141 research outputs found

    Cancer associated fibroblasts predict for poor outcome and promote periostin-dependent invasion in oesophageal adenocarcinoma

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    Interactions between cancer cells and cancer-associated fibroblasts (CAF) play an important role in tumour development and progression. In this study we investigated the functional role of CAF in oesophageal adenocarcinoma (EAC). We used immunochemistry to analyse a cohort of EAC patients (183 patients) for CAF markers related to disease mortality. We characterized CAF and normal oesophageal fibroblasts (NOF) using western blotting, immunofluorescence and gel contraction. Transwell assays, 3-D organotypic culture and xenograft models were used to examine effects on EAC cell function, and dissect molecular mechanisms regulating invasion. Most EAC (93%) contained CAF with a myofibroblastic (?-SMA-positive) phenotype, which correlated significantly with poor survival (p?=?0.016; HR 7. 1 (1.7-29.4). Primary CAF, isolated from EAC, have a contractile, myofibroblastic phenotype, and promote EAC cell invasion in vitro (Transwell assays, p?=?<0.05; organotypic culture, p?<?0.001) and in vivo (p?=?<0.05). In vitro, this pro-invasive effect is modulated through the matricellular protein periostin. Periostin is secreted by CAF, and acts as a ligand for EAC cell integrins ?v?3 and ?v?5, promoting activation of the PI3kinase/Akt pathway. In patient samples, periostin expression at the tumour cell/stromal interface correlates with poor overall and disease-free survival. Our study highlights the importance of the tumour stroma in EAC progression. Paracrine interaction between CAF-secreted periostin and EAC-expressed integrins results in PI3 kinase/Akt activation and increased tumour cell invasion. Most EAC contain a myofibroblastic CAF-rich stroma; this may explain the aggressive, highly infiltrative nature of the disease, and suggests that stromal targeting may produce therapeutic benefit in EAC patient

    Effective Caspase Inhibition Blocks Neutrophil Apoptosis and Reveals Mcl-1 as Both a Regulator and a Target of Neutrophil Caspase Activation

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    Human tissue inflammation is terminated, at least in part, by the death of inflammatory neutrophils by apoptosis. The regulation of this process is therefore key to understanding and manipulating inflammation resolution. Previous data have suggested that the short-lived pro-survival Bcl-2 family protein, Mcl-1, is instrumental in determining neutrophil lifespan. However, Mcl-1 can be cleaved following caspase activity, and the possibility therefore remains that the observed fall in Mcl-1 levels is due to caspase activity downstream of caspase activation, rather than being a key event initiating apoptosis in human neutrophils

    Homeschooling and the criticism of school: hybridisms and educational (dis)continuities

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    Desde os anos 1960, o homeschooling apresenta dinâmicas de crescimento atualizadas nos diagnósticos da crise do capitalismo e dos sistemas educativos. Por ser praticado por famílias próximas do progressismo libertário, do cristianismo conservador ou de outras inspirações axiológicas, a abordagem investigativa presente neste texto pressupôs romper com uma visão unívoca e alheia à sua diversidade e aos diferentes graus de (in)formalidade dos quotidianos educativos de crianças e de jovens que caracterizam este fenómeno educativo. Procura-se captar as especificidades do ensino doméstico (ED) em Portugal e a sua crescente expressão social e educacional e reflete-se sobre os sentidos das aprendizagens que ele encerra. Conclui-se que o ED parece ser contrário aos horizontes formativos da criança segundo o interesse da sociedade, sendo omisso sobre o seu papel na emancipação dos sujeitos. Confrontam-se a escola e o seu modo de funcionamento a partir do racional do ED, à procura de novas epistemologias e de novas linhas de pesquisa.Since the 1960s, homeschooling has shown growth dynamics updated by the diagnosis of the crisis of capitalism and of educational systems. Because it is practiced by families close to libertarian progressivism, conservative Christianity, or other axiological inspirations, this paper’s approach sought to break with a univocal conception alien to its diversity and to the different degrees of (in)formality of the children’s and young people’s educational daily lives inherent to this educational practice. Therefore, this paper seeks to understand the specificities of Portuguese homeschooling and its increasing social and educational expression, and to reflect on the meanings of the learning it entails. Being unclear about its role on the emancipation of the subjects, homeschooling seems to be contrary to the educational horizons of the child according to the interests of the whole society. This paper confronts school and its way of functioning with the homeschooling rationale in order to search for new epistemologies and new lines of research.info:eu-repo/semantics/publishedVersio

    GLADX: An Automated Approach to Analyze the Lineage-Specific Loss and Pseudogenization of Genes

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    A well-established ancestral gene can usually be found, in one or multiple copies, in different descendant species. Sometimes during the course of evolution, all the representatives of a well-established ancestral gene disappear in specific lineages; such gene losses may occur in the genome by deletion of a DNA fragment or by pseudogenization. The loss of an entire gene family in a given lineage may reflect an important phenomenon, and could be due either to adaptation, or to a relaxation of selection that leads to neutral evolution. Therefore, the lineage-specific gene loss analyses are important to improve the understanding of the evolutionary history of genes and genomes. In order to perform this kind of study from the increasing number of complete genome sequences available, we developed a unique new software module called GLADX in the DAGOBAH framework, based on a comparative genomic approach. The software is able to automatically detect, for all the species of a phylum, the presence/absence of a representative of a well-established ancestral gene, and by systematic steps of re-annotation, confirm losses, detect and analyze pseudogenes and find novel genes. The approach is based on the use of highly reliable gene phylogenies, of protein predictions and on the analysis of genomic mutations. All the evidence associated to evolutionary approach provides accurate information for building an overall view of the evolution of a given gene in a selected phylum. The reliability of GLADX has been successfully tested on a benchmark analysis of 14 reported cases. It is the first tool that is able to fully automatically study the lineage-specific losses and pseudogenizations. GLADX is available at http://ioda.univ-provence.fr/IodaSite/gladx/

    Small interfering RNA targeting mcl-1 enhances proteasome inhibitor-induced apoptosis in various solid malignant tumors

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    <p>Abstract</p> <p>Background</p> <p>Targeting the ubiquitin-proteasome pathway is a promising approach for anticancer strategies. Recently, we found Bik accumulation in cancer cell lines after they were treated with bortezomib. However, recent evidence indicates that proteasome inhibitors may also induce the accumulation of anti-apoptotic Bcl-2 family members. The current study was designed to analyze the levels of several anti-apoptotic members of Bcl-2 family in different human cancer cell lines after they were treated with proteasome inhibitors.</p> <p>Methods</p> <p>Different human cancer cell lines were treated with proteasome inhibitors. Western blot were used to investigate the expression of Mcl-1 and activation of mitochondrial apoptotic signaling. Cell viability was investigated using SRB assay, and induction of apoptosis was measured using flow cytometry.</p> <p>Results</p> <p>We found elevated Mcl-1 level in human colon cancer cell lines DLD1, LOVO, SW620, and HCT116; human ovarian cancer cell line SKOV3; and human lung cancer cell line H1299, but not in human breast cancer cell line MCF7 after they were treated with bortezomib. This dramatic Mcl-1 accumulation was also observed when cells were treated with other two proteasome inhibitors, MG132 and calpain inhibitor I (ALLN). Moreover, our results showed Mcl-1 accumulation was caused by stabilization of the protein against degradation. Reducing Mcl-1 accumulation by Mcl-1 siRNA reduced Mcl-1 accumulation and enhanced proteasome inhibitor-induced cell death and apoptosis, as evidenced by the increased cleavage of caspase-9, caspase-3, and poly (ADP-ribose) polymerase.</p> <p>Conclusions</p> <p>Our results showed that it was not only Bik but also Mcl-1 accumulation during the treatment of proteasome inhibitors, and combining proteasome inhibitors with Mcl-1 siRNA would enhance the ultimate anticancer effect suggesting this combination might be a more effective strategy for cancer therapy.</p

    Authentication and characterisation of a new oesophageal adenocarcinoma cell line: MFD-1.

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    New biological tools are required to understand the functional significance of genetic events revealed by whole genome sequencing (WGS) studies in oesophageal adenocarcinoma (OAC). The MFD-1 cell line was isolated from a 55-year-old male with OAC without recombinant-DNA transformation. Somatic genetic variations from MFD-1, tumour, normal oesophagus, and leucocytes were analysed with SNP6. WGS was performed in tumour and leucocytes. RNAseq was performed in MFD-1, and two classic OAC cell lines FLO1 and OE33. Transposase-accessible chromatin sequencing (ATAC-seq) was performed in MFD-1, OE33, and non-neoplastic HET1A cells. Functional studies were performed. MFD-1 had a high SNP genotype concordance with matched germline/tumour. Parental tumour and MFD-1 carried four somatically acquired mutations in three recurrent mutated genes in OAC: TP53, ABCB1 and SEMA5A, not present in FLO-1 or OE33. MFD-1 displayed high expression of epithelial and glandular markers and a unique fingerprint of open chromatin. MFD-1 was tumorigenic in SCID mouse and proliferative and invasive in 3D cultures. The clinical utility of whole genome sequencing projects will be delivered using accurate model systems to develop molecular-phenotype therapeutics. We have described the first such system to arise from the oesophageal International Cancer Genome Consortium project.Cancer Research UK, Medical Research CouncilThis is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/srep3241

    Ageing exacerbates damage of systemic and salivary neutrophils from patients presenting Candida-related denture stomatitis

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    <p>Abstract</p> <p>Background</p> <p>Ageing leads to a decline in the function of the immune system, increasing the body's susceptibility to infections through the impairment of T-cells, macrophages, neutrophils and dendritic cells Denture stomatitis is a primary oral disease affecting elderly denture wearers. The major etiologic factor involved in this pathology is the infection by <it>Candida albicans</it>, an opportunistic pathogen that causes local and disseminated diseases in immunosuppressed humans. Neutrophils play a critical role in the immune response against <it>C. albicans </it>and are continually present in the salivary fluid and in the blood. The aim of this study was to determine ageing-related changes in salivary and blood neutrophils and their potential implications in <it>Candida</it>-related denture stomatitis.</p> <p>Results</p> <p>Our results showed a lower number of neutrophils in the saliva from patients presenting <it>Candida</it>-related denture stomatitis in comparison to their matched controls. Furthermore, fewer neutrophils were isolated from the saliva of aged control individuals in comparison to matched younger subjects. CXCR1, CD62L and CD11b expression were significantly greater on systemic neutrophils from younger control individuals. Elderly individuals showed more apoptotic salivary neutrophils and lower GM-CSF levels than younger ones, regardless of the occurrence of <it>Candida </it>infection. On the other hand, CXCL-8 concentrations were higher in the saliva from elderly individuals. Besides, TNF-α was detected at elevated levels in the saliva from infected elderly subjects. Salivary neutrophils from elderly and young patients presented impaired phagocytic activity against <it>C. albicans</it>. However, just systemic neutrophils from elderly showed decreased phagocytosis when compared to the younger ones, regardless of the occurrence of infection. In addition, neutrophils from aged individuals and young patients presented low fungicidal activity.</p> <p>Conclusion</p> <p>The data suggests that the <it>Candida </it>related-denture stomatitis is associated to neutrophils function deficiency, and ageing drastically appears to alter important characteristics of such cells, facilitating the establishment of this infection.</p
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