66 research outputs found

    Nuclear factor IA is expressed in astrocytomas and is associated with improved survival

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    Nuclear factor IA (NFIA) is a transcription factor that specifies glial cell identity and promotes astrocyte differentiation during embryonic development. Its expression and function in gliomas are not known. Here, we examined NFIA protein expression in gliomas and its association with clinical outcome in pediatric malignant astrocytomas. We analyzed expression of NFIA by immunohistochemistry in 88 existing glioma specimens from Childrens Hospital Los Angeles and the University of Southern California. Association between NFIA expression and progression-free survival (PFS) was examined in high-grade astrocytomas for which clinical data were available (n = 23, all children). NFIA was highly expressed in astrocytomas of all grades, but only in a minority of cells in oligodendroglial tumors. NFIA was expressed on a higher percentage of tumor cells in low-grade astrocytomas (91 ± 5% and 77 ± 14% in World Health Organization [WHO] I and II, respectively) compared with high-grade astrocytomas (48 ± 18% and 37 ± 16% in WHO III and IV, respectively; P < .001, low- vs high-grade astrocytomas). There was a significant association between NFIA expression and PFS in children with astrocytoma WHO grade III or IV (Cox regression P = .019; logrank trend test for NFIA tertiles P = .0040 and NFIA quartiles P = .014). The association was not consistently significant in this small series of patients after adjustment was made for WHO grade III or IV. This is the first study to demonstrate expression of NFIA protein in astrocytomas and its association with grades of astrocytoma and PFS, suggesting that NFIA may play a role in astrocytoma biology

    oA novel nonparametric approach for estimating cut-offs in continuous risk indicators with application to diabetes epidemiology

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    <p>Abstract</p> <p>Background</p> <p>Epidemiological and clinical studies, often including anthropometric measures, have established obesity as a major risk factor for the development of type 2 diabetes. Appropriate cut-off values for anthropometric parameters are necessary for prediction or decision purposes. The cut-off corresponding to the Youden-Index is often applied in epidemiology and biomedical literature for dichotomizing a continuous risk indicator.</p> <p>Methods</p> <p>Using data from a representative large multistage longitudinal epidemiological study in a primary care setting in Germany, this paper explores a novel approach for estimating optimal cut-offs of anthropomorphic parameters for predicting type 2 diabetes based on a discontinuity of a regression function in a nonparametric regression framework.</p> <p>Results</p> <p>The resulting cut-off corresponded to values obtained by the Youden Index (maximum of the sum of sensitivity and specificity, minus one), often considered the optimal cut-off in epidemiological and biomedical research. The nonparametric regression based estimator was compared to results obtained by the established methods of the Receiver Operating Characteristic plot in various simulation scenarios and based on bias and root mean square error, yielded excellent finite sample properties.</p> <p>Conclusion</p> <p>It is thus recommended that this nonparametric regression approach be considered as valuable alternative when a continuous indicator has to be dichotomized at the Youden Index for prediction or decision purposes.</p

    Strategies to inhibit tumour associated integrin receptors: rationale for dual and multi-antagonists

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    YesThe integrins are a family of 24 heterodimeric transmembrane cell surface receptors. Involvement in cell attachment to the extracellular matrix, motility, and proliferation identifies integrins as therapeutic targets in cancer and associated conditions; thrombosis, angiogenesis and osteoporosis. The most reported strategy for drug development is synthesis of an agent that is highly selective for a single integrin receptor. However, the ability of cancer cells to change their integrin repertoire in response to drug treatment renders this approach vulnerable to the development of resistance and paradoxical promotion of tumor growth. Here, we review progress towards development of antagonists targeting two or more members of the RGD-binding integrins, notably αvβ3, αvβ5, αvβ6, αvβ8, α5β1, and αIIbβ3, as anticancer therapeutics

    Induction of Membrane Ceramides: A Novel Strategy to Interfere with T Lymphocyte Cytoskeletal Reorganisation in Viral Immunosuppression

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    Silencing of T cell activation and function is a highly efficient strategy of immunosuppression induced by pathogens. By promoting formation of membrane microdomains essential for clustering of receptors and signalling platforms in the plasma membrane, ceramides accumulating as a result of membrane sphingomyelin breakdown are not only essential for assembly of signalling complexes and pathogen entry, but also act as signalling modulators, e. g. by regulating relay of phosphatidyl-inositol-3-kinase (PI3K) signalling. Their role in T lymphocyte functions has not been addressed as yet. We now show that measles virus (MV), which interacts with the surface of T cells and thereby efficiently interferes with stimulated dynamic reorganisation of their actin cytoskeleton, causes ceramide accumulation in human T cells in a neutral (NSM) and acid (ASM) sphingomyelinase–dependent manner. Ceramides induced by MV, but also bacterial sphingomyelinase, efficiently interfered with formation of membrane protrusions and T cell spreading and front/rear polarisation in response to β1 integrin ligation or αCD3/CD28 activation, and this was rescued upon pharmacological or genetic ablation of ASM/NSM activity. Moreover, membrane ceramide accumulation downmodulated chemokine-induced T cell motility on fibronectin. Altogether, these findings highlight an as yet unrecognised concept of pathogens able to cause membrane ceramide accumulation to target essential processes in T cell activation and function by preventing stimulated actin cytoskeletal dynamics

    Anti-angiogenic alternatives to VEGF blockade

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    Angiogenesis is a major requirement for tumour formation and development. Anti-angiogenic treatments aim to starve the tumour of nutrients and oxygen and also guard against metastasis. The main anti-angiogenic agents to date have focused on blocking the pro-angiogenic vascular endothelial growth factors (VEGFs). While this approach has seen some success and has provided a proof of principle that such anti-angiogenic agents can be used as treatment, the overall outcome of VEGF blockade has been somewhat disappointing. There is a current need for new strategies in inhibiting tumour angiogenesis; this article will review current and historical examples in blocking various membrane receptors and components of the extracellular matrix important in angiogenesis. Targeting these newly discovered pro-angiogenic proteins could provide novel strategies for cancer therapy
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