashion.


Assuntos
Senescência Celular/fisiologia , Craniofaringioma/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias Hipofisárias/metabolismo , Compostos de Anilina/farmacologia , Animais , Compostos de Bifenilo/farmacologia , Transformação Celular Neoplásica , Criança , Craniofaringioma/patologia , Modelos Animais de Doenças , Proteínas de Homeodomínio/metabolismo , Humanos , Camundongos , Nitrofenóis/farmacologia , Oncogenes/fisiologia , Piperazinas/farmacologia , Hipófise/metabolismo , Hipófise/patologia , Neoplasias Hipofisárias/patologia , Proteínas Repressoras/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Sulfonamidas/farmacologia , Sequenciamento do Exoma , Adulto Jovem , beta Catenina/metabolismo
13.
J Neuropathol Exp Neurol ; 76(9): 779-788, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28859336

RESUMO

Pediatric adamantinomatous craniopharyngioma (ACP) is a highly solid and cystic tumor, often causing substantial damage to critical neuroendocrine structures such as the hypothalamus, pituitary gland, and optic apparatus. Paracrine signaling mechanisms driving tumor behavior have been hypothesized, with IL-6R overexpression identified as a potential therapeutic target. To identify potential novel therapies, we characterized inflammatory and immunomodulatory factors in ACP cyst fluid and solid tumor components. Cytometric bead analysis revealed a highly pro-inflammatory cytokine pattern in fluid from ACP compared to fluids from another cystic pediatric brain tumor, pilocytic astrocytoma. Cytokines and chemokines with particularly elevated concentrations in ACPs were IL-6, CXCL1 (GRO), CXCL8 (IL-8) and the immunosuppressive cytokine IL-10. These data were concordant with solid tumor compartment transcriptomic data from a larger cohort of ACPs, other pediatric brain tumors and normal brain. The majority of receptors for these cytokines and chemokines were also over-expressed in ACPs. In addition to IL-10, the established immunosuppressive factor IDO-1 was overexpressed by ACPs at the mRNA and protein levels. These data indicate that ACP cyst fluids and solid tumor components are characterized by an inflammatory cytokine and chemokine expression pattern. Further study regarding selective cytokine blockade may inform novel therapeutic interventions.


Assuntos
Craniofaringioma/metabolismo , Líquido Cístico/metabolismo , Citocinas/metabolismo , Neoplasias Hipofisárias/metabolismo , Criança , Pré-Escolar , Estudos de Coortes , Craniofaringioma/genética , Craniofaringioma/patologia , Líquido Cístico/imunologia , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Análise em Microsséries , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/patologia , RNA Mensageiro/metabolismo , Receptores de Interleucina-6/genética , Receptores de Interleucina-6/metabolismo
14.
Development ; 144(18): 3289-3302, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28807898

RESUMO

Sonic hedgehog (SHH) is an essential morphogenetic signal that dictates cell fate decisions in several developing organs in mammals. In vitro data suggest that SHH is required to specify LHX3+/LHX4+ Rathke's pouch (RP) progenitor identity. However, in vivo studies have failed to reveal such a function, supporting instead a crucial role for SHH in promoting proliferation of these RP progenitors and for differentiation of pituitary cell types. Here, we have used a genetic approach to demonstrate that activation of the SHH pathway is necessary to induce LHX3+/LHX4+ RP identity in mouse embryos. First, we show that conditional deletion of Shh in the anterior hypothalamus results in a fully penetrant phenotype characterised by a complete arrest of RP development, with lack of Lhx3/Lhx4 expression in RP epithelium at 9.0 days post coitum (dpc) and total loss of pituitary tissue by 12.5 dpc. Conversely, overactivation of the SHH pathway by conditional deletion of Ptch1 in RP progenitors leads to severe hyperplasia and enlargement of the Sox2+ stem cell compartment by the end of gestation.


Assuntos
Linhagem da Célula , Proteínas Hedgehog/metabolismo , Hipotálamo/embriologia , Hipotálamo/metabolismo , Proteínas com Homeodomínio LIM/metabolismo , Hipófise/embriologia , Hipófise/metabolismo , Fatores de Transcrição/metabolismo , Compartimento Celular , Contagem de Células , Diferenciação Celular , Proliferação de Células , Células Clonais , Cruzamentos Genéticos , Ectoderma/embriologia , Ectoderma/metabolismo , Embrião de Mamíferos/metabolismo , Endoderma/embriologia , Endoderma/metabolismo , Epitélio/embriologia , Epitélio/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genótipo , Proteínas Hedgehog/genética , Humanos , Masculino , Mutação/genética , Hipófise/patologia , Transdução de Sinais , Células-Tronco
15.
Development ; 144(12): 2141-2152, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28506993

RESUMO

Despite the importance of the RAS-RAF-MAPK pathway in normal physiology and disease of numerous organs, its role during pituitary development and tumourigenesis remains largely unknown. Here, we show that the over-activation of the MAPK pathway, through conditional expression of the gain-of-function alleles BrafV600E and KrasG12D in the developing mouse pituitary, results in severe hyperplasia and abnormal morphogenesis of the gland by the end of gestation. Cell-lineage commitment and terminal differentiation are disrupted, leading to a significant reduction in numbers of most of the hormone-producing cells before birth, with the exception of corticotrophs. Of note, Sox2+ stem cells and clonogenic potential are drastically increased in the mutant pituitaries. Finally, we reveal that papillary craniopharyngioma (PCP), a benign human pituitary tumour harbouring BRAF p.V600E also contains Sox2+ cells with sustained proliferative capacity and disrupted pituitary differentiation. Together, our data demonstrate a crucial function of the MAPK pathway in controlling the balance between proliferation and differentiation of Sox2+ cells and suggest that persistent proliferative capacity of Sox2+ cells may underlie the pathogenesis of PCP.


Assuntos
Craniofaringioma/fisiopatologia , Sistema de Sinalização das MAP Quinases/fisiologia , Neoplasias Hipofisárias/fisiopatologia , Animais , Diferenciação Celular , Proliferação de Células , Craniofaringioma/genética , Craniofaringioma/patologia , Células-Tronco Embrionárias/patologia , Células-Tronco Embrionárias/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Hipófise/citologia , Hipófise/embriologia , Hipófise/enzimologia , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/patologia , Gravidez , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição SOXB1/metabolismo
16.
Mol Cell Endocrinol ; 445: 27-34, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-27720895

RESUMO

The presence of adult pituitary stem cells (PSCs) has been described in murine systems by comprehensive cellular profiling and genetic lineage tracing experiments. PSCs are thought to maintain multipotent capacity throughout life and give rise to all hormone-producing cell lineages, playing a role in pituitary gland homeostasis. Additionally, PSCs have been proposed to play a role in pituitary tumorigenesis, in both adenomas and adamantinomatous craniopharyngiomas. In this manuscript, we discuss the different approaches used to demonstrate the presence of PSCs in the murine adult pituitary, from marker analyses to genetic tracing. In addition, we review the published literature suggesting the existence of tumor stem cells in mouse and human pituitary tumors. Finally, we discuss the potential role of PSCs in pituitary tumorigenesis in the context of current models of carcinogenesis and present evidence showing that in contrast to pituitary adenoma, which follows a classical cancer stem cell paradigm, a novel mechanism has been revealed for paracrine, non-cell autonomous tumor initiation in adamantinomatous craniopharyngioma, a benign but clinically aggressive pediatric tumor.


Assuntos
Craniofaringioma/patologia , Células-Tronco Neoplásicas/patologia , Hipófise/citologia , Neoplasias Hipofisárias/patologia , Animais , Carcinogênese/patologia , Humanos , Camundongos , Comunicação Parácrina , Hipófise/patologia
17.
Genes Dev ; 30(19): 2187-2198, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27737960

RESUMO

Oncogene-induced senescence (OIS) is a potent tumor suppressor mechanism. To identify senescence regulators relevant to cancer, we screened an shRNA library targeting genes deleted in hepatocellular carcinoma (HCC). Here, we describe how knockdown of the SWI/SNF component ARID1B prevents OIS and cooperates with RAS to induce liver tumors. ARID1B controls p16INK4a and p21CIP1a transcription but also regulates DNA damage, oxidative stress, and p53 induction, suggesting that SWI/SNF uses additional mechanisms to regulate senescence. To systematically identify SWI/SNF targets regulating senescence, we carried out a focused shRNA screen. We discovered several new senescence regulators, including ENTPD7, an enzyme that hydrolyses nucleotides. ENTPD7 affects oxidative stress, DNA damage, and senescence. Importantly, expression of ENTPD7 or inhibition of nucleotide synthesis in ARID1B-depleted cells results in re-establishment of senescence. Our results identify novel mechanisms by which epigenetic regulators can affect tumor progression and suggest that prosenescence therapies could be employed against SWI/SNF-mutated cancers.


Assuntos
Carcinoma Hepatocelular/genética , Senescência Celular/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Hepáticas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Animais , Apirase/metabolismo , Carcinoma Hepatocelular/enzimologia , Linhagem Celular , Linhagem Celular Tumoral , Epigênese Genética/genética , Feminino , Humanos , Neoplasias Hepáticas/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação , RNA Interferente Pequeno/genética
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