51 research outputs found

    Long lasting MDM2/Translocator protein modulator: a new strategy for irreversible apoptosis of human glioblastoma cells

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    The development of multi-target drugs and irreversible modulators of deregulated signalling proteins is the major challenge for improving glioblastoma multiforme (GBM) treatment. Reversible single-target drugs are not sufficient to sustain a therapeutic effect over time and may favour the activation of alternative signalling pathways and the onset of resistance phenomena. Thus, a multi-target compound that has a long-lasting mechanism of action might have a greater and longer life span of anti-proliferative activity. Recently, a dual-target indol-3ylglyoxyldipeptide derivative, designed to bind to the Translocator Protein (TSPO) and reactivate p53 function via dissociation from its physiological inhibitor, murine double minute 2 (MDM2), has been developed as a potent GBM pro-apoptotic agent. In this study, this derivative was chemically modified to irreversibly bind MDM2 and TSPO. The new compound elicited a TSPO-mediated mitochondrial membrane dissipation and restored p53 activity, triggering a long-lasting apoptosis of GBM cells. These effects were sustained over time, involved a stable activation of extracellular signal regulated kinases and were specifically observed in cancer cells, in which these protein kinases are deregulated. Dual-targeting and irreversible binding properties combined in the same molecule may represent a useful strategy to overcome the time-limited effects elicited by classical chemotherapies

    Poorly differentiated clusters (PDC) in colorectal cancer: Does their localization in tumor matter?

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    Poorly differentiated clusters (PDC) are aggregates of at least five neoplastic cells lacking evidence of glandular differentiation. By definition, they can be present at the invasive front (peripheral PDC or pPDC) and within the tumor stroma (central PDC or cPDC). In colorectal cancer (CRC), PDC are considered adverse prognosticators and seem to reflect epithelial mesenchymal transition (EMT). In this study, we have investigated the immuno-expression of two EMT-related proteins, E-cadherin and \u3b2-catenin, in PDC of primary CRCs and matched liver metastases. pPDC always showed nuclear \u3b2-catenin staining and diffusely reduced/absence of E-cadherin expression as opposed cPDC which showed nuclear \u3b2-catenin immunoreactivity and E-cadherin expression in about 50% of cases. In addition, the pattern of \u3b2-catenin and E-cadherin expression differed between PDC and the main tumor, and between primary CRC and liver metastasis (LM), in a percentage of cases. A discordant pattern of \u3b2-catenin and E-cadherin expression between pPDC and cPDC, between main tumor and cPDC, and between primary CRC and LM, confirms that EMT is a dynamic and reversible process in CRC. On the overall, this suggests that pPDC and cPDC are biologically different. We may advocate that PDC develop at the tumor center (cPDC) and then some of them migrate towards the tumor periphery while progressively completing EMT process (pPDC). Based on these results, PDC presence and counting may have different prognostic relevance if the assessment is done at the invasive front of the tumor or in the intratumor stroma

    Apoptosis Therapy in Cancer: The First Single-molecule Co-activating p53 and the Translocator Protein in Glioblastoma

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    In the complex scenario of cancer, treatment with compounds targeting multiple cell pathways has been emerging. In Glioblastoma Multiforme (GBM), p53 and Translocator Protein (TSPO), both acting as apoptosis inducers, represent two attractive intracellular targets. On this basis, novel indolylglyoxylyldipeptides, rationally designed to activate TSPO and p53, were synthesized and biologically characterized. The new compounds were able to bind TSPO and to reactivate p53 functionality, through the dissociation from its physiological inhibitor, murine double minute 2 (MDM2). In GBM cells, the new molecules caused Δψm dissipation and inhibition of cell viability. These effects resulted significantly higher with respect to those elicited by the single target reference standards applied alone, and coherent with the synergism resulting from the simultaneous activation of TSPO and p53. Taken together, these results suggest that TSPO/MDM2 dual-target ligands could represent a new attractive multi-modal opportunity for anti-cancer strategy in GBM

    The Interplay between CD27dull and CD27bright B Cells Ensures the Flexibility, Stability, and Resilience of Human B Cell Memory

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    Summary: Memory B cells (MBCs) epitomize the adaptation of the immune system to the environment. We identify two MBC subsets in peripheral blood, CD27dull and CD27bright MBCs, whose frequency changes with age. Heavy chain variable region (VH) usage, somatic mutation frequency replacement-to-silent ratio, and CDR3 property changes, reflecting consecutive selection of highly antigen-specific, low cross-reactive antibody variants, all demonstrate that CD27dull and CD27bright MBCs represent sequential MBC developmental stages, and stringent antigen-driven pressure selects CD27dull into the CD27bright MBC pool. Dynamics of human MBCs are exploited in pregnancy, when 50% of maternal MBCs are lost and CD27dull MBCs transit to the more differentiated CD27bright stage. In the postpartum period, the maternal MBC pool is replenished by the expansion of persistent CD27dull clones. Thus, the stability and flexibility of human B cell memory is ensured by CD27dull MBCs that expand and differentiate in response to change. : Grimsholm et al. show that CD27dull and CD27bright represent sequential MBC developmental stages. T cell- and germinal center (GC)-independent CD27dull MBCs are the plastic source of strongly selected and GC-dependent CD27bright MBCs. CD27dull MBCs, able to expand and differentiate in response to change, ensure stability and flexibility of human B cell memory. Keywords: memory B cells, pregnancy, immunological memory, CD27, VH repertoire, immunodeficiency, aging, spleen, vaccine, germinal cente

    Semantic based indexing technique for optimisation and intelligent document representation : application to structured and unstructured document clustering

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    The advances in data collection and the increasing amount of unstructured and unlabeled text documents have led to the need for better disambiguation and indexing techniques, which allow for the effective and intelligent organisation of large amounts of documents into a small number of significant clusters; facilitating the analysis, browsing, and searching of document collections. Traditionally, document clustering systems have relied on bag-of-words and term frequency approaches to represent and subsequently classify documents, by only taking into account document syntax and with no consideration for semantic aspects. To address this issue, more complex indexing and clustering techniques, which consider the semantic associations between the words contained in a document and differentiate the degree of semantic importance of terms during the classification process, need to be further investigated in order to enable appropriate and automatic contextualisation of text documents and information. This research proposes a new indexing technique, which can be used to effectively represent, and subsequently cluster, collections of unstructured or structured documents. The presented technique aims at overcoming some of the major problems related to the bag-of-words approach; such as its lack of consideration for synonyms as well as its usual failure in differentiating the degree of semantic importance of terms. The main idea behind the proposed technique is to map each document into a lower dimensional space; by considering the semantic associations between the words contained in the document. To address the semantic problems posed by traditional indexing, the investigated method focuses on word sense disambiguation and document concepts. The proposed technique extracts concepts from documents and uses a set of these concepts as indexing units, achieving vector dimensionality reduction as well as more cohesive and separated clusters. Good results are also achieved in terms of purity, entropy, and when compared with similar studies in the field of semantic-based concept indexing.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Do pathological variables have prognostic significance in rectal adenocarcinoma treated with neoadjuvant chemoradiotherapy and surgery?

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    AIMTo clarify which factors may influence pathological tumor response and affect clinical outcomes in patients with locally advanced rectal carcinoma treated with neo-adjuvant chemoradiotherapy and surgery.METHODSTumor regression grade (TRG) according to the Dworak system and yTNM stage were assessed and correlated with pre-treatment clinico-pathological variables in 215 clinically locally advanced (cTNM stage. and.) rectal carcinomas. Prognostic value of all pathological and clinical factors on disease free survival (DFS) and cancer specific survival (CSS) was analyzed by Kaplan Meier and Cox-regression analyses.RESULTScN+ status, mucinous histotype or poor differentiation in the pre-treatment biopsy were significantly associated with lower pathological response (low Dworak grade and TNM remaining unchanged/upstaging). Cases showing acellular mucin pools in surgical specimens all had unremarkable clinical courses with no deaths or recurrences during follow-up. Dworak grade had prognostic significance for DFS and CSS. However, compared to the 5-tiered system, a simplified two-tiered grading system, in which grades 0, 1 and 2 were grouped as absent/partial regression and grades 3 and 4 were grouped as total/subtotal regression, was more reproducible and prognostically informative. The two-tiered Dworak system, yN stage, craniocaudal extension of the tumor and radial margin status were significant independent prognostic variables.CONCLUSIONOur data suggest that caution should be applied in using a conservative approach in rectal carcinomas with cN+ status, extensive/lower involvement of the rectum and mucinous histotype or poor differentiation. Although Dworak TRG is prognostically significant, a simplified two-tiered system could be preferable. Finally, cases with acellular mucin pools should be carefully evaluated to definitely exclude residual mucinous carcinoma

    Prognostic significance of CDX2 immunoexpression in poorly differentiated clusters of colorectal carcinoma

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    CDX2 is a transcription factor that acts as a tumor suppressor in colorectal cancer (CRC). Its loss triggers metastatic process and tumor progression; however, its prognostic role in patients with CRC is still controversial. Poorly differentiated clusters (PDCs) are aggregates of neoplastic cells which likely have high metastatic potential in CRC. In this study, we analyzed and compared CDX2 expression in PDC (CDX2-PDC) and corresponding main tumor (CDX2 main tumor) in 42 CRCs showing at least 10 PDC (PDC G3). Five of 42 CRCs (12%) were classified as CDX2 main tumor negative (4/5 were also PDC-CDX2 negative); all had tumor recurrence and died of CRC. Twenty nine of 42 cases were CDX2-PDC negative. Among CRC CDX2 main tumor positive, 15 had recurrences and 13 died from CRC; 13 and 11 of them, respectively, were CDX2-PDC negative. By assigning one point to CDX2 main tumor or CDX2-PDC positivity, we assessed CDX2-staining score for each case. Twelve cases had CDX2-staining score 2 (CDX2 positive in main tumor and PDC); 26 had score 1 (CDX2 positive in main tumor or PDC), and 4 had CDX2 score 0 (CDX2 negative in main tumor and PDC). In our patients, CDX2-staining score had higher prognostic value compared to CDX2 main tumor or CDX2-PDC alone. In addition, it represented a significant and independent prognostic variable for disease-free survival (DFS) and cancer-specific survival (CSS). Our findings suggest that, although loss of CDX2 in the main tumor identifies high-risk patients with high specificity, CDX2-PDC should also be considered in CDX2 main tumor positive cases to predict prognosis

    Setting up the Open Semantic Infrastructure for the European Construction Sector - the FUNSIEC Project

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    International audienceThis paper describes the work to be done by the FUNSIEC project, which aims to evaluate the feasibility of building an Open Semantic Infrastructure for the European Construction Sector (OSIECS). Such an infrastructure is to be built by selecting semantic resources devoted to construction in different languages,exploiting some public results produced by international initiatives (e.g. IFC) and European funded projects. OSIECS will be open to any linguistic resources; in particular those developed for less widely spoken languages and those of the Candidates countries. The innovation in OSIECS is to be on the semantic mappings to be established among the existing semantic resources. The assessment of the results produced by FUNSIEC iscentred on the main subjects: its business plan and the education (in the large sense) of the practitioners from Construction regarding the use of semantic resources
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