Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
Nat Metab ; 5(4): 660-676, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37024754

RESUMO

Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is known to contain an active-site cysteine residue undergoing oxidation in response to hydrogen peroxide, leading to rapid inactivation of the enzyme. Here we show that human and mouse cells expressing a GAPDH mutant lacking this redox switch retain catalytic activity but are unable to stimulate the oxidative pentose phosphate pathway and enhance their reductive capacity. Specifically, we find that anchorage-independent growth of cells and spheroids is limited by an elevation of endogenous peroxide levels and is largely dependent on a functional GAPDH redox switch. Likewise, tumour growth in vivo is limited by peroxide stress and suppressed when the GAPDH redox switch is disabled in tumour cells. The induction of additional intratumoural oxidative stress by chemo- or radiotherapy synergized with the deactivation of the GAPDH redox switch. Mice lacking the GAPDH redox switch exhibit altered fatty acid metabolism in kidney and heart, apparently in compensation for the lack of the redox switch. Together, our findings demonstrate the physiological and pathophysiological relevance of oxidative GAPDH inactivation in mammals.


Assuntos
Cisteína , Gliceraldeído-3-Fosfato Desidrogenases , Humanos , Animais , Camundongos , Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/química , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Oxirredução , Cisteína/metabolismo , Estresse Oxidativo , Peróxido de Hidrogênio/farmacologia , Mamíferos/metabolismo
2.
Science ; 378(6615): eabn5637, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36074822

RESUMO

Mammalian cells can generate amino acids through macropinocytosis and lysosomal breakdown of extracellular proteins, which is exploited by cancer cells to grow in nutrient-poor tumors. Through genetic screens in defined nutrient conditions, we characterized LYSET, a transmembrane protein (TMEM251) selectively required when cells consume extracellular proteins. LYSET was found to associate in the Golgi with GlcNAc-1-phosphotransferase, which targets catabolic enzymes to lysosomes through mannose-6-phosphate modification. Without LYSET, GlcNAc-1-phosphotransferase was unstable because of a hydrophilic transmembrane domain. Consequently, LYSET-deficient cells were depleted of lysosomal enzymes and impaired in turnover of macropinocytic and autophagic cargoes. Thus, LYSET represents a core component of the lysosomal enzyme trafficking pathway, underlies the pathomechanism for hereditary lysosomal storage disorders, and may represent a target to suppress metabolic adaptations in cancer.


Assuntos
Complexo de Golgi , Doenças por Armazenamento dos Lisossomos , Lisossomos , Proteínas , Animais , Complexo de Golgi/metabolismo , Humanos , Doenças por Armazenamento dos Lisossomos/genética , Doenças por Armazenamento dos Lisossomos/metabolismo , Lisossomos/metabolismo , Camundongos , Transporte Proteico , Proteínas/genética , Proteínas/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo
3.
J Exp Clin Cancer Res ; 41(1): 190, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35655310

RESUMO

BACKGROUND: MicroRNAs (miRNAs) and isomiRs play important roles in tumorigenesis as essential regulators of gene expression. 5'isomiRs exhibit a shifted seed sequence compared to the canonical miRNA, resulting in different target spectra and thereby extending the phenotypic impact of the respective common pre-miRNA. However, for most miRNAs, expression and function of 5'isomiRs have not been studied in detail yet. Therefore, this study aims to investigate the functions of miRNAs and their 5'isomiRs. METHODS: The expression of 5'isomiRs was assessed in The Cancer Genome Atlas (TCGA) breast cancer patient dataset. Phenotypic effects of miR-183 overexpression in triple-negative breast cancer (TNBC) cell lines were investigated in vitro and in vivo by quantifying migration, proliferation, tumor growth and metastasis. Direct targeting of E2F1 by miR-183-5p|+2 was validated with a 3'UTR luciferase assay and linked to the phenotypes of isomiR overexpression. RESULTS: TCGA breast cancer patient data indicated that three variants of miR-183-5p are highly expressed and upregulated, namely miR-183-5p|0, miR-183-5p|+1 and miR-183-5p|+2. However, TNBC cell lines displayed reduced proliferation and invasion upon overexpression of pre-miR-183. While invasion was reduced individually by all three isomiRs, proliferation and cell cycle progression were specifically inhibited by overexpression of miR-183-5p|+2. Proteomic analysis revealed reduced expression of E2F target genes upon overexpression of this isomiR, which could be attributed to direct targeting of E2F1, specifically by miR-183-5p|+2. Knockdown of E2F1 partially phenocopied the effect of miR-183-5p|+2 overexpression on cell proliferation and cell cycle. Gene set enrichment analysis of TCGA and METABRIC patient data indicated that the activity of E2F strongly correlated with the expression of miR-183-5p, suggesting transcriptional regulation of the miRNA by a factor of the E2F family. Indeed, in vitro, expression of miR-183-5p was regulated by E2F1. Hence, miR-183-5p|+2 directly targeting E2F1 appears to be part of a negative feedback loop potentially fine-tuning its activity. CONCLUSIONS: This study demonstrates that 5'isomiRs originating from the same arm of the same pre-miRNA (i.e. pre-miR-183-5p) may exhibit different functions and thereby collectively contribute to the same phenotype. Here, one of three isomiRs was shown to counteract expression of the pre-miRNA by negatively regulating a transcriptional activator (i.e. E2F1). We speculate that this might be part of a regulatory mechanism to prevent uncontrolled cell proliferation, which is disabled during cancer progression.


Assuntos
MicroRNAs , Neoplasias de Mama Triplo Negativas , Linhagem Celular Tumoral , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Retroalimentação , Humanos , MicroRNAs/metabolismo , Proteômica , Neoplasias de Mama Triplo Negativas/metabolismo
4.
Front Immunol ; 13: 1063313, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36591284

RESUMO

Use of chimeric antigen receptor (CAR) T cells to treat B cell lymphoma and leukemia has been remarkably successful. Unfortunately, the therapeutic efficacy of CAR T cells against solid tumors is very limited, with immunosuppression by the pro-oxidative tumor microenvironment (TME) a major contributing factor. High levels of reactive oxygen species are well-tolerated by tumor cells due to their elevated expression of antioxidant proteins; however, this is not the case for T cells, which consequently become hypo-responsive. The aim of this study was to improve CAR T cell efficacy in solid tumors by empowering the antioxidant capacity of CAR T cells against the pro-oxidative TME. To this end, HER2-specific human CAR T cells stably expressing two antioxidant systems: thioredoxin-1 (TRX1), and glutaredoxin-1 (GRX1) were generated and characterized. Thereafter, antitumor functions of CAR T cells were evaluated under control or pro-oxidative conditions. To provide insights into the role of antioxidant systems, gene expression profiles as well as global protein oxidation were analyzed. Our results highlight that TRX1 is pivotal for T cell redox homeostasis. TRX1 expression allows CAR T cells to retain their cytolytic immune synapse formation, cytokine release, proliferation, and tumor cell-killing properties under pro-oxidative conditions. Evaluation of differentially expressed genes and the first comprehensive redoxosome analysis of T cells by mass spectrometry further clarified the underlying mechanisms. Taken together, enhancement of the key antioxidant TRX1 in human T cells opens possibilities to increase the efficacy of CAR T cell treatment against solid tumors.


Assuntos
Imunoterapia Adotiva , Neoplasias , Estresse Oxidativo , Linfócitos T , Microambiente Tumoral , Humanos , Antioxidantes/metabolismo , Imunoterapia Adotiva/métodos , Neoplasias/imunologia , Neoplasias/terapia , Oxirredução , Estresse Oxidativo/genética , Estresse Oxidativo/imunologia , Linfócitos T/imunologia , Tiorredoxinas/genética , Tiorredoxinas/imunologia , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
5.
Stem Cell Reports ; 17(1): 143-158, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-34942088

RESUMO

The genetic modification of stem cells (SCs) is typically achieved using integrating vectors, whose potential integrative genotoxicity and propensity for epigenetic silencing during differentiation limit their application. The genetic modification of cells should provide sustainable levels of transgene expression, without compromising the viability of a cell or its progeny. We developed nonviral, nonintegrating, and autonomously replicating minimally sized DNA nanovectors to persistently genetically modify SCs and their differentiated progeny without causing any molecular or genetic damage. These DNA vectors are capable of efficiently modifying murine and human pluripotent SCs with minimal impact and without differentiation-mediated transgene silencing or vector loss. We demonstrate that these vectors remain episomal and provide robust and sustained transgene expression during self-renewal and targeted differentiation of SCs both in vitro and in vivo through embryogenesis and differentiation into adult tissues, without damaging their phenotypic characteristics.


Assuntos
Diferenciação Celular , Expressão Gênica , Vetores Genéticos/genética , Plasmídeos/genética , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Animais , Diferenciação Celular/genética , Linhagem Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Fibroblastos , Perfilação da Expressão Gênica , Humanos , Camundongos , Transgenes
6.
Cell Rep ; 36(7): 109559, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34407399

RESUMO

Acute myeloid leukemia (AML) is a rapidly progressing cancer, for which chemotherapy remains standard treatment and additional therapeutic targets are requisite. Here, we show that AML cells secrete the stem cell growth factor R-spondin 2 (RSPO2) to promote their self-renewal and prevent cell differentiation. Although RSPO2 is a well-known WNT agonist, we reveal that it maintains AML self-renewal WNT independently, by inhibiting BMP receptor signaling. Autocrine RSPO2 signaling is also required to prevent differentiation and to promote self-renewal in normal hematopoietic stem cells as well as primary AML cells. Comprehensive datamining reveals that RSPO2 expression is elevated in patients with AML of poor prognosis. Consistently, inhibiting RSPO2 prolongs survival in AML mouse xenograft models. Our study indicates that in AML, RSPO2 acts as an autocrine BMP antagonist to promote cancer cell renewal and may serve as a marker for poor prognosis.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Leucemia Mieloide Aguda/metabolismo , Transdução de Sinais , Animais , Comunicação Autócrina/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Autorrenovação Celular/efeitos dos fármacos , Citarabina/farmacologia , Células HEK293 , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Humanos , Leucemia Mieloide Aguda/patologia , Camundongos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Prognóstico , Fatores de Risco , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Int J Cancer ; 148(8): 1993-2009, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33368291

RESUMO

Uncontrolled proliferation and altered metabolic reprogramming are hallmarks of cancer. Active glycolysis and glutaminolysis are characteristic features of these hallmarks and required for tumorigenesis. A fine balance between cancer metabolism and autophagy is a prerequisite of homeostasis within cancer cells. Here we show that glutamate pyruvate transaminase 2 (GPT2), which serves as a pivot between glycolysis and glutaminolysis, is highly upregulated in aggressive breast cancers, particularly the triple-negative breast cancer subtype. Abrogation of this enzyme results in decreased tricarboxylic acid cycle intermediates, which promotes the rewiring of glucose carbon atoms and alterations in nutrient levels. Concordantly, loss of GPT2 results in an impairment of mechanistic target of rapamycin complex 1 activity as well as the induction of autophagy. Furthermore, in vivo xenograft studies have shown that autophagy induction correlates with decreased tumor growth and that markers of induced autophagy correlate with low GPT2 levels in patient samples. Taken together, these findings indicate that cancer cells have a close network between metabolic and nutrient sensing pathways necessary to sustain tumorigenesis and that aminotransferase reactions play an important role in maintaining this balance.


Assuntos
Autofagia/genética , Regulação Neoplásica da Expressão Gênica , Transaminases/genética , Neoplasias de Mama Triplo Negativas/genética , Carga Tumoral/genética , Animais , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Feminino , Técnicas de Inativação de Genes , Humanos , Células MCF-7 , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Interferência de RNA , Análise de Sobrevida , Transaminases/antagonistas & inibidores , Transaminases/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/terapia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
8.
Cancers (Basel) ; 12(10)2020 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-33050633

RESUMO

Breast cancer is one of the leading causes of death for women worldwide. Patients whose tumors express Estrogen Receptor α account for around 70% of cases and are mostly treated with targeted endocrine therapy. However, depending on the degree of severity of the disease at diagnosis, 10 to 40% of these tumors eventually relapse due to resistance development. Even though recent novel approaches as the combination with CDK4/6 inhibitors increased the overall survival of relapsing patients, this remains relatively short and there is a urgent need to find alternative targetable pathways. In this study we profiled the early phases of the resistance development process to uncover drivers of this phenomenon. Time-resolved analysis revealed that ATF3, a member of the ATF/CREB family of transcription factors, acts as a novel regulator of the response to therapy via rewiring of central signaling processes towards the adaptation to endocrine treatment. ATF3 was found to be essential in controlling crucial processes such as proliferation, cell cycle, and apoptosis during the early response to treatment through the regulation of MAPK/AKT signaling pathways. Its essential role was confirmed in vivo in a mouse model, and elevated expression of ATF3 was verified in patient datasets, adding clinical relevance to our findings. This study proposes ATF3 as a novel mediator of endocrine resistance development in breast cancer and elucidates its role in the regulation of downstream pathways activities.

10.
Virology ; 538: 53-60, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31569015

RESUMO

We have previously showed that a transgenic (Tg) mouse model with cytokeratin 14 promoter (K14)-driven expression of E6 and E7 from beta-3 HPV49 in the basal layer of the epidermis and of the mucosal epithelia of the digestive tract (K14 HPV49 E6/E7 Tg mice) are highly susceptible to upper digestive tract carcinogenesis upon exposure to 4-nitroquinoline 1-oxide (4NQO). Using whole-exome sequencing, we show that in K14 HPV49 E6/E7 Tg mice, development of 4NQO-induced cancers tightly correlates with the accumulation of somatic mutations in cancer-related genes. The mutational signature in 4NQO-treated mice was similar to the signature observed in humans exposed to tobacco smoking and tobacco chewing. Similar results were obtained with K14 Tg animals expressing mucosal high-risk HPV16 E6 and E7 oncogenes. Thus, beta-3 HPV49 share some functional similarities with HPV16 in Tg animals.


Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Betapapillomavirus/metabolismo , Neoplasias/genética , Nicotiana/efeitos adversos , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/virologia , Animais , Betapapillomavirus/genética , Suscetibilidade a Doenças , Feminino , Humanos , Camundongos , Camundongos Transgênicos , Mutação/efeitos dos fármacos , Neoplasias/etiologia , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/genética , Infecções por Papillomavirus/genética
11.
BMC Cancer ; 19(1): 914, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519152

RESUMO

BACKGROUND: NY-BR-1 has been described as a breast cancer associated differentiation antigen with intrinsic immunogenicity giving rise to endogenous T and B cell responses. The current study presents the first murine tumor model allowing functional investigation of NY-BR-1-specific immune responses in vivo. METHODS: A NY-BR-1 expressing tumor model was established in DR4tg mice based on heterotopic transplantation of stable transfectant clones derived from the murine H2 compatible breast cancer cell line EO771. Composition and phenotype of tumor infiltrating immune cells were analyzed by qPCR and FACS. MHC I binding affinity of candidate CTL epitopes predicted in silico was determined by FACS using the mutant cell line RMA-S. Frequencies of NY-BR-1 specific CTLs among splenocytes of immunized mice were quantified by FACS with an epitope loaded Db-dextramer. Functional CTL activity was determined by IFNγ catch or IFNγ ELISpot assays and statistical analysis was done applying the Mann Whitney test. Tumor protection experiments were performed by immunization of DR4tg mice with replication deficient recombinant adenovirus followed by s.c. challenge with NY-BR-1 expressing breast cancer cells. RESULTS: Our results show spontaneous accumulation of CD8+ T cells and F4/80+ myeloid cells preferentially in NY-BR-1 expressing tumors. Upon NY-BR-1-specific immunization experiments combined with in silico prediction and in vitro binding assays, the first NY-BR-1-specific H2-Db-restricted T cell epitope could be identified. Consequently, flow cytometric analysis with fluorochrome conjugated multimers showed enhanced frequencies of CD8+ T cells specific for the newly identified epitope in spleens of immunized mice. Moreover, immunization with Ad.NY-BR-1 resulted in partial protection against outgrowth of NY-BR-1 expressing tumors and promoted intratumoral accumulation of macrophages. CONCLUSION: This study introduces the first H2-Db-resctricted CD8+ T cell epitope-specific for the human breast cancer associated tumor antigen NY-BR-1. Our novel, partially humanized tumor model enables investigation of the interplay between HLA-DR4-restricted T cell responses and CTLs within their joint attack of NY-BR-1 expressing tumors.


Assuntos
Antígenos de Neoplasias/imunologia , Epitopos de Linfócito T/imunologia , Cadeias HLA-DRB1/genética , Neoplasias/etiologia , Neoplasias/patologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Antígenos de Neoplasias/genética , Biomarcadores , Linhagem Celular Tumoral , Modelos Animais de Doenças , Cadeias HLA-DRB1/imunologia , Xenoenxertos , Humanos , Imunização , Imunofenotipagem , Leucócitos/imunologia , Leucócitos/metabolismo , Camundongos , Camundongos Transgênicos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
12.
Blood ; 134(5): 445-455, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31167801

RESUMO

Therapeutic options for cutaneous T-cell lymphoma (CTCL) are limited and curative treatment regimens are not available. Thus, new targeted and well-tolerated therapeutic approaches are urgently needed. In this respect, we have recently shown that dimethyl fumerate (DMF) inhibits NF-κB acting as a survival factor in CTCL. Similarly, inhibition of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) has been shown to induce cell death in CTCL especially when combined with histone deacetylase inhibitors. Therefore, we hypothesized that inhibition of Bcl-2 should potentiate NF-κB inhibition in a novel combination treatment of CTCL. We show that, in vitro, the Bcl-2 inhibitors ABT-199 and ABT-263 induced specific cell death in primary CD4+ cells from CTCL patients as well as in the CTCL cell line SeAx, but not in T cells of healthy donors nor in the CTCL cell line HH, which lacks Bcl-2. Combined treatment with ABT-199 and DMF caused synergistic cell death specifically in CTCL cells engaging 2 independent signaling pathways. To verify these findings in vivo, we performed combined ABT-199 and DMF treatment in a xenograft mouse model for CTCL. The combined treatment effectively reduced tumor growth and increased overall survival via synergistic induction of CTCL cell death and suppression of tumor cell proliferation. Essentially, the combination treatment was superior to ABT-199 monotherapy with respect to both efficacy and tolerability. To sum up, our data provide proof of principle for the therapeutic potential of combining Bcl-2 and NF-κB inhibitors in treating CTCL. Next, this potential should be explored further in a clinical study.


Assuntos
Antineoplásicos/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Linfoma Cutâneo de Células T/metabolismo , NF-kappa B/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Animais , Apoptose , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Linfoma Cutâneo de Células T/diagnóstico , Linfoma Cutâneo de Células T/tratamento farmacológico , Linfoma Cutâneo de Células T/genética , Camundongos , NF-kappa B/genética , Estadiamento de Neoplasias , Ligação Proteica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Nat Commun ; 10(1): 2197, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-31097693

RESUMO

In colorectal cancer (CRC), aberrant Wnt signalling is essential for tumorigenesis and maintenance of cancer stem cells. However, how other oncogenic pathways converge on Wnt signalling to modulate stem cell homeostasis in CRC currently remains poorly understood. Using large-scale compound screens in CRC, we identify MEK1/2 inhibitors as potent activators of Wnt/ß-catenin signalling. Targeting MEK increases Wnt activity in different CRC cell lines and murine intestine in vivo. Truncating mutations of APC generated by CRISPR/Cas9 strongly synergize with MEK inhibitors in enhancing Wnt responses in isogenic CRC models. Mechanistically, we demonstrate that MEK inhibition induces a rapid downregulation of AXIN1. Using patient-derived CRC organoids, we show that MEK inhibition leads to increased Wnt activity, elevated LGR5 levels and enrichment of gene signatures associated with stemness and cancer relapse. Our study demonstrates that clinically used MEK inhibitors inadvertently induce stem cell plasticity, revealing an unknown side effect of RAS pathway inhibition.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Células-Tronco Neoplásicas/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Proteína da Polipose Adenomatosa do Colo/genética , Proteína da Polipose Adenomatosa do Colo/metabolismo , Animais , Antineoplásicos/uso terapêutico , Biópsia , Sistemas CRISPR-Cas/genética , Carcinogênese/efeitos dos fármacos , Linhagem Celular Tumoral , Plasticidade Celular/efeitos dos fármacos , Neoplasias Colorretais/patologia , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Intestinos/citologia , Intestinos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Proteômica , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas ras/metabolismo
14.
J Proteome Res ; 18(3): 1352-1362, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30609375

RESUMO

Hypoxia as well as metabolism are central hallmarks of cancer, and hypoxia-inducible factors (HIFs) and metabolic effectors are crucial elements in oxygen-compromised tumor environments. Knowledge of changes in the expression of metabolic proteins in response to HIF function could provide mechanistic insights into adaptation to hypoxic stress, tumorigenesis, and disease progression. We analyzed time-resolved alterations in metabolism-associated protein levels in response to different oxygen potentials across breast cancer cell lines. Effects on the cellular metabolism of both HIF-dependent and -independent processes were analyzed by reverse-phase protein array profiling and a custom statistical model. We revealed a strong induction of glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA) as well as reduced glutamate-ammonia ligase (GLUL) protein levels across all cell lines tested as consistent changes upon hypoxia induction. Low GLUL protein levels were correlated with aggressive molecular subtypes in breast cancer patient data sets and also with hypoxic tumor regions in a xenograft mouse tumor model. Moreover, low GLUL expression was associated with poor survival in breast cancer patients and with high HIF-1α-expressing patient subgroups. Our data reveal time-resolved changes in the regulation of metabolic proteins under oxygen-deprived conditions and elucidate GLUL as a strong responder to HIFs and the hypoxic environment.


Assuntos
Neoplasias da Mama/genética , Glutamato-Amônia Ligase/genética , Proteoma/genética , Proteômica , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Transportador de Glucose Tipo 1/genética , Xenoenxertos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , L-Lactato Desidrogenase/genética , Células MCF-7 , Camundongos , Oxigênio/metabolismo , Hipóxia Tumoral
15.
Cell Discov ; 4: 37, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29977599

RESUMO

Use of the diabetes type II drug Metformin is associated with a moderately lowered risk of cancer incidence in numerous tumor entities. Studying the molecular changes associated with the tumor-suppressive action of Metformin we found that the oncogene SOX4, which is upregulated in solid tumors and associated with poor prognosis, was induced by Wnt/ß-catenin signaling and blocked by Metformin. Wnt signaling inhibition by Metformin was surprisingly specific for cancer cells. Unraveling the underlying specificity, we identified Metformin and other Mitochondrial Complex I (MCI) inhibitors as inducers of intracellular acidification in cancer cells. We demonstrated that acidification triggers the unfolded protein response to induce the global transcriptional repressor DDIT3, known to block Wnt signaling. Moreover, our results suggest that intracellular acidification universally inhibits Wnt signaling. Based on these findings, we combined MCI inhibitors with H+ ionophores, to escalate cancer cells into intracellular hyper-acidification and ATP depletion. This treatment lowered intracellular pH both in vitro and in a mouse xenograft tumor model, depleted cellular ATP, blocked Wnt signaling, downregulated SOX4, and strongly decreased stemness and viability of cancer cells. Importantly, the inhibition of Wnt signaling occurred downstream of ß-catenin, encouraging applications in treatment of cancers caused by APC and ß-catenin mutations.

16.
PLoS Pathog ; 14(1): e1006783, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29324843

RESUMO

Cutaneous beta human papillomavirus (HPV) types are suspected to be involved, together with ultraviolet (UV) radiation, in the development of non-melanoma skin cancer (NMSC). Studies in in vitro and in vivo experimental models have highlighted the transforming properties of beta HPV E6 and E7 oncoproteins. However, epidemiological findings indicate that beta HPV types may be required only at an initial stage of carcinogenesis, and may become dispensable after full establishment of NMSC. Here, we further investigate the potential role of beta HPVs in NMSC using a Cre-loxP-based transgenic (Tg) mouse model that expresses beta HPV38 E6 and E7 oncogenes in the basal layer of the skin epidermis and is highly susceptible to UV-induced carcinogenesis. Using whole-exome sequencing, we show that, in contrast to WT animals, when exposed to chronic UV irradiation K14 HPV38 E6/E7 Tg mice accumulate a large number of UV-induced DNA mutations, which increase proportionally with the severity of the skin lesions. The mutation pattern detected in the Tg skin lesions closely resembles that detected in human NMSC, with the highest mutation rate in p53 and Notch genes. Using the Cre-lox recombination system, we observed that deletion of the viral oncogenes after development of UV-induced skin lesions did not affect the tumour growth. Together, these findings support the concept that beta HPV types act only at an initial stage of carcinogenesis, by potentiating the deleterious effects of UV radiation.


Assuntos
Carcinogênese/efeitos da radiação , Neoplasias Induzidas por Radiação/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Neoplasias Cutâneas/metabolismo , Pele/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Proteínas Virais/metabolismo , Animais , Betapapillomavirus/metabolismo , Epiderme/metabolismo , Epiderme/patologia , Epiderme/efeitos da radiação , Feminino , Deleção de Genes , Genes p53/efeitos da radiação , Camundongos , Camundongos Transgênicos , Mutagênese/efeitos da radiação , Mutação , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Induzidas por Radiação/patologia , Proteínas Oncogênicas Virais/genética , Receptores Notch/genética , Receptores Notch/metabolismo , Proteínas Recombinantes/metabolismo , Pele/metabolismo , Pele/patologia , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/patologia , Carga Tumoral/efeitos da radiação , Proteínas Virais/genética
17.
Cell Metab ; 26(6): 842-855.e5, 2017 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-29056512

RESUMO

Breast tumor recurrence and metastasis represent the main causes of cancer-related death in women, and treatments are still lacking. Here, we define the lipogenic enzyme acetyl-CoA carboxylase (ACC) 1 as a key player in breast cancer metastasis. ACC1 phosphorylation was increased in invading cells both in murine and human breast cancer, serving as a point of convergence for leptin and transforming growth factor (TGF) ß signaling. ACC1 phosphorylation was mediated by TGFß-activated kinase (TAK) 1, and ACC1 inhibition was indispensable for the elevation of cellular acetyl-CoA, the subsequent increase in Smad2 transcription factor acetylation and activation, and ultimately epithelial-mesenchymal transition and metastasis induction. ACC1 deficiency worsened tumor recurrence upon primary tumor resection in mice, and ACC1 phosphorylation levels correlated with metastatic potential in breast and lung cancer patients. Given the demonstrated effectiveness of anti-leptin receptor antibody treatment in halting ACC1-dependent tumor invasiveness, our work defines a "metabolocentric" approach in metastatic breast cancer therapy.


Assuntos
Acetil-CoA Carboxilase/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias Pulmonares/secundário , Recidiva Local de Neoplasia/patologia , Acetil-CoA Carboxilase/genética , Acetilação , Animais , Modelos Animais de Doenças , Feminino , Células HEK293 , Humanos , Leptina/metabolismo , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Metástase Neoplásica , Recidiva Local de Neoplasia/metabolismo , Análise Serial de Tecidos
18.
Stem Cell Res Ther ; 8(1): 229, 2017 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-29037217

RESUMO

BACKGROUND: Human induced pluripotent stem cells (hiPSC) harbor the potential to differentiate into diverse cardiac cell types. Previous experimental efforts were primarily directed at the generation of hiPSC-derived cells with ventricular cardiomyocyte characteristics. Aiming at a straightforward approach for pacemaker cell modeling and replacement, we sought to selectively differentiate cells with nodal-type properties. METHODS: hiPSC were differentiated into spontaneously beating clusters by co-culturing with visceral endoderm-like cells in a serum-free medium. Subsequent culturing in a specified fetal bovine serum (FBS)-enriched cell medium produced a pacemaker-type phenotype that was studied in detail using quantitative real-time polymerase chain reaction (qRT-PCR), immunocytochemistry, and patch-clamp electrophysiology. Further investigations comprised pharmacological stimulations and co-culturing with neonatal cardiomyocytes. RESULTS: hiPSC co-cultured in a serum-free medium with the visceral endoderm-like cell line END-2 produced spontaneously beating clusters after 10-12 days of culture. The pacemaker-specific genes HCN4, TBX3, and TBX18 were abundantly expressed at this early developmental stage, while levels of sarcomeric gene products remained low. We observed that working-type cardiomyogenic differentiation can be suppressed by transfer of early clusters into a FBS-enriched cell medium immediately after beating onset. After 6 weeks under these conditions, sinoatrial node (SAN) hallmark genes remained at high levels, while working-type myocardial transcripts (NKX2.5, TBX5) were low. Clusters were characterized by regular activity and robust beating rates (70-90 beats/min) and were triggered by spontaneous Ca2+ transients recapitulating calcium clock properties of genuine pacemaker cells. They were responsive to adrenergic/cholinergic stimulation and able to pace neonatal rat ventricular myocytes in co-culture experiments. Action potential (AP) measurements of cells individualized from clusters exhibited nodal-type (63.4%) and atrial-type (36.6%) AP morphologies, while ventricular AP configurations were not observed. CONCLUSION: We provide a novel culture media-based, transgene-free approach for targeted generation of hiPSC-derived pacemaker-type cells that grow in clusters and offer the potential for disease modeling, drug testing, and individualized cell-based replacement therapy of the SAN.


Assuntos
Relógios Biológicos , Diferenciação Celular , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/citologia , Potenciais de Ação , Animais , Sinalização do Cálcio , Células Cultivadas , Proteína Homeobox Nkx-2.5/genética , Proteína Homeobox Nkx-2.5/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Contração Miocárdica , Miócitos Cardíacos/classificação , Ratos , Nó Sinoatrial/citologia , Nó Sinoatrial/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo
19.
Cell Rep ; 20(6): 1422-1434, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28793265

RESUMO

Increased pro-inflammatory signaling is a hallmark of metabolic dysfunction in obesity and diabetes. Although both inflammatory and energy substrate handling processes represent critical layers of metabolic control, their molecular integration sites remain largely unknown. Here, we identify the heterodimerization interface between the α and ß subunits of transcription factor GA-binding protein (GAbp) as a negative target of tumor necrosis factor alpha (TNF-α) signaling. TNF-α prevented GAbpα and ß complex formation via reactive oxygen species (ROS), leading to the non-energy-dependent transcriptional inactivation of AMP-activated kinase (AMPK) ß1, which was identified as a direct hepatic GAbp target. Impairment of AMPKß1, in turn, elevated downstream cellular cholesterol biosynthesis, and hepatocyte-specific ablation of GAbpα induced systemic hypercholesterolemia and early macro-vascular lesion formation in mice. As GAbpα and AMPKß1 levels were also found to correlate in obese human patients, the ROS-GAbp-AMPK pathway may represent a key component of a hepato-vascular axis in diabetic long-term complications.


Assuntos
Aterosclerose/metabolismo , Fator de Transcrição de Proteínas de Ligação GA/metabolismo , Hepatócitos/metabolismo , Hipercolesterolemia/metabolismo , Proteínas Quinases/metabolismo , Transdução de Sinais , Quinases Proteína-Quinases Ativadas por AMP , Animais , Aterosclerose/etiologia , Aterosclerose/patologia , Linhagem Celular , Células Cultivadas , Colesterol/metabolismo , Fator de Transcrição de Proteínas de Ligação GA/química , Hipercolesterolemia/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Multimerização Proteica , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
20.
Cancer Res ; 77(10): 2557-2563, 2017 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-28507049

RESUMO

The devastating diseases of human cancer are mimicked in basic and translational cancer research by a steadily increasing number of tumor models, a situation requiring a platform with standardized reports to share model data. Models in Translational Oncology (MiTO) database was developed as a unique Web platform aiming for a comprehensive overview of preclinical models covering genetically engineered organisms, models of transplantation, chemical/physical induction, or spontaneous development, reviewed here. MiTO serves data entry for metastasis profiles and interventions. Moreover, cell lines and animal lines including tool strains can be recorded. Hyperlinks for connection with other databases and file uploads as supplementary information are supported. Several communication tools are offered to facilitate exchange of information. Notably, intellectual property can be protected prior to publication by inventor-defined accessibility of any given model. Data recall is via a highly configurable keyword search. Genome editing is expected to result in changes of the spectrum of model organisms, a reason to open MiTO for species-independent data. Registered users may deposit own model fact sheets (FS). MiTO experts check them for plausibility. Independently, manually curated FS are provided to principle investigators for revision and publication. Importantly, noneditable versions of reviewed FS can be cited in peer-reviewed journals. Cancer Res; 77(10); 2557-63. ©2017 AACR.


Assuntos
Bases de Dados Factuais , Oncologia , Modelos Animais , Neoplasias/etiologia , Neoplasias/patologia , Pesquisa Translacional Biomédica , Animais , Transformação Celular Neoplásica , Modelos Animais de Doenças , Humanos , Pesquisa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA