54 research outputs found
PDGFR\u3b2 and FGFR2 mediate endothelial cell differentiation capability of triple negative breast carcinoma cells
Triple negative breast cancer (TNBC) is a very aggressive subgroup of breast carcinoma, still lacking specific markers for an effective targeted therapy and with a poorer prognosis compared to other breast cancer subtypes. In this study we investigated the possibility that TNBC cells contribute to the establishment of tumor vascular network by the process known as vasculogenic mimicry, through endothelial cell differentiation. Vascular-like functional properties of breast cancer cell lines were investigated in vitro by tube formation assay and in vivo by confocal microscopy, immunofluorescence or immunohistochemistry on frozen tumor sections. TNBCs express endothelial markers and acquire the ability to form vascular-like channels in vitro and in vivo, both in xenograft models and in human specimens, generating blood lacunae surrounded by tumor cells. Notably this feature is significantly associated with reduced disease free survival. The impairment of the main pathways involved in vessel formation, by treatment with inhibitors (i.e. Sunitinib and Bevacizumab) or by siRNA-mediating silencing, allowed the identification of PDGFR\u3b2 and FGFR2 as relevant players in this phenomenon. Inhibition of these tyrosine kinase receptors negatively affects vascular lacunae formation and significantly inhibits TNBC growth in vivo. In summary, we demonstrated that TNBCs have the ability to form vascular-like channels in vitro and to generate blood lacunae lined by tumor cells in vivo. Moreover, this feature is associated with poor outcome, probably contributing to the aggressiveness of this breast cancer subgroup. Finally, PDGFR\u3b2 and FGFR2-mediated pathways, identified as relevant in mediating this characteristic, potentially represent valid targets for a specific therapy of this breast cancer subgroup
CDCP1 is a novel marker of the most aggressive human triple-negative breast cancers
CDCP1, a transmembrane noncatalytic receptor, the expression of which has been associated with a poor prognosis in certain epithelial cancers, was found to be expressed in highly aggressive triple-negative breast cancer (TNBC) cell models, in which it promoted aggressive activities-ie, migration, invasion, anchorage-independent tumor growth, and the formation of vascular-like structures in vitro. By immunohistochemical (IHC) analysis of 100 human TNBC specimens, CDCP1 was overexpressed in 57% of samples, 38% of which exhibited a gain in CDCP1 copy number by fluorescence in situ hybridization (FISH). CDCP1 positivity was significantly associated between FISH and IHC. CDCP1 expression and gains in CDCP1 copy number synergized with nodal (N) status in determining disease-free and distant disease-free survival. The hazard ratios (HRs) of the synergies between CDCP1 positivity by IHC and FISH and lymph node positivity in predicting relapse did not differ significantly, indicating that CDCP1 overexpression in human primary TNBCs, regardless of being driven by gains in CDCP1, is for a critical factor in the progression of N-positive TNBCs. Thus, CDCP1 is a novel marker of the most aggressive N-positive TNBCs and a potential therapeutic target
The Usability of E-learning Platforms in Higher Education: A Systematic Mapping Study
The use of e-learning in higher education has increased significantly in recent years, which has led to several studies being conducted to investigate the usability of the platforms that support it. A variety of different usability evaluation methods and attributes have been used, and it has therefore become important to start reviewing this work in a systematic way to determine how the field has developed in the last 15 years. This paper describes a systematic mapping study that performed searches on five electronic libraries to identify usability issues and methods that have been used to evaluate e-learning platforms. Sixty-one papers were selected and analysed, with the majority of studies using a simple research design reliant on questionnaires. The usability attributes measured were mostly related to effectiveness, satisfaction, efficiency, and perceived ease of use. Furthermore, several research gaps have been identified and recommendations have been made for further work in the area of the usability of online learning
Web Technologies to Support a Community of Pratice
This paper presents a case of study on the experience of the group of work involved in the project PRIN 2006 "technological and educational component integration to design e-learning platform" (National program funded by the MIUR - Italian Ministry of University and Research). It is referred to the constitution of a work and practice community supported by web technologies.
The project has arisen to answer the need of supplying the workgroup with a tool to improve the co-ordination and the spirit of belonging for the researchers involved. In order to capitalize research experiences, create new knowledge and use problem solving methodologies, the fundamental characteristics of a web community have been defined
Towards Supporting Effective Interaction in E-learning
In this contribution, we describe our preliminary statement towards the long-term goal of creating an intelligent agent for monitoring interaction in the communication environments of the communities of practice. The assumption underlying our research work is that embedding some form of artificial intelligence in these environments enhances effective interaction during collaborative learning and knowledge sharing. We start by providing a description of the theoretical conceptual framework, illustrate the state of the art in the domain and conclude by sketching the guidelines for a method we intend to implement and test in our future work on real data collected through a web forum developed in our previous researc
Networking technologies to foster mathematical metacognitive processes
This paper presents a web-based system implementing cooperative type strategies in a suitable environment for learning math, and a pilot study aiming to investigate students' metacognitive processes in mathematical problem-solving supported by networked technology. By stimulating students' mental processes, our system should enable them to develop higher level math skills and acquire problem solving abilities. The cultural hypotheses underlying the project are not only the studies on Cooperative Learning and on the role of this approach in teaching/learning mathematics, but also the assumption, confirmed by various studies, of the effectiveness of Computer Supported Cooperative Learning
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