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Several Cell Lines (several + cell_line)
Selected AbstractsNeurocutaneous syndrome with mental delay, autism, blockage in intracellular vescicular trafficking and melanosome defectsEUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2006S. Buoni We evaluated a 11-year-old male patient with mental delay, autism and brownish and whitish skin spots. The former resembled those of neurofibromatosis, the latter those of tuberous sclerosis. The patient received a complete clinical work-up to exclude neurofibromatosis, tuberous sclerosis, or any other known neurocutaneous disease, with biochemistry, chromosome analysis and analysis of skin specimens. Being all the other tests not significant, two main ultrastructural defects were observed. The first was a blockage in intracellular vescicular trafficking with sparing of the mitochondria; the second an aberrant presence of melanosomes in vacuoles of several cell lines and abnormal transfer of these organelles to keratinocytes. This patient presented with a unique clinical picture distinct from neurofibromatosis or tuberous sclerosis or any other known neurocutaneous disease. The ultrastructural abnormalities suggested a defect in cell trafficking involving several cell lines and compartments. [source] Therapy with Cell Encapsulation for Substitution of Organ Function and Tumor Treatment,ADVANCED ENGINEERING MATERIALS, Issue 8 2009J. Matthias Löhr Cell encapsulation represents an innovative technique. However, clinical applications are sparse. Most experiments and clinical studies have been performed with either alginate or cellulose sulfate capsules, containing several cell lines and a broad variety of applications, ranging all the way from substitution for impaired organ function and release of cytokines or growth factors to gene-directed enzyme prodrug therapy. A few clinical studies have been conducted and/or are under way. [source] The A-subunit of surface-bound Shiga toxin stimulates clathrin-dependent uptake of the toxinFEBS JOURNAL, Issue 16 2005Maria L. Torgersen Shiga toxin can be internalized by clathrin-dependent endocytosis in different cell lines, although it binds specifically to the glycosphingolipid Gb3. It has been demonstrated previously that the toxin can induce recruitment of the toxin,receptor complex to clathrin-coated pits, but whether this process is concentration-dependent or which part of the toxin molecule is involved in this process, have so far been unresolved issues. In this article, we show that the rate of Shiga toxin uptake is dependent on the toxin concentration in several cell lines [HEp-2, HeLa, Vero and baby hamster kidney (BHK)], and that the increased rate observed at higher concentrations is strictly dependent on the presence of the A-subunit of cell surface-bound toxin. Surface-bound B-subunit has no stimulatory effect. Furthermore, this increase in toxin endocytosis is dependent on functional clathrin, as it did not occur in BHK cells after induction of antisense to clathrin heavy chain, thereby blocking clathrin-dependent endocytosis. By immunofluorescence, we show that there is an increased colocalization between Alexa-labeled Shiga toxin and Cy5-labeled transferrin in HeLa cells upon addition of unlabeled toxin. In conclusion, the data indicate that the Shiga toxin A-subunit of cell surface-bound toxin stimulates clathrin-dependent uptake of the toxin. Possible explanations for this phenomenon are discussed. [source] Growth inhibition of mammalian cells by eosinophil cationic proteinFEBS JOURNAL, Issue 1 2002Takashi Maeda Eosinophil cationic protein (ECP), one of the major components of basic granules of eosinophils, is cytotoxic to tracheal epithelium. However, the extent of this effect on other cell types has not been evaluated in vitro. In this study, we evaluated the effect of ECP on 13 mammalian cell lines. ECP inhibited the growth of several cell lines including those derived from carcinoma and leukemia in a dose-dependent manner. The IC50 values on A431 cells, MDA-MB-453 cells, HL-60 cells and K562 cells were,estimated to be ,,1,5 µm. ECP significantly suppressed the size of colonies of A431 cells, and decreased K562 cells in G1/G0 phase. However, there was little evidence that ECP killed cells in either cell line. These effects of ECP were not enhanced by extending its N-terminus. Rhodamine B isothiocyanate-labeled ECP started to bind to A431 cells after 0.5 h and accumulated for up to 24 h, indicating that specific affinity for the cell surface may be important. The affinity of ECP for heparin was assessed and found to be reduced when tryptophan residues, one of which is located at a position in the catalytic subsite of ribonuclease in ECP, were modified. The growth-inhibitory effect was also attenuated by this modification. These results suggest that growth inhibition by ECP is dependent on cell type and is cytostatic. [source] Complete and unambiguous assignments of 1H and 13C chemical shifts of new arylamino derivatives of ortho -naphthofuranquinonesMAGNETIC RESONANCE IN CHEMISTRY, Issue 12 2008Eufrānio N. da Silva Jśnior Abstract Six new nor-,-lapachones have been synthesized from reaction of 3-bromo-nor-,-lapachone with arylamines. These derivatives have potent anticancer properties against several cell lines. Here, we report complete unambiguous assignments of 1H and 13C chemical shifts of the new compounds. The assignments were made using a combination of one- and two-dimensional NMR techniques (1H, 13C, 1H1H COSY, 1H13C HSQC, and 1H13C HMBC). Copyright © 2008 John Wiley & Sons, Ltd. [source] Functional Expression, Targeting and Ca2+ Signaling of a Mouse Melanopsin-eYFP Fusion Protein in a Retinal Pigment Epithelium Cell Line,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2008Maikel E. Giesbers Melanopsin, first discovered in Xenopus melanophores, is now established as a functional sensory photopigment of the intrinsically photosensitive retinal ganglion cells. These ganglion cells drive circadian rhythm and pupillary adjustments through projection to the brain. Melanopsin shares structural similarities with all known opsins. Comprehensive characterization of melanopsin with respect to its spectral properties, photochemical cascade and signaling partners requires a suitable recombinant system and high expression levels. This combination has not yet been described. To address this issue, we have expressed recombinant mouse melanopsin in several cell lines. Using enhanced yellow fluorescent protein (eYFP) as a visualization tag, expression was observed in all cell lines. Confocal microscopy revealed that melanopsin was properly routed to the plasma membrane only in retinal pigment epithelium (RPE)-derived D407 cells and in human embryonic kidney (HEK) cells. Further, we performed intracellular calcium measurements in order to probe the melanopsin signaling activity of this fusion protein. Transfected cells were loaded with the calcium indicator Fura2-AM. Upon illumination, an immediate but transient calcium response was observed in HEK as well as in D407 cells, while mock-transfected cells showed no calcium response under identical conditions. Supplementation with 11- cis retinal or all- trans retinal enhanced the response. After prolonged illumination the cells became desensitized. Thus, RPE-derived cells expressing recombinant melanopsin may constitute a suitable system for the study of the structural and functional characteristics of melanopsin. [source] Improved Fermentation Processes for NS0 Cell Lines Expressing Human Antibodies and Glutamine SynthetaseBIOTECHNOLOGY PROGRESS, Issue 1 2003Jonathan Dempsey To meet the increasing requirement for therapeutic antibodies to conduct clinical trials, an enhanced culture medium and fed-batch process was developed for GS-NS0 cell lines. This process was shown to produce high concentrations of monoclonal antibodies for several cell lines expressing different antibodies. Cells were adapted to growth in a glutamine- and serum-free medium containing bovine serum albumin (BSA), cholesterol, and transferrin. A number of amino acids were found to be depleted during cell culture. The concentrations of these amino acids were increased, and further cell culture analyses were performed. This process of cell growth and analysis was repeated over multiple cycles until no depletion was detected. This resulted in an amino acid supplement that was shown to be generic and enhanced antibody productivity up to 5-fold for the three cell lines tested. Transferrin was replaced using tropolone, a lipophilic iron chelator and ferric ammonium citrate. Cell growth was equivalent to that in transferrin-containing medium over the wide ranges tested. A concentrated feed solution, based on the amino acid supplement and the components of the serum-and protein-free supplements, was formulated. Addition of this feed in response to metabolic requirements resulted in a harvest titer a further 2-fold higher than the enhanced culture medium. Harvest antibody titers of up to 600 mg/L were achieved for three cell lines expressing different antibodies, representing an increase of 10-fold over the starting concentrations. [source] Mutant p53 melanoma cell lines respond differently to CP-31398-induced apoptosisBRITISH JOURNAL OF DERMATOLOGY, Issue 5 2005C.K. Ho Summary Background, p53, a commonly mutated gene in human cancers, participates in cell cycle arrest, DNA repair and apoptosis. A small pharmacological compound, CP-31398, was found to have the ability to promote proper p53 protein folding, activate p53 transcription of downstream targets, and slow tumour growth in mice. Additionally, CP-31398 was found to be able to convert mutant p53 to wild-type conformation in several cell lines. Objectives, To examine if CP-31398 can revert all mutant p53 proteins to wild-type function. Methods, We studied a series of apoptotic responses to CP-31398 in three melanoma cell lines varying in p53 mutation status. Results, Upon a moderate dose of CP-31398 treatment (15 µg mL,1), only the wild-type p53 MMRU and the single p53 point mutation MeWo cells exhibited apoptosis. Another melanoma cell line, Sk-mel-110, containing multiple p53 mutations, did not exhibit apoptosis. Although CP-31398 enhanced overall p53 protein level, its ability to promote proper folding of p53 protein was limited to CP-31398-sensitive MMRU and MeWo cells. These sensitive cells showed an increased Bax and PUMA transcription, altered mitochondrial membrane potential, followed by the release of cytochrome c, and cleaved caspase-9 and caspase-3. We also demonstrated that Apaf-1 was not involved in CP-31398-mediated apoptosis. Conclusions, Our results suggest that the ability of CP-31398 to revert mutant p53 proteins to wild-type conformation may be correlated to p53 mutational status. More studies are necessary, to further investigate the effect of CP-31398 on mutant p53 and its potential applications as an anticancer agent. [source] The Laulimalide Family: Total Synthesis and Biological Evaluation of Neolaulimalide, Isolaulimalide, Laulimalide and a Nonnatural AnalogueCHEMISTRY - A EUROPEAN JOURNAL, Issue 24 2009Andreas Gollner Dipl.-Ing. Abstract A sensitive family: The first total synthesis of the antitumor agents neolaulimalide and isolaulimalide as well as a highly efficient route to laulimalide is described. A Kulinkovich reaction followed by a cyclopropyl,allyl rearrangement is used to install the exo -methylene group. The cytotoxicity of neolaulimalide could be confirmed for the first time since its original isolation and it could be shown that it induces tubulin polymerization as efficiently as laulimalide. We herein describe in full detail the first total synthesis of the antitumor agents neolaulimalide and isolaulimalide as well as a highly efficient route to laulimalide. A Kulinkovich reaction followed by a cyclopropyl,allyl rearrangement is used to install the exo -methylene group. The C2,C16 aldehyde fragment is coupled with the C17,C28 sulfone fragments by a highly (E)-selective Julia,Lythgoe,Kocienski olefination to deliver the key intermediates of all three syntheses. Various conditions for the Yamaguchi macrolactonization are applied to close the individual macrocycles. Finally a carefully elaborated endgame was developed to solve the problem of acyl migration in the case of neolaulimalide. All compounds were tested against several cell lines. The cytotoxicity of neolaulimalide could be confirmed for the first time since its original isolation and it could be shown that it induces tubulin polymerization as efficiently as laulimalide. [source] |