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Results 451 - 500 of 1019
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Aterini S - - 1994
A number of agents stimulate transmembrane cell-signaling in different cell types through the formation of the second messenger diacylglycerol (DAG) which activates protein kinase C (PKC). The aim of this study was to investigate phospholipase C activation, DAG formation, and cellular adhesion to dialysis membranes after simulated dialytic treatment of ...
Enomoto T - - 1994
To investigate the responsiveness to phorbol ester-mediated malignant cell transformation of Balb/c 3T3 variant clones that were morphologically phorbol ester-sensitive and -resistant, we used an in vitro two-stage transformation assay in which cells were treated with 0.1 microgram/ml of MCA as an initiator and subsequently with 12-O-tetradecanoylphorbol-13-acetate (TPA) as a ...
Takahashi N - - 1994
The intermediate filament proteins which include vimentin, desmin, and the keratins are one of three major classes of cytoskeletal proteins in eukaryotic cells. In this study we found that most of the vimentin of undifferentiated HL60 and cells induced to differentiate either along the monocytoid pathway by 12-O-tetradecanoylphorbol-13-acetate (TPA) or ...
Jalava A - - 1994
In this study we have investigated DNA-protein interactions at an AP1-like motif of the neuropeptide tyrosine (NPY) promoter during in vitro differentiation of human neuroblastoma cells SH-SY5Y to mature nonproliferative sympathetic neuron-like cells. These neuroblast-like cells originate from the parental cell line SK-N-SH from which two phenotypically distinct major cell ...
Wang X H - - 1994
The proliferation of the human prostatic cancer JCA-1 cells showed a complex response to different concentrations of TPA. Whereas cells exposed for 24 h had growth reduction which was proportional to the concentration of TPA added to the culture media, they showed resistance to low (0.016 and 0.16 nM) but ...
Tohda M - - 1994
The differences of intracellular signalling mechanisms between muscarinic acetylcholine m1 and m3 receptors, which are coupled with polyphosphoinositide turnover, were examined by using m1- and m3-transfected NG108-15 cells. The c-fos mRNA was induced by 1 mM acetylcholine peak at 60 min in both m1 and m3 cells. The c-fos induction ...
Jones K T - - 1994
Proliferating cell nuclear antigen (PCNA) is a co-factor for DNA polymerase delta, which replicates genomic DNA during cell growth and division. Using a monoclonal antibody to PCNA (PC10) and conventional immunofluorescent techniques, we have compared the effect of differentiation stimuli on PCNA expression in normal and HPV immortalised keratinocytes. Two ...
Paulson A F - - 1994
We investigated whether the growth state of NRK cells (proliferating or quiescent by serum deprivation) affected the ability of oncogenic Ki-ras p21 and the protein kinase C activator, 12-O-tetradecanoylphorbol-13-acetate (TPA), to alter gap junctional communication. We evaluated gap junctional permeance by rate analysis of the transfer of a fluorescent dye, ...
Beckmann R - - 1994
The protein kinase C (PKC) alpha, beta and epsilon isoforms have distinct nuclear localizations in neuroblastoma x glioma hybrid cells NG 108-15. We found by immunoblotting that PKC alpha, beta II, delta and epsilon are the predominant isoforms in these cells. In contrast to other neuronal cell lines, none of ...
Solito E - - 1994
Lipocortin (annexin) 1 is a putative mediator of the inflammatory effects of glucocorticoids. By flow cytometric analysis (FACS) we have studied the effect of dexamethasone on the cellular localization of lipocortin 1. U-937 cells were incubated with or without 10 nM phorbol 12-myristate 13-acetate (PMA) to induce cell differentiation. Then ...
Venkataraman L - - 1994
Primary B cells are induced to proliferate by cross-linking surface immunoglobulin or by its pharmacological equivalent, phorbol ester and calcium ionophore. However, nuclear responses that have been studied in activated B cells are typically inducible with phorbol esters alone. We show that a factor, indistinguishable from the nuclear factor of ...
Alfonso A - - 1994
Thapsigargin elicits histamine release on rat mast cells, and this effect is increased if cells are pretreated with thapsigargin before the addition of external calcium. Okadaic acid does not modify the response of mast cells to thapsigargin, while sodium fluoride or the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) increases several fold the ...
Koong A C - - 1994
PURPOSE: By understanding the signal transduction pathways through which a cell responds to changes in environmental oxygen levels, we may be able to therapeutically exploit this response by manipulating these pathways. MATERIALS AND METHODS: The human adenocarcinoma cell line A549 was exposed to varying durations of hypoxia alone and then ...
Aepfelbacher M - - 1994
In a search for a model cell system that might allow studies of the function of the Rho-related GTPase CDC42Hs in human cells, we measured the content and distribution of CDC42Hs in monocytes that were differentiating into macrophages. The total content of this protein increased 5- to 6-fold in phorbol ...
Solary E - - 1994
In the human leukemic HL-60 cell line, we have reported previously that monocytic/macrophage-like differentiation induced by TPA (12-O-tetradecanoylphorbol-13-acetate) was associated with a decreased sensitivity to various apoptosis-inducing stimuli (Solary, Bertrand, Pommier, Blood 1993; 81:1359-1368). In the present study, we studied further the effects of TPA alone on the induction of ...
Jing Y - - 1994
Bufalin, an active principle of the traditional Chinese medicine chan'su, has been proved to be a potent differentiation inducer in human leukemia cells. To study the mechanism of the differentiation of human leukemia ML1 cells induced by bufalin, we measured the effect of 10 nM bufalin on cell growth, activities ...
Körner M - - 1994
The nuclear factor kappa B (NF-kappa B) is a eukaryotic transcription factor. In B cells and macrophages it is constitutively present in cell nuclei, whereas in many other cell types, NF-kappa B translocates from cytosol to nucleus as a result of transduction by tumor necrosis factor alpha (TNF alpha), phorbol ...
Soma M R - - 1994
The parallel effects of simvastatin on cell cycle and PKC activity in rat C6 glioma cells were investigated. Simvastatin, 2.5 microM, for 24 h resulted in cell growth arrest in early G1 phase of the cell cycle and in a significant increase of total PKC activity (283 +/- 42 vs ...
Scott J E - - 1994
Undifferentiated type II alveolar cells were isolated from the fetal rabbit lung on the 24th gestational day, grown in vitro for 2-3 days, and used to test the hypothesis that activation of protein kinase C by 4 beta-phorbol ester (TPA) or the diacylglycerol analogue, sn-1-oleoyl-2-acetylglycerol (OAG), stimulates disaturated phosphatidylcholine (DSPC) ...
Hamilton D - - 1994
An in vitro assay that measures the activation level of ex vivo activated (EVA) T cells currently being used in the adoptive immunotherapy of metastatic renal cell carcinoma has been developed. This assay is based on the ability of activated, but not resting. T cells to proliferate in response to ...
Laing J G - - 1994
Connexin45 is a gap junction protein which forms channels with unique characteristics. RNA blots demonstrated that connexin45 is expressed in a number of cell lines including WB, SK Hep1, BHK, A7r5, CLEM, and BWEM cells. Connexin45 was further studied in BWEM cells using specific affinity-purified antibodies directed against a synthetic ...
He Z X - - 1994
A solid leukemia sarcoma has been successfully developed after subcutaneous inoculation of the cultured human promyelocytic leukemia cells (HL-60 cells) into nude mice. The solid leukemia sarcoma is a more plentiful source than the cultured cells for enzymatic study and its growing environment is closer to that of the human ...
Morimoto K - - 1994
Hyaluronan-binding function of the CD44 molecule has not been so far detected in myeloid cells. To study pure populations of primitive myeloid cells, we investigated the hyaluronan-binding function of the CD44 molecule from three myeloid cell lines: KG1a, KG1, and HL60. Both KG1a and KG1 cells express the CD34 antigen ...
Xing M - - 1994
We compared the regulation of cytosolic phospholipase A2 (cPLA2) activity in undifferentiated and neutrophil-like HL60 cells. Although Ca(2+)-mobilizing P2-purinergic receptors are expressed in both cell types, arachidonic acid (AA) release stimulated by P2-purinergic agonists was 5-7-fold higher in the differentiated cells. Similarly, the stimulation of AA release by AlF4- in ...
Mazurek N - - 1994
Sphingosine-1-phosphate (Sph-1-P) has been implicated as a second messenger in control of cell motility and proliferation (e.g., Sadahira Y, et al., PNAS 89:9686, 1992; Olivera A & Spiegel S, Nature 365:557, 1993). The control mechanism for its synthesis, as catalyzed by sphingosine kinase, is crucial in signal transduction. Synthesis of ...
Baumgold J - - 1994
Previous studies have shown that activation of various PI-coupled receptors stimulates DNA synthesis in some cells, and inhibits DNA synthesis in others. In order to study this effect further, we measured carbachol-mediated [3H]thymidine incorporation in m1-transfected A9 L cells and in m1-transfected CHO cells, and found that carbachol profoundly inhibited ...
Wada T - - 1994
The effect of the tumor promoter phorbol 12-myristate 13-acetate (PMA) on proliferation and differentiation of normal mammary epithelial cells from 50-day-old virgin rats was investigated using a model system that allows for full morphological and functional development of the cells. In this model, mammary epithelial cells are grown within a ...
Caccamo D V - - 1994
The tissue (tPA) and urokinase (uPA) types of plasminogen activator and the plasminogen activator inhibitor 1 (PAI-1) are enzymatic proteins that may play an important role in the degradation of the extracellular matrix in physiologic and neoplastic conditions. In particular, urokinase may underlie key properties of malignant cells, such as ...
Budunova I V - - 1994
We have examined the effect of protein kinase (PKC) depletion in SV40-transformed Djungarian hamster fibroblasts (DM15 cells) on the level of gap junction permeability. Cx43 electrophoretic mobility, and cell sensitivity to different uncoupling stimuli. After 24 hr exposure to 12-O-tetradecanoyl-phorbol-13-acetate (TPA), the total PKC activity in DM15 cells was reduced ...
Nabeshima K - - 1993
We previously found that the enhanced activity to invade Matrigel upon stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA) was one of the major properties of a highly metastatic variant (L-10) of a human rectal adenocarcinoma cell line RCM-1. To clarify the mechanism of this enhancement, we examined the effect of TPA on 2 ...
Melcangi R C - - 1993
The ability of the human neuroblastoma cell line SH-SY5Y to metabolize androgens and progesterone was studied by incubating the cells in the presence of labeled testosterone (T) or progesterone (P) to measure, respectively, the formation of dihydrotestosterone (DHT) or dihydroprogesterone (DHP) (5 alpha-reductase activity). The 3 alpha-hydroxysteroid dehydrogenase activity was ...
Muraosa Y - - 1993
The human monocytic leukemia cell line THP-1 differentiates into macrophage-like cells when treated with a variety of agents, including 12-O-tetradecanoylphorbol-13-acetate (TPA). We show here that during this process, the expression of heme oxygenase, a rate-limiting enzyme in heme catabolism, is induced. Treatment with TPA increases heme oxygenase mRNA in other ...
Porreca E - - 1993
Alterations of vascular smooth muscle cell (VSMC) proliferation have been implicated in the age-dependent susceptibility to atherosclerosis. Although it is known that protein kinase C (PKC) is involved in the mechanism of VSMC proliferation, there are no data on the possible involvement of PKC in disregulating VSMC proliferation in aged ...
Ouaaz F - - 1993
The effects of interleukin 4 (IL-4) on human leukemic precursor B-cell lines were investigated. Recombinant IL-4 (rIL-4) was added to three acute lymphoblastic leukemia-derived pre B-cell lines: Reh, Km3 and Nalm-6. Our results show that rIL-4 significantly decreases continuous proliferation of Reh and Km3 cells while Nalm-6 cells have a ...
Bols B L - - 1993
Previous findings on the induction of immortalization in SHE cells have been explained with the activation/alteration hypothesis which postulates that treatment with a carcinogen results in the induction of a so-called "activated state" which enhances the rate of a probabilistic event in the progeny of the treated cells. This event ...
Dong L - - 1993
Immunocytofluorescence studies were used to compare alpha-protein kinase C (PKC) localization in primary cultures of renal proximal tubule epithelial cells (RPTE) with E1A-immortalized and SV40-transformed derivatives. Both cytosolic and nuclear staining were apparent in all of the RPTE. In primary RPTE, Triton X-100-insoluble alpha-PKC was also apparent and was concentrated ...
Fabre M - - 1993
The effects of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) on the growth characteristics of the colon cancer cell line HT-29 M6 were studied. TPA induced the scattering of proliferative HT-29 M6 cells: in the presence of the phorbol ester, HT-29 M6 colonies scattered and the cells acquired a flatter aspect with diminished ...
Muthukkumar S - - 1993
Recently, we have described that anti-IgM antibodies profoundly inhibited the growth of BKS-2, an immature B cell lymphoma. In this report, we demonstrated that ionomycin alone at very low concentrations (20 nM) inhibited the growth of BKS-2 cells completely. The levels of intracellular Ca2+ induced by the inhibitory concentrations of ...
Hirata J - - 1993
The ability of 12-O-tetradecanoylphorbol-13-acetate (TPA) and D,L-buthionine-S,R-sulphoximine (BSO) to modulate cis-diamminedichloroplatinum(II) (CDDP) sensitivity was investigated in human ovarian cancer cell lines sensitive (KF) or with intrinsic resistance (KK and MH) to CDDP. The KK and MH cell lines were derived from ascites of patients with clear-cell carcinoma and serous cystadenocarcinoma ...
Migliaccio S - - 1993
The osteoblast-like osteosarcoma cell line ROS 17/2.8, which expresses very low levels of estrogen receptor (ER), was stably transfected with the mouse ER in order to more easily evaluate the physiological role of estrogens in bone cell homeostasis. These transfected ROS.SMER 14 cells are highly responsive to estrogenic stimulation at ...
Murate T - - 1993
The selection of differentiation lineages into either erythroid or megakaryocytic series was analyzed with human erythroleukemia cell lines K562, HEL, and cytokine-dependent TF1. A tumor promoter, TPA, induced a megakaryocyte marker, glycoprotein IIb/IIIa (GP IIb/IIIa) or IIIa (GP IIIa), but suppressed erythroid differentiation. On the other hand, aphidicolin, which is ...
Roseng L E - - 1993
Exposure of early passage Syrian hamster embryo cells to high TPA concentrations (8 or 16 mum) decreased gap junctional intercellular communication (GJIC) to about 20% of the control during the first hour. Subsequently, the GJIC capacity recovered to 70-80% after 4-10 hr. Exposure to lower TPA concentrations also reduced GJIC, ...
Roseng L E - - 1993
The transformation-sensitive cell-line BPNi was more susceptible to 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inhibition of gap junctional intercellular communication (GJIC) than early passage Syrian hamster embryo (SHE) cells, while the potency of TPA to down-regulate EGF-binding was similar in the two cell types. The kinetics of TPA-induced inhibition of GJIC suggested that different ...
Perego P - - 1993
The effect of modulation of protein kinase C (PKC) activity by 12-O-tetradecanoylphorbol-13-acetate (TPA) on cisplatin cytotoxicity was examined in a human osteosarcoma U2-OS cell line and in a U2-OS variant (U2-OS/Pt) selected after continuous exposure to increasing concentrations of cisplatin. U2-OS/Pt cells showed a 7.5-fold resistance to the drug. A ...
Liabakk N B - - 1993
A highly specific and sensitive immunoassay for soluble p55 tumor necrosis factor receptor (TNFR) has been established. The immunoassay was based on a newly developed monoclonal antibody (IV4E) recognizing a non-TNF-binding site of the p55 TNFR. The IV4E antibody immunoprecipitated a 55 kDa TNF binding protein from HL-60 cells. No ...
Kumagai-Tohda C - - 1993
We previously reported that growth-associated protein-43 (GAP-43) could be involved in the maintenance of elongated neurites and that a decline in protein kinase C activity may be involved in accumulation of GAP-43. In the present study, to clarify the functional significance of GAP-43 for neurite maintenance and acetylcholine (ACh) release, ...
Emura M - - 1993
The proliferative cystic squamous cell lesion inducible by inhalation of particulate matter in the rat lung is characterized by the formation of keratin-filled cystic cavities of various sizes bordered by multiple layers of keratinizing squamous epithelial cells. The current investigation is primarily concerned with two points. One is whether the ...
García de Herreros A - - 1993
Recently developed HT-29-derived cell lines, which display variable differentiated phenotypes provide an invaluable opportunity to analyze the mechanism by which cell differentiation is regulated in the intestine. We have studied the effects of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in the differentiation phenotype of mucus-secreting (HT-29 M6) and absorptive (HT-29 M3) ...
Brackman D - - 1993
The growth-modulating effects of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] were studied on three mouse embryo fibroblast cell lines. Concentrations ranging from 0.1 to 100 nM inhibited dose-dependently proliferation in the non-tumorigenic C3H/10T1/2 Cl 8 (10T1/2) and the chemically transformed C3H/10T1/2 Cl 16 (Cl 16) cells. The hormone had a biphasic effect on ...
Katayama T - - 1993
This study was undertaken to assess the role of protein kinase C (PKC) in activin action in the rat pituitary. Pretreatment with 500 nM phorbol 12-myristate 13-acetate (PMA) for 22-24 h reduced subsequent FSH and LH release (percentage of total cellular FSH and LH released) in response to 100 nM ...
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