MicroRNA-26a Is Strongly Downregulated in Melanoma and Induces Cell Death through Repression of Silencer of Death Domains (SODD)

Melanoma is an aggressive cancer that metastasizes rapidly and is refractory to conventional chemotherapies. Identifying microRNAs (miRNAs) that are responsible for this pathogenesis is therefore a promising means of developing new therapies. We identified miR-26a through microarray and quantitative reverse-transcription–PCR (qRT-PCR) experiments as an miRNA that is strongly downregulated in melanoma cell lines as compared with primary melanocytes. Treatment of cell lines with miR-26a mimic caused significant and rapid cell death compared with a negative control in most melanoma cell lines tested. In surveying targets of miR-26a, we found that protein levels of SMAD1 (mothers against decapentaplegic homolog 1) and BAG-4/SODD were strongly decreased in sensitive cells treated with miR-26a mimic as compared with the control. The luciferase reporter assays further demonstrated that miR-26a can repress gene expression through the binding site in the 3′ untranslated region (3′UTR) of SODD (silencer of death domains). Knockdown of these proteins with small interfering RNA (siRNA) showed that SODD has an important role in protecting melanoma cells from apoptosis in most cell lines sensitive to miR-26a, whereas SMAD1 may have a minor role. Furthermore, transfecting cells with a miR-26a inhibitor increased SODD expression. Our findings indicate that miR-26a replacement is a potential therapeutic strategy for metastatic melanoma, and that SODD, in particular, is a potentially useful therapeutic target

Effects of nutrients, salinity, pH and light:dark cycle on the production of reactive oxygen species in the alga Chattonella marina

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Experimental Marine Biology and Ecology 346 (2007): 76-86, doi:10.1016/j.jembe.2007.03.007.Experiments were carried out to investigate the effects of nutrients, salinity, pH and light:dark cycle on growth rate and production of reactive oxygen species (ROS) by Chattonella marina, a harmful algal bloom (HAB) species that often causes fish kills. Different nitrogen forms (organic-N and inorganic-N), N:P ratios, light:dark cycles and salinity significantly influenced algal growth, but not ROS production. However, iron concentration and pH significantly affected both growth and ROS production in C. marina. KCN (an inhibitor of mitochondrial respiration) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (an inhibitor of photosynthesis) had no significant effects on ROS production. Vitamin K3 (a plasma membrane electron shuttle) enhanced ROS production while its antagonist, dicumarol, decreased ROS production. Taken together, our results suggest that ROS production by C. marina is related to a plasma membrane enzyme system regulated by iron availability but is independent of growth, photosynthesis, availability of macronutrients, salinity and irradiance.The work described in this paper was supported by a CERG grant from the University Grants Committee of the Hong Kong Special Administrative Region, China to RSSW (Project No. 9040864). Support for DMA is provided by U.S. National Science Foundation grant # OCE-0136861

A Systematic Analysis of Cell Cycle Regulators in Yeast Reveals That Most Factors Act Independently of Cell Size to Control Initiation of Division

Upstream events that trigger initiation of cell division, at a point called START in yeast, determine the overall rates of cell proliferation. The identity and complete sequence of those events remain unknown. Previous studies relied mainly on cell size changes to identify systematically genes required for the timely completion of START. Here, we evaluated panels of non-essential single gene deletion strains for altered DNA content by flow cytometry. This analysis revealed that most gene deletions that altered cell cycle progression did not change cell size. Our results highlight a strong requirement for ribosomal biogenesis and protein synthesis for initiation of cell division. We also identified numerous factors that have not been previously implicated in cell cycle control mechanisms. We found that CBS, which catalyzes the synthesis of cystathionine from serine and homocysteine, advances START in two ways: by promoting cell growth, which requires CBS's catalytic activity, and by a separate function, which does not require CBS's catalytic activity. CBS defects cause disease in humans, and in animals CBS has vital, non-catalytic, unknown roles. Hence, our results may be relevant for human biology. Taken together, these findings significantly expand the range of factors required for the timely initiation of cell division. The systematic identification of non-essential regulators of cell division we describe will be a valuable resource for analysis of cell cycle progression in yeast and other organisms

Crosstalk between Chemokine Receptor CXCR4 and Cannabinoid Receptor CB2 in Modulating Breast Cancer Growth and Invasion

Cannabinoids bind to cannabinoid receptors CB(1) and CB(2) and have been reported to possess anti-tumorigenic activity in various cancers. However, the mechanisms through which cannabinoids modulate tumor growth are not well known. In this study, we report that a synthetic non-psychoactive cannabinoid that specifically binds to cannabinoid receptor CB(2) may modulate breast tumor growth and metastasis by inhibiting signaling of the chemokine receptor CXCR4 and its ligand CXCL12. This signaling pathway has been shown to play an important role in regulating breast cancer progression and metastasis.We observed high expression of both CB(2) and CXCR4 receptors in breast cancer patient tissues by immunohistochemical analysis. We further found that CB(2)-specific agonist JWH-015 inhibits the CXCL12-induced chemotaxis and wound healing of MCF7 overexpressing CXCR4 (MCF7/CXCR4), highly metastatic clone of MDA-MB-231 (SCP2) and NT 2.5 cells (derived from MMTV-neu) by using chemotactic and wound healing assays. Elucidation of the molecular mechanisms using various biochemical techniques and confocal microscopy revealed that JWH-015 treatment inhibited CXCL12-induced P44/P42 ERK activation, cytoskeletal focal adhesion and stress fiber formation, which play a critical role in breast cancer invasion and metastasis. In addition, we have shown that JWH-015 significantly inhibits orthotopic tumor growth in syngenic mice in vivo using NT 2.5 cells. Furthermore, our studies have revealed that JWH-015 significantly inhibits phosphorylation of CXCR4 and its downstream signaling in vivo in orthotopic and spontaneous breast cancer MMTV-PyMT mouse model systems.This study provides novel insights into the crosstalk between CB(2) and CXCR4/CXCL12-signaling pathways in the modulation of breast tumor growth and metastasis. Furthermore, these studies indicate that CB(2) receptors could be used for developing innovative therapeutic strategies against breast cancer

A Gain-of-Function Germline Mutation in Drosophila ras1 Affects Apoptosis and Cell Fate during Development

The RAS/MAPK signal transduction pathway is an intracellular signaling cascade that transmits environmental signals from activated receptor tyrosine kinases (RTKs) on the cell surface and other endomembranes to transcription factors in the nucleus, thereby linking extracellular stimuli to changes in gene expression. Largely as a consequence of its role in oncogenesis, RAS signaling has been the subject of intense research efforts for many years. More recently, it has been shown that milder perturbations in Ras signaling during embryogenesis also contribute to the etiology of a group of human diseases. Here we report the identification and characterization of the first gain-of-function germline mutation in Drosophila ras1 (ras85D), the Drosophila homolog of human K-ras, N-ras and H-ras. A single amino acid substitution (R68Q) in the highly conserved switch II region of Ras causes a defective protein with reduced intrinsic GTPase activity, but with normal sensitivity to GAP stimulation. The ras1R68Q mutant is homozygous viable but causes various developmental defects associated with elevated Ras signaling, including cell fate changes and ectopic survival of cells in the nervous system. These biochemical and functional properties are reminiscent of germline Ras mutants found in patients afflicted with Noonan, Costello or cardio-facio-cutaneous syndromes. Finally, we used ras1R68Q to identify novel genes that interact with Ras and suppress cell death

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

Cancer Biomarker Discovery: The Entropic Hallmark

Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

Desempenho ocupacional das famílias cuidadoras de pessoas com transtornos mentais atendidas em dispositivo de atenção psicossocial

With the process of psychiatric institutionalization, treatment of people with mental disorders, characterized by long before psychiatric hospitalizations, chronicity and social exclusion, went on to defend the humanized care, the integration of the individual in the family and society. The family of the person with a mental disorder, for a considerable time was excluded from the assistance provided to his family. He is currently an important partner of care, since most people who were treated in closed institutions, today live daily with their caregivers, at home. However, families often are not prepared to act as caretakers of close family members with mental disorders, and thus experience a context of overloads in everyday life. It is not uncommon the fact they have not with satisfactory support to deal with the complex situation of caring for a relative who needs care at length in daily life. This research aims to describe the areas of occupational performance (work, rest and sleep, leisure and social participation), the caregivers families before and after the mental illness of his family and the repercussions of this fact in daily life and living conditions of family caregivers; Identify among the areas of occupational performance (work, rest and sleep, leisure and social participation), those considered most important for family caregivers, and the strategies used by them for the development of these areas, with a view to changes in their daily lives and their living conditions. This is a qualitative, critical and reflective study. Approved by the Research Ethics Committee (CEP) of the University Hospital Lauro Wanderley the Federal University of Paraíba, in the period from July 2014 to February 2015. The instrument for data collection was semi-structured interviews. Data collection took place in October and November 2014, after receiving the assent of the CEP. The material was subjected to the analysis of data according to Minayo (2008), following three methodological steps: pre-analysis, material exploration, processing of data and interpretation. The research findings revealed that with regard to the areas of occupational performance (work, rest and sleep, leisure and social participation) of family before becoming caregivers, four of them worked before the mental illness of their relatives and family, by the will of spouse, only performed housework. With regard to rest and sleep, the five family caregivers, two reported not enjoy a good rest and sleep before getting sick of your family, a fact surely occasioned negative impact on the dynamics of your everyday life . The other three caregivers had a good rest and sleep. It was identified that the leisure of the caregivers in this study, before the mental illness of the family, was designed and related to diverse aspects. The five family caregivers interviewed reported an active social participation, whether in church, community groups, in the family. With regard to the areas of occupational performance after mental illness the family, all family caregivers have had to stop work activities outside the home to care for relatives with mental disorders. The rest and sleep of them had to suffer. The leisure and social participation of family caregivers were determined by dynamic behavior of their relatives with mental disorders. With regard to the areas of occupational performance considered the most important by family caregivers, they elected two: rest and sleep and social participation. With the completion of this study, we can see the relevance of the intervention of health workers, because through dialogue and more systematic follow-up to these families, you can help minimize the impact of a life in organized care and overloads generated by these care and so contribute to improving the quality of life of families and caregivers also of users with mental disorders.Com o processo de desinstitucionalização psiquiátrica, o tratamento das pessoas com transtornos mentais antes caracterizados por longas internações psiquiátricas, cronificação e exclusão social, passou a defender o cuidado humanizado, a reinserção do indivíduo na família e na sociedade. A família da pessoa com transtorno mental, durante tempo considerável foi excluída da assistência prestada ao seu familiar. Atualmente é uma importante parceira do cuidado, pois muitas pessoas que eram tratadas em instituições fechadas, hoje convivem diariamente com seus cuidadores, no domicílio. Porém, as famílias, muitas vezes, não estão preparadas para atuar como cuidadoras desses familiares com transtornos mentais, e assim vivenciam um contexto de sobrecargas no cotidiano. Não é raro o fato de não contarem com suporte satisfatório para lidar com a complexa situação de cuidar de um familiar, o qual necessita de cuidados durante um tempo considerável no cotidiano. Esta pesquisa tem como objetivo descrever as áreas de desempenho ocupacional (trabalho; descanso e sono; lazer e participação social), das famílias cuidadoras, antes e após o adoecimento mental dos seus familiares e as repercussões desse fato no cotidiano e nas condições de vida dos familiares cuidadores; Identificar dentre as áreas de desempenho ocupacional (trabalho; descanso e sono; lazer e participação social), as que são consideradas mais importantes para os familiares cuidadores, e as estratégias utilizadas por eles para o desenvolvimento dessas áreas, com vistas a mudanças no seu cotidiano e nas suas condições de vida. Trata-se de estudo qualitativo, crítico e reflexivo. Aprovado pelo Comitê de Ética e Pesquisa (CEP) do Hospital Universitário Lauro Wanderley da Universidade Federal da Paraíba, desenvolvido no período de julho de 2014 a fevereiro de 2015. O instrumento para coleta de dados foi a entrevista semiestruturada. A coleta de dados aconteceu nos meses de outubro e novembro de 2014, após recebimento do parecer favorável do CEP. O material foi submetido a análise de dados segundo Minayo (2008), seguindo três passos metodológicos: pré-análise, exploração do material, tratamento dos dados obtidos e interpretação. Os achados da pesquisa revelaram que no tocante às áreas de desempenho ocupacional (trabalho, descanso e sono, lazer e participação social) dos familiares antes de se tornarem cuidadores, quatro delas trabalhavam antes do adoecimento mental de seus familiares e uma familiar, por vontade do esposo, só realizava trabalhos domésticos. No que diz respeito ao descanso e sono, das cinco cuidadoras familiares, duas relataram não desfrutarem de um bom descanso e sono, antes do processo de adoecimento do seu familiar, fato este, com certeza, que ocasionava repercussões negativas na dinâmica de seu dia a dia. As outras três cuidadoras apresentavam bom descanso e sono. Identificou-se que o lazer das cuidadoras desse estudo, antes do adoecimento mental do familiar, era concebido e relacionado a aspectos diversificados. As cinco cuidadoras familiares entrevistadas relataram uma participação social atuante, seja na igreja, nos grupos comunitários e na família. No que diz respeito às áreas de desempenho ocupacional após o adoecimento mental do familiar, todas as cuidadoras familiares tiveram de interromper as atividades de trabalho fora de casa para cuidar de familiares com transtornos mentais. O descanso e sono delas apresentavam-se prejudicados. O lazer e a participação social das cuidadoras familiares eram determinados pela dinâmica de comportamento dos seus familiares com transtornos mentais. No concernente às áreas de desempenho ocupacional consideradas as mais importantes pelas cuidadoras familiares, estas elegeram duas: descanso e sono e participação social. Com a realização desse estudo, percebe-se a relevância da intervenção dos trabalhadores da saúde, pois mediante o diálogo e acompanhamento mais sistemático a essas famílias, pode-se contribuir para minimizar o impacto de uma vida organizada em cuidados e sobrecargas geradas por esses cuidados e assim colaborar para a melhoria da qualidade de vida das famílias cuidadoras e também dos usuários com transtornos mentais