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2.
BMC Public Health ; 23(1): 2281, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978484

RESUMO

BACKGROUND: In 2020/2021 in Germany, several non-pharmacological interventions were introduced to lower the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We investigated to what extent knowledge of prior infection with SARS-CoV-2 or vaccination status influenced the use of personal protection measures (PPM). Further, we were interested in the effect of compliance with PPM on SARS-CoV-2 serostatus. METHODS: Data was based on a sequential, multilocal seroprevalence study (MuSPAD), carried out in eight locations from July 2020 to August 2021. We estimated the association between a known SARS-CoV-2 serostatus (reported positive PCR test or vaccination) and self-reported PPM behavior (hand hygiene, physical distancing, wearing face mask), just as the association of PPM compliance with seropositivity against nucleocapsid (NC), receptor-binding domain (RBD), and spike protein (S) antigens. We identified relevant variables and deduced adjustment sets with directed acyclic graphs (DAG), and applied mixed logistic regression. RESULTS: Out of the 22,297 participants (median age: 54 years, 43% male), 781 were classified as SARS-CoV-2-infected and 3,877 had a vaccinated immune response. Vaccinated individuals were less likely to keep 1.5 m distance [OR = 0.74 (95% CI: 0.57-0.97)] and only partly physically distanced [OR = 0.71 (95% CI: 0.58-0.87)]. Participants with self-reported positive PCR test had a lower chance of adhering partly to physical distancing [OR = 0.70 (95% CI: 0.50-0.99)] in comparison to the reference group. Higher odds of additionally wearing a face mask was observed in vaccinated [OR = 1.28 (95% CI: 1.08-1.51)] even if it was not obligatory. Overall, among unvaccinated participants, we found little evidence of lower odds of seropositivity given mask wearing [OR: 0.91 (95% CI: 0.71-1.16)], physical distancing [OR: 0.84 (95% CI: 0.59-1.20)] and no evidence for completely adhering to hand cleaning [OR: 0.97 (95% CI: 0.29-3.22)]. CONCLUSIONS: A known confirmed prior infection and vaccination may have the potential to influence adherence to PPM.


Assuntos
COVID-19 , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , COVID-19/epidemiologia , COVID-19/prevenção & controle , Estudos Transversais , SARS-CoV-2 , Estudos Soroepidemiológicos , Alemanha/epidemiologia
3.
Biotechnol Biofuels ; 14(1): 193, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598727

RESUMO

BACKGROUND: Even if the loss of production capacity of a microorganism is said to be a serious problem in various biotechnology industries, reports in literature are rather rare. Strains of the genera Trichoderma reesei are used for large-scale production of cellulases, which are needed in food and feed, textile, paper industries and biofuel production. RESULTS: Here, we describe the phenomenon of spontaneous degeneration of T. reesei strains during large-scale cultivation. The phenotype of the degenerated population is characterized most importantly by a loss of any cellulase formation. Interestingly, promoter regions of relevant genes had a more compact chromatin in the (cel -) strains compared to productive strains. For a systematic investigation of the phenomenon a protocol for artificially induced and lab-scaled strain degeneration was developed. This workflow allows to determine the degeneration rate and thus, to compare the occurrence of a degenerated population in differently productive strains on the one hand, and to monitor the success of any strategies to prevent or decrease the degeneration on the other hand. While highly productive strains have higher degeneration rates compared to moderate producers, the degeneration can hardly be triggered in moderate producers. The observed (cel -) phenotype is not caused by a mutation in the gene encoding the essential transactivator Xyr1. The development of a non-producing population is also not triggered by any compounds released by either producing or non-producing cells. CONCLUSIONS: The extent of the occurrence of a degenerated strain population relates to the production capacity of the strain and goes along with chromatin condensation in relevant promoter regions.

4.
AJNR Am J Neuroradiol ; 41(1): 122-127, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31806594

RESUMO

BACKGROUND AND PURPOSE: Mechanical thrombectomy for acute ischemic stroke is performed with the patient under local anesthesia, conscious sedation, or general anesthesia. According to recent trials, up to 16% of patients require emergency conversion to general anesthesia during mechanical thrombectomy. This study investigated the procedural and clinical outcomes after emergency conversion in comparison with local anesthesia, conscious sedation, and general anesthesia. MATERIALS AND METHODS: This retrospective study included 254 patients undergoing mechanical thrombectomy for acute large-vessel occlusion. The procedure was started with the patient either under local anesthesia, conscious sedation, or general anesthesia. Emergency conversion was defined as induction of general anesthesia during mechanical thrombectomy. The primary outcomes were successful reperfusion (TICI 2b/3) and functional independence (mRS at 90 days, ≤2). RESULTS: Twenty-five patients (9.8%) required emergency conversion to general anesthesia. The time from admission to flow restoration was increased under general anesthesia (median, 137 minutes) and emergency conversion (median, 138 minutes) compared with local anesthesia (median 110 minutes). After adjustment for confounders, emergency conversion to general anesthesia and primary general anesthesia had comparable chances of successful reperfusion (OR = 1.28; 95% CI, 0.31-5.25). Patients with emergency conversion had a tendency toward higher chances of functional independence (OR = 4.48; 95% CI, 0.49-40.86) compared with primary general anesthesia, but not compared with local anesthesia (OR = 0.86; 95% CI, 0.14-5.11) and conscious sedation (OR = 1.07; 95% CI, 0.17-6.53). CONCLUSIONS: Patients with emergency conversion did not have lower chances of successful reperfusion or functional independence compared those with primary general anesthesia, and time to flow restoration was also similar. We found no evidence supporting the primary induction of general anesthesia in patients at risk for emergency conversion.


Assuntos
Anestesia Geral/métodos , Sedação Consciente/métodos , Acidente Vascular Cerebral/cirurgia , Trombectomia/métodos , Idoso , Isquemia Encefálica/etiologia , Isquemia Encefálica/cirurgia , Procedimentos Endovasculares/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologia , Resultado do Tratamento
5.
Clin Neuroradiol ; 29(2): 231-242, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29392347

RESUMO

PURPOSE: To compare the influence of two different regions of interest (ROIs) on diffusion tensor metrics in dystrophic thigh muscles using a custom-made (whole muscle) ROI including and a selective ROI excluding areas of fatty replacement. METHODS: Diffusion tensor imaging (DTI) and chemical-shift-encoded water-fat magnetic resonance imaging (MRI) of the thigh was conducted on a 3-Tesla system in 15 cases with muscular dystrophy and controls. The ROIs were chosen according to patterns of fatty replacement on co-registered axial DTI and gradient echo sequence (GRE) images. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), fiber track length (FTL), and muscle fat fractions (MFF) were compared between both ROI segmentations. These comparisons, muscle-specific correlation coefficients, and the influence of ROI localization on tensor metrics were derived based on linear mixed effects regression models. RESULTS: In the cases a high correlation was observed for ADC and FA with MFF using a custom ROI. The correlation was weaker but still significant with a selective ROI method. Using the custom ROI, FTL correlated significantly with MFF in 3 out of 4 muscles (r ≤ -0.51). A correlation was not found for the selective ROI method. Interaction analysis revealed that the association of ADC and FA with MFF was not significantly influenced by the ROI localization. For FTL the ROI localization significantly reduced the negative association with MFF. CONCLUSION: The DTI metrics and FTL of custom ROI segmentation are significantly influenced by MFF. Contrary to ADC and FA, the effect of MFF on FTL is significantly reduced when applying selective ROI segmentation, which could therefore be a better option for MR tractography.


Assuntos
Músculo Esquelético/patologia , Distrofias Musculares/patologia , Tecido Adiposo/patologia , Adulto , Idoso , Água Corporal , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Coxa da Perna , Adulto Jovem
6.
Biochim Biophys Acta Mol Cell Res ; 1866(2): 175-189, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30389373

RESUMO

Overcoming apoptosis resistance is one major issue in glioblastoma (GB) therapies. Accumulating evidence indicates that resistance to apoptosis in GB is mediated via upregulation of pro-survival BCL2-family members. The synthetic BH3-mimetic ABT-737 effectively targets BCL2, BCL2 like 1 and BCL2 like 2 but still barely affects cell survival which is presumably due to its inability to inhibit myeloid cell leukemia 1 (MCL1). The constitutively active serine/threonine kinase proviral integration site for moloney murine leukemia virus 1 (PIM1) was recently found to be overexpressed in GB patient samples and to maintain cell survival in these tumors. For different GB cell lines, Western Blot, mitochondrial fractionation, fluorescence microscopy, effector caspase assays, flow cytometry, and an adult organotypic brain slice transplantation model were used to investigate the putative PIM1/MCL1 signaling axis regarding potential synergistic effects with ABT-737. We demonstrate that combination of the PIM1 inhibitor SGI-1776 or the pan-PIM kinase inhibitor AZD1208 with ABT-737 strongly sensitizes GB cells to apoptosis. Unexpectedly, this effect was found to be MCL1-independent, but could be partially blocked by caspase 8 (CASP8) inhibition. Remarkably, the analysis of autophagy markers in combination with the observation of massive accumulation and hampered degradation of autophagosomes suggests a completely novel function of PIM1 as a late stage autophagy regulator, maintaining the autophagic flux at the level of autophagosome/lysosome fusion. Our data indicate that PIM1 inhibition and ABT-737 synergistically induce apoptosis in an MCL1-independent but CASP8-dependent manner in GB. They also identify PIM1 as a suitable target for overcoming apoptosis resistance in GB.


Assuntos
Apoptose/efeitos dos fármacos , Glioblastoma/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose/fisiologia , Autofagia/fisiologia , Compostos de Bifenilo/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular , Glioma/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Nitrofenóis/farmacologia , Fragmentos de Peptídeos/metabolismo , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-pim-1/fisiologia , Sulfonamidas/farmacologia , Tiazolidinas
7.
Appl Microbiol Biotechnol ; 102(2): 587-595, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29196787

RESUMO

Erythritol is a naturally abundant sweetener gaining more and more importance especially within the food industry. It is widely used as sweetener in calorie-reduced food, candies, or bakery products. In research focusing on sugar alternatives, erythritol is a key issue due to its, compared to other polyols, challenging production. It cannot be chemically synthesized in a commercially worthwhile way resulting in a switch to biotechnological production. In this area, research efforts have been made to improve concentration, productivity, and yield. This mini review will give an overview on the attempts to improve erythritol production as well as their development over time.


Assuntos
Eritritol/biossíntese , Edulcorantes/metabolismo , Bactérias/metabolismo , Biotecnologia , Indústria Alimentícia , Leveduras/metabolismo
8.
Int J Pharm ; 526(1-2): 178-187, 2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-28456652

RESUMO

RNA interference (RNAi) is a promising technique to treat severe diseases on a pre-protein level. We and others postulate that the release of nanoparticle-complexed small interfering RNA (siRNA) from implanted biomaterials could provide structural support for tissue repair, combined with local siRNA transfection of invading and regenerating cells. In this study, we systematically investigated cross-linked gelatin based hydrogel formulations (cGEL) as degradable controlled release matrices for siRNA. Aiming at the definition of correlations between cGEL composition, siRNA nanoparticle formulation, release kinetics of complexed siRNA and transfection efficiency, we combined five different cGEL formulations and three transfection systems, i.e. polyplexes with polyethyleneimine (PEI), PEI in combination with liposomes (lipopolyplexes) and polyplexes based on tyrosin-modified PEI (P10Y). It was found that the distribution of these poly-/lipopolyplexes, when applied onto the negatively charged hydrogels, was strongly dependent on their zeta potential. Furthermore, siRNA release from the hydrogel was a multifactorial process, as diffusion, hydrogel degradation and nanoparticle decomplexation overlapped over time. This resulted in a prolonged release of siRNA for up to 21days. In the case of PEI complexes and lipopolyplexes, release kinetics depended on the cGEL formulation. In contrast, when employing P10Y polyplexes, an initial burst release was observed with no further release thereafter. Silencing activity was determined using constitutively luciferase-expressing SKOV-3-Luc reporter cells. Surface and bulk porosity in hydrogels was introduced by addition of soluble polyethylene glycol during fabrication, leading to improved knockdown. The rapid onset of knockdown efficacy will also provide the basis for the determination of long-term effects.


Assuntos
Gelatina/química , Hidrogéis/química , RNA Interferente Pequeno/administração & dosagem , Transfecção/métodos , Linhagem Celular Tumoral , Humanos , Polietilenoimina , Interferência de RNA
9.
Oncogene ; 36(24): 3464-3476, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28114277

RESUMO

Megakaryoblastic Leukemia 1 and 2 (MKL1/2) are transcriptional coactivators of Serum Response Factor (SRF) with an essential role for hepatocellular carcinoma (HCC) growth and oncogene-induced senescence. In this report, we identified myoferlin as a novel MKL/SRF target gene by gene expression profiling and verification in vivo in HCC xenografts. Myoferlin was overexpressed in human and murine HCCs triggered by conditional expression of constitutively active SRF-VP16 protein in hepatocytes. Furthermore, myoferlin was required for HCC cell invasion, proliferation and anchorage-independent cell growth. We provide evidence that myoferlin is a crucial gene target of MKL1/2 mediating its effect on oncogene-induced senescence by modulating the activation state of the EGFR and downstream MAPK and p16-/Rb pathways. Depletion of myoferlin in tumour cells from SRF-VP16-derived murine HCCs induced a senescence phenotype. These findings identify MKL1/2 and myoferlin as novel therapeutic targets to treat human HCC by a senescence-inducing strategy.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Carcinoma Hepatocelular/metabolismo , Perfilação da Expressão Gênica/métodos , Neoplasias Hepáticas/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Musculares/metabolismo , Fator de Resposta Sérica/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Proteínas de Membrana/genética , Camundongos , Proteínas Musculares/genética , Células NIH 3T3 , Invasividade Neoplásica , Transplante de Neoplasias
10.
Spinal Cord ; 55(5): 435-440, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27845354

RESUMO

STUDY DESIGN: Retrospective analysis of prospectively collected longitudinal data. Variables of interest are timed and untimed walking assessments (10MWT, 6MWT, TUG, WISCI, SCIM3a, SCIM3b) and lower extremities motor scores (LEMS) from both sides' lower limb motor segments, measured five times within the first year after acute spinal cord injury (SCI). OBJECTIVES: Assessing concurrent validity of single and groups of walking assessments in comparison with LEMS in SCI patients. SETTING: European Multicenter study about Spinal Cord Injury, a collaboration of 22 centers. METHODS: Canonical correlation analysis (CCA) was applied to single and groups of assessments at each time point, separately for patients able to perform timed walking assessments (less impaired; patient subgroup I) and for all patients (no selection; patient subgroup II). RESULTS: In patient subgroup I, SCIM3b, WISCI, 10MWT and 6MWT all had high and similar concurrent validity one year after injury. Among all groups of three walking assessments, SCIM3a, WISCI and 10MWT had highest concurrent validity, similar to all six walking assessments together. Timed walking assessments generally had higher concurrent validity than untimed ones. In patient subgroup II, WISCI distinctly had highest concurrent validity one year after injury, similar to all three untimed walking assessments together. CONCLUSIONS: CCA can assess concurrent validity of single and groups of assessments. Minimal sets of walking assessments with comparable concurrent validity as all assessments together were proposed. As these sets differ by patient group, walking assessments should be specified according to expected walking ability to allow for targeted, cost-effective application of assessments.


Assuntos
Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/fisiopatologia , Caminhada/fisiologia , Doença Aguda , Adolescente , Adulto , Avaliação da Deficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Retrospectivos , Índice de Gravidade de Doença , Traumatismos da Medula Espinal/reabilitação , Adulto Jovem
11.
Pharmazie ; 71(1): 27-34, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26867350

RESUMO

In principle, RNA interference (RNAi) allows for the inhibition of any oncogene of choice, thus leading to novel concepts in tumor therapy. For their delivery, the RNAi-inducing small RNA molecules (small interfering RNAs, siRNAs) can be formulated in various nanoparticle systems, prior to testing them in preclinical animal models. The same is true for miRNAs that have more recently been explored in therapeutic miRNA replacement strategies. This puts high demands on the properties of the nanoparticles. This review article discusses various nanoparticulate systems for RNA delivery in vivo and gives an overview of preclinical studies on siRNA- or miRNA-based tumor therapy.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Nanopartículas , Neoplasias/tratamento farmacológico , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/uso terapêutico , Animais , Sistemas de Liberação de Medicamentos , Humanos , Neoplasias/genética
12.
Oncogene ; 31(7): 918-28, 2012 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-21743487

RESUMO

The constitutively active serine/threonine kinase Pim-1 is upregulated in different cancer types, mainly based on the action of several interleukines and growth factors at the transcriptional level. So far, a regulation of oncogenic Pim-1 by microRNAs (miRNAs) has not been reported. Here, we newly establish miR-33a as a miRNA with potential tumor suppressor activity, acting through inhibition of Pim-1. A screen for miRNA expression in K562 lymphoma, LS174T colon carcinoma and several other cell lines revealed generally low endogenous miR-33a levels relative to other miRNAs. Transfection of K562 and LS174T cells with a miR-33a mimic reduced Pim-1 levels substantially. In contrast, the cell-cycle regulator cyclin-dependent kinase 6 predicted to be a conserved miR-33a target, was not downregulated by the miR-33a mimic. Seed mutagenesis of the Pim-1 3'-untranslated region in a luciferase reporter construct and in a Pim-1 cDNA expressed in Pim-1-deficient Skov-3 cells demonstrated specific and direct downregulation of Pim-1 by the miR-33a mimic. The persistence of this effect was comparable to that of a small interfering RNA-mediated knockdown of Pim-1, resulting in decelerated cell proliferation. In conclusion, we demonstrate the potential of miR-33a to act as a tumor suppressor miRNA, which suggests miR-33a replacement therapy through delivery of miR mimics as a novel therapeutic strategy.


Assuntos
Regiões 3' não Traduzidas/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-pim-1/genética , Apoptose , Sequência de Bases , Sítios de Ligação/genética , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células , Perfilação da Expressão Gênica , Genes Supressores de Tumor , Células HEK293 , Células Hep G2 , Humanos , Células K562 , MicroRNAs/metabolismo , Mimetismo Molecular/genética , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência do Ácido Nucleico , Transfecção
13.
Gut ; 59(8): 1101-10, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20442202

RESUMO

BACKGROUND AND AIMS: The transcription factor CUX1 is known as a regulator of cell differentiation and cell cycle progression. Previously, CUX1 was identified as a modulator of invasiveness in various cancers. Based on expression profiles suggesting a role for CUX1 in mediating chemoresistance, the aim of this study was to characterise the effect of CUX1 on apoptosis as well as its regulation by signalling pathways modulating drug resistance in pancreatic cancer. METHODS: The effect of CUX1 on TRAIL- (tumour necrosis factor-related apoptosis-inducing ligand) and drug-induced apoptosis was analysed using overexpression and knock-down strategies. Regulation of CUX1 by phosphatidylinositol-3-kinase (PI3K)/Akt signalling was examined at the mRNA and protein level. The effect of CUX1 knock-down by nanoparticle-complexed small interfering RNA (siRNA) in vivo was analysed in a murine xenograft model. Furthermore, CUX1 RNA and protein expression was evaluated in human pancreatic cancer and adjacent normal tissues. RESULTS: Knock-down of CUX1 resulted in significantly enhanced TRAIL- and drug-induced apoptosis, associated with increased PARP (poly ADP-ribose polymerase) cleavage and caspase activity. Vice versa, overexpression of CUX1 inhibited apoptosis. CUX1 expression was induced by activation of Akt/protein kinase B signalling, and decreased by PI3K inhibitors. The antiapoptotic effect of CUX1 was associated with upregulation of BCL2 and downregulation of tumour necrosis factor alpha. CUX1 was significantly overexpressed in pancreatic cancers, as analysed by in situ hybridisation and immunohistochemistry. In vivo, silencing of CUX1 by intratumourally administered polyethylenimine-complexed siRNA led to reduced tumour growth and increased apoptosis in pancreatic cancer xenografts. CONCLUSION: CUX1 was identified as an important mediator of tumour cell survival in pancreatic cancer in vitro and in vivo.


Assuntos
Apoptose/fisiologia , Proteínas de Homeodomínio/fisiologia , Proteínas Nucleares/fisiologia , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Proteínas Repressoras/fisiologia , Animais , Apoptose/efeitos dos fármacos , Caspases Efetoras/metabolismo , Sobrevivência Celular/fisiologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Terapia Genética/métodos , Proteínas de Homeodomínio/genética , Humanos , Camundongos , Proteínas de Neoplasias/fisiologia , Transplante de Neoplasias , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/terapia , Poli(ADP-Ribose) Polimerases/metabolismo , RNA Interferente Pequeno/genética , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Transdução de Sinais/fisiologia , Ligante Indutor de Apoptose Relacionado a TNF/fisiologia , Fatores de Transcrição , Transplante Heterólogo , Células Tumorais Cultivadas
14.
Placenta ; 30(7): 649-53, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19481257

RESUMO

Pleiotrophin (PTN) is a heparin-binding protein with multiple activities in cell growth, migration and differentiation mediated through multiple receptors. In mammals, PTN expression in trophoblast is found exclusively in the human and in some of the apes in which an endogenous retrovirus upstream of the first coding exon generates a phylogenetically new trophoblast-specific promoter associated with exon UV3. To understand the functions of ERV promoter-mediated trophoblastic PTN expression in pregnancy, we correlated the expression of PTN and its receptors anaplastic lymphoma kinase (ALK), receptor protein tyrosine phosphatase beta/zeta (RPTPbeta/zeta), and Syndecan-1 and Syndecan-3 (SDC1 and SDC3) with key developmental processes in first-trimester human placentation. In an extensive survey of cell lines and primary tissues, we found that trophoblastic transcription of PTN is initiated exclusively from the ERV promoter, whereas decidual expression is initiated at the phylogenetically ancient U1 exon-associated promoter. Using immunohistochemistry, we found that different patterns of overlapping expression of PTN and its receptors occur in different trophoblast subtypes. Notably, a role in angiogenesis is supported by expression of PTN and its receptors in villous mesenchyme, fetal macrophages and villus core fetal vessels. PTN staining of extravillous cytotrophoblasts and the syncytial microvillous membrane is consistent with increasing levels of PTN, as measured by ELISA, in the maternal bloodstream as pregnancy progresses.


Assuntos
Proteínas de Transporte/genética , Citocinas/genética , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Sindecana-1/genética , Sindecana-2/genética , Trofoblastos/fisiologia , Quinase do Linfoma Anaplásico , Proteínas de Transporte/metabolismo , Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Linhagem da Célula/fisiologia , Citocinas/metabolismo , Feminino , Expressão Gênica/fisiologia , Humanos , Neovascularização Fisiológica/fisiologia , Circulação Placentária/fisiologia , Gravidez , Proteínas Tirosina Quinases/metabolismo , Receptores Proteína Tirosina Quinases , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Sindecana-1/metabolismo , Sindecana-2/metabolismo , Trofoblastos/citologia
15.
Curr Pharm Des ; 14(34): 3603-19, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19075737

RESUMO

RNAi interference (RNAi) is an almost standard method for the knockdown of any target gene of interest in vitro, exploring a naturally occurring catalytic mechanism. Beyond functional analyses, the downregulation of pathologically relevant genes which are aberrantly expressed in a given disease will offer novel therapeutic approaches, also with regard to otherwise 'undruggable' genes. RNAi is mediated by small interfering RNAs (siRNA), and thus siRNA delivery in vivo is of critical importance for its implementation. Due to the instability and physicochemical properties of siRNAs, the development of strategies and formulations for siRNA protection, cellular uptake, correct intracellular localization and endosomal release, in combination with favourable pharmacokinetic properties, preferential delivery to the target organ, high biocompatibility and absence of unwanted side effects is crucial for the success of RNAi-based therapeutics. Approaches include the encapsulation in lipids, the complex formation with a variety of liposomes or cationic polymers, the chemical conjugation of siRNAs for example to peptides, aptamers or antibodies as well as other formulations. This review discusses non-viral strategies, based on different siRNA formulations and various modes of administration, for the delivery of therapeutic siRNAs to induce RNAi in vivo. It gives a comprehensive overview including a detailed listing of in vivo studies which have successfully employed various strategies for analytical or therapeutic siRNA-mediated gene targeting in different animal models, and presents a more in-depth description of some promising approaches with a special emphasis on polymers.


Assuntos
RNA Interferente Pequeno/administração & dosagem , Animais , Química Farmacêutica , Vias de Administração de Medicamentos , Sistemas de Liberação de Medicamentos , Humanos , Conformação de Ácido Nucleico , RNA Interferente Pequeno/farmacocinética , RNA Interferente Pequeno/uso terapêutico
16.
Gene Ther ; 12(5): 461-6, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15616603

RESUMO

RNA interference (RNAi) represents a powerful, naturally occurring biological strategy for inhibition of gene expression. It is mediated through small interfering RNAs (siRNAs), which trigger specific mRNA degradation. In mammalian systems, however, the application of siRNAs is severely limited by the instability and poor delivery of unmodified siRNA molecules into the cells in vivo. In this study, we show that the noncovalent complexation of synthetic siRNAs with low molecular weight polyethylenimine (PEI) efficiently stabilizes siRNAs and delivers siRNAs into cells where they display full bioactivity at completely nontoxic concentrations. More importantly, in a subcutaneous mouse tumor model, the systemic (intraperitoneal, i.p.) administration of complexed, but not of naked siRNAs, leads to the delivery of the intact siRNAs into the tumors. The i.p. injection of PEI-complexed, but not of naked siRNAs targeting the c-erbB2/neu (HER-2) receptor results in a marked reduction of tumor growth through siRNA-mediated HER-2 downregulation. Hence, we establish a novel and simple system for the systemic in vivo application of siRNAs through PEI complexation as a powerful tool for future therapeutic use.


Assuntos
Marcação de Genes , Terapia Genética/métodos , Neoplasias Ovarianas/terapia , Polietilenoimina/administração & dosagem , Interferência de RNA , RNA Interferente Pequeno/administração & dosagem , Animais , Linhagem Celular Tumoral , Feminino , Genes erbB-2 , Injeções Intraperitoneais , Camundongos , Camundongos Nus , Neoplasias Experimentais , Neoplasias Ovarianas/metabolismo , Receptor ErbB-2/metabolismo
17.
Ann Oncol ; 14(10): 1525-9, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14504053

RESUMO

BACKGROUND: Malignant tumors of the testis are among the most common cancers in men between the ages of 15 and 30 years. The sensitivity of detection of known tumor markers depends upon the tumor histology and stage. In other cancers, increased serum concentrations of various angiogenic growth factors have been described as potential markers for tumor progression and metastasis. One main histological feature of testicular cancer is profound angiogenesis. DESIGN: In this study, we investigated by sensitive enzyme-linked immunosorbent assays (ELISAs) the levels of various growth and angiogenesis factors in the serum of testicular cancer patients as compared with normal control subjects. For the most profoundly increased growth factors, pleiotrophin (PTN) and fibroblast growth factor-2 (FGF-2), we furthermore analyzed tumor lysates by northern blotting, RT-PCR and ELISA. RESULTS: We demonstrate a marked elevation of average serum levels of PTN ( approximately 20-fold) and of FGF-2 ( approximately 7-fold) in patients and expression of both growth factors in tumor biopsies. To a lesser extent, vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) serum levels were increased, whereas FGF-4 and transforming growth factor-beta levels were similar to those in normal control subjects. Elevation of PTN, FGF-2, EGF and VEGF was detected in seminomatous as well as non-seminatous tumors, and even in early stages. CONCLUSIONS: PTN and FGF-2 may represent promising new diagnostic markers for testicular cancer with high sensitivity even in early-stage testicular cancer. Further studies are warranted to extend our analyses.


Assuntos
Biomarcadores Tumorais/análise , Proteínas de Transporte/análise , Citocinas/análise , Neovascularização Patológica , Neoplasias Testiculares/patologia , Adulto , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática , Fator 2 de Crescimento de Fibroblastos , Humanos , Masculino , Fatores de Crescimento Neural/análise , Proteínas Proto-Oncogênicas/análise , Sensibilidade e Especificidade , Neoplasias Testiculares/diagnóstico
18.
Gene Ther ; 9(24): 1700-7, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12457284

RESUMO

The sequence-specific cleavage of RNA molecules through ribozyme targeting is particularly attractive since it allows the effective abrogation of protein expression. So far, however, use of enzymatically active RNA molecules (ribozymes) has, without chemical modification, been severely hampered by ribozyme instability and poor cellular uptake. In this paper, we present a method for protection and cellular delivery of ribozymes by complexation with a low molecular weight polyethylenimine (LMW-PEI). We show that LMW-PEI almost completely stabilizes ribozymes or any RNA against degradation in vitro. Upon their highly efficient cellular uptake, non-toxic LMW-PEI-complexed ribozymes display intracellular bioactivity already at low concentrations as demonstrated by down-regulation of two different genes in different cell lines. In vivo, LMW-PEI-complexed ribozymes were stabilized after intraperitoneal (i.p.) injections, showed prolonged circulation time and intact ribozymes were detected in the subcutaneous (s.c.) tumor mass 60 min after the injection. In addition, i.p. injections of LMW-PEI-complexed ribozymes targeted against the growth factor pleiotrophin (PTN) resulted in marked reduction of s.c. human melanoma tumor growth and of intratumoral PTN levels in a mouse xenograft model. Thus, this paper describes a novel method for exogenous delivery of any bioactive RNA ribozyme in vitro and in vivo without chemical modification.


Assuntos
Marcação de Genes , Terapia Genética/métodos , Melanoma/terapia , RNA Catalítico , Neoplasias Cutâneas/terapia , Animais , Proteínas de Transporte/genética , Citocinas/genética , Feminino , Regulação da Expressão Gênica , Engenharia Genética , Injeções Intraperitoneais , Melanoma/metabolismo , Camundongos , Camundongos Nus , Microscopia Confocal , Modelos Animais , Polietilenoimina , Neoplasias Cutâneas/metabolismo , Transplante Heterólogo , Células Tumorais Cultivadas
19.
Br J Cancer ; 86(6): 858-63, 2002 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-11953815

RESUMO

Pleiotrophin is a heparin-binding growth factor involved in the differentiation and proliferation of neuronal tissue during embryogenesis, and also secreted by melanoma and breast carcinoma cells. Pleiotrophin exhibits mitogenic and angiogenic properties and has been shown to influence the vascular supply, expansion and metastasis of tumour cells. Our aim was to study the serum and plasma concentrations of pleiotrophin and the classical angiogenic growth factor vascular endothelial growth factor. Using a specific ELISA-test we studied patients with small cell lung cancer (n=63), and patients with non-small cell lung cancer (n=22) in comparison to healthy control subjects (n=41). In most of the lung cancer patients (81%), we found serum levels of pleiotrophin above those of control subjects (P<0.001). Of the 63 small cell lung cancer patients in the study pleiotrophin serum levels were elevated in 55 cases (87%) and in 14 cases (63%) of the 22 non-small cell lung cancer patients. Pleiotrophin mean serum concentrations were 10.8-fold higher in the tumour patient group as compared to the control group (P<0.001). Furthermore, pleiotrophin serum levels correlated positively with the stage of disease and inversely with the response to therapy. Plasma vascular endothelial growth factor concentrations were elevated in only in 28.6% of small cell lung cancer and 45.5% of non-small cell lung cancer patients by an average of 2.3-fold. Quite strikingly, there was no apparent correlation between the plasma vascular endothelial growth factor concentration and the stage of disease. Our study suggests that pleiotrophin may be an early indicator of lung cancer and might be of use in monitoring the efficacy of therapy, which needs to be confirmed by larger studies.


Assuntos
Proteínas de Transporte/sangue , Citocinas/sangue , Neoplasias Pulmonares/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma de Células Pequenas/sangue , Proteínas de Transporte/genética , Citocinas/genética , Fatores de Crescimento Endotelial/sangue , Feminino , Humanos , Neoplasias Pulmonares/patologia , Linfocinas/sangue , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , RNA Mensageiro/análise , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
20.
Oncogene ; 20(50): 7430-6, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11704874

RESUMO

Fibroblast growth factor binding protein (FGF-BP) is a secreted protein that binds FGF-1 and FGF-2 and is involved in mobilization and activation of FGFs from the extracellular matrix. FGF-BP overexpression as well as ribozyme-mediated reduction of endogenous FGF-BP revealed that FGF-BP can be rate-limiting for tumor growth and angiogenesis. Recent studies showed that FGF-BP expression is up-regulated during early phases of tumorigenesis, indicating that the role of FGF-BP in angiogenesis is a critical early step in the development and progression of tumors. Human papillomavirus type 16 (HPV 16) is highly associated with the development of anogenital cancers. Here we demonstrate that the stable expression of the E6 oncogene of HPV 16 leads to an activation of the FGF-BP promoter in primary human foreskin keratinocytes (one of the natural host cells of these viruses). This is associated with an increase in the steady state levels of FGF-BP mRNA and FGF-BP protein in cells stably expressing E6. Transient E6 expression revealed that the observed activation of the FGF-BP promoter by the viral oncogene is an early process which is independent from immortalization/transformation events in the cells.


Assuntos
Proteínas de Transporte/biossíntese , Regulação Viral da Expressão Gênica , Queratinócitos/metabolismo , Neovascularização Patológica/genética , Proteínas Oncogênicas Virais/fisiologia , Proteínas Repressoras , Proteínas de Transporte/genética , Linhagem Celular , Senescência Celular , Genes Reporter , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Queratinócitos/citologia , Luciferases/biossíntese , Masculino , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus , Pênis/citologia , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Vírus 40 dos Símios/genética , Ativação Transcricional , Transfecção , Proteína Supressora de Tumor p53/biossíntese
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