11 research outputs found

    BRCA1-regulated RRM2 expression protects glioblastoma cells from endogenous replication stress and promotes tumorigenicity

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    Oncogene-evoked replication stress (RS) fuels genomic instability in diverse cancer types. Here we report that BRCA1, traditionally regarded a tumour suppressor, plays an unexpected tumour-promoting role in glioblastoma (GBM), safeguarding a protective response to supraphysiological RS levels. Higher BRCA1 positivity is associated with shorter survival of glioma patients and the abrogation of BRCA1 function in GBM enhances RS, DNA damage (DD) accumulation and impairs tumour growth. Mechanistically, we identify a novel role of BRCA1 as a transcriptional co-activator of RRM2 (catalytic subunit of ribonucleotide reductase), whereby BRCA1-mediated RRM2 expression protects GBM cells from endogenous RS, DD and apoptosis. Notably, we show that treatment with a RRM2 inhibitor triapine reproduces the BRCA1-depletion GBM-repressive phenotypes and sensitizes GBM cells to PARP inhibition. We propose that GBM cells are addicted to the RS-protective role of the BRCA1-RRM2 axis, targeting of which may represent a novel paradigm for therapeutic intervention in GBM

    Analysis of Snail-1, E-Cadherin and Claudin-1 Expression in Colorectal Adenomas and Carcinomas

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    We report the expression of Snail-1, E-cadherin and claudin-1 by indirect immunohistochemistry in colonic neoplasia. Snail-1 is a zinc finger transcription factor expressed in cells that already have undergone almost complete epithelial-mesenchymal transition (EMT) and have already evaded from the tumor. The main mechanism by which Snail induces EMT is downregulation of E-cadherin, of which expression was shown to be frequently downregulated in many different types of tumors, where it accompanies the invasiveness and metastatic behavior of malignant cells. Moreover, Snail-1 may downregulate the expression of claudin-1, a cell-cell adhesion protein which plays a likely role in progression and dissemination during tumorigenesis. Snail-1 was expressed in both carcinoma and adenoma cells with histologically normal epithelium in the mucosa, adjacent to the tumors, without significant differences, and predominant strong intensity of staining. Statistically significant differences were revealed between normal and tumorous epithelium (p = 0.003) at the subcellular level, where the shift of the protein to the cytoplasm with combined cytoplasmic/nuclear or pure cytoplasmic expression was observed. E-cadherin expression was present in 100% of cases of both adenocarcinomas and adenomas, with prevailing strong membranous immunoreactivity and no differences between protein expression in tumors and normal mucosa. Predominating strong positivity of claudin-1 was detected in tumor cells of adenocarcinomas and adenomas. Marked differences were seen in protein localization, where membranous staining, typical for nontumorous epithelium, changed to combined membranous/cytoplasmic expression in adenocarcinomas (p = 0.0001) and adenomas (0.0002), in which cytoplasmic shift was associated with a higher degree of dysplasia. Furthermore, membranous/cytoplasmic localization was more frequent in the carcinoma group (87%) in comparison with adenomas (51%) (p = 0.0001). We conclude that dystopic subcellular localizations of Snail-1 and claudin-1 may participate in changes of cellular morphology and behavior which might be associated with altered effectory pathways of proteins and thus substantially contribute to the cancer development

    Impact of creative accounting on the company value: Empirical study for Slovakia

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    Research background: Procedures and methods for determining the value of a company are different. The purpose of determining the value of the company, what results the company reports and also who performs the valuation has a significant influence on the choice of the method. Purpose of the article: The determination of the final value of the company is influenced by many factors, economic, technical, specifics of the company and also the date on which the value is calculated and who performs the evaluation. Methods: In expert practice in determining the value of the company, we work mainly with methods based on property and income principles (asset method, yield method). The basic material for calculating the value of a company is the company’s accounting, which, however, can often be influenced. There can be several purposes for distorting accounting information (financial statements). The most common reason is the reduction of the tax base, or artificial improvement of the achieved results. Creative accounting practices significantly affect the structure of the company as well as its financial results. Findings & Value added: The main goal of the paper is to quantify a few examples, which will contribute to reducing the economic result. Subsequently, we analyse these interventions how they can affect the resulting general value of the company determined by the expert and whether the expert is able to detect them

    Skin manifestations of pancreatic diseases

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    Although symptoms of pancreatic diseases such as pancreatitis, acute and chronic and, carcinoma of the pancreas are mainly gastrointestinal in nature, the extra-pancreatic symptoms are also important. These include skin symptoms, such as pancreatic panniculitis, acanthosis nigricans, livedo reticularis, necrolytic migratory erythema, cutaneous signs of hemorrhage, as in persons with severe acute pancreatitis, or the finding of cutaneous metastases of pancreatic carcinoma, which may be a sign of advanced disease. The pancreas is therefore one of those organs for which diagnosis and therapy are often multidisciplinary. In this review article, we summarize current knowledge of the possible skin manifestations of pancreatic disorders

    Radiological evolution of spinal disease in alkaptonuria and the effect of nitisinone

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    ObjectivesOchronotic spondyloarthropathy represents one of the main clinical manifestations of alkaptonuria (AKU); however, prospective data and description of the effect of nitisinone treatment are lacking.MethodsPatients with AKU aged 25 years or older were randomly assigned to receive either oral nitisinone 10 mg/day (N=69) or no treatment (N=69). Spine radiographs were recorded yearly at baseline, 12, 24, 36 and 48 months, and the images were scored for the presence of intervertebral space narrowing, soft tissue calcifications, vacuum phenomena, osteophytes/hyperostosis and spinal fusion in the cervical, thoracic and lumbosacral segment at each of the time points.ResultsAt baseline, narrowing of the intervertebral spaces, the presence of osteophytes/hyperostosis and calcifications were the three most frequent radiographic features in AKU. The rate of progression of the five main features during the 4 years, ranked from the highest to lowest was as follows: intervertebral spaces narrowing, calcifications, vacuum phenomena, osteophytes/hyperostosis and fusions. The rate of progression did not differ between the treated and untreated groups in any of the five radiographic parameters except for a slower rate of progression (sum of all five features) in the treatment group compared with the control group (0.45 (1.11) nitisinone vs 0.74 (1.11) controls, p=0.049) in the thoracic segment.ConclusionThe present study shows a relatively slow but significant worsening of radiographic features in patients with AKU over 4 years. Our results demonstrate a modest beneficial effect of 10 mg/day of nitisinone on the slowly progressing spondylosis in AKU during the relatively limited follow-up time.Trial registration numberNCT01916382
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