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Dunakeszi, Hungary

Berta J.,Medical University of Vienna | Berta J.,National Koranyi Institute of Pulmonology | Kenessey I.,Semmelweis University | Dobos J.,National Institute of Oncology | And 18 more authors.
Journal of Thoracic Oncology

Introdution: The recently discovered bioactive peptide, apelin, has been demonstrated to stimulate angiogenesis in various experimental systems. However, its clinical significance and role in tumor vascularization have not yet been investigated in a human malignancy. Therefore, our aim was to study whether apelin expression is associated with angiogenesis and/or tumor growth/behavior in human non-small cell lung cancer (NSCLC). Methods:A total of 94 patients with stage I-IIIA NSCLC and complete follow-up information were included. Apelin expression in human NSCLC samples and cell lines was measured by quantitative reverse-transcriptase polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry. Effects of exogenous apelin and apelin transfection were studied on NSCLC cell lines in vitro. In vivo growth of tumors expressing apelin or control vectors were also assessed. Morphometric variables of human and mouse tumor capillaries were determined by anti-CD31 labeling. Results: Apelin was expressed in all of the six investigated NSCLC cell lines both at the mRNA and protein levels. Although apelin overexpression or apelin treatments did not increase NSCLC cell proliferation in vitro, increasing apelin levels by gene transfer to NSCLC cells significantly stimulated tumor growth and microvessel densities and perimeters in vivo. Apelin mRNA levels were significantly increased in human NSCLC samples compared with normal lung tissue, and high apelin protein levels were associated with elevated microvessel densities and poor overall survival. Conclusions: This study reveals apelin as a novel angiogenic factor in human NSCLC. Moreover, it also provides the first evidence for a direct association of apelin expression with clinical outcome in a human cancer. © 2010 by the International Association for the Study of Lung Cancer. Source

Kenessey I.,Semmelweis University | Kenessey I.,National Institute of Oncology | Keszthelyi M.,National Koranyi Institute of Pulmonology | Kramer Z.,Semmelweis University | And 19 more authors.
Current Cancer Drug Targets

The hepatocyte growth factor/scatter factor (HGF/SF) tyrosine kinase (TK) receptor c-Met plays a crucial role in the development of the invasive phenotype of tumors and thus represents an attractive candidate for targeted therapies in a variety of malignancies, including human malignant melanoma (MM). In contrast to what has been shown previously, we were not able to detect any genetic alterations, either in the juxtamembrane- or in the TK-domain of c-Met, in the studied MM cell lines. Nevertheless, c-Met was constitutively active in these cell lines without exogenous HGF/SF stimulation. The active receptor was localized to the adhesion sites of the cells. Addition of the c-Met TK inhibitor SU11274 specifically decreased the phosphotyrosine signal at the focal adhesion sites, which was accompanied by a decrease in cell proliferation as well as an increase in apoptotic cells. In addition, non-apoptotic concentrations of SU11274 significantly reduced the in vitro migratory capacity of MM cells in the modified Boyden-chamber assay. Administration of SU11274 significantly decreased primary tumor growth as well as the capacity for liver colony formation of MM cells in SCID mice. Our study provides the first evidence for an in vivo antitumor activity of SU11274 in a human melanoma xenograft model, and suggests c-Met as a valid target for the therapy of MM. Consequently, SU11274 treatment might represent a useful strategy for controlling melanoma progression and metastasis in patients with MM. © 2010 Bentham Science Publishers Ltd. Source

Dobi K.,Targetex Ltd. | Hajdu I.,Targetex Ltd. | Hajdu I.,Hungarian Academy of Sciences | Flachner B.,Targetex Ltd. | And 9 more authors.

Rapid in silico selection of target focused libraries from commercial repositories is an attractive and cost effective approach. If structures of active compounds are available rapid 2D similarity search can be performed on multimillion compound databases but the generated library requires further focusing by various 2D/3D chemoinformatics tools. We report here a combination of the 2D approach with a ligand-based 3D method (Screen3D) which applies flexible matching to align reference and target compounds in a dynamic manner and thus to assess their structural and conformational similarity. In the first case study we compared the 2D and 3D similarity scores on an existing dataset derived from the biological evaluation of a PDE5 focused library. Based on the obtained similarity metrices a fusion score was proposed. The fusion score was applied to refine the 2D similarity search in a second case study where we aimed at selecting and evaluating a PDE4B focused library. The application of this fused 2D/3D similarity measure led to an increase of the hit rate from 8.5% (1st round, 47% inhibition at 10 ìM) to 28.5% (2nd round at 50% inhibition at 10 μM) and the best two hits had 53 nM inhibitory activities. © 2014 by the authors. Source

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