Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 342
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 604(7906): 457-462, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35444321

RESUMO

Gate-model quantum computers promise to solve currently intractable computational problems if they can be operated at scale with long coherence times and high-fidelity logic. Neutral-atom hyperfine qubits provide inherent scalability owing to their identical characteristics, long coherence times and ability to be trapped in dense, multidimensional arrays1. Combined with the strong entangling interactions provided by Rydberg states2-4, all the necessary characteristics for quantum computation are available. Here we demonstrate several quantum algorithms on a programmable gate-model neutral-atom quantum computer in an architecture based on individual addressing of single atoms with tightly focused optical beams scanned across a two-dimensional array of qubits. Preparation of entangled Greenberger-Horne-Zeilinger (GHZ) states5 with up to six qubits, quantum phase estimation for a chemistry problem6 and the quantum approximate optimization algorithm (QAOA)7 for the maximum cut (MaxCut) graph problem are demonstrated. These results highlight the emergent capability of neutral-atom qubit arrays for universal, programmable quantum computation, as well as preparation of non-classical states of use for quantum-enhanced sensing.

2.
Pathologe ; 39(4): 308-312, 2018 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-29876651

RESUMO

BACKGROUND: Over the last 15 years, an estimated 3000 large centralized biobanks have been established worldwide, making important contributions to the further development of precision medicine. In many cases, these biobanks are affiliated with pathological institutes or work closely with them. OBJECTIVE: In which translational research projects, and during which phases in the development of new drugs are human bioprobes being used and can their use be easily traced in the literature? METHODS: PubMed, Internet research, and information from the German Biobank Alliance and the European initiative BBMRI-ERIC. RESULTS: High-quality biosamples from centralized biobanks are increasingly used in clinical research and development projects. Success stories, where bioprobes have contributed to the further development of precision medicine, are shown in this paper using among others the example of RET gene fusion discovery in lung cancer. Interestingly enough, many key publications in the field of precision medicine do not contain exact references to the biobanks involved. CONCLUSIONS: The importance of centralized biobanks in translational research and clinical development is constantly increasing. However, in order to ensure the acceptance and visibility of biobanks, their participation in success stories of biomedical progress must be systematically documented and published.


Assuntos
Bancos de Espécimes Biológicos , Pesquisa Biomédica , Academias e Institutos , Humanos , Medicina de Precisão , Pesquisa Translacional Biomédica
3.
Pathologe ; 39(Suppl 2): 193-198, 2018 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-30377787

RESUMO

BACKGROUND: Use of liquid biopsy for minimal invasive follow-up diagnostics of non-small-cell lung carcinomas (NSCLCs). OBJECTIVES: Systematic search for new putative blood-based hypermethylation biomarkers to discriminate NSCLC patients from patients without a malign disease. METHODS: Quantitative analysis of gene promoter DNA methylation of potential biomarkers from cfDNA (plasma) with pyrosequencing. RESULTS: cfDNA hypermethylation in plasma confirmed significant higher methylation frequencies of the candidate gene CFTR of the NSCLC patients compared to the combined control groups and to NSCLC patients after curative therapy of primary NSCLC (post-NSCLC). ROC-analysis of the best discriminatory CpGs of the CFTR promotor (CpG1-2-4) revealed a sensitivity of 52% in NSCLC patients and a specificity of 90% in the post-NSCLC group (AUC: 0.69; p < 0.05). CONCLUSIONS: Promotor hypermethylation of the potential biomarker CFTR shows a discriminatory potential for differentiation of NSCLC patients to patients without a malign disease and should further be investigated.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Metilação de DNA , Humanos , Biópsia Líquida , Regiões Promotoras Genéticas
4.
Clin Radiol ; 72(8): 693.e9-693.e13, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28388969

RESUMO

AIM: To assess the value of computed tomography (CT) in the diagnosis of symptomatic sacroiliac (SI) joint degeneration. MATERIALS AND METHODS: CT images from 123 patients with clinically diagnosed SI joint pain were compared to age- and gender-matched controls without chronic back pain or previous back surgery. Degeneration was graded assessing joint space narrowing, osteophytes, subchondral sclerosis, cysts, and vacuum phenomena. RESULTS: The mean total score for the patients was 9.6 and for the controls 9.7 (p=0.77). A subgroup analysis of the mean score for the SI joints that were subjected to surgery was 4.3, compared to 4.8 in the conservatively treated SI joints in the patient group (p=0.23) and 4.8 for all SI joints in the control group (p=0.25). For patients with unilateral left-sided pain (n=40), the mean score for the left side was 5.2 and for the right side 4.9 (p=0.49). For patients with right-sided pain (n=41), the mean score for the right side was 4.8 and the left side 4.7 (p=0.55). CONCLUSION: The prevalence of SI joint degeneration on CT is equal in symptomatic and non-symptomatic individuals. This study indicates that the value of CT is limited, but further studies are needed to establish if CT has a place in diagnosing SI joint degeneration.


Assuntos
Artropatias/diagnóstico por imagem , Articulação Sacroilíaca , Tomografia Computadorizada por Raios X , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
5.
Pathologe ; 36(6): 572-8, 2015 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-26395890

RESUMO

Molecular biological analysis of nucleic acids in blood or other bodily fluids (i.e. liquid biopsy analyses) may supplement the pathologists' diagnostic armamentarium in a reasonable way-particularly in cancer precision medicine. Within the field of oncology, liquid biopsy can potentially be used to monitor tumor burden in the blood and to early detect emerging resistance in the course of targeted cancer therapies. An already approved application of liquid biopsy is the detection of epidermal growth factor receptor (EGFR) driver mutations in blood samples of lung cancer patients in those cases where no tissue biopsy is available. However, there is still currently considerable insecurity associated with blood-based DNA analytic methods that must be solved before liquid biopsy can be implemented for broader routine application in the diagnosis of cancer. In this article, the current state of development of liquid biopsy in molecular diagnostics from a pathology point of view is presented.


Assuntos
Biópsia/métodos , Sistema Livre de Células/patologia , Análise Citogenética/métodos , DNA de Neoplasias/análise , Neoplasias/patologia , Patologia Molecular/métodos , Medicina de Precisão , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Humanos , Pulmão/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias/tratamento farmacológico , Neoplasias/genética
6.
Reprod Biomed Online ; 26(3): 231-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23337421

RESUMO

Much has been written about the ethics of sex selection. This article thoroughly explores the ethical arguments put forth in the literature both for and against non-medical sex selection using sperm sorting. While most of these arguments come from philosophers, feminist scholars, social scientists and members of the healthcare community, they are often echoed in empirical studies that have explored community values. This review is timely because the first efficacious method for sex selection via sperm sorting, MicroSort, is currently in clinical trials and moving closer to FDA approval for marketing in the USA. While the clinical trials are currently focused on the use of MicroSort to avoid X-linked genetic diseases, MicroSort can also be used to satisfy parental preferences.


Assuntos
Citometria de Fluxo/ética , Pré-Seleção do Sexo/ética , Espermatozoides/citologia , Ensaios Clínicos como Assunto , Feminino , Citometria de Fluxo/métodos , Doenças Genéticas Ligadas ao Cromossomo X/prevenção & controle , Direitos Humanos , Humanos , Masculino , Técnicas de Reprodução Assistida , Razão de Masculinidade , Valores Sociais
8.
J Evol Biol ; 25(6): 1066-76, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22587843

RESUMO

Chronic stress often affects growth and development negatively, and these effects are often mediated via glucocorticoid hormones, which elevate during stress. We investigated latitudinal variation in corticosterone (CORT) response to chronic predator stress in Rana temporaria tadpoles along a 1500-km latitudinal cline in Sweden tadpoles, in a laboratory experiment. We hypothesized that more time-constrained high-latitude populations have evolved a lower CORT response to chronic stress to maintain higher growth under stressful conditions. Southern tadpoles had higher CORT content in response to predators after 1 day of exposure, whereas there was no increase in CORT in the northern populations. Two weeks later, there were no predator-induced CORT elevations. Artificially elevated CORT levels strongly decreased growth, development and survival in both northern and southern tadpoles. We suggest that the lower CORT response in high-latitude populations can be connected with avoidance of CORT-mediated reduction in growth and development, but also discuss other possible explanations.


Assuntos
Corticosterona/metabolismo , Geografia , Comportamento Predatório , Rana temporaria/fisiologia , Estresse Fisiológico , Animais , Tamanho Corporal , Corticosterona/análise , Meio Ambiente , Insetos/fisiologia , Larva/crescimento & desenvolvimento , Larva/metabolismo , Larva/fisiologia , Densidade Demográfica , Radioimunoensaio , Rana temporaria/crescimento & desenvolvimento , Rana temporaria/metabolismo , Especificidade da Espécie , Suécia
9.
Br J Cancer ; 102(12): 1736-45, 2010 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-20531416

RESUMO

BACKGROUND: We aimed to clarify the incidence and the clinicopathological value of non-muscle myoglobin (Mb) in a large cohort of non-invasive and invasive breast cancer cases. METHODS: Matched pairs of breast tissues from 10 patients plus 17 breast cell lines were screened by quantitative PCR for Mb mRNA. In addition, 917 invasive and 155 non-invasive breast cancer cases were analysed by immunohistochemistry for Mb expression and correlated to clinicopathological parameters and basal molecular characteristics including oestrogen receptor-alpha (ERalpha)/progesteron receptor (PR)/HER2, fatty acid synthase (FASN), hypoxia-inducible factor-1alpha (HIF-1alpha), HIF-2alpha, glucose transporter 1 (GLUT1) and carbonic anhydrase IX (CAIX). The spatial relationship of Mb and ERalpha or FASN was followed up by double immunofluorescence. Finally, the effects of estradiol treatment and FASN inhibition on Mb expression in breast cancer cells were analysed. RESULTS: Myoglobin mRNA was found in a subset of breast cancer cell lines; in microdissected tumours Mb transcript was markedly upregulated. In all, 71% of tumours displayed Mb protein expression in significant correlation with a positive hormone receptor status and better prognosis. In silico data mining confirmed higher Mb levels in luminal-type breast cancer. Myoglobin was also correlated to FASN, HIF-2alpha and CAIX, but not to HIF-1alpha or GLUT1, suggesting hypoxia to participate in its regulation. Double immunofluorescence showed a cellular co-expression of ERalpha or FASN and Mb. In addition, Mb levels were modulated on estradiol treatment and FASN inhibition in a cell model. CONCLUSION: We conclude that in breast cancer, Mb is co-expressed with ERalpha and co-regulated by oestrogen signalling and can be considered a hallmark of luminal breast cancer phenotype. This and its possible new role in fatty acid metabolism may have fundamental implications for our understanding of Mb in solid tumours.


Assuntos
Neoplasias da Mama/metabolismo , Carcinoma Intraductal não Infiltrante/metabolismo , Mioglobina/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Estudos de Coortes , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Mioglobina/genética , Invasividade Neoplásica , Neoplasias Hormônio-Dependentes/metabolismo , Fenótipo , Prognóstico , RNA Mensageiro/análise
11.
Pathologe ; 31 Suppl 2: 234-8, 2010 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-20665023

RESUMO

Results of molecular pathology have supported changes in the 2004 WHO classification of urothelial cancer. Since then new molecular data such as the distribution pattern of the fibroblast growth factor receptor 3 (FGFR3) has further supported the principle of low and high grade entities of urothelial carcinoma. Animal experiments with knockout mice and conditional knockout systems reveal important parallels to humans and results emphasize the cellular context as a trigger for malignancy. One special feature of the urothelium is its high protection of the urothelial cells by members of the retinoblastoma gene family, efficiently inhibiting invasion even in the presence of p53 mutations. In search of the tumor stem cell phenotype the basal cell phenotype is the focus of attention providing a high clonogenic potential. At the same time detailed analysis of the distribution of mutations in the mitochondrial genome within the urothelium will help to gain insight into the spreading of normal cell or tumor cell clones. The overall data in urological oncology provide evidence that diagnostic and prognostic tools for urothelial cancer can only be reached with multiparametric approaches.


Assuntos
Carcinoma de Células de Transição/genética , Carcinoma de Células de Transição/patologia , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Cromossomos Humanos Par 19/genética , Inibidor p16 de Quinase Dependente de Ciclina , Análise Mutacional de DNA , Genes do Retinoblastoma/genética , Humanos , Camundongos , Camundongos Knockout , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Proteínas de Neoplasias/genética , Estadiamento de Neoplasias , Células-Tronco Neoplásicas/patologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Proteína Supressora de Tumor p53/genética , Urotélio/patologia
12.
Pathologe ; 31 Suppl 2: 244-50, 2010 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-20798943

RESUMO

Despite considerable advances in recent years in our understanding of the genetic changes occurring in urinary bladder cancer, similar progress in the field of epigenetics has hitherto been lacking. Increasingly, however, focus has shifted in the direction of aberrant DNA methylation as a result of recent studies showing the direct impact of such promoter hypermethylation on the loss of tumor suppressor gene expression and function, therefore potentially affecting tumor genesis and progression. The purpose of this study is the identification and characterization of new DNA methylation markers in urinary bladder cancer, with the expectation that these markers could then be incorporated in a multi-gene panel for clinical use in early cancer detection. In addition, better understanding of the signalling pathways involved will undoubtedly impact the development of new treatment strategies. Potential candidate genes, including the Wnt antagonist SFRP5 among others, will be validated by different epigenetic techniques using invasive and superficial urothelial cell lines as well as tumor and urine samples from bladder cancer patients.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células de Transição/genética , Carcinoma de Células de Transição/patologia , Metilação de DNA/genética , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Proteínas Adaptadoras de Transdução de Sinal , Carcinoma de Células de Transição/diagnóstico , Linhagem Celular Tumoral , Deleção Cromossômica , Análise Mutacional de DNA , Diagnóstico Precoce , Epigenômica , Proteínas do Olho/genética , Humanos , Proteínas de Membrana/genética , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Estadiamento de Neoplasias , Prognóstico , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/diagnóstico
13.
Urologe A ; 59(3): 318-325, 2020 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-31541269

RESUMO

BACKGROUND: Technical advancement and availability of high-throughput analysis has advanced molecular subtyping of most cancers. Thus, new possibilities for precision oncology have emerged. AIM: Therefore, we aimed to collect data regarding availability and use of next generation sequencing (NGS) for urothelial cancer within the uropathology working group of the German Society of Pathology. METHODS: We collected data by questionnaires and additionally asked for sequencing results of bladder cancers in the participating institutions. RESULTS: A total of 13 university-affiliated institutes of pathology took part in the survey. All university institutes offer NGS-based molecular panel diagnostics and provide panels covering between 15 and 170 genes. Altogether, only 20 bladder cancers were sequenced in routine diagnostics and for 10 cancers potential targeted treatment options were available. DISCUSSION: So far, despite availability of NGS diagnostics at university institutes of pathology, only few bladder cancer samples have been sequenced. Based on current data from the molecular subtyping of bladder cancers, we recommend a step-by-step protocol with basic immunohistochemistry analysis and subsequent subtype-dependent analyses, e.g., alterations of the fibroblast growth factor receptors (FGFR) or comprehensive gene panel analyses.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Medicina de Precisão , Humanos , Mutação , Patologia Molecular , Inquéritos e Questionários , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
14.
J Cell Biol ; 114(5): 1049-57, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1651942

RESUMO

The coding sequence (333 amino acids) of a new connexin protein, designated mouse connexin37 (Cx37 or Cx37.6) due to the deduced theoretical molecular mass of 37.600 kD, has been determined from cDNA and genomic clones. As seen in other connexins, its gene has no introns within the coding region and the deduced amino acid sequence is predicted to have similar topology to other connexins that form intercellular channels. The amino acid sequence of mouse Cx37 is most similar to rat connexin43 (59% identity) and Xenopus connexin38 (66% identity) when compared from the NH2 terminus to the end of the fourth putative transmembrane region. When expressed in Xenopus oocytes Cx37 forms functional intercellular channels that exhibit more sensitive and rapid gating in response to voltage than any previously characterized vertebrate gap junction. Under stringent conditions the Cx37 cDNA hybridizes to an mRNA of 1.7 kb that is found highly abundant in lung and to progressively lesser extents in brain, kidney, skin, spleen, liver, intestine, and heart. Embryonic brain, kidney, and skin express two to fivefold higher levels of the Cx37 transcript than the corresponding adult tissues. Cx37 transcripts were also found to increase two to threefold in response to retinoic acid treatment of cultured embryonic carcinoma F9 cells.


Assuntos
Proteínas de Membrana/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Southern Blotting , Clonagem Molecular , Conexinas , DNA/genética , Condutividade Elétrica , Expressão Gênica , Genes , Junções Intercelulares/fisiologia , Junções Intercelulares/ultraestrutura , Pulmão/fisiologia , Proteínas de Membrana/fisiologia , Camundongos , Dados de Sequência Molecular , Oócitos , RNA Mensageiro/genética , Transfecção , Xenopus laevis
15.
J Cell Biol ; 117(6): 1299-310, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1318884

RESUMO

From a mouse genomic library, a clone has been isolated that codes for a connexin-homologous sequence of 358 amino acids. Because of its theoretical molecular mass of 40.418 kD it is named connexin40 (Cx40). Based on both protein and nucleotide sequence, mouse Cx40 is more closely related to mouse Cx43 (alpha subgroup of connexins) than to mouse Cx32 (beta subgroup). The highest overall homology detected, however, was to chick Cx42 (67% amino acid and 86% nucleotide identity), raising the possibility that Cx40 may be the mouse analogue. The coding region of Cx40 is uninterrupted by introns and is detected as a single copy gene in the mouse genome. High stringency hybridization of Northern blots with the coding sequence of Cx40 identified a single transcript of 3.5 kb that is at least 16-fold more abundant in lung-similar to mouse Cx37-than in other adult tissues (kidney, heart, and skin). In embryonic kidney, skin, and liver the level of the Cx40 transcript is two- to fourfold higher than in the corresponding adult tissues. Microinjection of Cx40 cRNA into Xenopus oocytes induced functional cell-to-cell channels between pairs. These channels show a symmetrical and markedly cooperative closure in response to transjunctional voltage (Boltzmann parameters of Vo = +/- 35 mV; A = 0.32) which is also fast relative to other connexin channels recorded similarly (tau = 580 ms at Vj of +/- 50 mV). Although Cx40-expressing oocytes did not couple efficiently with oocytes expressing endogenous connexins, they did couple well to Cx37-expressing oocytes. The heterotypic channels which formed had voltage-gating properties modified from those of the original homotypic forms. Transfection of mouse Cx40 DNA, under control of the SV-40 early promoter, into coupling-deficient human HeLa or SK-Hep-1 cells resulted in expression of the expected transcript and restoration of fluorescent dye transfer in transfected clones.


Assuntos
Pulmão/metabolismo , Proteínas de Membrana/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Southern Blotting , Clonagem Molecular , Conexinas , DNA , Condutividade Elétrica , Células HeLa , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Dados de Sequência Molecular , Especificidade de Órgãos/genética , RNA Mensageiro/metabolismo , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico , Xenopus
16.
Science ; 170(3959): 739-40, 1970 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-17776340

RESUMO

Sexual dimorphism in the second antennae of the amphipod Gammarus duebeni Lilljeborg is connected with the reception in the male of a female sex pheromone transported through the water. Investigations on tritium-labeled specimens were carried out with scintillator and autoradiographic techniques.

18.
Trends Biochem Sci ; 26(2): 83-5, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11166557

RESUMO

We report the discovery of a protein domain, hereafter referred to as DAPIN, in diverse vertebrate and viral proteins that is associated with tumor biology, apoptosis and inflammation. Based on a secondary structure prediction, we suggest an all-alpha fold for DAPIN, which is also adopted by apoptotic protein domains of the CARD, death domain and death effector domain type.


Assuntos
Apoptose , Interferons/metabolismo , Sequência de Aminoácidos , Animais , Éxons , Humanos , Dados de Sequência Molecular , Família Multigênica , Fases de Leitura Aberta , Dobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/química , Fatores de Transcrição/genética
19.
Oncogene ; 26(35): 5046-59, 2007 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-17310986

RESUMO

The phosphoinositide-3-kinase (PI3K)/Akt signaling pathway plays an important role in cell survival and the development of cancer. Macrophage migration inhibitory factor (MIF) is a critical inflammatory cytokine that was recently associated with tumorigenesis and that potently inhibits apoptosis. This may involve inhibition of p53-dependent genes, but the initiating molecular mechanism of how MIF controls survival/apoptosis is unknown. Here, we show that MIF prevents apoptosis and promotes tumor cell survival by directly activating the Akt pathway. MIF enhanced Akt activity in primary and immortalized fibroblasts (MEF and NIH/3T3), HeLa cervix carcinoma cells and various breast cancer cell lines. Activation was abolished by kinase inhibitors Ly294002 and PP2 and in Src/Yes/Fyn(SYF)(-/-) and CD74(-/-)(MEFs), while being enhanced in CD74-overexpressing MEFs, demonstrating that the MIF-induced Akt pathway encompasses signaling through the MIF receptor CD74 and the upstream kinases Src and PI3K. Akt was activated by exogenous rMIF and autocrine MIF action, as revealed by experiments in MIF(-/-)MEFs and antibody blockade. siRNA knockdown of CSN5/JAB1, a tumor marker and MIF-binding protein, showed that JAB1 controls autocrine MIF-mediated Akt signaling by inhibition of MIF secretion. Akt activation by MIF led to phosphorylation of the proapoptotic proteins BAD and Foxo3a. Apoptosis inhibition by MIF was functionally associated with Akt activation as it was abolished by overexpression of the Akt pathway inhibitor PTEN and occurred independently of p53. This was shown by studying DNA damage-induced apoptosis in fibroblasts, the Fas death pathway in HeLa cells that do not express functional p53, and etoposide-induced apoptosis in breast carcinoma cells expressing mutant p53. Importantly, dependence of breast cancer cell survival on MIF correlated with Akt activation and the PTEN status of these cells. Thus, MIF can directly promote cell survival through activation of the PI3K/Akt pathway and this effect is critical for tumor cell survival.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Fatores Inibidores da Migração de Macrófagos/metabolismo , Neoplasias/metabolismo , Peptídeo Hidrolases/fisiologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Antígenos de Diferenciação de Linfócitos B/metabolismo , Comunicação Autócrina , Neoplasias da Mama/metabolismo , Complexo do Signalossomo COP9 , Linhagem Celular Tumoral , Sobrevivência Celular , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Neoplasias/patologia , Peptídeo Hidrolases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Quinases da Família src/metabolismo
20.
Oncogene ; 26(38): 5680-91, 2007 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-17353908

RESUMO

Oncogenic wingless-related mouse mammary tumour virus (Wnt) signalling, caused by epigenetic inactivation of specific pathway regulators like the putative tumour suppressor secreted frizzled-related protein 1 (SFRP1), may be causally involved in the carcinogenesis of many human solid tumours including breast, colon and kidney cancer. To evaluate the incidence of SFRP1 deficiency in human tumours, we performed a large-scale SFRP1 expression analysis using immunohistochemistry on a comprehensive tissue microarray (TMA) comprising 3448 tumours from 36 organs. This TMA contained 132 different tumour subtypes as well as 26 different normal tissues. Although tumour precursor stages of, for example kidney, colon, endometrium or adrenal gland still exhibited moderate to abundant SFRP1 expression, this expression was frequently lost in the corresponding genuine tumours. We defined nine novel tumour entities with apparent loss of SFRP1 expression, i.e., cancers of the kidney, stomach, small intestine, pancreas, parathyroid, adrenal gland, gall bladder, endometrium and testis. Renal cell carcinoma (RCC) exhibited the highest frequency of SFRP1 loss (89% on mRNA level; 75% on protein level) and was selected for further analysis to investigate the cause of SFRP1 loss in human tumours. We performed expression, mutation and methylation analysis in RCC and their matching normal kidney tissues. SFRP1 promoter methylation was frequently found in RCC (68%, n=38) and was correlated with loss of SFRP1 mRNA expression (p<0.05). Although loss of heterozygosity was found in 16% of RCC, structural mutations in the coding or promoter region of the SFRP1 gene were not observed. Our results indicate that loss of SFRP1 expression is a very common event in human cancer, arguing for a fundamental role of aberrant Wnt signalling in the development of solid tumours. In RCC, promoter hypermethylation seems to be the predominant mechanism of SFRP1 gene silencing and may contribute to initiation and progression of this disease.


Assuntos
Perfilação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Membrana/genética , Neoplasias/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Perda de Heterozigosidade , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Neoplasias/genética , Neoplasias/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise Serial de Tecidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA