Publications (6)14.88 Total impact
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Article: Cellular distribution of metastasis suppressor 1 and the shape of cell bodies are temporarily altered in Engrailed-2 overexpressing cerebellar Purkinje cells.
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ABSTRACT: Metastasis suppressor 1 (MTSS1, BEG4, MIM) is well described for its function as a metastasis suppressor gene and is expressed in a variety of tissues. However, only little is known about its expression in the central nervous system (CNS), and functions within the CNS have not been addressed so far. Here, we show that MTSS1 was expressed in postmitotic neurons of the cerebellar cortex. Within Purkinje cells, higher amounts of MTSS1 were temporarily localized in the axonal somatic compartment than in the dendritic compartment. In L7En-2 transgenic mice, in which the segment-polarity gene and regulator of neuronal maturation Engrailed-2 is overexpressed specifically in cerebellar Purkinje cells, MTSS1 was homogenously distributed within Purkinje cell somata throughout development. In parallel to the altered distribution of MTSS1 in L7En-2 Purkinje cells, L7En-2 Purkinje cell somata were distorted and in some cells invaginations of the plasma membrane were observed. These invaginations were only found in L7En-2 neurons, and displayed multiple synapses which could not be seen at the smooth surface of wildtype Purkinje cell somata. Current knowledge about MTSS1 function in vitro and the correlation between MTSS1 localization and the occurrence of membrane alterations in L7En-2 Purkinje cells described here suggest that MTSS1 might be involved in shaping neuronal membranes in vivo.Neuroscience 06/2011; 189:68-78. · 3.38 Impact Factor -
Article: Magnetic nanoparticles coated with tailored polysaccharide-based shells – Interaction with human cells
Journal of Magnetism and Magnetic Materials 01/2009; 321(10):1469–1473. · 1.78 Impact Factor -
Article: Improvement of the separation of tumour cells from peripheral blood cells using magnetic nanoparticles
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ABSTRACT: Circulating tumour cells are a key challenge in tumour therapy. Numerous approaches are on the way to achieving the elimination of these potential sources of metastasis formation. Antibody-directed magnetic cell sorting is supposed to enrich tumour cells with high selectivity, but low efficiency. The short term application of carboxymethyl dextran (CMD) coated magnetit/maghemit nanoparticles allows the discrimination of tumour cells from leukocytes. In the present work we show that the interaction of CMD nanoparticles is cell-type specific and time dependent. The breast cancer cell line MCF-7 and the CML cell line K-562 are characterized by a rapid and high interaction rate, whereas leukocytes exhibit a decelerated behaviour. The addition of carboxymethyl dextran or glucose stimulated the magnetic labelling of leukocytes. The variation of the degree of substitution of dextran with carboxymethyl groups did not affect the labelling profile of leukocytes and MCF-7 cells. In order to verify the in vitro results, whole blood samples from 13 cancer patients were analysed ex vivo. Incubation of the purified leukocyte fraction with CMD nanoparticles in the presence of low amounts of plasma reduced the overall cell content in the positive fraction. In contrast, the absolute number of residual tumour cells in the positive fraction was 90% of the initial amount.Journal of Physics Condensed Matter 09/2006; 18(38):S2865. · 2.55 Impact Factor -
Article: Differential interaction of magnetic nanoparticles with tumor cells and peripheral blood cells.
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ABSTRACT: The separation of tumor cells from healthy cells is a vital problem in oncology and hematology, especially from peripheral blood. Magnetic assisted cell sorting (MACS) is a possibility to fulfill these needs. Tumor cell lines and leukocytes from peripheral blood were incubated with carboxymethyl dextran-coated magnetic nanoparticles under various conditions and separated by MACS. We studied the interaction of magnetic nanoparticles devoid of antibodies with healthy and tumor cells. The magnetic nanoparticles interact with tumor cells and leukocytes and are located predominantly within the cell cytoplasm. Incubation of cell culture cells with magnetic nanoparticles led to a labeling of these cells without reduced biological properties for at least 14 days. The interaction of the magnetic nanoparticles with cells depends on several factors. The ionic strength (osmolality) of the solvent plays an important role. We could show that an increase in osmolality led to a dramatic reduction of labeled leukocytes. Tumor cells, however, are mildly affected. This could be detected not only in pure cultures of tumor cells or leukocytes but also in mixed cell populations. This observation gives us the opportunity to selectively label and separate tumor cells but not leukocytes from the peripheral blood.Journal of Cancer Research and Clinical Oncology 06/2006; 132(5):287-92. · 2.56 Impact Factor -
Article: Synthesis of oligonucleotide-functionalized magnetic nanoparticles and study on their in vitro cell uptake
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ABSTRACT: Carboxymethyl dextran (CMD) with varying degrees of substitution was prepared and used as biocompatible coating for magnetic iron oxide nanoparticles. An oligonucleotide (19-mer) was coupled to the CMD-coated particles as a model compound for DNA fragments. Transmission electron microscopy investigations on the cellular uptake of the particles by different tumor cell lines demonstrated that both the CMD-coated and the oligonucleotide-coupled particles are internalized by the cells and deposited in cellular endosomes. The nanoparticles prepared have potential applications in tumor diagnosis and therapy.Applied Organometallic Chemistry 01/2004; 18:514-519. · 2.06 Impact Factor -
Article: Bone morphogenetic protein 2 (BMP-2) induces sequential changes of Id gene expression in the breast cancer cell line MCF-7.
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ABSTRACT: Bone morphogenetic proteins (BMPs) are involved in the development of various organs including the mammary gland. They are well-regulated and act in a time-, concentration- and cell-type-specific manner. We found that BMP-2 is expressed in primary breast tumor tissue samples and in breast cancer cell lines. Hybridization of labeled cDNA, obtained from the breast cancer cell line MCF-7, against the Atlas human cDNA expression array revealed differential gene expression depending on BMP-2 treatment. The most prominent changes were observed for the helix-loop-helix proteins Id-1, Id-2 and Id-3. Id-1 expression had increased severalfold after 4 h and was even higher after 24 h. Id-2 and Id-3 were more strongly induced after 4 h and showed no further significant change after 24 h. Analysis of cell-cycle distribution revealed a marked increase of the sub-G1 phase after 48 h in serum-deprived cells. In the presence of BMP-2 no change was observed over 48 h indicating that BMP-2 does not induce apoptosis. In addition, expression of caspase-3 was reduced in BMP-2-treated cells after 24 h. In summary, our results clearly indicate that BMP-2 is a susceptibility factor keeping the cells ready for the integration of various other signals for cell progression.Journal of Cancer Research and Clinical Oncology 06/2000; 126(5):271-9. · 2.56 Impact Factor
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Institutions
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2009
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Universitätsklinikum Jena
Jena, Thuringia, Germany
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