50 research outputs found

    In vivo efficacy of the histone deacetylase inhibitor suberoylanilide hydroxamic acid in combination with radiotherapy in a malignant rhabdoid tumor mouse model

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    <p>Abstract</p> <p>Purpose</p> <p>Histone deacetylase inhibitors are promising new substances in cancer therapy and have also been shown to sensitize different tumor cells to irradiation (XRT). We explored the effect as well as the radiosensitizing properties of suberoylanilide hydroxamic acid (SAHA) in vivo in a malignant rhabdoid tumor (MRT) mouse model.</p> <p>Methods and material</p> <p>Potential radiosensitization by SAHA was assessed in MRT xenografts by analysis of tumor growth delay, necrosis (HE), apoptosis (TUNEL), proliferation (ki-67) and γH2AX expression as well as dynamic <sup>18</sup>F-Fluorodeoxyglucose Positron Emission Tomography (<sup>18</sup>F-FDG -PET) after treatment with either SAHA alone, single-dose (10 Gy) or fractionated XRT (3 × 3Gy) solely as well as in combination with SAHA compared to controls.</p> <p>Results</p> <p>SAHA only had no significant effect on tumor growth. Combination of SAHA for 8 days with single-dose XRT resulted in a higher number of complete remissions, but failed to prove a significant growth delay compared to XRT only. In contrast fractionated XRT plus SAHA for 3 weeks did induce significant tumor growth delay in MRT-xenografts.</p> <p>The histological examination showed a significant effect of XRT in tumor necrosis, expression of Ki-67, γH2AX and apoptosis. SAHA only had no significant effect in the histological examination. Comparison of xenografts treated with XRT and XRT plus SAHA revealed a significantly increased γH2AX expression and apoptosis induction in the mice tumors after combination treatment with single-dose as well as fractionated XRT. The combination of SAHA with XRT showed a tendency to increased necrosis and decrease of proliferation compared to XRT only, which, however, was not significant. The <sup>18</sup>F-FDG-PET results showed no significant differences in the standard uptake value or glucose transport kinetics after either treatment.</p> <p>Conclusion</p> <p>SAHA did not have a significant effect alone, but proved to enhance the effect of XRT in our MRT in vivo model.</p

    Combination of suberoylanilide hydroxamic acid with heavy ion therapy shows promising effects in infantile sarcoma cell lines

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    <p>Abstract</p> <p>Introduction</p> <p>The pan-HDAC inhibitor (HDACI) suberoylanilide hydroxamic acid (SAHA) has previously shown to be a radio-sensitizer to conventional photon radiotherapy (XRT) in pediatric sarcoma cell lines. Here, we investigate its effect on the response of two sarcoma cell lines and a normal tissue cell line to heavy ion irradiation (HIT).</p> <p>Materials and methods</p> <p>Clonogenic assays after different doses of heavy ions were performed. DNA damage and repair were evaluated by measuring γH2AX via flow-cytometry. Apoptosis and cell cycle analysis were also measured via flow cytometry. Protein expression of repair proteins, p53 and p21 were measured using immunoblot analysis. Changes of nuclear architecture after treatment with SAHA and HIT were observed in one of the sarcoma cell lines via light microscopy after staining towards chromatin and γH2AX.</p> <p>Results</p> <p>Corresponding with previously reported photon data, SAHA lead to an increase of sensitivity to heavy ions along with an increase of DSB and apoptosis in the two sarcoma cell lines. In contrast, in the osteoblast cell line (hFOB 1.19), the combination of SAHA and HIT showed a significant radio-protective effect. Laser scanning microscopy revealed no significant morphologic changes after HIT compared to the combined treatment with SAHA. Immunoblot analysis revealed no significant up or down regulation of p53. However, p21 was significantly increased by SAHA and combination treatment as compared to HIT only in the two sarcoma cell lines - again in contrast to the osteoblast cell line. Changes in the repair kinetics of DSB p53-independent apoptosis with p21 involvement may be part of the underlying mechanisms for radio-sensitization by SAHA.</p> <p>Conclusion</p> <p>Our <it>in vitro </it>data suggest an increase of the therapeutic ratio by the combination of SAHA with HIT in infantile sarcoma cell lines.</p

    Hox-C9 activates the intrinsic pathway of apoptosis and is associated with spontaneous regression in neuroblastoma

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    Neuroblastoma is an embryonal malignancy of the sympathetic nervous system. Spontaneous regression and differentiation of neuroblastoma is observed in a subset of patients, and has been suggested to represent delayed activation of physiologic molecular programs of fetal neuroblasts. Homeobox genes constitute an important family of transcription factors, which play a fundamental role in morphogenesis and cell differentiation during embryogenesis. In this study, we demonstrate that expression of the majority of the human HOX class I homeobox genes is significantly associated with clinical covariates in neuroblastoma using microarray expression data of 649 primary tumors. Moreover, a HOX gene expression-based classifier predicted neuroblastoma patient outcome independently of age, stage and MYCN amplification status. Among all HOX genes, HOXC9 expression was most prominently associated with favorable prognostic markers. Most notably, elevated HOXC9 expression was significantly associated with spontaneous regression in infant neuroblastoma. Re-expression of HOXC9 in three neuroblastoma cell lines led to a significant reduction in cell viability, and abrogated tumor growth almost completely in neuroblastoma xenografts. Neuroblastoma growth arrest was related to the induction of programmed cell death, as indicated by an increase in the sub-G1 fraction and translocation of phosphatidylserine to the outer membrane. Programmed cell death was associated with the release of cytochrome c from the mitochondria into the cytosol and activation of the intrinsic cascade of caspases, indicating that HOXC9 re-expression triggers the intrinsic apoptotic pathway. Collectively, our results show a strong prognostic impact of HOX gene expression in neuroblastoma, and may point towards a role of Hox-C9 in neuroblastoma spontaneous regression

    Модернизация автоматизированной системы блока стабилизации давления магистрального насосного агрегата на нефтеперекачивающей станции

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    Объектом исследования является блок стабилизации давления магистрального насосного агрегата. Цель работы – модернизация автоматизированной системы блока стабилизации давления магистрального трубопровода нефтеперекачивающей станции с использованием ПЛК, на основе выбранной SCADA-системы. В данном проекте была разработана система контроля и управления технологическим процессом на базе промышленных контроллеров Modicon M340 BMXP34 2020, с применением SCADA-системы.The object of investigation is the pressure stabilization unit of the main pump unit. The purpose of the work is the modernization of the automated system for stabilizing the pressure of the main pipeline of the oil pumping station using PLCs, based on the SCADA system chosen. In this project, a system for monitoring and controlling the process was developed on the basis of industrial controllers Modicon M340 BMXP34 2020, using a SCADA system

    Maturity model for determining digitalization levels within different product lifecycle phases

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    Maintaining pace with ongoing changes due to digitalization is challenging for manufacturing companies. For successful implementation of digitalization, manufacturing companies must consider their existing technical systems, organizational structures, and processes, as well as social aspects. With the support of a maturity model, a company-specific digitalization level can be evaluated to provide manufacturing companies with an initial insight into their particular status quo; this can serve as a starting point for future optimization and digitalization projects. Furthermore, the results of such an analysis allow objective comparison of different areas within the company and with competitors. In this paper, the “Integrierte Arbeitssystemgestaltung in digitalisierten Produktionsunternehmen” (InAsPro) maturity model is presented, which considers the Development, Production, and Assembly product lifecycle phases, as well as Aftersales, and assesses their digitalization level focusing on the four dimensions of Technology, Organization, Social Issues, and Corporate Strategy. The maturity model’s rating scale distinguishes between four maturity levels. The results given by the InAsPro maturity model for an entire company are presented, along with those for each product lifecycle phase. Extensive descriptions for each specific maturity level are also provided
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