86 research outputs found
Soft tissue mixed tumor of the hand
Mixed tumors are relatively common in the skin and salivary glands, but extremely rare in soft tissues, often resulting in diagnostic problems. The occurrence of these tumors in the hand is especially limited. In this article we report the clinical, radiological, and histological features of a mixed tumor of the hypothenar region of the right hand
Fibroid explants reveal a higher sensitivity against MDM2-inhibitor nutlin-3 than matching myometrium
<p>Abstract</p> <p>Background</p> <p>Spontaneous cessation of growth is a frequent finding in uterine fibroids. Increasing evidence suggests an important role of cellular senescence in this growth control. Deciphering the underlying mechanisms of growth control that can be expected not only to shed light on the biology of the tumors but also to identify novel therapeutic targets.</p> <p>Methods</p> <p>We have analyzed uterine leiomyomas and matching normal tissue for the expression of p14<sup>Arf </sup>and used explants to see if reducing the MDM2 activity using the small-molecule inhibitor nutlin-3 can induce p53 and activate genes involved in senescence and/or apoptosis. For these studies quantitative real-time RT-PCR, Western blots, and immunohistochemistry were used. Statistical analyses were performed using the student's <it>t </it>test.</p> <p>Results</p> <p>An in depth analysis of 52 fibroids along with matching myometrium from 31 patients revealed in almost all cases a higher expression of p14<sup>Arf </sup>in the tumors than in the matching normal tissue. In tissue explants, treatment with the MDM2 inhibitor nutlin-3 induced apoptosis as well as senescence as revealed by a dose-dependent increase of the expression of <it>BAX </it>as well as of <it>p21</it>, respectively. Simultaneously, the expression of the proliferation marker Ki-67 drastically decreased. Western-blot analysis identified an increase of the p53 level as the most likely reason for the increased activity of its downstream markers <it>BAX </it>and <it>p21</it>. Because as a rule fibroids express much higher levels of p14<sup>Arf</sup>, a major negative regulator of MDM2, than matching myometrium it was then analyzed if fibroids are more sensitive against nutlin-3 treatment than matching myometrium. We were able to show that in most fibroids analyzed a higher sensibility than that of matching myometrium was noted with a corresponding increase of the p53 immunopositivity of the fibroid samples compared to those from myometrium.</p> <p>Conclusions</p> <p>The results show that uterine fibroids represent a cell population of advanced cellular age compared to matching myometrium. Moreover, the data point to members of the p53-network as to potential novel therapeutic targets for the treatment of uterine fibroids.</p
Chromatin Immunoprecipitation to Analyze DNA Binding Sites of HMGA2
BACKGROUND: HMGA2 is an architectonic transcription factor abundantly expressed during embryonic and fetal development and it is associated with the progression of malignant tumors. The protein harbours three basically charged DNA binding domains and an acidic protein binding C-terminal domain. DNA binding induces changes of DNA conformation and hence results in global overall change of gene expression patterns. Recently, using a PCR-based SELEX (Systematic Evolution of Ligands by Exponential Enrichment) procedure two consensus sequences for HMGA2 binding have been identified. METHODOLOGY/PRINCIPAL FINDINGS: In this investigation chromatin immunoprecipitation (ChIP) experiments and bioinformatic methods were used to analyze if these binding sequences can be verified on chromatin of living cells as well. CONCLUSION: After quantification of HMGA2 protein in different cell lines the colon cancer derived cell line HCT116 was chosen for further ChIP experiments because of its 3.4-fold higher HMGA2 protein level. 49 DNA fragments were obtained by ChIP. These fragments containing HMGA2 binding sites have been analyzed for their AT-content, location in the human genome and similarities to sequences generated by a SELEX study. The sequences show a significantly higher AT-content than the average of the human genome. The artificially generated SELEX sequences and short BLAST alignments (11 and 12 bp) of the ChIP fragments from living cells show similarities in their organization. The flanking regions are AT-rich, whereas a lower conservation is present in the center of the sequences
Decrease in thyroid adenoma associated (THADA) expression is a marker of dedifferentiation of thyroid tissue
<p>Abstract</p> <p>Background</p> <p><it>Thyroid adenoma associated (THADA) </it>has been identified as the target gene affected by chromosome 2p21 translocations in thyroid adenomas, but the role of THADA in the thyroid is still elusive. The aim of this study was to quantify <it>THADA </it>gene expression in normal tissues and in thyroid hyper- and neoplasias, using real-time PCR.</p> <p>Methods</p> <p>For the analysis <it>THADA </it>and 18S rRNA gene expression assays were performed on 34 normal tissue samples, including thyroid, salivary gland, heart, endometrium, myometrium, lung, blood, and adipose tissue as well as on 85 thyroid hyper- and neoplasias, including three adenomas with a 2p21 translocation. In addition, <it>NIS </it>(<it>sodium-iodide symporter</it>) gene expression was measured on 34 of the pathological thyroid samples.</p> <p>Results</p> <p>Results illustrated that <it>THADA </it>expression in normal thyroid tissue was significantly higher (<it>p </it>< 0.0001, exact Wilcoxon test) than in the other tissues. Significant differences were also found between non-malignant pathological thyroid samples (goiters and adenomas) and malignant tumors (<it>p </it>< 0.001, Wilcoxon test, t approximation), anaplastic carcinomas (ATCs) and all other samples and also between ATCs and all other malignant tumors (<it>p </it>< 0.05, Wilcoxon test, t approximation). Furthermore, in thyroid tumors <it>THADA </it>mRNA expression was found to be inversely correlated with <it>HMGA2 </it>mRNA. <it>HMGA2 </it>expression was recently identified as a marker revealing malignant transformation of thyroid follicular tumors. A correlation between <it>THADA </it>and <it>NIS </it>has also been found in thyroid normal tissue and malignant tumors.</p> <p>Conclusions</p> <p>The results suggest <it>THADA </it>being a marker of dedifferentiation of thyroid tissue.</p
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