19 research outputs found

    Enhanced Antiproliferative and Apoptotic Response of HT-29 Adenocarcinoma Cells to Combination of Photoactivated Hypericin and Farnesyltransferase Inhibitor Manumycin A

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    Several photodynamically-active substances and farnesyltransferase inhibitors are currently being investigated as promising anticancer drugs. In this study, the combined effect of hypericin (the photodynamically-active pigment from Hypericum perforatum) and selective farnesyltransferase inhibitor manumycin (manumycin A; the selective farnesyltransferase inhibitor from Streptomyces parvulus) on HT-29 adenocarcinoma cells was examined. We found that the combination treatment of cells with photoactivated hypericin and manumycin resulted in enhanced antiproliferative and apoptotic response compared to the effect of single treatments. This was associated with increased suppression of clonogenic growth, S phase cell cycle arrest, elevated caspase-3/7 activity and time-dependent total cleavage of procaspase-3 and lamin B, cleavage of p21Bax into p18Bax and massive PARP cleavage. Moreover, we found that the apoptosis-inducing factor is implicated in signaling events triggered by photoactivated hypericin. Our results showed the relocalization of apoptosis-inducing factor (AIF) to the nuclei after hypericin treatment. In addition, we discovered that not only manumycin but also photoactivated hypericin induced the reduction of total Ras protein level. Manumycin decreased the amount of farnesylated Ras, and the combination treatment decreased the amount of both farnesylated and non-farnesylated Ras protein more dramatically. The present findings indicate that the inhibition of Ras processing may be the determining factor for enhancing the antiproliferative and apoptotic effects of combination treatment on HT-29 cells

    Optimalizácia nákladov a profitability produktov využitím what-if analýzy v recipročnej alokačnej aplikácii

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    Thesis is focused on one of the most discussed area of Management Information Systems currently -- Corporate Performance Management. It does not aim on detail explanation of theme itself, but orientate to specific problematic of setting key solution of managerial accounting -- cost allocation, to the Performance Management systems. Thesis is divided into theoretical and practical part. First part is devoted to Corporate Performance Management definition, its placement in architecture of Business Intelligence devices as well as reasoning for its implementation considering current economical situation. From the main three pillars of Performance Management is major attention dedicated to analytical part enabling execution of what-if analyses. Part devoted to cost allocation identifies contributions of its implementation in optimization and minimization of expenditures as well as offers reasons for using them in bank sphere. Practical case study documents particular project phases of implementation of cost allocation analytical solution in fictive bank, while major section is dedicated to architecture and design part of the calculation engine. Project is concluded with description and explanation of advanced implementation techniques and methods in IBM Cognos TM1 software

    Súčasné prístupy k nákladovej alokácii a vývoj typizovaného programového rozhrania v nástroji IBM Cognos TM1

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    Thesis is devoted to current trends in approaching cost allocation developed in IBM Cognos TM1 software. Concept, which was originally elaborated in my bachelor thesis, has recently experienced restrictions caused by increasing requirements on analytical tools and information they provide. Goal of the thesis is therefore to analyse causalities of emerging weaknesses, design and develop optimalized and reengineered solution answering current demands. Reqarding the quantitative evaluation of attained results, the thesis is extended with analysis of frameworks and standards dedicated to benchmarking of OLAP tools and their synthesis into own complex model. Proposed model specializes on measuring multiple OLAP applications across four main perspectives including performance, development, usability and financial benefits. Attained results prove, that reengineered model is faster, data richer, easier to use and appropriate for any organization with structured and algorithmic approach to cost allocation. Second half of the thesis focuses on extending the presentation layer to web browser, designing and developing of custom visualizations for most usual analytic tasks. Considering the absence of advanced application interface in IBM Cognos TM1, the thesis also includes theoretical analysis of current trends in API development and design of concept allowing communication and data transportation between applications and TM1 server. In the concluding section of the thesis, proposed concept is materialized into universal library developed in PHP and applied to novel allocation model. Leveraging the library, two exemplary interfaces for allocator operation and data consumption are implemented. Gained knowledge can serve as basis for development of additional components communicationg with TM1 in variety of projects or theoretical framework for API implementation in general

    Potentiality, Limitations, and Consequences of Different Experimental Models to Improve Photodynamic Therapy for Cancer Treatment in Relation to Antiangiogenic Mechanism

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    The relevance of experimentally gained information represents a long-term debating issue in the field of molecular biology research. The loss of original conditions in the in vitro environment affects various biological mechanisms and cellular interactions. Consequently, some biochemical mechanisms are lost or critically altered. Analyses in these modified conditions could, therefore, distort the relevancy of experimentally gained information. In some cases, the similarities with original conditions are so small that utilization of simpler in vitro models seems impossible, or could occur in a very limited way. To conclude, the study of more complex phenomena places higher demands on the complexity of the experimental model. The latest information highlights the fact that the tumor angiogenesis mechanism has very complex features. This complexity can be associated with a wide range of angiogenic factors expressed by a variety of malignant and non-malignant cells. Our article summarizes the results from various experimental models that were utilized to analyze a photodynamic therapy effect on tumor angiogenic mechanisms. Additionally, based on the latest information, we present the most important attributes and limitations of utilized experimental models. We also evaluate the essential problems associated with angiogenic mechanism induction after photodynamic therapy application

    Multifunctional Nanoplatforms as a Novel Effective Approach in Photodynamic Therapy and Chemotherapy, to Overcome Multidrug Resistance in Cancer

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    It is more than sixty years since the era of modern photodynamic therapy (PDT) for cancer began. Enhanced selectivity for malignant cells with a reduced selectivity for non-malignant cells and good biocompatibility along with the limited occurrence of side effects are considered to be the most significant advantages of PDT in comparison with conventional therapeutic approaches, e.g., chemotherapy. The phenomenon of multidrug resistance, which is associated with drug efflux transporters, was originally identified in relation to the application of chemotherapy. Unfortunately, over the last thirty years, numerous papers have shown that many photosensitizers are the substrates of efflux transporters, significantly restricting the effectiveness of PDT. The concept of a dynamic nanoplatform offers a possible solution to minimize the multidrug resistance effect in cells affected by PDT. Indeed, recent findings have shown that the utilization of nanoparticles could significantly enhance the therapeutic efficacy of PDT. Additionally, multifunctional nanoplatforms could induce the synergistic effect of combined treatment regimens, such as PDT with chemotherapy. Moreover, the surface modifications that are associated with nanoparticle functionalization significantly improve the target potential of PDT or chemo-PDT in multidrug resistant and cancer stem cells

    Acridine Based N-Acylhydrazone Derivatives as Potential Anticancer Agents: Synthesis, Characterization and ctDNA/HSA Spectroscopic Binding Properties

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    A series of novel acridine N-acylhydrazone derivatives have been synthesized as potential topoisomerase I/II inhibitors, and their binding (calf thymus DNA—ctDNA and human serum albumin—HSA) and biological activities as potential anticancer agents on proliferation of A549 and CCD-18Co have been evaluated. The acridine-DNA complex 3b (-F) displayed the highest Kb value (Kb = 3.18 × 103 M−1). The HSA-derivatives interactions were studied by fluorescence quenching spectra. This method was used for the calculation of characteristic binding parameters. In the presence of warfarin, the binding constant values were found to decrease (KSV = 2.26 M−1, Kb = 2.54 M−1), suggesting that derivative 3a could bind to HSA at Sudlow site I. The effect of tested derivatives on metabolic activity of A549 cells evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assay decreased as follows 3b(-F) > 3a(-H) > 3c(-Cl) > 3d(-Br). The derivatives 3c and 3d in vitro act as potential dual inhibitors of hTopo I and II with a partial effect on the metabolic activity of cancer cells A594. The acridine-benzohydrazides 3a and 3c reduced the clonogenic ability of A549 cells by 72% or 74%, respectively. The general results of the study suggest that the novel compounds show potential for future development as anticancer agents

    Tacrine-Coumarin Derivatives as Topoisomerase Inhibitors with Antitumor Effects on A549 Human Lung Carcinoma Cancer Cell Lines

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    A549 human lung carcinoma cell lines were treated with a series of new drugs with both tacrine and coumarin pharmacophores (derivatives 1a–2c) in order to test the compounds’ ability to inhibit both cancer cell growth and topoisomerase I and II activity. The ability of human topoisomerase I (hTOPI) and II to relax supercoiled plasmid DNA in the presence of various concentrations of the tacrine-coumarin hybrid molecules was studied with agarose gel electrophoresis. The biological activities of the derivatives were studied using MTT assays, clonogenic assays, cell cycle analysis and quantification of cell number and viability. The content and localization of the derivatives in the cells were analysed using flow cytometry and confocal microscopy. All of the studied compounds were found to have inhibited topoisomerase I activity completely. The effect of the tacrine-coumarin hybrid compounds on cancer cells is likely to be dependent on the length of the chain between the tacrine and coumarin moieties (1c, 1d = tacrine-(CH2)8–9-coumarin). The most active of the tested compounds, derivatives 1c and 1d, both display longer chains
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