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Same Cell Line (same + cell_line)
Selected AbstractsInvolvement of Cdc42 and Rac small G proteins in invadopodia formation of RPMI7951 cellsGENES TO CELLS, Issue 12 2003Hirokazu Nakahara Background:, Invadopodia are membrane protrusions into the extracellular matrix by aggressive tumour cells. These structures are associated with sites of matrix degradation and invasiveness of malignant tumour cells in an in vitro fibronectin degradation/invasion assay. The Rho family small G proteins, consisting of the Rho, Rac and Cdc42 subfamilies, are implicated in various cell functions, such as cell shape change, adhesion, and motility, through reorganization of the actin cytoskeleton. We studied the roles of the Rho family small G proteins in invadopodia formation. Results:, We first demonstrated that invadopodia of RPMI7951 human melanoma cells extended into the matrix substratum on a vertical view using a laser scanning confocal microscope system. We confirmed that invadopodia were rich in actin filaments (F-actin) and visualized clearly with F-actin staining on a vertical view as well as on a horizontal view. We then studied the roles of Rho, Rac, and Cdc42 in invasiveness of the same cell line. In the in vitro fibronectin degradation/invasion assay, a dominant active mutant of Cdc42 enhanced dot-like degradation, whereas a dominant active mutant of Rac enhanced diffuse-type degradation. Furthermore, frabin, a GDP/GTP exchange protein for Cdc42 with F-actin-binding activity, enhanced both dot-like and diffuse-type degradation. However, a dominant active mutant of Rho did not affect the fibronectin degradation. Moreover, inhibition of phosphatidylinositol-3 kinase (PI3K) disrupted the Rac and Cdc42-dependent actin structures and blocked the fibronectin degradation. Conclusion:, These results suggest that Cdc42 and Rac play important roles in fibronectin degradation and invasiveness in a coordinate manner through the frabin-Cdc42/Rac-PI3K signalling pathway. [source] Assessment by M-FISH of karyotypic complexity and cytogenetic evolution in bladder cancer in vitroGENES, CHROMOSOMES AND CANCER, Issue 4 2005Sarah V. Williams We carried out multiplex fluorescence in situ hybridization (M-FISH) and follow-up FISH studies on a large series of transitional cell carcinoma (TCC) cell lines and 2 normal urothelium,derived cell lines, several of which have not had karyotypes reported previously. M-FISH analysis, with appropriate follow-up, complements conventional cytogenetic analysis and array CGH studies, allowing a more accurate definition of karyotype. The detailed karyotypic data obtained will assist in choosing suitable cell lines for functional studies and identifies common losses, gains, breakpoints and potential fusion gene sites in TCC. We have shown changes in cell lines RT112 and DSH1 following prolonged culture, and differences in karyotype, between RT112 cultures obtained from different sources. We propose a model for the evolutionary changes leading to these differences. A comparison with the literature found other examples of differences in cell-line karyotypes between different sources. Nevertheless, several karyotypic changes were preserved between different sources of the same cell line and were also seen in more than one cell line. These may be the most important changes and include ,8p, +20, 4q,, 10p,, 16p, and breaks in 8p21. We carried out a more detailed follow-up of some regions, which showed involvement of 8p breaks and losses in 15 of 16 TCC cell lines but in neither of the normal urothelium,derived cell lines. Some changes represented distal loss, whereas others were small deletions. Further study of this region is warranted. Supplementary material for this article can be found on the Genes, Chromosomes and Cancer website at http://www.interscience.wiley.com/jpages/1045-2257/suppmat/index.html. © 2005 Wiley-Liss, Inc. [source] Poster Session BP07: Neurodegenerative DiseasesJOURNAL OF NEUROCHEMISTRY, Issue 2002F. Jayman Presynaptic terminals contain an abundant 140-amino acid phosphoprotein, dubbed ,-synuclein, which is accumulated in Lewy bodies typically observed in neurons in neurodegenerative diseases, such as Parkinson's disease. In this study, the role of ,-synuclein in regulating cycle, differentiation, and survival of neuronal cells was studied using a rat dopaminergic cell line ZN27D. To delineate specific effects of ,-synuclein the same cell line was engineered to express human ,-synuclein and a vector-transfected cell line RK27 was used as a second control. All three cell lines showed significant proliferation even in serum-free medium, and complete inhibition of cell division and differentiation could be achieved in the ZN27D cells only when both dibutyryl cAMP (dbcAMP) and retinoic acid were present. In contrast, the ,-synuclein expressing cells could be differentiated in the presence of only dbcAMP. Dose dependence of MPP+(1-methyl-4-phenylpyridinium iodide)-mediated caspase3 activation was studied in undifferentiated ZN27D cells. At 200 ,m MPP+ a significant cleavage of the caspase3 substrate PARP was observed and it was reversed in the presence of ,-synuclein. MPP+ also inhibited aminophospholipid translocase (APTL), a P-type ATPase that is responsible for inner plasma membrane localization of phophotidylserine in healthy cells. The role of ,-synuclein in regulating cell cycle, differentiation, APTL activity and cell death is being investigated further in the dopaminergic ZN27D cell line. [source] In-vitro antiproliferative effects on human tumour cell lines of extracts and jacaranone from Senecio leucanthemifolius PoiretJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2005M. R. Loizzo We have studied the cytotoxic activity of extracts and jacaranone from Senecio leucanthemifolius Poiret. Extracts from S. leucanthemifolius were able to inhibit the in-vitro proliferation of a series of human tumour cell lines. The dichloromethane extract demonstrated effective cytotoxic activity with an IC50 of 20.1 ,g mL,1 on the large cell carcinoma cell line COR-L23. The ethyl acetate extract showed an IC50 value of 5.0 ,g mL,1 and the butanol extract an IC50 value of 6.4 ,g mL,1 on the same cell line. A major active constituent of the dichloromethane extract was shown to be jacaranone, which was demonstrated to have a very strong activity against all of the tumour cell lines with IC50 values between 2.86 and 3.85 ,g mL,1, although it did not account for all the activity observed. Constituents of S. leucanthemifolius extracts were identified by GC/MS analysis and NMR. [source] Ultra scale-down approaches for clarification of mammalian cell culture broths in disc-stack centrifugesBIOTECHNOLOGY PROGRESS, Issue 6 2009Ferhana Zaman Abstract Ultra-scale down (USD) methodology developed by University College London for cell broth clarification with industrial centrifuges was applied to two common cell lines (NS0 and GS-CHO) expressing various therapeutic monoclonal antibodies. A number of centrifuges at various scales were used with shear devices operating either by high speed rotation or flow-through narrow channels. The USD methodology was found effective in accounting for both gravitational and shear effects on clarification performance with three continuous centrifuges at pilot and manufacturing scales. Different shear responses were observed with the two different cell lines and even with the same cell line expressing different products. Separate particle size analysis of the treated broths seems consistent with the shear results. Filterability of the centrifuged solutions was also evaluated to assess the utility of the USD approach for this part of the clarification operation. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] N-linked glycosylation is an important parameter for optimal selection of cell lines producing biopharmaceutical human IgGBIOTECHNOLOGY PROGRESS, Issue 1 2009Patrick H. C. van Berkel Abstract We studied the variations in N-linked glycosylation of human IgG molecules derived from 105 different stable cell lines each expressing one of the six different antibodies. Antibody expression was based on glutamine synthetase selection technology in suspension growing CHO-K1SV cells. The glycans detected on the Fc fragment were mainly of the core-fucosylated complex type containing zero or one galactose and little to no sialic acid. The glycosylation was highly consistent for the same cell line when grown multiple times, indicating the robustness of the production and glycan analysis procedure. However, a twofold to threefold difference was observed in the level of galactosylation and/or non-core-fucosylation between the 105 different cell lines, suggesting clone-to-clone variation. These differences may change the Fc-mediated effector functions by such antibodies. Large variation was also observed in the oligomannose-5 glycan content, which, when present, may lead to undesired rapid clearance of the antibody in vivo. Statistically significant differences were noticed between the various glycan parameters for the six different antibodies, indicating that the variable domains and/or light chain isotype influence Fc glycosylation. The glycosylation altered when batch production in shaker was changed to fed-batch production in bioreactor, but was consistent again when the process was scaled from 400 to 5,000 L. Taken together, the observed clone-to-clone glycosylation variation but batch-to-batch consistency provides a rationale for selection of optimal production cell lines for large-scale manufacturing of biopharmaceutical human IgG. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Two New Eremophilane-Type Sesquiterpenoids from the Rhizomes of Ligularia veitchiana (Hemsl.) GreenmHELVETICA CHIMICA ACTA, Issue 9 2008Cai-Fang Wang Abstract Two new eremophilane-type sesquiterpenoids eremophil-6-en-11-ol (1) and (7,,9,,10,)-9,10-epoxy-eremophilan-11-ol (2), together with a known eremophilane-type (6,,8,)-6,8-dihydroxyeremophil-7(11)-en-12-oic acid 12,8-lactone (3) were isolated from the rhizomes of Ligularia veitchiana. The structures of 1 and 2 were established by spectral analysis including 1H- and 13C-NMR, HSQC, HMBC, and HR-ESI-MS data. The compounds 1 and 3 were assessed against lung-cancer (A549) and stomach-cancer (BCG823) cell lines by the MTT method. The results showed that 1 exhibited significant inhibiting activities on the growth of these cancer cells with IC50 values between 1,100,,g/ml, whereas compound 3 had no effect on the same cell lines. [source] Identification of genes involved in radiation-induced G1 arrest,JOURNAL OF CHEMOMETRICS, Issue 10-11 2007Giuseppe Musumarra Abstract The advent of microarray gene expression technology permits the simultaneous analysis of the levels of expression of thousands of genes and provides large dataset requiring multivariate analysis tools. Multiple genetic factors may modulate the occurrence and magnitude of the arrest in the G1 phase of the cell cycle following exposure to ionizing radiation in human tumour cell lines. The ability to G1 arrest after exposure to gamma rays and the global gene expression profile, evaluated by cDNA microarray technology, have been reported for the National Cancer Institute (NCI) 60 tumour cell lines panel. The sensitivity of the tumour cell lines to radiations represents an activity fingerprinting that can be correlated by partial least squares (PLS) to the transcriptional profiles of the same cell lines. VIP values obtained by the PLS method are able to detect transcripts relevant to the radiation-induced G1 arrest. High VIP values were obtained for the basal levels of transcripts such as p21/Waf1/Cip1 and MDM2, that are well known for their roles in G1 arrest after irradiation. Novel functional relationships suggested by high VIP values can be investigated experimentally. As an example, in the present study, we report that the transcript for the FLJ11046 protein is induced dose-dependently by gamma-irradiation in a cell line with mutated p53, but not in cell lines with wild-type p53. Moreover specific silencing of FLJ11046 transcript by RNA interference technology results in a block of cell growth. Copyright © 2007 John Wiley & Sons, Ltd. [source] Decreased DNA repair rates and protection from heat induced apoptosis mediated by electromagnetic field exposureBIOELECTROMAGNETICS, Issue 2 2002Jacob G. Robison Abstract In this study, we demonstrate that electromagnetic field (EMF) exposure results in protection from heat induced apoptosis in human cancer cell lines in a time dependent manner. Apoptosis protection was determined by growing HL-60, HL-60R, and Raji cell lines in a 0.15 mT 60 Hz sinusoidal EMF for time periods between 4 and 24 h. After induction of apoptosis, cells were analyzed by the neutral comet assay to determine the percentage of apoptotic cells. To discover the duration of this protection, cells were grown in the EMF for 24 h and then removed for 24 to 48 h before heat shock and neutral comet assays were performed. Our results demonstrate that EMF exposure offers significant protection from apoptosis (P<.0001 for HL-60 and HL-60R, P<.005 for Raji) after 12 h of exposure and that protection can last up to 48 h after removal from the EMF. In this study we further demonstrate the effect of the EMF on DNA repair rates. DNA repair data were gathered by exposing the same cell lines to the EMF for 24 h before damaging the exposed cells and non-exposed cells with H2O2. Cells were allowed to repair for time periods between 0 and 15 min before analysis using the alkaline comet assay. Results showed that EMF exposure significantly decreased DNA repair rates in HL-60 and HL-60R cell lines (P<.001 and P<.01 respectively), but not in the Raji cell line. Importantly, our apoptosis results show that a minimal time exposure to an EMF is needed before observed effects. This may explain previous studies showing no change in apoptosis susceptibility and repair rates when treatments and EMF exposure were administered concurrently. More research is necessary, however, before data from this in vitro study can be applied to in vivo systems. Bioelectromagnetics 23:106,112, 2002. © 2002 Wiley-Liss, Inc. [source] Characterization of the epithelial cell adhesion molecule (EpCAM)+ cell population in hepatocellular carcinoma cell linesCANCER SCIENCE, Issue 10 2010Osamu Kimura Accumulating evidence suggests that cancer stem cells (CSC) play an important role in tumorigenicity. Epithelial cell adhesion molecule (EpCAM) is one of the markers that identifies tumor cells with high tumorigenicity. The expression of EpCAM in liver progenitor cells prompted us to investigate whether CSC could be identified in hepatocellular carcinoma (HCC) cell lines. The sorted EpCAM+ subpopulation from HCC cell lines showed a greater colony formation rate than the sorted EpCAM, subpopulation from the same cell lines, although cell proliferation was comparable between the two subpopulations. The in vivo evaluation of tumorigenicity, using supra-immunodeficient NOD/scid/,cnull (NOG) mice, revealed that a smaller number of EpCAM+ cells (minimum 100) than EpCAM, cells was necessary for tumor formation. The bifurcated differentiation of EpCAM+ cell clones into both EpCAM+ and EpCAM, cells was obvious both in vitro and in vivo, but EpCAM, clones sustained their phenotype. These clonal analyses suggested that EpCAM+ cells may contain a multipotent cell population. Interestingly, the introduction of exogenous EpCAM into EpCAM+ clones, but not into EpCAM, clones, markedly enhanced their tumor-forming ability, even though both transfectants expressed a similar level of EpCAM. Therefore, the difference in the tumor-forming ability between EpCAM+ and EpCAM, cells is probably due to the intrinsic biological differences between them. Collectively, our results suggest that the EpCAM+ population is biologically quite different from the EpCAM, population in HCC cell lines, and preferentially contains a highly tumorigenic cell population with the characteristics of CSC. (Cancer Sci 2010) [source] | ||||||||||||||||