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INTRODUCTION: PI3K inhibitors are evaluated for relapsed and refractory Diffuse large B-cell lymphoma (DLBCL) patients. OBJECTIVE: As rituximab has shown to influence B-cell receptor (BCR) signaling, we investigated the interaction of anti-CD20 antibody rituximab and the new type II glycoengineered anti-CD20 antibody obinutuzumab in combination with the PI3K delta inhibitor idelalisib. METHODS: Established DLBCL cell lines were treated with either rituximab or obinutuzumab alone or in combination with PI3K delta inhibitor idelalisib. RESULTS: Rituximab and to a lesser extent obinutuzumab monotherapy resulted in a temporary upregulation of p-Akt, p42/44, and p38 signaling pathways. Idelalisib reduced p-Akt expression. Rituximab antagonized the p-Akt downregulation at early time points, while obinutuzumab did not interfere with idelalisib's effects. In cell growth analysis, early antagonism could also be detected. CONCLUSION: The combination of idelalisib with CD antibodies shows an initial antagonism of rituximab but not obinutuzumab in downregulation of PI3K-signaling targets.
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Transcription factors of the SoxD protein family have previously been shown to prevent precocious specification and terminal differentiation of oligodendrocyte progenitor cells in the developing spinal cord. Using mice with specific deletion of the SoxD proteins Sox5 and Sox6 in the central nervous system, we now show that SoxD proteins additionally influence migration of oligodendrocyte progenitors in the spinal cord as well as in the forebrain. In mutant mice, emigration of oligodendrocyte progenitors from the ventricular zone and colonization of the mantle zone are significantly delayed probably because of reduced expression of Pdgf receptor alpha and decreased responsiveness toward Pdgf-A as a main migratory cue. In addition to this direct cell-autonomous effect on Pdgf receptor alpha expression, SoxD proteins furthermore promote oligodendroglial migration by keeping the cells in an undifferentiated state and preventing a premature loss of their migratory capacity. This indirect effect becomes particularly important during late embryonic and early postnatal phases of oligodendroglial development. Finally, we show that Sox5 and Sox6 cooperate with Sox9 and Sox10 to activate Pdgf receptor alpha expression and thereby maintain oligodendrocyte progenitors in the immature state. This contrasts with their behavior on myelin genes where they antagonize the function of SoxE proteins. It argues that SoxD proteins can function either as repressors or as co-activators of SoxE proteins thereby modulating their function in a stage-specific manner.
Assuntos
Movimento Celular/fisiologia , Oligodendroglia/fisiologia , Prosencéfalo/fisiologia , Fatores de Transcrição SOXD/metabolismo , Fatores de Transcrição SOXE/metabolismo , Medula Espinal/fisiologia , Animais , Células Cultivadas , Camundongos Transgênicos , Células-Tronco Neurais/fisiologia , Fator de Crescimento Derivado de Plaquetas/metabolismo , Prosencéfalo/embriologia , Ratos , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Fatores de Transcrição SOXD/genética , Fatores de Transcrição SOXE/genética , Medula Espinal/embriologiaRESUMO
The mammalian target of rapamycin (mTOR) is a protein kinase involved in the phosphatidylinositol 3-kinase (PI3K)/AKT signalling pathway. It plays a pivotal role in the control of cell proliferation, survival, and angiogenesis with multiple and frequent dysregulations of this pathway in human tumors. Temsirolimus is an intravenous drug, specifically inhibiting the mTOR pathway. Bendamustine is well known for its clinical activity in indolent non-Hodgkin-lymphoma (NHL) and has lately shown clinical activity in mantle cell lymphoma (MCL). Here, we present a case report of temsirolimus in combination with bendamustine and rituximab leading to a CR in a pretreated male. In addition, our in vitro data underlines the additive and synergistic efficacy in cell growth reduction of temsirolimus combined with bendamustine in MCL cell lines and in DLBCL cell lines. Furthermore, as an underlying mechanism of this additive, effects on cell cycle inhibition and apoptosis induction could be identified.
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Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Cloridrato de Bendamustina/administração & dosagem , Linfoma de Célula do Manto/diagnóstico , Linfoma de Célula do Manto/tratamento farmacológico , Sirolimo/análogos & derivados , Idoso , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Sinergismo Farmacológico , Fase G1/efeitos dos fármacos , Fase G1/fisiologia , Humanos , Masculino , Rituximab/administração & dosagem , Sirolimo/administração & dosagemRESUMO
Single-agent bortezomib, a potent, selective, and reversible inhibitor of the 26S proteasome, has demonstrated clinical efficacy in relapsed and refractory mantle cell lymphoma (MCL). Objective response is achieved in up to 45% of the MCL patients; however, complete remission rates are low and duration of response proved to be relatively short. These limitations may be overcome by combining proteasome inhibition with conventional chemotherapy. Rational combination treatment and schedules require profound knowledge of underlying molecular mechanisms. Here we show that single-agent bortezomib treatment of MCL cell lines leads to G2/M arrest and induction of apoptosis accompanied by downregulation of EIF4E and CCND1 mRNA but upregulation of p15(INK4B) and p21 mRNA. We further present synergistic efficacy of bortezomib combined with cytarabine in MCL cell lines. Interestingly this sequence-dependent synergistic effect was seen almost exclusively in combination with AraC, indicating that pretreatment with cytarabine, followed by proteasome inhibition, may be the preferred approach.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Ácidos Borônicos/administração & dosagem , Ácidos Borônicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linfoma de Célula do Manto/tratamento farmacológico , Pirazinas/administração & dosagem , Pirazinas/farmacologia , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bortezomib , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Esquema de Medicação , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células Jurkat , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Inibidores de Proteases/administração & dosagem , Inibidores de Proteases/farmacologia , Inibidores de ProteassomaAssuntos
Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais Murinos/farmacologia , Antígenos CD20/imunologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Linfoma de Célula do Manto/tratamento farmacológico , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Murinos/administração & dosagem , Anticorpos Monoclonais Murinos/imunologia , Anticorpos Monoclonais Murinos/uso terapêutico , Especificidade de Anticorpos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Técnicas In Vitro , Linfoma de Célula do Manto/patologia , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , RituximabRESUMO
A strategy is presented to realize textile-based photovoltaic cells motivated by developments of textile-based electronics and their demand of grid-independent energy supply. Beyond this, a development of textile-based photovoltaics also represents an attractive pathway towards very flexible and rugged solar cells. The need for compatibility of an appropriate photovoltaic technology with the physical limitations of textiles is stressed. Electrodeposition from aqueous solutions is presented as a successful strategy to realize semiconductor structures on textiles and detailed control and influence of the deposition conditions is discussed. The role of microelectrode effects, options of forced convection, deposition under pulsed potential, alternative deposition baths and different substrate metals are emphasized. An active electrode material is presented which reaches a conversion efficiency close to the 1% limit under AM 1.5 illumination conditions and thereby opens the door for a further optimization towards devices of technical interest.
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The design of flexible sensors which can be incorporated in textile structures is of decisive importance for the future development of wearables. In addition to their technical functionality, the materials chosen to construct the sensor should be nontoxic, affordable, and compatible with future recycling. Conductive fibres were produced by incorporation of carbon black into regenerated cellulose fibres. By incorporation of 23 wt.% and 27 wt.% carbon black, the surface resistance of the fibres reduced from 1.3 × 1010 Ω·cm for standard viscose fibres to 2.7 × 103 and 475 Ω·cm, respectively. Fibre tenacity reduced to 30-50% of a standard viscose; however, it was sufficient to allow processing of the material in standard textile operations. A fibre blend of the conductive viscose fibres with polyester fibres was used to produce a needle-punched nonwoven material with piezo-electric properties, which was used as a pressure sensor in the very low pressure range of 400-1000 Pa. The durability of the sensor was demonstrated in repetitive load/relaxation cycles. As a regenerated cellulose fibre, the carbon-black-incorporated cellulose fibre is compatible with standard textile processing operations and, thus, will be of high interest as a functional element in future wearables.
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Male Neotropical orchid bees (Euglossini) collect volatile substances (fragrances) from flowers and other sources (e.g., decaying wood) and store them in specialized hind tibial pockets. The accumulated chemicals are later emitted during courtship display, presumably to lure conspecific females for mating. We analyzed tibial fragrances of males of 15 sympatric Panamanian species in the genus Euglossa to test whether communities of euglossine bees are chemically structured, and to elucidate whether male fragrance signals evolve to convey premating isolation. Our analysis revealed substantial chemical disparity among all lineages. Disparity was mediated by compounds that were exclusive to certain species but also by differences in relative quantity of shared compounds. We mapped tibial fragrance compounds present in each species on a DNA-based phylogeny (reconstructed using partial sequences of COI, EF1-alpha, ArgK, and Pol-II) and found that most dominant compounds were highly homoplasious. In an analysis of chemical differentiation in relation to phylogenetic divergence through time, disparity was greater than expected from a null model at any point during evolutionary history, suggesting that diversifying selection has shaped fragrance phenotypes. Notably, chemical disparity was greater within recently diverged lineages than among them, suggesting that chemical preferences in orchid bees evolved rapidly in the early stages of species divergence. We postulate communication interference as the possible mechanism behind the observed fragrance differentiation, which may be the product of reproductive character (fragrance) displacement. Our findings are consistent with the hypothesis that male fragrance signals evolve to convey premating isolation.
Assuntos
Abelhas/genética , Abelhas/fisiologia , Atrativos Sexuais/química , Animais , Ecossistema , Feminino , Geografia , Masculino , Orchidaceae , Panamá , Filogenia , Atrativos Sexuais/fisiologia , Comportamento Sexual Animal/fisiologia , Especificidade da EspécieRESUMO
Although gene expression following bortezomib treatment has been previously explored, direct effects of bortezomib-induced proteasome inhibition on protein level has not been analyzed so far. Using 2-D PAGE in five mantle cell lymphoma cell lines, we screened for cellular protein level alterations following treatment with 25 nM bortezomib for up to 4 h. Using MS, we identified 38 of the 41 most prominent reliably detected protein spots. Twenty-one were affected in all cell lines, whereas the remaining 20 protein spots were exclusively altered in sensitive cell lines. Western blot analysis was performed for 17 of the 38 identified proteins and 70.6% of the observed protein level alterations in 2-D gels was verified. All cell lines exhibited alterations of the cellular protein levels of heat shock-induced protein species (HSPA9, HSP7C, HSPA5, HSPD1), whereas sensitive cell lines also displayed altered cellular protein levels of energy metabolism (ATP5B, AK5, TPI1, ENO-1, ALDOC, GAPDH), RNA and transcriptional regulation (HNRPL, SFRS12) and cell division (NEBL, ACTB, SMC1A, C20orf23) as well as tumor suppressor genes (ENO-1, FH). These proteins clustered in a tight interaction network centered on the major cellular checkpoints TP53. The results were confirmed in primary mantle cell lymphoma, thus confirming the critical role of these candidate proteins of proteasome inhibition.
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Ácidos Borônicos/farmacologia , Eletroforese em Gel Bidimensional , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Linfoma de Célula do Manto , Inibidores de Proteases/farmacologia , Pirazinas/farmacologia , Western Blotting , Bortezomib , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Chaperona BiP do Retículo Endoplasmático , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Mapeamento de Interação de Proteínas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Enfleurage, the extraction of elusive floral scents with the help of a lipophilic carrier (grease), is widely used in the perfume industry. Male neotropical orchid bees (Euglossini), which accumulate exogenous fragrances as pheromone analogues, use a similar technique. To collect fragrances, the bees apply large amounts of straight-chain lipids to odoriferous surfaces from their cephalic labial glands, which dissolve the volatiles, and the mixture is then transferred to voluminous hind-leg pockets. Here, we show that males do in fact operate a lipid conveyor belt to accumulate and concentrate their perfume. From the hind-leg pockets of caged male Euglossa viridissima, deuterated derivatives of carrier lipids were consecutively sequestered, shuttled back to the labial glands and reused on consecutive bouts of fragrance collection. Such lipid cycling is instrumental in creating complex perfume bouquets. Furthermore, we found that labial glands of male orchid bees are strikingly similar to those of scent-marking male bumblebees in terms of size, form and structure. This, and a prominent overlap in secretory products, led us to propose that perfume collection evolved from scent-marking in ancestral corbiculate bees.
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Abelhas/fisiologia , Comportamento Animal , Lipídeos/química , Odorantes , Orchidaceae/química , Animais , Abelhas/anatomia & histologia , Transporte Biológico , Metabolismo dos Lipídeos , MasculinoRESUMO
Microsatellite instability (MSI) and p53 alterations which may represent major mechanisms of genetic instability, are rarely observed in de novo acute myeloid leukemia (AML) but may play a substantial role in subgroups characterized by either a myelodysplastic prephase (sAML), previous chemotherapy (tAML) or a complex aberrant karyotype. We performed allelotyping and p53 mutation analysis in 75 patients with morphologically and cytogenetically classified AML.
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Genes p53 , Leucemia Mieloide/genética , Repetições de Microssatélites , Doença Aguda , Alelos , Transformação Celular Neoplásica/genética , Aberrações Cromossômicas , Cromossomos Humanos/genética , Cromossomos Humanos/ultraestrutura , Seguimentos , Genótipo , Humanos , Cariotipagem , Leucemia Mieloide/classificação , Leucemia Mieloide/mortalidade , Análise de SobrevidaRESUMO
Lately, mTOR inhibitors have gained clinical relevance in malignant lymphoma. Still, rapamycin derivatives may activate a pro-survival feedback loop through PI3K-Akt. In this current study, temsirolimus effectively reduced cell growth in GCB and ABC diffuse large cell B-cell lymphoma (GCB=30-66%, ABC=45-57%). Combination treatment with the PI3K-δ inhibitor idelalisib additively effected ABC and GCB lymphoma (GCB=16-38%, ABC=25-50%). Since Bruton's Tyrosine Kinase (BTK) plays a significant role for the survival of ABC lymphoma, this study also combined the BTK inhibitor ibrutinib with temsirolimus, which resulted in additive cell growth reduction (ibrutinib 50%, temsirolimus 44%, combination 25%) in ABC lymphoma. In contrast, bortezomib, which has been shown previously to be efficient in ABC lymphoma, revealed an antagonistic effect with temsirolimus in some GCB lymphoma (temsirolimus 53%, temsirolimus+bortezomib 63%). Western blot analysis identified the increase of phosphorylated pro-survival kinases Akt and PDK as a possible underlying mechanism of this interaction.
Assuntos
Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptores de Antígenos de Linfócitos B/antagonistas & inibidores , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirolimo/análogos & derivados , Adenina/análogos & derivados , Bortezomib/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Antagonismo de Drogas , Sinergismo Farmacológico , Humanos , Linfoma Difuso de Grandes Células B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Piperidinas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Purinas/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Quinazolinonas/farmacologia , Sirolimo/farmacologiaRESUMO
Despite recent advances in treatment, mantle cell lymphoma (MCL) still represents a disease with dismal prognosis due to its progressive clinical course, high rate of therapy refractory cases and frequent relapses. During recent years, the proteasome inhibitor bortezomib and enzastaurin, an inhibitor of protein kinase c have been explored in MCL. In relapsed disease enzastaurin achieved disease stabilization in a subset of patients. Bortezomib in relapsed and refractory MCL achieves response rates of 30-40%. To identify signal pathways and manifold interactions regulating cellular response to molecular targeted approaches several high throughput screening methods were applied. A combined network analysis of the identified target molecules based on both RNA array expression data and a survey of cellular protein levels resulted in a unified interaction network more comprehensive (bortezomib: 394 and enzastaurin: 174 molecules) than the networks of the individual screening techniques (329/44 and 117/36 molecules respectively). Interestingly, although none of the target molecules were matched in both RNA-expression and protein level analysis they were mapped nonetheless to common pathways. Additionally, the ranking of identified pathways allowed an improved characterization of the observed induction of cell apoptosis.
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Apoptose/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Eletroforese em Gel Bidimensional/métodos , Perfilação da Expressão Gênica/métodos , Indóis/farmacologia , Linfoma de Célula do Manto/patologia , Pirazinas/farmacologia , Bortezomib , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Ensaios de Triagem em Larga Escala , Humanos , Linfoma de Célula do Manto/genética , Prognóstico , Inibidores de Proteases/farmacologia , Proteína Quinase C/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2 , RecidivaRESUMO
Allozyme analyses have suggested that Neotropical orchid bee (Euglossini) pollinators are vulnerable because of putative high frequencies of diploid males, a result of loss of sex allele diversity in small hymenopteran populations with single locus complementary sex determination. Our analysis of 1010 males from 27 species of euglossine bees sampled across the Neotropics at 211 polymorphic microsatellite loci revealed only five diploid males at an overall frequency of 0.005 (95% CIs 0.0020.010); errors through genetic nondetection of diploid males were likely small. In contrast to allozyme-based studies, we detected very weak or insignificant population genetic structure, even for a pair of populations >500 km apart, possibly accounting for low diploid male frequencies. Technical flaws in previous allozyme-based analyses have probably led to considerable overestimation of diploid male production in orchid bees. Other factors may have a more immediate impact on population persistence than the genetic load imposed by diploid males on these important Neotropical pollinators.
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Abelhas/genética , Abelhas/fisiologia , Diploide , Repetições de Microssatélites , Modelos Genéticos , Alelos , Animais , Evolução Molecular , Feminino , Variação Genética , Genética Populacional , Masculino , Modelos Estatísticos , Orchidaceae , Polinização , Fatores Sexuais , Especificidade da EspécieRESUMO
Silver-coated polyamide filaments were used as substrates for the electrodeposition of ZnO/eosinY hybrid thin films from aqueous mixed solutions containing Zn(NO(3))(2) and eosinY. Electrodeposition under pulsed potentiostatic control turned out advantageous to control the conditions of mass flow and to suppress parasitic currents and thereby obtain homogeneous porous films of ZnO as proven by scanning electron microscopy. Crystalline films of ZnO were formed as shown by X-ray diffraction. Diffuse optical reflectance spectra revealed the successful processing of the dye content of the porous ZnO coatings on the textile substrates. Photovoltage measurements served to proof sensitization of the textile based ZnO films.
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Nylons/química , Prata/química , Galvanoplastia , Microscopia Eletrônica de Varredura , Estrutura Molecular , Porosidade , Difração de Raios X , Óxido de ZincoRESUMO
In mantle cell lymphoma (MCL), overexpression of cyclin D1 is the hallmark of malignant transformation and results from it's juxtaposition to the immunoglobulin heavy chain enhancer. In addition, genomic deletions or point mutations leading to premature truncation of the cyclin D1 3' untranslated region (UTR) have been reported in a several MCL patients as well as in cell lines isolated from various tumors types. We demonstrate that the expression of cyclin D1 with or without the 3'UTR has different phenotypic consequences in stably transduced fibroblasts, with the hyper-proliferative phenotype of cyclin D1 closely linked to the deletion of its 3'UTR. In our study, the loss of the cyclin D1 3'UTR led to a significant upregulation of the protein. However, the loss of AU-rich elements (AREs) from the cyclin D1 3'UTR results in a significant decrease in cyclin D1 protein and UTR-tagged reporter expression. In contrast, the levels of cyclin D1 protein can be significantly reduced by microRNAs of the miR-15/16 family and the miR17-92 cluster that directly target the cyclin D1 3'UTR. Most importantly, these microRNAs regulated the levels of the endogenous cyclin D1 protein encoded by an mRNA with a full 3'UTR but not with 3' UTR deletions. Taken together, our data highlight the regulatory role of the cyclin D1 3'UTR in the expression and phenotype of cyclin D1 and suggest that in MCL and solid tumors with cyclin D1 3'UTR mutations, the loss of microRNA target sites, rather than ARE elements contribute to the pathogenic overexpression of the cyclin D1 protein.
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Regiões 3' não Traduzidas/fisiologia , Ciclina D1/metabolismo , Fibroblastos/metabolismo , Linfoma de Célula do Manto/metabolismo , MicroRNAs/metabolismo , Regiões 3' não Traduzidas/genética , Sequência de Bases , Linhagem Celular , Linhagem Celular Tumoral , Ciclina D1/genética , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Dados de Sequência Molecular , Mutação/genética , Mutação/fisiologia , Proto-Oncogene Mas , Alinhamento de Sequência , Transdução Genética , TransfecçãoRESUMO
Metal-coated polyamide threads and filaments were chosen as substrate electrodes to deposit highly porous ZnO films for photovoltaic application. The films were electrodeposited at 70 degrees C from oxygen-saturated aqueous zinc salt solutions containing EosinY as a structure directing agent. The current density during deposition was increased compared with planar electrodes by enhanced diffusion at the filaments operating as cylindrical microelectrodes. Analysis by scanning electron microscopy showed an influence of geometrical constraints within the textiles and the hydrodynamic flow rate in the deposition solution on the film morphology. Photoelectrochemical characterization of sensitized films revealed the feasibility of the presented approach and indicated further steps needed for electrode optimization.
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Galvanoplastia/métodos , Nanoestruturas/química , Têxteis , Óxido de Zinco/química , Eletroquímica , Galvanoplastia/instrumentação , Amarelo de Eosina-(YS)/química , Corantes Fluorescentes/química , Teste de Materiais , Microeletrodos , Microscopia Eletrônica de Varredura , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Porosidade , Soluções/química , Propriedades de SuperfícieRESUMO
Saltational changes may underlie the diversification of pheromone communication systems in insects, which are normally under stabilizing selection favoring high specificity in signals and signal perception. In orchid bees (Euglossini), the production of male signals depends on the sense of smell: males collect complex blends of volatiles (perfumes) from their environment, which are later emitted as pheromone analogs at mating sites. We analyzed the behavioral and antennal response to perfume components in two male morphotypes of Euglossa cf. viridissima from Mexico, which differ in the number of mandibular teeth. Tridentate males collected 2-hydroxy-6-nona-1,3-dienyl-benzaldehyde (HNDB) as the dominant component of their perfume. In bidentate males, blends were broadly similar but lacked HNDB. Population genetic analysis revealed that tri- and bidentate males belong to two reproductively isolated lineages. Electroantennogram tests (EAG and GC-EAD) showed substantially lower antennal responses to HNDB in bidentate versus tridentate males, revealing for the first time a mechanism by which closely related species acquire different chemical compounds from their habitat. The component-specific differences in perfume perception and collection in males of two sibling species are in agreement with a saltational, olfaction-driven mode of signal perfume evolution. However, the response of females to the diverged signals remains unknown.
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Abelhas/classificação , Abelhas/fisiologia , Perfumes/química , Olfato/fisiologia , Comunicação Animal , Animais , Abelhas/anatomia & histologia , Abelhas/genética , Comportamento Animal/fisiologia , Benzaldeídos/análise , Benzaldeídos/química , Masculino , México , Orchidaceae , Feromônios/química , Feromônios/fisiologia , Especificidade da EspécieRESUMO
Mantle cell lymphomas (MCL), characterized by the t(11;14)(q13;q32), frequently carry secondary genetic alterations such as deletions in chromosome 17p involving the TP53 locus. Given that the association between TP53-deletions and concurrent mutations of the remaining allele is weak and based on our recent report that the Hypermethylated in Cancer 1 (HIC1) gene, that is located telomeric to the TP53 gene, may be targeted by deletions in 17p in diffuse large B-cell lymphoma (DLBCL), we investigated whether HIC1 inactivations might also occur in MCL. Monoallelic deletions of the TP53 locus were detected in 18 out of 59 MCL (31%), while overexpression of p53 protein occurred in only 8 out of 18 of these MCL (44%). In TP53-deleted MCL, the HIC1 gene locus was co-deleted in 11 out of 18 cases (61%). However, neither TP53 nor HIC1 deletions did affect survival of MCL patients. In most analyzed cases, no hypermethylation of the HIC1 exon 1A promoter was observed (17 out of 20, 85%). However, in MCL cell lines without HIC1-hypermethylation, the mRNA expression levels of HIC1 were nevertheless significantly reduced, when compared to reactive lymph node specimens, pointing to the occurrence of mechanisms other than epigenetic or genetic events for the inactivation of HIC1 in this entity.
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Mantle cell lymphoma (MCL) is characterized by the chromosomal translocation t(11;14)(q13;q32), resulting in overexpression of CCND1 in the vast majority of cases. In addition, alterations of other cell-cycle-regulating signal pathways (CDKN2B/CDKN2A-CCND1 and ARF-MDM2-TP53) are frequently observed. However, the hierarchy of promoter methylations and genomic alterations as well as the interaction with other cell-cycle regulator CDKN1A is poorly understood. A complete methylation-specific PCR coupled with direct sequencing of 71 MCL patient samples previously characterized for TP53 alterations, Ki67 expression by immunohistochemistry, and other genomic alterations was performed. In contrast to rare p16(INK4a) promoter methylation (9%), frequent p15(INK4b) (62%) and p14(ARF) (70%) promoter methylation was detectable in MCL. In an additional 16% of MCL cases, LOH for p16(INK4a) was detected. However, MCL cases with p15(INK4b) methylation tended to have lower proliferation (73% vs. 57%), and p15(INK4b) and p14(ARF) promoter methylation was also detected in normal stem cells. Therefore, epigenetic changes of those genes seem not to represent primary oncogenic mechanisms but physiological mechanisms of cell regulation. The rare p16(INK4a) promoter methylation and p16(INK4a) genetic alterations were directly correlated to cell proliferation and therefore are regarded as additional molecular alterations involved in the cell-cycle dysregulation of MCL.