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1.

001-es BibID:BIBFORM006025
Első szerző:Balázs Margit (sejtbiológus, molekuláris genetikus)
Cím:Fluorescent tetradecanoylphorbol acetate : a novel probe of phorbol ester binding domains / Balázs, M., Szöllösi, J., Lee, W. C., Haugland, R. P., Guzikowski, A. P., Fulwyler, M. J., Damjanovich, S., Feuerstein, B. G., Pershadsingh, H. A.
Dátum:1991
Megjegyzések:Protein kinase C (PKC) has a prominent role in signal transduction of many bioactive substances. We synthesized the fluorescent derivative, phorbol-13-acetate-12-N-methyl-N-4-(N,N'-di(2-hydroxyethyl)amino)-7-n itr obenz-2-oxa-1,3-diazole-aminododecanoate (N-C12-Ac(13)) of 12-O-tetradecanoylphorbol-13-acetate (TPA) to monitor the location of phorbol ester binding sites and evaluate its potential use as a probe of PKC in viable cells. The excitation maximum wavelength of N-C12-Ac(13) is close to 488 nm, facilitating its use in argon-ion laser flow and imaging cytometry. When incubated with 100 nM N-C12-Ac(13) at 25 degrees C, P3HR-1 Burkitt lymphoma cells accumulated the dye rapidly, reaching maximum fluorescence within 25 min, 20-fold above autofluorescence. Addition of unlabeled TPA significantly decreased the fluorescence of N-C12-Ac(13) stained cells in a dose-dependent manner indicating specific displacement of the bound fluoroprobe. Competitive displacement of [3H]-phorbol-12,13-dibutyrate ([3H]-PBu2) from rat brain cytosol with N-C12-Ac(13) gave an apparent dissociation constant (Kd) of 11 nM. N-C12-Ac(13) possessed biological activity similar to TPA. Like TPA (final concentration 65 nM) N-C12-Ac(13), at a lower concentration (51 nM), induced expression of Epstein-Barr viral glycoprotein in P3HR-1 cells, differentiation of promyelocytic HL60 cells, and caused predicted changes in the mitotic cycle of histiocytic DD cells. Microspectrofluorometric images of single cells labeled with N-C12-Ac(13) showed bright fluorescence localized intracellularly and dim fluorescence in the nuclear region, consistent with dye binding mainly to cytoplasmic structures and/or organelles and being mostly excluded from the nucleus. Because of the high level of non-specific binding of N-C12-Ac(13), this probe is not ideal for visualizing PKC in intact cells, but would be a valuable fluoroprobe to investigate the kinetic properties of purified PKC. Also, knowledge gained from these studies allows us to predict structures of fluorescent phorbols likely to have less non-specific binding and, consequently, be potentially useful for monitoring PKC in viable cells.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
analysis
Animal
Antigens,Viral
Binding Sites
Brain Chemistry
Cell Cycle
chemical synthesis
Cytosol
Dyes
Female
Flow Cytometry
Fluorescence
Fluorescence Polarization
Fluorescent Dyes
Gene Expression
Herpesvirus 4,Human
Image Processing,Computer-Assisted
immunology
metabolism
Oxadiazoles
pharmacology
Phorbol Esters
Protein Kinase C
Rats
Rats,Inbred Strains
Signal Transduction
Support,Non-U.S.Gov't
Support,U.S.Gov't,P.H.S.
Tetradecanoylphorbol Acetate
Tumor Cells,Cultured
Megjelenés:Journal of Cellular Biochemistry. - 46 : 3 (1991), p. 266-276. -
További szerzők:Szöllősi János (1953-) (biofizikus) Lee, W. C. Haugland, R. P. Guzikowski, A. P. Fulwyler, Mack J. Damjanovich Sándor (1936-2017) (biofizikus) Feuerstein, Burt G. Pershadsingh, Harrihar A.
Internet cím:elektronikus változat
Borító:

2.

001-es BibID:BIBFORM004634
035-os BibID:(scopus)0032101894 (wos)000073937700007
Első szerző:Nagy Péter (biofizikus)
Cím:EGF-induced redistribution of erbB2 on breast tumor cells : flow and image cytometric energy transfer measurements / Nagy, P., Bene, L., Balazs, M., Hyun, W. C., Lockett, S. J., Chiang, N. Y., Waldman, F., Feuerstein, B. G., Damjanovich, S., Szollosi, J.
Dátum:1998
Megjegyzések:erbB2, a member of the epidermal growth factor (EGF) receptor-type tyrosine kinase receptor family, is overexpressed in breast carcinomas with poor prognosis. We examined the cell surface association of this receptor with itself and with other cell surface proteins by the Forster-type fluorescence resonance energy transfer using whole antibodies and Fab fragments. We found that erbB2 molecules homoassociate in unstimulated SK-BR-3, BT474 and BT474-M (a metastatic version of the parent BT474 line) breast tumor cells, and that the interaction was enhanced by EGF treatment in suspensions of SK-BR-3 and BT474-M cells. BT474 cells (with low EGF receptor expression) and attached SK-BR-3 cells do not respond to EGF. Image microscopic energy transfer measurements found considerable pixel-by-pixel heterogeneity in the homoassociation state of erbB2. In accordance with the EGF-induced redistribution of erbB2, EGF receptor was found to be in close proximity to erbB2 in FRET measurements. By labeling different epitopes on erbB2 and the lipid bilayer, we were able to prepare an epitope map of erbB2 molecule. Our data suggest the existence of dynamic cell surface patterns of erbB2 and point to functions fulfilled by these molecular complexes.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
analysis
biosynthesis
Breast Neoplasms
Carcinoma
Cell Membrane
chemistry
drug effects
Energy Transfer
Epidermal Growth Factor
Female
Flow Cytometry
Fluorescence
Human
Hungary
metabolism
methods
Models
Molecular
pharmacology
Receptor
erbB-2
Receptors
Transferrin
Support
Non-U.S.Gov't
Tumor Cells,Cultured
Squamous Cell
ultrastructure
Megjelenés:Cytometry. - 32 : 2 (1998), p. 120-131. -
További szerzők:Bene László (1963-) (biofizikus) Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Hyun, William C. Lockett, Steven J. Chiang, Nancy Y. Waldman, Frederick Feuerstein, Burt G. Damjanovich Sándor (1936-2017) (biofizikus) Szöllősi János (1953-) (biofizikus)
Internet cím:elektronikus változat
DOI
Borító:

3.

001-es BibID:BIBFORM004934
Első szerző:Szöllősi János (biofizikus)
Cím:ERBB-2 (HER2/neu) gene copy number, p185HER-2 overexpression, and intratumor heterogeneity in human breast cancer / Szollosi, J., Balazs, M., Feuerstein, B. G., Benz, C. C., Waldman, F. M.
Dátum:1995
Megjegyzések:Amplification of the ERBB-2 (HER-2/neu) gene is accompanied by overexpression of its cell surface receptor product, p185HER-2. Heterogeneity has been observed for both the gene copy number and the level of overexpression of its protein product. To better understand their relationship, correlation between the level of cellular expression of p185HER-2 and ERBB-2 gene amplification was studied in four human breast cancer cell lines (BT-474, SK-BR-3, MDA-453, and MCF-7) and in a primary human breast tumor sample. The relative expression of p185HER-2 was measured by immunofluorescence by using flow and/or image cytometry while correlated DNA analysis was performed on the same cells by fluorescence in situ hybridization to determine ERBB-2 gene and chromosome 17 copy numbers. Marked heterogeneity was observed in both protein expression and ERBB-2 copy number. Despite this heterogeneity, and in accordance with previous studies, the average levels of p185HER-2 expression correlated well with average ERBB-2 gene copy numbers in the four lines examined (r = 0.99). When the relationship between copy number and protein expression was studied on a cell-by-cell basis, p185HER-2 expression correlated with both the absolute number of ERBB-2 gene copies/cell (r = 0.59-0.63) and chromosome 17 copy number (r = 0.45-0.61). It is of interest that there was weak or no correlation between p185HER-2 protein expression and the ERBB-2 copy number:chromosome 17 copy number ratio (r = 0.0-0.25). In more than one-half of cells expressing a high level of p185HER-2, the chromosome 17 copy number was high (two or three times the average copy number), whereas < 2% of an unselected population had a high chromosome 17 copy number. Bromodeoxyuridine incorporation indicated that the S-phase-labeling index was homogeneous across various p185HER-2-expressing subpopulations in the SK-BR-3 cell line. Analysis of the primary breast tumor sample showed results similar to the cell lines, supporting the strong possibility of a mechanistic link among p185HER-2 overexpression, ERBB-2 amplification, and high chromosome 17 copy number.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
analysis
biosynthesis
Breast Neoplasms
Cell Line
Chromosomes,Human,Pair 17
Dna
Female
Fluorescence
Gene Amplification
Gene Dosage
Genes,erbB-2
genetics
Human
Hybridization
Image Cytometry
Receptor,erbB-2
Support,Non-U.S.Gov't
Support,U.S.Gov't,P.H.S.
Tumor Cells,Cultured
Megjelenés:Cancer Research. - 55 : 22 (1995), p. 5400-5407. -
További szerzők:Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Feuerstein, Burt G. Benz, Christopher C. Waldman, Frederick
Internet cím:elektronikus változat
Borító:

4.

001-es BibID:BIBFORM006077
Első szerző:Vereb György (biofizikus, orvos)
Cím:Depletion of intracellular calcium stores facilitates the influx of extracellular calcium in platelet derived growth factor stimulated A172 glioblastoma cells / Vereb, G., Jr., Szollosi, J., Matyus, L., Balazs, M., Hyun, W. C., Feuerstein, B. G.
Dátum:1996
Megjegyzések:Calcium signaling in non-excitable cells is the consequence of calcium release from intracellular stores, at times followed by entry of extracellular calcium through the plasma membrane. To study whether entry of calcium depends upon the level of saturation of intracellular stores, we measured calcium channel opening in the plasma membrane of single confluent A172 glioblastoma cells stimulated with platelet derived growth factor (PDGF) and/or bradykinin (BK). We monitored the entry of extracellular calcium by measuring manganese quenching of Indo-1 fluorescence. PDGF raised intracellular calcium concentration ([Ca2+]i) after a dose-dependent delay (tdel) and then opened calcium channels after a dose-independent delay (tch). At higher doses (> 3 nM), BK increased [Ca2+]i after a tdel approximately 0 s, and tch decreased inversely with both dose and peak [Ca2+]i. Experiments with thapsigargin (TG), BK, and PDGF indicated that BK and PDGF share intracellular Ca2+ pools that are sensitive to TG. When these stores were depleted by treatment with BK and intracellular BAPTA, tdel did not change, but tch fell to almost 0 s in PDGF stimulated cells, indicating that depletion of calcium stores affects calcium channel opening in the plasma membrane. Our data support the capacitative model for calcium channel opening and the steady-state model describing quantal Ca2+ release from intracellular stores.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
antagonists and inhibitors
Biophysics
Bradykinin
Ca(2+)-Transporting ATPase
Calcium
Calcium Channel Blockers
Calcium Channels
Calcium Signaling
Dose-Response Relationship,Drug
drug effects
Fluorescence
Glioblastoma
Human
Hungary
Lanthanum
Manganese
metabolism
Neuroglia
pharmacology
Platelet-Derived Growth Factor
Signal Transduction
Support, Non-U.S. Gov't
Support, U.S.Gov't, Non-P.H.S.
Support, U.S.Gov't, P.H.S.
Terpenes
Thapsigargin
Tumor Cells,Cultured
Megjelenés:Cytometry. - 24 : 1 (1996), p. 64-73. -
További szerzők:Szöllősi János (1953-) (biofizikus) Mátyus László (1956-) (biofizikus) Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Hyun, William C. Feuerstein, Burt G.
Internet cím:Intézményi repozitóriumban (DEA) tárolt változa
Borító:

5.

001-es BibID:BIBFORM004890
035-os BibID:(scopus)26444597596 (wos)000232299300017
Első szerző:Vereb György (biofizikus, orvos)
Cím:Biphasic calcium response of platelet-derived growth factor stimulated glioblastoma cells is a function of cell confluence / Vereb, G., Feuerstein, B. G., Hyun, W. C., Fulwyler, M. J., Balazs, M., Szollosi, J.
Dátum:2005
ISSN:1552-4922
Megjegyzések:Previous reports have linked the spiking or two-phased character of calcium transients evoked by platelet-derived growth factor (PDGF) to the position of cells in the cell cycle without regard to cell-cell contact and communication. Because cell confluence can regulate growth factor receptor expression and dephosphorylation, we investigated the effect of cell culture confluence and cell cycle on calcium responses of PDGF-BB-stimulated A172 glioblastoma cells. METHODS: Digital imaging cytometry was used to correlate the peak and duration of calcium response with bromodeoxyuridine positivity and DNA content and with culture confluence on a cell-by-cell basis. RESULTS: In serum-starved cultures, complete two-phase calcium signals and shorter, lower spikes occurred independent of cell cycle phase. However, the confluence of cell culture seemed essential for inducing a complete response because cells in sparse cultures exhibited mostly short spikes with lower peaks or no transients at all. CONCLUSION: Because cell confluence, by virtue of cell-cell contacts, is assumed to be an important regulator of proliferation, one is tempted to speculate that in transformed cells the ability to produce stronger growth signals upon reaching confluence and facing contact inhibition could provide a proliferative advantage.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
analysis
Biophysics
Bromodeoxyuridine
Calcium
Calcium Signaling
Cell Adhesion
Cell Culture
Cell Cycle
Cells
Cells,Cultured
Dna
drug effects
genetics
Glioblastoma
Hungary
metabolism
methods
pathology
pharmacology
Platelet-Derived Growth Factor
Research
Spectrometry,Fluorescence
Support
Megjelenés:Cytometry. Part A. - 67 : 2 (2005), p. 172-179. -
További szerzők:Feuerstein, Burt G. Hyun, William C. Fulwyler, Mack J. Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Szöllősi János (1953-) (biofizikus)
Internet cím:elektronikus változat
DOI
Borító:
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