182 research outputs found

    Inhibition of DUSP6 sensitizes ovarian cancer cells to chemotherapeutic agents via regulation of ERK signaling response genes

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    Dual specificity phosphatase 6 (DUSP6) is a protein phosphatase that deactivates extracellular-signal-regulated kinase (ERK). Since the ovarian cancer biomarker human epididymis protein 4 (HE4) interacts with the ERK pathway, we sought to determine the relationship between DUSP6 and HE4 and elucidate DUSP6’s role in epithelial ovarian cancer (EOC). Viability assays revealed a significant decrease in cell viability with pharmacological inhibition of DUSP6 using (E/Z)-BCI hydrochloride in ovarian cancer cells treated with carboplatin or paclitaxel, compared to treatment with either agent alone. Quantitative PCR was used to evaluate levels of ERK pathway response genes to BCI in combination with recombinant HE4 (rHE4), carboplatin, and paclitaxel. Expression of EGR1, a promoter of apoptosis, was higher in cells co-treated with BCI and paclitaxel or carboplatin than in cells treated with chemotherapeutic agents alone, while expression of the proto-oncogene c-JUN was decreased with co-treatment. The effect of BCI on the expression of these two genes opposed that of rHE4. Pathway focused quantitative PCR also revealed suppression of ERBB3 in cells co-treated with BCI plus carboplatin or paclitaxel. Finally, expression levels of DUSP6 in EOC tissue were evaluated by immunohistochemistry, revealing significantly increased levels of DUSP6 in serous EOC tissue compared to adjacent normal tissue. A positive correlation between HE4 and DUSP6 levels was determined by Spearman Rank correlation. In conclusion, DUSP6 inhibition sensitizes ovarian cancer cells to chemotherapeutic agents and alters gene expression of ERK response genes, suggesting that DUSP6 could plausibly function as a novel therapeutic target to reduce chemoresistance in EOC

    In vitro and in vivo effects of ulvan polysaccharides from Ulva rigida

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    One of the main bioactive compounds of interest from the Ulva species is the sulfated polysaccharide ulvan, which has recently attracted attention for its anticancer properties. This study investigated the cytotoxic activity of ulvan polysaccharides obtained from Ulva rigida in the following scenarios: (i) in vitro against healthy and carcinogenic cell lines (1064sk (human fibroblasts), HACAT (immortalized human keratinocytes), U-937 (a human leukemia cell line), G-361 (a human malignant melanoma), and HCT-116 (a colon cancer cell line)) and (ii) in vivo against zebrafish embryos. Ulvan exhibited cytotoxic effects on the three human cancer cell lines tested. However, only HCT-116 demonstrated sufficient sensitivity to this ulvan to make it relevant as a potential anticancer treatment, presenting an LC50 of 0.1 mg mL−1. The in vivo assay on the zebrafish embryos showed a linear relationship between the polysaccharide concentration and growth retardation at 7.8 hpf mL mg−1, with an LC50 of about 5.2 mg mL−1 at 48 hpf. At concentrations near the LC50, toxic effects, such as pericardial edema or chorion lysis, could be found in the experimental larvae. Our in vitro study supports the potential use of polysaccharides extracted from U. rigida as candidates for treating human colon cancer. However, the in vivo assay on zebrafish indicated that the potential use of ulvan as a promising, safe compound should be limited to specific concentrations below 0.001 mg mL−1 since it revealed side effects on the embryonic growth rate and osmolar balance.Partial funding for open access charge: Universidad de Málag

    The biomarker HE4 (WFDC2) promotes a pro-angiogenic and immunosuppressive tumor microenvironment via regulation of STAT3 target genes

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    © 2020, The Author(s). Epithelial ovarian cancer (EOC) is a highly lethal gynecologic malignancy arising from the fallopian tubes that has a high rate of chemoresistant recurrence and low five-year survival rate. The ovarian cancer biomarker HE4 is known to promote proliferation, metastasis, chemoresistance, and suppression of cytotoxic lymphocytes. In this study, we sought to examine the effects of HE4 on signaling within diverse cell types that compose the tumor microenvironment. HE4 was found to activate STAT3 signaling and promote upregulation of the pro-angiogenic STAT3 target genes IL8 and HIF1A in immune cells, ovarian cancer cells, and endothelial cells. Moreover, HE4 promoted increases in tube formation in an in vitro model of angiogenesis, which was also dependent upon STAT3 signaling. Clinically, HE4 and IL8 levels positively correlated in ovarian cancer patient tissue. Furthermore, HE4 serum levels correlated with microvascular density in EOC tissue and inversely correlated with cytotoxic T cell infiltration, suggesting that HE4 may cause deregulated blood vessel formation and suppress proper T cell trafficking in tumors. Collectively, this study shows for the first time that HE4 has the ability to affect signaling events and gene expression in multiple cell types of the tumor microenvironment, which could contribute to angiogenesis and altered immunogenic responses in ovarian cancer

    Distância genética em caprinos naturalizados por meio de microssatélites de DNA.

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    Há uma necessidade de adotar estratégias de conservação para as populações naturalizadas de animais domésticos para assegurar a manutenção destas para o futuro. Este estudo visa contribuir para o conhecimento da variabilidade genética por meio de marcadores de microssatélites em caprinos naturalizados Moxotó, Canindé e Marota. Foram amostrados 124 animais adultos dos grupos Moxotó, Canindé e Marota dos núcleos de conservação da Embrapa. O DNA extraído foi amplificado mediante a reação em cadeia polimerase (PCR) e genotipado através do programa Fragment Profile (Amersham Bioscience). O método UPGMA (Unweighted Pair Group Method With Arithmetic Mean) foi utilizado para construção do dendograma com bootstrap (1000 repetições) pelo programa TFPGA (Miller, 1997). O dendograma agrupou no primeiro nódulo as populações Moxotó e Canindé e o bootstrap apresentou 75% de similaridade neste nódulo. No segundo nódulo houve a inclusão das três populações e obteve bootstrap de 100%. O número de loci suportando cada nódulo foram quatro e cinco, respectivamente. O método UPGMA, utilizando as distâncias de Nei (1978), permitiu o discernimento das populações caprinas com base em dados moleculares

    Application of COMPOCHIP Microarray to Investigate the Bacterial Communities of Different Composts

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    A microarray spotted with 369 different 16S rRNA gene probes specific to microorganisms involved in the degradation process of organic waste during composting was developed. The microarray was tested with pure cultures, and of the 30,258 individual probe-target hybridization reactions performed, there were only 188 false positive (0.62%) and 22 false negative signals (0.07%). Labeled target DNA was prepared by polymerase chain reaction amplification of 16S rRNA genes using a Cy5-labeled universal bacterial forward primer and a universal reverse primer. The COMPOCHIP microarray was applied to three different compost types (green compost, manure mix compost, and anaerobic digestate compost) of different maturity (2, 8, and 16 weeks), and differences in the microorganisms in the three compost types and maturity stages were observed. Multivariate analysis showed that the bacterial composition of the three composts was different at the beginning of the composting process and became more similar upon maturation. Certain probes (targeting Sphingobacterium, Actinomyces, Xylella/Xanthomonas/ Stenotrophomonas, Microbacterium, Verrucomicrobia, Planctomycetes, Low G + C and Alphaproteobacteria) were more influential in discriminating between different composts. Results from denaturing gradient gel electrophoresis supported those of microarray analysis. This study showed that the COMPOCHIP array is a suitable tool to study bacterial communities in composts

    Lagrangian Curves in a 4-dimensional affine symplectic space

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    Lagrangian curves in R4 entertain intriguing relationships with second order deformation of plane curves under the special affine group and null curves in a 3-dimensional Lorentzian space form. We provide a natural affine symplectic frame for Lagrangian curves. It allows us to classify La- grangrian curves with constant symplectic curvatures, to construct a class of Lagrangian tori in R4 and determine Lagrangian geodesic

    Crescimento e mortalidade em um rebanho de conservação de caprinos Marota no Brasil.

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    O caprino Marota consiste em um importante recurso genético adaptado ao Semiárido brasileiro e encontra-se em risco de extinção. A Embrapa Meio-Norte mantém um núcleo de conservação destes caprinos no município de Castelo do Piauí, região de transição caatinga-cerrado. O manejo deste rebanho é semi-extensivo para sobrepujar as características de rusticidade do ecotipo Marota. Esta pesquisa foi realizada com o objetivo de monitorar o desempenho fenotípico do núcleo com relação ao peso ao nascimento, prolificidade e mortalidade nos anos de 2004 a 2008, e relacioná-los a outros dados observados no Semiárido e obtidos na literatura especializada. As médias obtidas corrigidas foram 1,89±0,09 e 22,8±5,9 kg, respectivamente para peso ao nascer e peso ao parto. Os resultados obtidos demonstram peso ao nascer abaixo das raças exóticas no Semiárido e de ecotipos brasileiros em menor risco de extinção (p.ex. Moxotó). As taxas de mortalidade e a prolificidade obtidas são vantajosas em relação às apresentadas por raças exóticas presentes no Semiárido, mas não superiores aos demais tipos naturalizados. Estudos econômicos devem estabelecer se a relação entre tais caracteristicas implicam em eficiência para o sistema produtivo
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