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1.
Gastroenterology ; 146(2): 401-11.e1, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24512910

RESUMO

BACKGROUND & AIMS: Patients with colorectal tumors with microsatellite instability (MSI) have better prognoses than patients with tumors without MSI, but have a poor response to 5-fluorouracil­based chemotherapy. A dominant-negative form of heat shock protein (HSP)110 (HSP110DE9) expressed by cancer cells with MSI, via exon skipping caused by somatic deletions in the T(17) intron repeat, sensitizes the cells to 5-fluorouracil and oxaliplatin.We investigated whether HSP110 T(17) could be used to identify patients with colorectal cancer who would benefit from adjuvant chemotherapy with 5-fluorouracil and oxaliplatin. METHODS: We characterized the interaction between HSP110 and HSP110DE9 using surface plasmon resonance. By using polymerase chain reaction and fragment analysis, we examined how the size of somatic allelic deletions in HSP110 T(17) affected the HSP110 protein expressed by tumor cells. We screened 329 consecutive patients with stage II­III colorectal tumors with MSI who underwent surgical resection at tertiary medical centers for HSP110 T(17). RESULTS: HSP110 and HSP110DE9 interacted in a1:1 ratio. Tumor cells with large deletions in T(17) had increased ratios of HSP110DE9:HSP110, owing to the loss of expression of full-length HSP110. Deletions in HSP110 T(17) were mostly biallelic in primary tumor samples with MSI. Patients with stage II­III cancer who received chemotherapy and had large HSP110 T(17) deletions (≥5 bp; 18 of 77 patients, 23.4%) had longer times of relapse-free survival than patients with small or no deletions (≤4 bp; 59 of 77 patients, 76.6%) in multivariate analysis (hazard ratio, 0.16; 95% confidence interval, 0.012­0.8; P = .03). We found a significant interaction between chemotherapy and T17 deletion (P =.009). CONCLUSIONS: About 25% of patients with stages II­III colorectal tumors with MSI have an excellent response to chemotherapy, due to large, biallelic deletions in the T(17) intron repeat of HSP110 in tumor DNA.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Sequência de Bases , Biomarcadores Tumorais/genética , Neoplasias Colorretais/tratamento farmacológico , Proteínas de Choque Térmico HSP110/genética , Instabilidade de Microssatélites , Deleção de Sequência , Idoso , Antineoplásicos/administração & dosagem , Biomarcadores Tumorais/química , Biomarcadores Tumorais/metabolismo , Western Blotting , Linhagem Celular Tumoral , Quimioterapia Adjuvante , Colectomia , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Proteínas de Choque Térmico HSP110/química , Proteínas de Choque Térmico HSP110/metabolismo , Humanos , Íntrons , Leucovorina/administração & dosagem , Masculino , Modelos Moleculares , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Estudos Retrospectivos , Ressonância de Plasmônio de Superfície , Análise de Sobrevida , Resultado do Tratamento
2.
Mediators Inflamm ; 2015: 970242, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26549943

RESUMO

Myeloproliferative neoplasms (MPN) are clonal stem cell disorders that lead to the excessive production of one or more blood cell lineages. It has been reported that, in most MPN, inflammatory cytokines are frequently increased, indicating that inflammation plays a crucial role in these disorders. Heat shock proteins (HSP) are induced in response to many stressful conditions from heat shock to hypoxia and inflammation. Besides their chaperone and cytoprotective functions, HSPs are key players during inflammation, hence the term "chaperokine." Through their chaperone activity, HSP90, a stabilizer of many oncogenes (e.g., JAK2), and HSP70, a powerful antiapoptotic chaperone, tightly regulate Nuclear Factor-kappa B signalling, a critical pathway in mediating inflammatory responses. In light of this potential, several HSP90 inhibitors have been generated as anticancer agents able to degrade oncogenes. As it turns out, however, these drugs are also potent inhibitors of the inflammatory response in various diseases. Given the chaperone potential of HSP70 and the fact that HSP90 inhibitors induce HSP70, interest in HSP70 inhibitors is also increasing. Here, we focus on the implication of HSP90 and HSP70 in inflammatory responses and on the emergence of new therapeutic approaches in MPN based on HSP inhibitors.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Mediadores da Inflamação/metabolismo , Transtornos Mieloproliferativos/etiologia , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Mediadores da Inflamação/antagonistas & inibidores , Modelos Biológicos , Terapia de Alvo Molecular , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/metabolismo , Transdução de Sinais
3.
Blood ; 119(6): 1532-42, 2012 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-22160620

RESUMO

Normal human erythroid cell maturation requests the transcription factor GATA-1 and a transient activation of caspase-3, with GATA-1 being protected from caspase-3-mediated cleavage by interaction with the chaperone heat shock protein 70 (Hsp70) in the nucleus. Erythroid cell dysplasia observed in early myelodysplastic syndromes (MDS) involves impairment of differentiation and excess of apoptosis with a burst of caspase activation. Analysis of gene expression in MDS erythroblasts obtained by ex vivo cultures demonstrates the down-regulation of a set of GATA-1 transcriptional target genes, including GYPA that encodes glycophorin A (GPA), and the up-regulation of members of the HSP70 family. GATA-1 protein expression is decreased in MDS erythroblasts, but restores in the presence of a pan-caspase inhibitor. Expression of a mutated GATA-1 that cannot be cleaved by caspase-3 rescues the transcription of GATA-1 targets, and the erythroid differentiation, but does not improve survival. Hsp70 fails to protect GATA-1 from caspases because the protein does not accumulate in the nucleus with active caspase-3. Expression of a nucleus-targeted mutant of Hsp70 protects GATA-1 and rescues MDS erythroid cell differentiation. Alteration of Hsp70 cytosolic-nuclear shuttling is a major feature of MDS that favors GATA-1 cleavage and differentiation impairment, but not apoptosis, in dysplastic erythroblasts.


Assuntos
Núcleo Celular/metabolismo , Eritropoese/genética , Fator de Transcrição GATA1/genética , Proteínas de Choque Térmico HSP70/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Caspase 3/genética , Caspase 3/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Eritroblastos/metabolismo , Células Eritroides/metabolismo , Feminino , Fator de Transcrição GATA1/metabolismo , Perfilação da Expressão Gênica , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Immunoblotting , Masculino , Microscopia de Fluorescência , Pessoa de Meia-Idade , Mutação , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células U937
4.
Cell Stress Chaperones ; 29(1): 143-157, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38311120

RESUMO

Preserving and regulating cellular homeostasis in the light of changing environmental conditions or developmental processes is of pivotal importance for single cellular and multicellular organisms alike. To counteract an imbalance in cellular homeostasis transcriptional programs evolved, called the heat shock response, unfolded protein response, and integrated stress response, that act cell-autonomously in most cells but in multicellular organisms are subjected to cell-nonautonomous regulation. These transcriptional programs downregulate the expression of most genes but increase the expression of heat shock genes, including genes encoding molecular chaperones and proteases, proteins involved in the repair of stress-induced damage to macromolecules and cellular structures. Sixty-one years after the discovery of the heat shock response by Ferruccio Ritossa, many aspects of stress biology are still enigmatic. Recent progress in the understanding of stress responses and molecular chaperones was reported at the 12th International Symposium on Heat Shock Proteins in Biology, Medicine and the Environment in the Old Town Alexandria, VA, USA from 28th to 31st of October 2023.


Assuntos
Proteínas de Choque Térmico , Medicina , Biologia , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico/genética , Chaperonas Moleculares/metabolismo
5.
Blood ; 116(1): 85-96, 2010 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-20410505

RESUMO

Heat shock protein 27 (HSP27) is a chaperone whose cellular expression increases in response to various stresses and protects the cell either by inhibiting apoptotic cell death or by promoting the ubiquitination and proteasomal degradation of specific proteins. Here, we show that globin transcription factor 1 (GATA-1) is a client protein of HSP27. In 2 models of erythroid differentiation; that is, in the human erythroleukemia cell line, K562 induced to differentiate into erythroid cells on hemin exposure and CD34(+) human cells ex vivo driven to erythroid differentiation in liquid culture, depletion of HSP27 provokes an accumulation of GATA-1 and impairs terminal maturation. More specifically, we demonstrate that, in the late stages of the erythroid differentiation program, HSP27 is phosphorylated in a p38-dependent manner, enters the nucleus, binds to GATA-1, and induces its ubiquitination and proteasomal degradation, provided that the transcription factor is acetylated. We conclude that HSP27 plays a role in the fine-tuning of terminal erythroid differentiation through regulation of GATA-1 content and activity.


Assuntos
Diferenciação Celular , Células Eritroides/metabolismo , Fator de Transcrição GATA1/metabolismo , Proteínas de Choque Térmico HSP27/metabolismo , Animais , Antígenos CD34/sangue , Células COS , Núcleo Celular/metabolismo , Células Cultivadas , Chlorocebus aethiops , Células Eritroides/citologia , Células Eritroides/efeitos dos fármacos , Fator de Transcrição GATA1/genética , Proteínas de Choque Térmico HSP27/genética , Células HeLa , Proteínas de Choque Térmico , Humanos , Imidazóis/farmacologia , Immunoblotting , Interleucina-6/farmacologia , Células K562 , Leupeptinas/farmacologia , Chaperonas Moleculares , Fosforilação/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma , Ligação Proteica , Piridinas/farmacologia , Interferência de RNA , Fator de Crescimento Transformador beta/farmacologia , Ubiquitinação/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
6.
Nat Commun ; 13(1): 7002, 2022 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-36385105

RESUMO

Patients carrying autosomal dominant mutations in the histone/lysine acetyl transferases CBP or EP300 develop a neurodevelopmental disorder: Rubinstein-Taybi syndrome (RSTS). The biological pathways underlying these neurodevelopmental defects remain elusive. Here, we unravel the contribution of a stress-responsive pathway to RSTS. We characterize the structural and functional interaction between CBP/EP300 and heat-shock factor 2 (HSF2), a tuner of brain cortical development and major player in prenatal stress responses in the neocortex: CBP/EP300 acetylates HSF2, leading to the stabilization of the HSF2 protein. Consequently, RSTS patient-derived primary cells show decreased levels of HSF2 and HSF2-dependent alteration in their repertoire of molecular chaperones and stress response. Moreover, we unravel a CBP/EP300-HSF2-N-cadherin cascade that is also active in neurodevelopmental contexts, and show that its deregulation disturbs neuroepithelial integrity in 2D and 3D organoid models of cerebral development, generated from RSTS patient-derived iPSC cells, providing a molecular reading key for this complex pathology.


Assuntos
Proteína de Ligação a CREB , Proteínas de Choque Térmico , Transtornos do Neurodesenvolvimento , Síndrome de Rubinstein-Taybi , Fatores de Transcrição , Humanos , Proteína de Ligação a CREB/genética , Proteína de Ligação a CREB/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Histonas/genética , Mutação , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , Síndrome de Rubinstein-Taybi/genética , Síndrome de Rubinstein-Taybi/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína p300 Associada a E1A/genética , Proteína p300 Associada a E1A/metabolismo
7.
Cell Stress Chaperones ; 26(5): 819-833, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34331200

RESUMO

Cancer cells rely on heat shock proteins (HSPs) for growth and survival. Especially HSP90 has multiple client proteins and plays a critical role in malignant transformation, and therefore different types of HSP90 inhibitors are being developed. The bioactive natural compound gambogic acid (GB) is a prenylated xanthone with antitumor activity, and it has been proposed to function as an HSP90 inhibitor. However, there are contradicting reports whether GB induces a heat shock response (HSR), which is cytoprotective for cancer cells and therefore a potentially problematic feature for an anticancer drug. In this study, we show that GB and a structurally related compound, called gambogenic acid (GBA), induce a robust HSR, in a thiol-dependent manner. Using heat shock factor 1 (HSF1) or HSF2 knockout cells, we show that the GB or GBA-induced HSR is HSF1-dependent. Intriguingly, using closed form ATP-bound HSP90 mutants that can be co-precipitated with HSF1, a known facilitator of cancer, we show that also endogenous HSF2 co-precipitates with HSP90. GB and GBA treatment disrupt the interaction between HSP90 and HSF1 and HSP90 and HSF2. Our study implies that these compounds should be used cautiously if developed for cancer therapies, since GB and its derivative GBA are strong inducers of the HSR, in multiple cell types, by involving the dissociation of a HSP90-HSF1/HSF2 complex.


Assuntos
Fatores de Transcrição de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Compostos de Sulfidrila/metabolismo , Fatores de Transcrição/metabolismo , Xantenos/farmacologia , Xantonas/farmacologia , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP90/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Humanos , Ligação Proteica/efeitos dos fármacos , Xantenos/química , Xantonas/química
8.
Neurosci Lett ; 725: 134895, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32147500

RESUMO

The Heat Shock Factors (HSFs) have been historically identified as a family of transcription factors that are activated and work in a stress-responsive manner, after exposure to a large variety of stimuli. However, they are also critical in normal conditions, in a life long manner, in a number of physiological processes that encompass gametogenesis, embryonic development and the integrity of adult organs and organisms. The importance of such roles is emphasized by the devastating impact of their deregulation on health, ranging from reproductive failure, neurodevelopmental disorders, cancer, and aging pathologies, including neurodegenerative disorders. Here, we provide an overview of the delicate choreography of the regulation of HSFs during neurodevelopment, at prenatal and postnatal stages. The regulation of HSFs acts at multiple layers and steps, and comprises the control of (i) HSF mRNA and protein levels, (ii) HSF activity in terms of DNA-binding and transcription, (iii) HSF homo- and hetero-oligomerization capacities, and (iv) HSF combinatory set of post-translational modifications. We also describe how these regulatory mechanisms operate in the normal developing brain and how their perturbation impact neurodevelopment under prenatal or perinatal stress conditions. In addition, we put into perspective the possible role of HSFs in the evolution of the vertebrate brains and the importance of the HSF pathway in a large variety of neurodevelopmental disorders.


Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Fatores de Transcrição de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Animais , Encéfalo/fisiopatologia , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Humanos , Transcrição Gênica/fisiologia
9.
Cell Rep ; 30(2): 583-597.e6, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31940498

RESUMO

Maintenance of protein homeostasis, through inducible expression of molecular chaperones, is essential for cell survival under protein-damaging conditions. The expression and DNA-binding activity of heat shock factor 2 (HSF2), a member of the heat shock transcription factor family, increase upon exposure to prolonged proteotoxicity. Nevertheless, the specific roles of HSF2 and the global HSF2-dependent gene expression profile during sustained stress have remained unknown. Here, we found that HSF2 is critical for cell survival during prolonged proteotoxicity. Strikingly, our RNA sequencing (RNA-seq) analyses revealed that impaired viability of HSF2-deficient cells is not caused by inadequate induction of molecular chaperones but is due to marked downregulation of cadherin superfamily genes. We demonstrate that HSF2-dependent maintenance of cadherin-mediated cell-cell adhesion is required for protection against stress induced by proteasome inhibition. This study identifies HSF2 as a key regulator of cadherin superfamily genes and defines cell-cell adhesion as a determinant of proteotoxic stress resistance.


Assuntos
Morte Celular/imunologia , Sobrevivência Celular/imunologia , Fatores de Transcrição de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Animais , Adesão Celular , Humanos , Regulação para Cima
10.
Oncogene ; 38(15): 2767-2777, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30542121

RESUMO

A multicenter clinical study demonstrated the presence of a loss-of-function HSP110 mutation in about 15% of colorectal cancers, which resulted from an alternative splicing and was produced at the detriment of wild-type HSP110. Patients expressing low levels of wild-type HSP110 had excellent outcomes (i.e. response to an oxaliplatin-based chemotherapy). Here, we show in vitro, in vivo, and in patients' biopsies that HSP110 co-localizes with DNA damage (γ-H2AX). In colorectal cancer cells, HSP110 translocates into the nucleus upon treatment with genotoxic chemotherapy such as oxaliplatin. Furthermore, we show that HSP110 interacts with the Ku70/Ku80 heterodimer, an essential element of the non-homologous end joining (NHEJ) repair machinery. We also demonstrate by evaluating the resolved 53BP1 foci that depletion in HSP110 impairs repair steps of the NHEJ pathway, which is associated with an increase in DNA double-strand breaks and in the cells' sensitivity to oxaliplatin. HSP110-depleted cells sensitization to oxaliplatin-induced DNA damage is abolished upon re-expression of HSP110. Confirming a role for HSP110 in DNA non-homologous repair, SCR7 and NU7026, two inhibitors of the NHEJ pathway, circumvents HSP110-induced resistance to chemotherapy. In conclusion, HSP110 through its interaction with the Ku70/80 heterodimer may participate in DNA repair, thereby inducing a protection against genotoxic therapy.


Assuntos
Núcleo Celular/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Reparo do DNA por Junção de Extremidades/genética , Proteínas de Choque Térmico HSP110/genética , Mutagênicos/farmacologia , Translocação Genética/genética , Animais , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Reparo do DNA por Junção de Extremidades/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Células HCT116 , Humanos , Autoantígeno Ku/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Oxaliplatina/farmacologia , Translocação Genética/efeitos dos fármacos
11.
Cell Signal ; 19(6): 1132-40, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17258890

RESUMO

Acute myeloid leukemia (AML) cell lines treated by genotoxic agents or by Tumor Necrosis Factor alpha (TNFalpha) acquire potent cytotoxicity towards myeloid cells through activation of granzyme B (GrB)/perforin (PFN) system. Here we first extend this observation to another death receptor activator, Fas Ligand (FasL). Moreover, we analyzed GrB induction signalling pathway in TNFalpha- and FasL-stimulated AML cells. The effects of TNFalpha and FasL on GrB expression were specifically mediated by p38MAPK (Mitogen-activated-protein-kinase) activation. Otherwise, TNFalpha and FasL stimulation led to radical oxygen species (ROS) generation and ASK1 (Apoptosis-signal-regulating-kinase-1) activation. Endogenous activation of ASK1 by either H2O2 or thioredoxin (Trx) reductase inhibition had the same effects as TNFalpha and FasL on GrB up regulation. Altogether, our results suggest that TNFalpha- and FasL-stimulated AML cell lytic induction is regulated by a signalling pathway involving sequentially, ROS generation, Trx oxidation, ASK1 activation, p38MAPK stimulation and GrB induction at mRNA and protein levels.


Assuntos
Proteína Ligante Fas/farmacologia , Granzimas/biossíntese , Granzimas/genética , Leucemia Mieloide Aguda/patologia , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Indução Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Granzimas/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , MAP Quinase Quinase Quinase 5/metabolismo , Glicoproteínas de Membrana/metabolismo , Camundongos , Perforina , Proteínas Citotóxicas Formadoras de Poros/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
12.
Cell Stress Chaperones ; 23(1): 115-126, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28712054

RESUMO

Abundant evidence has accumulated showing that fetal alcohol exposure broadly modifies DNA methylation profiles in the brain. DNA methyltransferases (DNMTs), the enzymes responsible for DNA methylation, are likely implicated in this process. However, their regulation by ethanol exposure has been poorly addressed. Here, we show that alcohol exposure modulates DNMT protein levels through multiple mechanisms. Using a neural precursor cell line and primary mouse embryonic fibroblasts (MEFs), we found that ethanol exposure augments the levels of Dnmt3a, Dnmt3b, and Dnmt3l transcripts. We also unveil similar elevation of mRNA levels for other epigenetic actors upon ethanol exposure, among which the induction of lysine demethylase Kdm6a shows heat shock factor dependency. Furthermore, we show that ethanol exposure leads to specific increase in DNMT3A protein levels. This elevation not only relies on the upregulation of Dnmt3a mRNA but also depends on posttranscriptional mechanisms that are mediated by NADPH oxidase-dependent production of reactive oxygen species (ROS). Altogether, our work underlines complex regulation of epigenetic actors in response to alcohol exposure at both transcriptional and posttranscriptional levels. Notably, the upregulation of DNMT3A emerges as a prominent molecular event triggered by ethanol, driven by the generation of ROS.


Assuntos
DNA (Citosina-5-)-Metiltransferases/metabolismo , Etanol/efeitos adversos , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima , Animais , DNA (Citosina-5-)-Metiltransferases/genética , DNA Metiltransferase 3A , Embrião de Mamíferos/citologia , Fibroblastos/metabolismo , Fatores de Transcrição de Choque Térmico/metabolismo , Camundongos , NADPH Oxidases/metabolismo , Células-Tronco Neurais/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
13.
Nat Commun ; 9(1): 1431, 2018 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-29650953

RESUMO

Heat shock protein 27 (HSP27/HSPB1) is a stress-inducible chaperone that facilitates cancer development by its proliferative and anti-apoptotic functions. The OGX-427 antisense oligonucleotide against HSP27 has been reported to be beneficial against idiopathic pulmonary fibrosis. Here we show that OGX-427 is effective in two murine models of thrombopoietin- and JAKV617F-induced myelofibrosis. OGX-427 limits disease progression and is associated with a reduction in spleen weight, in megakaryocyte expansion and, for the JAKV617F model, in fibrosis. HSP27 regulates the proliferation of JAK2V617F-positive cells and interacts directly with JAK2/STAT5. We also show that its expression is increased in both CD34+ circulating progenitors and in the serum of patients with JAK2-dependent myeloproliferative neoplasms with fibrosis. Our data suggest that HSP27 plays a key role in the pathophysiology of myelofibrosis and represents a new potential therapeutic target for patients with myeloproliferative neoplasms.


Assuntos
Proteínas de Choque Térmico HSP27/genética , Janus Quinase 2/genética , Oligonucleotídeos/farmacologia , Mielofibrose Primária/tratamento farmacológico , Mielofibrose Primária/genética , Fator de Transcrição STAT5/genética , Animais , Células da Medula Óssea/imunologia , Células da Medula Óssea/patologia , Transplante de Medula Óssea , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Células HEK293 , Proteínas de Choque Térmico HSP27/imunologia , Humanos , Janus Quinase 2/imunologia , Células K562 , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Leucócitos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Terapia de Alvo Molecular , Mutação , Mielofibrose Primária/imunologia , Mielofibrose Primária/patologia , Fator de Transcrição STAT5/imunologia , Trombopoetina/genética , Trombopoetina/imunologia , Transdução Genética , Irradiação Corporal Total
15.
Curr Med Chem ; 14(27): 2839-47, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18045130

RESUMO

Stress or heat shock proteins (Hsps) Hsp90, Hsp70 and Hsp27 are chaperones that assist the proteins in their folding, stability, assembly into multi-protein complexes and transport across cellular membranes. The expression of some of them is highly induced in response to a wide variety of physiological and environmental insults. Hsps have a dual function depending on their intracellular or extracellular location. Intracellular Hsps have a protective function. They allow the cells to survive to lethal conditions. The cytoprotective functions of Hsps can largely explain by their anti-apoptotic properties. Hsp90, Hsp70 and Hsp27 can directly interact with different proteins of the tightly regulated programmed cell death machinery and thereby block the apoptotic process at distinct key points. In cancer cells, where the expression of Hsp27, Hsp70 and/or Hsp90 is frequently abnormally high, they participate in oncogenesis and in resistance to chemotherapy. Therefore, the inhibition of Hsps has become an interesting strategy in cancer therapy. In contrast to intracellular Hsps, extracellular located or membrane-bound Hsps mediate immunological functions. They can elicit an immune response modulated either by the adaptive or innate immune system. In cancer, most immunotherapeutical approaches based on extracellular Hsps exploit their carrier function for immunogenic peptides. This review will discuss this different and often paradoxical approaches in cancer therapy based on the dual role of Hsps, protective/tumorigenic versus immunogenic.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Choque Térmico/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Antineoplásicos/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células Tumorais Cultivadas
16.
Cell Signal ; 17(9): 1149-57, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15993755

RESUMO

Previous studies have shown that Protein kinase C (PKC) stimulation may interfere with Fas signaling pathway and Fas ligand (FasL)-induced apoptosis. In this study, we investigated in Jurkat cells, a FasL-sensitive human T-cell model, whether PKC(zeta) targets apical events of Fas signaling. We describe for the first time that in Jurkat cells, both PKC(zeta) and Prostate apoptosis response-4 (Par-4), one of the major endogenous PKC(zeta) regulators, are components of the death inducing signaling complex (DISC). Using PKC(zeta) overexpressing cells or si-RNA depletion, we demonstrate that PKC(zeta) interferes neither with Fas expression nor Fas clustering in raft microdomains, but negatively regulates FasL-induced apoptosis by interfering with DISC formation and subsequent caspase-8 processing.


Assuntos
Apoptose , Glicoproteínas de Membrana/metabolismo , Proteína Quinase C/fisiologia , Receptores do Fator de Necrose Tumoral/metabolismo , Proteínas Reguladoras de Apoptose , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte , Proteína Ligante Fas , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/análise , Células Jurkat , Proteína Quinase C/análise , Proteína Quinase C/metabolismo , Transdução de Sinais
17.
J Natl Cancer Inst ; 108(3)2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26598503

RESUMO

BACKGROUND: Exosomes, via heat shock protein 70 (HSP70) expressed in their membrane, are able to interact with the toll-like receptor 2 (TLR2) on myeloid-derived suppressive cells (MDSCs), thereby activating them. METHODS: We analyzed exosomes from mouse (C57Bl/6) and breast, lung, and ovarian cancer patient samples and cultured cancer cells with different approaches, including nanoparticle tracking analysis, biolayer interferometry, FACS, and electron microscopy. Data were analyzed with the Student's t and Mann-Whitney tests. All statistical tests were two-sided. RESULTS: We showed that the A8 peptide aptamer binds to the extracellular domain of membrane HSP70 and used the aptamer to capture HSP70 exosomes from cancer patient samples. The number of HSP70 exosomes was higher in cancer patients than in healthy donors (mean, ng/mL ± SD = 3.5 ± 1.7 vs 0.17 ± 0.11, respectively, P = .004). Accordingly, all cancer cell lines examined abundantly released HSP70 exosomes, whereas "normal" cells did not. HSP70 had higher affinity for A8 than for TLR2; thus, A8 blocked HSP70/TLR2 association and the ability of tumor-derived exosomes to activate MDSCs. Treatment of tumor-bearing C57Bl/6 mice with A8 induced a decrease in the number of MDSCs in the spleen and inhibited tumor progression (n = 6 mice per group). Chemotherapeutic agents such as cisplatin or 5FU increase the amount of HSP70 exosomes, favoring the activation of MDSCs and hampering the development of an antitumor immune response. In contrast, this MDSC activation was not observed if cisplatin or 5FU was combined with A8. As a result, the antitumor effect of the drugs was strongly potentiated. CONCLUSIONS: A8 might be useful for quantifying tumor-derived exosomes and for cancer therapy through MDSC inhibition.


Assuntos
Aptâmeros de Peptídeos/metabolismo , Neoplasias da Mama/imunologia , Neoplasias do Colo/imunologia , Exossomos/imunologia , Proteínas de Choque Térmico HSP70/metabolismo , Neoplasias Pulmonares/imunologia , Células Mieloides/imunologia , Neoplasias Ovarianas/imunologia , Receptor 2 Toll-Like/metabolismo , Animais , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/tratamento farmacológico , Exossomos/efeitos dos fármacos , Feminino , Humanos , Interferometria/métodos , Neoplasias Pulmonares/tratamento farmacológico , Linfócitos do Interstício Tumoral/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/imunologia , Neoplasias Ovarianas/tratamento farmacológico , Baço
18.
EMBO Mol Med ; 6(8): 1043-61, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25027850

RESUMO

Fetal alcohol spectrum disorder (FASD) is a frequent cause of mental retardation. However, the molecular mechanisms underlying brain development defects induced by maternal alcohol consumption during pregnancy are unclear. We used normal and Hsf2-deficient mice and cell systems to uncover a pivotal role for heat shock factor 2 (HSF2) in radial neuronal migration defects in the cortex, a hallmark of fetal alcohol exposure. Upon fetal alcohol exposure, HSF2 is essential for the triggering of HSF1 activation, which is accompanied by distinctive post-translational modifications, and HSF2 steers the formation of atypical alcohol-specific HSF1-HSF2 heterocomplexes. This perturbs the in vivo binding of HSF2 to heat shock elements (HSEs) in genes that control neuronal migration in normal conditions, such as p35 or the MAPs (microtubule-associated proteins, such as Dclk1 and Dcx), and alters their expression. In the absence of HSF2, migration defects as well as alterations in gene expression are reduced. Thus, HSF2, as a sensor for alcohol stress in the fetal brain, acts as a mediator of the neuronal migration defects associated with FASD.


Assuntos
Transtornos do Espectro Alcoólico Fetal/patologia , Proteínas de Choque Térmico/metabolismo , Malformações do Desenvolvimento Cortical do Grupo II/induzido quimicamente , Estresse Fisiológico , Fatores de Transcrição/metabolismo , Animais , Córtex Cerebral/patologia , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Proteína Duplacortina , Regulação da Expressão Gênica , Fatores de Transcrição de Choque Térmico , Proteínas de Choque Térmico/deficiência , Camundongos , Camundongos Knockout , Ligação Proteica , Fatores de Transcrição/deficiência
19.
Int J Biochem Cell Biol ; 44(10): 1593-612, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22750029

RESUMO

The members of the small heat shock protein (sHSP) family are molecular chaperones that play major roles in development, stress responses, and diseases, and have been envisioned as targets for therapy, particularly in cancer. The molecular mechanisms that regulate their transcription, in normal, stress, or pathological conditions, are characterized by extreme complexity and subtlety. Although historically linked to the heat shock transcription factors (HSFs), the stress-induced or developmental expression of the diverse members, including HSPB1/Hsp27/Hsp25, αA-crystallin/HSPB4, and αB-crystallin/HSPB5, relies on the combinatory effects of many transcription factors. Coupled with remarkably different cis-element architectures in the sHsp regulatory regions, they confer to each member its developmental expression or stress-inducibility. For example, multiple regulatory pathways coordinate the spatio-temporal expression of mouse αA-, αB-crystallin, and Hsp25 genes during lens development, through the action of master genes, like the large Maf family proteins and Pax6, but also HSF4. The inducibility of Hsp27 and αB-crystallin transcription by various stresses is exerted by HSF-dependent mechanisms, by which concomitant induction of Hsp27 and αB-crystallin expression is observed. In contrast, HSF-independent pathways can lead to αB-crystallin expression, but not to Hsp27 induction. Not surprisingly, deregulation of the expression of sHSP is associated with various pathologies, including cancer, neurodegenerative, or cardiac diseases. However, many questions remain to be addressed, and further elucidation of the developmental mechanisms of sHsp gene transcription might help to unravel the tissue- and stage-specific functions of this fascinating class of proteins, which might prove to be crucial for future therapeutic strategies. This article is part of a Directed Issue entitled: Small HSPs in physiology and pathology.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Choque Térmico Pequenas/genética , Fatores de Transcrição/fisiologia , Animais , Sequência de Bases , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Sequência Consenso , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição de Choque Térmico , Proteínas de Choque Térmico Pequenas/metabolismo , Humanos , Dados de Sequência Molecular , Neoplasias/genética , Neoplasias/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Elementos de Resposta , Estresse Fisiológico , Fatores de Transcrição/metabolismo , Transcrição Gênica
20.
Cancers (Basel) ; 3(1): 1158-81, 2011 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24212658

RESUMO

Heat Shock Factors (HSF) form a family of transcription factors (four in mammals) which were named according to the discovery of their activation by a heat shock. HSFs trigger the expression of genes encoding Heat Shock Proteins (HSPs) that function as molecular chaperones, contributing to establish a cytoprotective state to various proteotoxic stresses and in pathological conditions. Increasing evidence indicates that this ancient transcriptional protective program acts genome-widely and performs unexpected functions in the absence of experimentally defined stress. Indeed, HSFs are able to re-shape cellular pathways controlling longevity, growth, metabolism and development. The most well studied HSF, HSF1, has been found at elevated levels in tumors with high metastatic potential and is associated with poor prognosis. This is partly explained by the above-mentioned cytoprotective (HSP-dependent) function that may enable cancer cells to adapt to the initial oncogenic stress and to support malignant transformation. Nevertheless, HSF1 operates as major multifaceted enhancers of tumorigenesis through, not only the induction of classical heat shock genes, but also of "non-classical" targets. Indeed, in cancer cells, HSF1 regulates genes involved in core cellular functions including proliferation, survival, migration, protein synthesis, signal transduction, and glucose metabolism, making HSF1 a very attractive target in cancer therapy. In this review, we describe the different physiological roles of HSFs as well as the recent discoveries in term of non-cogenic potential of these HSFs, more specifically associated to the activation of "non-classical" HSF target genes. We also present an update on the compounds with potent HSF1-modulating activity of potential interest as anti-cancer therapeutic agents.

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