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1.
Cell ; 174(6): 1559-1570.e22, 2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-30100185

RESUMO

The urea cycle (UC) is the main pathway by which mammals dispose of waste nitrogen. We find that specific alterations in the expression of most UC enzymes occur in many tumors, leading to a general metabolic hallmark termed "UC dysregulation" (UCD). UCD elicits nitrogen diversion toward carbamoyl-phosphate synthetase2, aspartate transcarbamylase, and dihydrooratase (CAD) activation and enhances pyrimidine synthesis, resulting in detectable changes in nitrogen metabolites in both patient tumors and their bio-fluids. The accompanying excess of pyrimidine versus purine nucleotides results in a genomic signature consisting of transversion mutations at the DNA, RNA, and protein levels. This mutational bias is associated with increased numbers of hydrophobic tumor antigens and a better response to immune checkpoint inhibitors independent of mutational load. Taken together, our findings demonstrate that UCD is a common feature of tumors that profoundly affects carcinogenesis, mutagenesis, and immunotherapy response.


Assuntos
Genômica , Metabolômica , Neoplasias/patologia , Ureia/metabolismo , Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Animais , Aspartato Carbamoiltransferase/genética , Aspartato Carbamoiltransferase/metabolismo , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/genética , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/metabolismo , Linhagem Celular Tumoral , Di-Hidro-Orotase/genética , Di-Hidro-Orotase/metabolismo , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Proteínas de Transporte da Membrana Mitocondrial , Neoplasias/metabolismo , Ornitina Carbamoiltransferase/antagonistas & inibidores , Ornitina Carbamoiltransferase/genética , Ornitina Carbamoiltransferase/metabolismo , Fosforilação/efeitos dos fármacos , Pirimidinas/biossíntese , Pirimidinas/química , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo
2.
Cell ; 149(1): 49-62, 2012 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-22401813

RESUMO

Decremental loss of PTEN results in cancer susceptibility and tumor progression. PTEN elevation might therefore be an attractive option for cancer prevention and therapy. We have generated several transgenic mouse lines with PTEN expression elevated to varying levels by taking advantage of bacterial artificial chromosome (BAC)-mediated transgenesis. The "Super-PTEN" mutants are viable and show reduced body size due to decreased cell number, with no effect on cell size. Unexpectedly, PTEN elevation at the organism level results in healthy metabolism characterized by increased energy expenditure and reduced body fat accumulation. Cells derived from these mice show reduced glucose and glutamine uptake and increased mitochondrial oxidative phosphorylation and are resistant to oncogenic transformation. Mechanistically we find that PTEN elevation orchestrates this metabolic switch by regulating PI3K-dependent and -independent pathways and negatively impacting two of the most pronounced metabolic features of tumor cells: glutaminolysis and the Warburg effect.


Assuntos
PTEN Fosfo-Hidrolase/metabolismo , Transdução de Sinais , Animais , Tamanho Corporal , Contagem de Células , Proliferação de Células , Respiração Celular , Metabolismo Energético , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo
3.
Cell ; 144(2): 187-99, 2011 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-21241890

RESUMO

PTEN is a frequently mutated tumor suppressor gene that opposes the PI3K/AKT pathway through dephosphorylation of phosphoinositide-3,4,5-triphosphate. Recently, nuclear compartmentalization of PTEN was found as a key component of its tumor-suppressive activity; however its nuclear function remains poorly defined. Here we show that nuclear PTEN interacts with APC/C, promotes APC/C association with CDH1, and thereby enhances the tumor-suppressive activity of the APC-CDH1 complex. We find that nuclear exclusion but not phosphatase inactivation of PTEN impairs APC-CDH1. This nuclear function of PTEN provides a straightforward mechanistic explanation for the fail-safe cellular senescence response elicited by acute PTEN loss and the tumor-suppressive activity of catalytically inactive PTEN. Importantly, we demonstrate that PTEN mutant and PTEN null states are not synonymous as they are differentially sensitive to pharmacological inhibition of APC-CDH1 targets such as PLK1 and Aurora kinases. This finding identifies a strategy for cancer patient stratification and, thus, optimization of targeted therapies. PAPERCLIP:


Assuntos
Caderinas/metabolismo , Senescência Celular , PTEN Fosfo-Hidrolase/metabolismo , Complexos Ubiquitina-Proteína Ligase/metabolismo , Ciclossomo-Complexo Promotor de Anáfase , Animais , Antígenos CD , Aurora Quinases , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Humanos , Masculino , Camundongos , Transplante de Neoplasias , PTEN Fosfo-Hidrolase/genética , Monoéster Fosfórico Hidrolases/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Transplante Heterólogo
4.
Proc Natl Acad Sci U S A ; 120(52): e2311674120, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38109528

RESUMO

The tumor microenvironment (TME) is a dynamic pseudoorgan that shapes the development and progression of cancers. It is a complex ecosystem shaped by interactions between tumor and stromal cells. Although the traditional focus has been on the paracrine communication mediated by protein messengers, recent attention has turned to the metabolic secretome in tumors. Metabolic enzymes, together with exchanged substrates and products, have emerged as potential biomarkers and therapeutic targets. However, traditional techniques for profiling secreted metabolites in complex cellular contexts are limited. Surface-enhanced Raman scattering (SERS) has emerged as a promising alternative due to its nontargeted nature and simplicity of operation. Although SERS has demonstrated its potential for detecting metabolites in biological settings, its application in deciphering metabolic interactions within multicellular systems like the TME remains underexplored. In this study, we introduce a SERS-based strategy to investigate the secreted purine metabolites of tumor cells lacking methylthioadenosine phosphorylase (MTAP), a common genetic event associated with poor prognosis in various cancers. Our SERS analysis reveals that MTAP-deficient cancer cells selectively produce methylthioadenosine (MTA), which is taken up and metabolized by fibroblasts. Fibroblasts exposed to MTA exhibit: i) molecular reprogramming compatible with cancer aggressiveness, ii) a significant production of purine derivatives that could be readily recycled by cancer cells, and iii) the capacity to secrete purine derivatives that induce macrophage polarization. Our study supports the potential of SERS for cancer metabolism research and reveals an unprecedented paracrine crosstalk that explains TME reprogramming in MTAP-deleted cancers.


Assuntos
Ecossistema , Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Purinas/metabolismo , Purina-Núcleosídeo Fosforilase/genética , Microambiente Tumoral
5.
Br J Cancer ; 131(8): 1250-1262, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38969865

RESUMO

Prostate cancer is one of the most commonly diagnosed cancers in men and is a major cause of cancer-related deaths worldwide. Among the molecular processes that contribute to this disease, the weight of metabolism has been placed under the limelight in recent years. Tumours exhibit metabolic adaptations to comply with their biosynthetic needs. However, metabolites also play an important role in supporting cell survival in challenging environments or remodelling the tumour microenvironment, thus being recognized as a hallmark in cancer. Prostate cancer is uniquely driven by androgen receptor signalling, and this knowledge has also influenced the paths of cancer metabolism research. This review provides a comprehensive perspective on the metabolic adaptations that support prostate cancer progression beyond androgen signalling, with a particular focus on tumour cell intrinsic and extrinsic pathways.


Assuntos
Neoplasias da Próstata , Humanos , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Masculino , Microambiente Tumoral , Receptores Androgênicos/metabolismo , Transdução de Sinais , Adaptação Fisiológica , Animais
6.
Cardiovasc Diabetol ; 23(1): 272, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048982

RESUMO

BACKGROUND: Metabolic syndrome (MetS) is a cluster of medical conditions and risk factors correlating with insulin resistance that increase the risk of developing cardiometabolic health problems. The specific criteria for diagnosing MetS vary among different medical organizations but are typically based on the evaluation of abdominal obesity, high blood pressure, hyperglycemia, and dyslipidemia. A unique, quantitative and independent estimation of the risk of MetS based only on quantitative biomarkers is highly desirable for the comparison between patients and to study the individual progression of the disease in a quantitative manner. METHODS: We used NMR-based metabolomics on a large cohort of donors (n = 21,323; 37.5% female) to investigate the diagnostic value of serum or serum combined with urine to estimate the MetS risk. Specifically, we have determined 41 circulating metabolites and 112 lipoprotein classes and subclasses in serum samples and this information has been integrated with metabolic profiles extracted from urine samples. RESULTS: We have developed MetSCORE, a metabolic model of MetS that combines serum lipoprotein and metabolite information. MetSCORE discriminate patients with MetS (independently identified using the WHO criterium) from general population, with an AUROC of 0.94 (95% CI 0.920-0.952, p < 0.001). MetSCORE is also able to discriminate the intermediate phenotypes, identifying the early risk of MetS in a quantitative way and ranking individuals according to their risk of undergoing MetS (for general population) or according to the severity of the syndrome (for MetS patients). CONCLUSIONS: We believe that MetSCORE may be an insightful tool for early intervention and lifestyle modifications, potentially preventing the aggravation of metabolic syndrome.


Assuntos
Biomarcadores , Espectroscopia de Ressonância Magnética , Síndrome Metabólica , Metabolômica , Valor Preditivo dos Testes , Humanos , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/sangue , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/urina , Feminino , Masculino , Biomarcadores/sangue , Biomarcadores/urina , Pessoa de Meia-Idade , Medição de Risco , Adulto , Idoso , Lipoproteínas/sangue , Prognóstico , Fatores de Risco , Fatores de Risco Cardiometabólico , Adulto Jovem
7.
Mol Cancer ; 22(1): 119, 2023 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-37516825

RESUMO

Newly growing evidence highlights the essential role that epitranscriptomic marks play in the development of many cancers; however, little is known about the role and implications of altered epitranscriptome deposition in prostate cancer. Here, we show that the transfer RNA N7-methylguanosine (m7G) transferase METTL1 is highly expressed in primary and advanced prostate tumours. Mechanistically, we find that METTL1 depletion causes the loss of m7G tRNA methylation and promotes the biogenesis of a novel class of small non-coding RNAs derived from 5'tRNA fragments. 5'tRNA-derived small RNAs steer translation control to favour the synthesis of key regulators of tumour growth suppression, interferon pathway, and immune effectors. Knockdown of Mettl1 in prostate cancer preclinical models increases intratumoural infiltration of pro-inflammatory immune cells and enhances responses to immunotherapy. Collectively, our findings reveal a therapeutically actionable role of METTL1-directed m7G tRNA methylation in cancer cell translation control and tumour biology.


Assuntos
Carcinogênese , Neoplasias da Próstata , Masculino , Humanos , Carcinogênese/genética , Transformação Celular Neoplásica , Neoplasias da Próstata/genética , Transcrição Gênica , Processamento Pós-Transcricional do RNA , Metiltransferases/genética
8.
Mol Cancer ; 22(1): 133, 2023 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-37573301

RESUMO

Prostate cancer (PCa) is a common and fatal type of cancer in men. Metastatic PCa (mPCa) is a major factor contributing to its lethality, although the mechanisms remain poorly understood. PTEN is one of the most frequently deleted genes in mPCa. Here we show a frequent genomic co-deletion of PTEN and STAT3 in liquid biopsies of patients with mPCa. Loss of Stat3 in a Pten-null mouse prostate model leads to a reduction of LKB1/pAMPK with simultaneous activation of mTOR/CREB, resulting in metastatic disease. However, constitutive activation of Stat3 led to high LKB1/pAMPK levels and suppressed mTORC1/CREB pathway, preventing mPCa development. Metformin, one of the most widely prescribed therapeutics against type 2 diabetes, inhibits mTORC1 in liver and requires LKB1 to mediate glucose homeostasis. We find that metformin treatment of STAT3/AR-expressing PCa xenografts resulted in significantly reduced tumor growth accompanied by diminished mTORC1/CREB, AR and PSA levels. PCa xenografts with deletion of STAT3/AR nearly completely abrogated mTORC1/CREB inhibition mediated by metformin. Moreover, metformin treatment of PCa patients with high Gleason grade and type 2 diabetes resulted in undetectable mTORC1 levels and upregulated STAT3 expression. Furthermore, PCa patients with high CREB expression have worse clinical outcomes and a significantly increased risk of PCa relapse and metastatic recurrence. In summary, we have shown that STAT3 controls mPCa via LKB1/pAMPK/mTORC1/CREB signaling, which we have identified as a promising novel downstream target for the treatment of lethal mPCa.


Assuntos
Diabetes Mellitus Tipo 2 , Metformina , Neoplasias da Próstata , Animais , Humanos , Masculino , Camundongos , Proteínas Quinases Ativadas por AMP/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Metformina/farmacologia , Recidiva Local de Neoplasia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo
9.
Small ; 19(51): e2207658, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37046181

RESUMO

During the response to different stress conditions, damaged cells react in multiple ways, including the release of a diverse cocktail of metabolites. Moreover, secretomes from dying cells can contribute to the effectiveness of anticancer therapies and can be exploited as predictive biomarkers. The nature of the stress and the resulting intracellular responses are key determinants of the secretome composition, but monitoring such processes remains technically arduous. Hence, there is growing interest in developing tools for noninvasive secretome screening. In this regard, it has been previously shown that the relative concentrations of relevant metabolites can be traced by surface-enhanced Raman scattering (SERS), thereby allowing label-free biofluid interrogation. However, conventional SERS approaches are insufficient to tackle the requirements imposed by high-throughput modalities, namely fast data acquisition and automatized analysis. Therefore, machine learning methods were implemented to identify cell secretome variations while extracting standard features for cell death classification. To this end, ad hoc microfluidic chips were devised, to readily conduct SERS measurements through a prototype relying on capillary pumps made of filter paper, which eventually would function as the SERS substrates. The developed strategy may pave the way toward a faster implementation of SERS into cell secretome classification, which can be extended even to laboratories lacking highly specialized facilities.


Assuntos
Secretoma , Análise Espectral Raman , Análise Espectral Raman/métodos , Microfluídica , Biomarcadores
10.
Cell ; 133(3): 403-14, 2008 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-18455982

RESUMO

Since its discovery as the elusive tumor suppressor gene at the frequently mutated 10q23 locus, PTEN has been identified as lost or mutated in several sporadic and heritable tumor types. A decade of work has established that PTEN is a nonredundant phosphatase that is essential for regulating the highly oncogenic prosurvival PI3K/AKT signaling pathway. This review discusses emerging modes of PTEN function and regulation, and speculates about how manipulation of PTEN function could be used for cancer therapy.


Assuntos
PTEN Fosfo-Hidrolase/metabolismo , Animais , Predisposição Genética para Doença , Humanos , Neoplasias/genética , Neoplasias/metabolismo , PTEN Fosfo-Hidrolase/genética , Transcrição Gênica
11.
Nano Lett ; 21(20): 8785-8793, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34614348

RESUMO

Monitoring dynamic processes in complex cellular environments requires the integration of uniformly distributed detectors within such three-dimensional (3D) networks, to an extent that the sensor could provide real-time information on nearby perturbations in a non-invasive manner. In this context, the development of 3D-printed structures that can function as both sensors and cell culture platforms emerges as a promising strategy, not only for mimicking a specific cell niche but also toward identifying its characteristic physicochemical conditions, such as concentration gradients. We present herein a 3D cancer model that incorporates a hydrogel-based scaffold containing gold nanorods. In addition to sustaining cell growth, the printed nanocomposite inks display the ability to uncover drug diffusion profiles by surface-enhanced Raman scattering, with high spatiotemporal resolution. We additionally demonstrate that the acquired information could pave the way to designing novel strategies for drug discovery in cancer therapy, through correlation of drug diffusion with cell death.


Assuntos
Nanocompostos , Nanotubos , Ouro , Hidrogéis , Análise Espectral Raman
12.
Int J Mol Sci ; 23(9)2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35562901

RESUMO

Glioma stem cells (GSCs) are critical targets for glioma therapy. SOX9 is a transcription factor with critical roles during neurodevelopment, particularly within neural stem cells. Previous studies showed that high levels of SOX9 are associated with poor glioma patient survival. SOX9 knockdown impairs GSCs proliferation, confirming its potential as a target for glioma therapy. In this study, we characterized the function of SOX9 directly in patient-derived glioma stem cells. Notably, transcriptome analysis of GSCs with SOX9 knockdown revealed STAT3 and PML as downstream targets. Functional studies demonstrated that SOX9, STAT3, and PML form a regulatory loop that is key for GSC activity and self-renewal. Analysis of glioma clinical biopsies confirmed a positive correlation between SOX9/STAT3/PML and poor patient survival among the cases with the highest SOX9 expression levels. Importantly, direct STAT3 or PML inhibitors reduced the expression of SOX9, STAT3, and PML proteins, which significantly reduced GSCs tumorigenicity. In summary, our study reveals a novel role for SOX9 upstream of STAT3, as a GSC pathway regulator, and presents pharmacological inhibitors of the signaling cascade.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Glioma/metabolismo , Humanos , Células-Tronco Neoplásicas/metabolismo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Fator de Transcrição STAT3/metabolismo
13.
Circulation ; 142(7): 688-704, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32466671

RESUMO

BACKGROUND: Pericytes regulate vessel stabilization and function, and their loss is associated with diseases such as diabetic retinopathy or cancer. Despite their physiological importance, pericyte function and molecular regulation during angiogenesis remain poorly understood. METHODS: To decipher the transcriptomic programs of pericytes during angiogenesis, we crossed Pdgfrb(BAC)-CreERT2 mice into RiboTagflox/flox mice. Pericyte morphological changes were assessed in mural cell-specific R26-mTmG reporter mice, in which low doses of tamoxifen allowed labeling of single-cell pericytes at high resolution. To study the role of phosphoinositide 3-kinase (PI3K) signaling in pericyte biology during angiogenesis, we used genetic mouse models that allow selective inactivation of PI3Kα and PI3Kß isoforms and their negative regulator phosphate and tensin homolog deleted on chromosome 10 (PTEN) in mural cells. RESULTS: At the onset of angiogenesis, pericytes exhibit molecular traits of cell proliferation and activated PI3K signaling, whereas during vascular remodeling, pericytes upregulate genes involved in mature pericyte cell function, together with a remarkable decrease in PI3K signaling. Immature pericytes showed stellate shape and high proliferation, and mature pericytes were quiescent and elongated. Unexpectedly, we demonstrate that PI3Kß, but not PI3Kα, regulates pericyte proliferation and maturation during vessel formation. Genetic PI3Kß inactivation in pericytes triggered early pericyte maturation. Conversely, unleashing PI3K signaling by means of PTEN deletion delayed pericyte maturation. Pericyte maturation was necessary to undergo vessel remodeling during angiogenesis. CONCLUSIONS: Our results identify new molecular and morphological traits associated with pericyte maturation and uncover PI3Kß activity as a checkpoint to ensure appropriate vessel formation. In turn, our results may open new therapeutic opportunities to regulate angiogenesis in pathological processes through the manipulation of pericyte PI3Kß activity.


Assuntos
Neovascularização Fisiológica , Pericitos/enzimologia , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Remodelação Vascular , Animais , Camundongos , Camundongos Transgênicos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/genética
14.
J Proteome Res ; 19(6): 2419-2428, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32380831

RESUMO

Prostate cancer is the second most common tumor and the fifth cause of cancer-related death among men worldwide. PC cells exhibit profound signaling and metabolic reprogramming that account for the acquisition of aggressive features. Although the metabolic understanding of this disease has increased in recent years, the analysis of such alterations through noninvasive methodologies in biofluids remains limited. Here, we used NMR-based metabolomics on a large cohort of urine samples (more than 650) from PC and benign prostate hyperplasia (BPH) patients to investigate the molecular basis of this disease. Multivariate analysis failed to distinguish between the two classes, highlighting the modest impact of prostate alterations on urine composition and the multifactorial nature of PC. However, univariate analysis of urine metabolites unveiled significant changes, discriminating PC from BPH. Metabolites with altered abundance in urine from PC patients revealed changes in pathways related to cancer biology, including glycolysis and the urea cycle. We found out that metabolites from such pathways were diminished in the urine from PC individuals, strongly supporting the notion that PC reduces nitrogen and carbon waste in order to maximize their usage in anabolic processes that support cancer cell growth.


Assuntos
Nitrogênio , Neoplasias da Próstata , Carbono , Humanos , Masculino , Metabolômica , Neoplasias da Próstata/diagnóstico , Espectroscopia de Prótons por Ressonância Magnética
15.
Bioinformatics ; 35(21): 4350-4355, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30923806

RESUMO

MOTIVATION: The development of computational tools exploiting -omics data and high-quality genome-scale metabolic networks for the identification of novel drug targets is a relevant topic in Systems Medicine. Metabolic Transformation Algorithm (MTA) is one of these tools, which aims to identify targets that transform a disease metabolic state back into a healthy state, with potential application in any disease where a clear metabolic alteration is observed. RESULTS: Here, we present a robust extension to MTA (rMTA), which additionally incorporates a worst-case scenario analysis and minimization of metabolic adjustment to evaluate the beneficial effect of gene knockouts. We show that rMTA complements MTA in the different datasets analyzed (gene knockout perturbations in different organisms, Alzheimer's disease and prostate cancer), bringing a more accurate tool for predicting therapeutic targets. AVAILABILITY AND IMPLEMENTATION: rMTA is freely available on The Cobra Toolbox: https://opencobra.github.io/cobratoolbox/latest/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Redes e Vias Metabólicas , Software , Algoritmos , Genoma , Análise de Sistemas
16.
Hepatology ; 67(4): 1420-1440, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28922472

RESUMO

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease associated with autoimmune phenomena targeting intrahepatic bile duct cells (cholangiocytes). Although its etiopathogenesis remains obscure, development of antimitochondrial autoantibodies against pyruvate dehydrogenase complex E2 is a common feature. MicroRNA (miR) dysregulation occurs in liver and immune cells of PBC patients, but its functional relevance is largely unknown. We previously reported that miR-506 is overexpressed in PBC cholangiocytes and directly targets both Cl- / HCO3- anion exchanger 2 and type III inositol 1,4,5-trisphosphate receptor, leading to cholestasis. Here, the regulation of miR-506 gene expression and its role in cholangiocyte pathophysiology and immune activation was studied. Several proinflammatory cytokines overexpressed in PBC livers (such as interleukin-8 [IL8], IL12, IL17, IL18, and tumor necrosis factor alpha) stimulated miR-506 promoter activity in human cholangiocytes, as revealed by luciferase reporter assays. Experimental overexpression of miR-506 in cholangiocytes dysregulated the cell proteomic profile (by mass spectrometry), affecting proteins involved in different biological processes including mitochondrial metabolism. In cholangiocytes, miR-506 (1) induced dedifferentiation with down-regulation of biliary and epithelial markers together with up-regulation of mesenchymal, proinflammatory, and profibrotic markers; (2) impaired cell proliferation and adhesion; (3) increased oxidative and endoplasmic reticulum stress; (4) caused DNA damage; and (5) sensitized to caspase-3-dependent apoptosis induced by cytotoxic bile acids. These events were also associated with impaired energy metabolism in mitochondria (proton leak and less adenosine triphosphate production) and pyruvate dehydrogenase complex E2 overexpression. Coculture of miR-506 overexpressing cholangiocytes with PBC immunocytes induced activation and proliferation of PBC immunocytes. CONCLUSION: Different proinflammatory cytokines enhance the expression of miR-506 in biliary epithelial cells; miR-506 induces PBC-like features in cholangiocytes and promotes immune activation, representing a potential therapeutic target for PBC patients. (Hepatology 2018;67:1420-1440).


Assuntos
Ductos Biliares Intra-Hepáticos/patologia , Células Epiteliais/metabolismo , Cirrose Hepática Biliar/metabolismo , MicroRNAs/metabolismo , Apoptose , Ductos Biliares Intra-Hepáticos/metabolismo , Técnicas de Cultura de Células , Ensaios de Migração Celular , Proliferação de Células , Citocinas/metabolismo , Imunofluorescência , Regulação da Expressão Gênica/genética , Humanos , Immunoblotting , Espectrometria de Massas , Estresse Oxidativo , Proteômica , Transdução de Sinais/genética
18.
Methods ; 77-78: 25-30, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25697760

RESUMO

Prostate cancer is among the most frequent cancers in men, and despite its high rate of cure, the high number of cases results in an elevated mortality worldwide. Importantly, prostate cancer incidence is dramatically increasing in western societies in the past decades, suggesting that this type of tumor is exquisitely sensitive to lifestyle changes. Prostate cancer frequently exhibits alterations in the PTEN gene (inactivating mutations or gene deletions) or at the protein level (reduced protein expression or altered sub-cellular compartmentalization). The relevance of PTEN in this type of cancer is further supported by the fact that the sole deletion of PTEN in the murine prostate epithelium recapitulates many of the features of the human disease. In order to study the molecular alterations in prostate cancer, we need to overcome the methodological challenges that this tissue imposes. In this review we present protocols and methods, using PTEN as proof of concept, to study different molecular characteristics of prostate cancer.


Assuntos
PTEN Fosfo-Hidrolase/análise , PTEN Fosfo-Hidrolase/biossíntese , Neoplasias da Próstata/metabolismo , Proteínas Supressoras de Tumor/análise , Proteínas Supressoras de Tumor/biossíntese , Animais , Humanos , Masculino , Camundongos , Mutação/genética , PTEN Fosfo-Hidrolase/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Supressoras de Tumor/genética
19.
Biochem Soc Trans ; 43(5): 1122-6, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26517935

RESUMO

Tribbles pseudokinase 3 (TRIB3) belongs to the tribbles family of pseudokinases. In this article, we summarize several observation obtained by our laboratories supporting that TRIB3 plays a crucial role in the anti-cancer activity of cannabinoids (a novel family of potential anti-cancer agents derived from marijuana) and that TRIB3 genetic inactivation enhances cancer generation and progression.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Transdução de Sinais/fisiologia , Apoptose/genética , Apoptose/fisiologia , Autofagia/genética , Autofagia/fisiologia , Proteínas de Ciclo Celular/genética , Endocanabinoides/metabolismo , Humanos , Modelos Biológicos , Neoplasias/genética , Neoplasias/patologia , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Repressoras/genética , Transdução de Sinais/genética
20.
Cancer Cell ; 9(4): 301-12, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16616335

RESUMO

One of the most exciting areas of current research in the cannabinoid field is the study of the potential application of these compounds as antitumoral drugs. Here, we describe the signaling pathway that mediates cannabinoid-induced apoptosis of tumor cells. By using a wide array of experimental approaches, we identify the stress-regulated protein p8 (also designated as candidate of metastasis 1) as an essential mediator of cannabinoid antitumoral action and show that p8 upregulation is dependent on de novo-synthesized ceramide. We also observe that p8 mediates its apoptotic effect via upregulation of the endoplasmic reticulum stress-related genes ATF-4, CHOP, and TRB3. Activation of this pathway may constitute a potential therapeutic strategy for inhibiting tumor growth.


Assuntos
Apoptose/efeitos dos fármacos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Canabinoides/farmacologia , Dronabinol/farmacologia , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Fator 4 Ativador da Transcrição/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Biópsia , Proteínas de Ciclo Celular/metabolismo , Retículo Endoplasmático/metabolismo , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Camundongos , Proteínas de Neoplasias/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais , Fator de Transcrição CHOP/metabolismo , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
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