Search Results
Results 251 - 300 of 1020
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Panagakos F S - - 2000
Gallium, a group IIIa metal salt, has been demonstrated to be an effective immunosuppressive agent. Gallium has also been shown to inhibit the production of inflammatory cytokines, such as IL-1beta, produced by macrophage-like cells in vitro. To further characterize the effects of gallium on the inflammatory process, we examined the ...
Kanamori M - - 2000
We characterized the cell growth and Epstein-Barr virus (EBV) reactivation for EBV infected epithelial cell lines, GT38, GT39, and GTC-4 using 12-O-tetradecanoylphorbol-13-acetate (TPA). These cell lines grew similarly in liquid medium, and formed colonies in soft agar. The cell growth was inhibited with TPA, dose-dependently in liquid medium. The colony ...
Fernandez N - - 2000
Several reports have indicated that protein kinase C (PKC) is an important regulator of proliferation in thyroid cells. Unlike TSH, the mitogenic effects of phorbol esters are accompanied by de-differentiation. The role of individual PKC isoforms in thyroid cell proliferation and differentiation has not been examined. Recent studies have implicated ...
Sahaf B - - 2000
Thioredoxins (TRX) are ubiquitous, small redox-active proteins with multiple functions, including antioxidant, cytoprotective, and chemoattractant activities. In addition to a 12-kDa intracellular form, extracellular 10-kDa and 12-kDa TRX have been defined. The biological activities of the 10-kDa TRX were previously measured as eosinophil cytotoxicity enhancing activity or B-cell stimulatory activity. ...
Yura Y - - 2000
A morphological change induced by syn- herpes simplex virus type 1 (HSV-1), polykaryocyte formation, was enhanced by treatment with 12-O-tetradecanoyl phorbol 13-acetate (TPA) in A431 cells. TPA treatment decreased the number of stress fibers, but led to the development of spike-like filopodia and actin-containing long projections. Similar reorganization of actin ...
Chien E J - - 2000
The increase of intracellular free calcium concentration ([Ca(2+)](i)) and protein kinase C (PKC) activity are two major early mitogenic signals to initiate proliferation of human peripheral T cells. Bacterial lipopolysaccharide (LPS) is nonmitogenic in human T cells. However, in the presence of monocytes, LPS becomes mitogenic to proliferate T cells. ...
Kumar S - - 2000
The physiological role of IP(3)-dependent Ca(2+) release in T cell activation was in question due to the contradictory findings that [8-(Diethylamino)octyl-3,4,5-trimethoxybenzoate, HCl] (TMB-8), an inhibitor of intracellular Ca(2+) mobilization, blocked T cell proliferation, curtailing specifically the level of released Ca(2+) did not affect T cell activation and T cell line ...
Dreikhausen U E - - 2000
To try to further define the mechanism of action of the putative second messenger inositol 1,3,4,5-tetrakisphosphate (InsP4), we have studied its effects in permeabilized cells expressing different levels of inositol trisphosphate receptor (InsP3R) types I and III and of the GTPase-activating protein GAP1IP4BP. During the growth curve of human HL-60 ...
Rochman M - - 2000
Migration of some tumor cells, and their lodgment in target organs, is dependent on the activation of cell surface CD44 receptor, usually detected by its ability to bind hyaluronic acid (HA) or other ligands. In an attempt to reveal the mechanism of tumor cell CD44 activation, we compared the physical ...
Belinsky G S - - 1999
To examine the importance of the N- or C-termini of PTH(1-34) the effects of truncated fragments of PTH on human receptors in osteoblast-like SaOS-2 cells and rat receptors in rats ROS 17/2 cells were examined. Fura-2-loaded cells were used to monitor cytosolic free Ca(2+) concentration ([Ca2+]i), and the Cytosensor microphysiometer ...
Slosberg E D - - 1999
To clarify the roles of specific isoforms of PKC in regulating growth and cell cycle progression of the HC11 mammary epithelial cell line, we investigated the effects of activating endogenous PKC isoforms with the phorbol ester tumor promoter TPA, and also the effects of TPA on genetically engineered cells containing ...
Fagnen G - - 1999
In order to determine the signal transduction pathways involved in the regulation of proteoglycan (PG) synthesis in immature rat Sertoli cells (SC), we have examined the effect of the tumor promoter phorbol ester PMA (phorbol myristate acetate) on [35S]sulfate and [3H]glucosamine incorporation into PG molecules neosynthesized by cultured rat SC. ...
Agadir A - - 1999
Phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) and all-trans-retinoic acid (trans-RA) are potent regulators of growth of cancer cells. In this study, we investigated the effect of TPA and trans-RA alone or their combination on proliferation of human breast cancer ZR75-1 and T47D and lung cancer H460 and H292 cell lines. trans-RA caused ...
Vääräniemi J - - 1999
The role of protein kinase C (PKC) in the regulation of the cytoskeleton of epithelial cells with tightly sealed contacts, poor contacts, and without contacts were investigated by incubating them with a protein kinase C activator phorbol myristoyl acetate (PMA). The morphology and organization of the membrane skeleton and stress ...
Okuda H - - 1999
Disruption of interactions between epithelial cells and extracellular matrix proteins leads to apoptosis of the cells, a phenomenon termed anoikis. Anoikis seems to play important roles in control of cellular positioning and inhibition of inappropriate cell growth. Here we found that a protein kinase C (PKC) activator phorbol ester 12-O-tetradecanoyl ...
Keenan C - - 1999
The Ramos-Burkitt lymphoma (BL) B cell line is driven into growth arrest and apoptosis by cross-linking surface immunoglobulin. We demonstrate that protein kinase C (PKC) activity is required for Ramos B cell proliferation and survival. A variety of PKC inhibitors trigger a significant decrease in [(3)H]thymidine incorporation with a concomitant ...
Ferreri N R - - 1999
The medullary thick ascending limb (MTAL) metabolizes arachidonic acid (AA) via cytochrome P-450 (CyP450)- and cyclooxygenase (COX)-dependent pathways. In the present study, we demonstrated that the COX-2-selective inhibitor, NS-398, prevented tumor necrosis factor-alpha (TNF)- and phorbol myristate acetate (PMA)-mediated increases in PGE(2) production by cultured MTAL cells. Accumulation of COX-2, ...
Korem S - - 1999
An imbalance between the activity of matrix metalloproteinases (MMPs) (proteolytic enzymes that degrade protein components of the extracellular matrix) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), may be one of the mechanisms responsible for tumor cell invasion. We have investigated the regulation of MMP-1 and TIMP-1 gene expression ...
Baatout S - - 1999
Megakaryocytes undergo a peculiar and irreversible program by which they become polyploid through repeated cycles of DNA synthesis without concomitant cell division. In order to study the possible concomitant role of protein kinase C and actin in megakaryocyte polyploidization, three cell lines (DAMI, HEL and K562), expressing some properties of ...
Farshori P - - 1999
We studied the expression, distribution, and phosphorylation of the tight junction (TJ) protein occludin in confluent MDCK cell monolayers following three procedures for opening and resealing of TJs. When Ca(2+) is transiently removed from the culture medium, the TJs open and the cells separate from each other, but the occludin ...
Liu T F - - 1999
In order to investigate the site of active phosphorylation under treatment with TPA, both wild type (WT) fibroblasts and fibroblasts from Cx43-knockout mice transfected with Cx43 mutated at ser368 were used to study the effects of TPA on dye leakage and gap junction assembly. Results showed that in control conditions ...
Baatout S - - 1999
Megakaryocyte polyploidization responds to platelet demand and results from the lack of cytoplasmic separation while the nucleus keeps dividing. In order to investigate the role of actin in the megakaryocyte polyploidization, phorbol myristate acetate (PMA, 5 x 10(-9) M), a differentiation marker known to induce megakaryocyte polyploidization, was added to ...
Ohigashi T - - 1999
Although protein kinase C (PKC) has been implicated as an effector of erythropoietin (EPO) production, its exact role is still uncertain. Hep3B human hepatocellular carcinoma cells were used for this study and were depleted of PKC in three different ways: long-term treatment with phorbol 12-myristate 13-acetate (PMA), selective inhibition with ...
Romanova L Y - - 1999
In the murine pre-B lymphoid cell line Baf3, the presence of IL-3 is required for the formation of membrane ruffles that intensely stain for actin and are responsible for the elongated cell phenotype. Withdrawal of IL-3 dissolves ruffled protrusions and converts the cell phenotype to round. Flow cytometric analysis of ...
Sinniger V - - 1999
A number of cell types have previously been shown to bind tissue plasminogen activator (tPA), which in some cases can remain active on the cell surface resulting in enhanced plasminogen activation kinetics. We have investigated several cultured cell lines, U937, THP1, K562, Molt4, and Nalm6 and shown that they bind ...
Banan A - - 1999
Prostaglandins (PG) protect gastrointestinal cells against damage induced by ethanol (EtOH) and other noxious agents, a process termed cytoprotection. The present study investigated the relationships between microtubule (MT) stability, protein kinase C (PKC) activation, and calcium efflux as a possible mechanism of PG's protective action using a human colonic cell ...
Bonizzi G - - 1999
It has previously been reported that distinct signaling pathways can lead to nuclear factor (NF)-kappaB activation following stimulation of different cell types with inflammatory cytokines. As the role of atypical protein kinase C (PKC) isoforms in NF-kappaB activation remains a matter of controversy, we investigated whether this role might be ...
Snawder J E - - 1999
The anchorage-independent growth of mouse epidermal cells (JB6) exposed to 60-Hz magnetic fields (MF) was investigated. Promotion-responsive JB6 cells were suspended in agar (10(4)cells/plate) and exposed continuously to 0.10 or 0.96 mT, 60-Hz magnetic fields for 10-14 days, with or without concurrent treatment with the tumor promoter tetradecanoylphorbol acetate (TPA). ...
Furuno T - - 1999
The relation between degranulation and rapid metabolic responses (acidification rate changes) in RBL-2H3 cells was studied using a cytosensor microphysiometer, a silicon-based biosensor system. The metabolic responses in RBL-2H3 cells by antigen stimulation were compared with those by inhibitors of Ca2+ -ATPase. The former resulted in a rapid transient increase ...
Thiébot B - - 1999
The influence of phorbol myristate acetate (PMA), dibutyryl cAMP and insulin-like growth factor (IGF-1) as well as cytoskeletal disrupting drugs on morphological changes has been studied in peritubular cells isolated from immature rat testis. Morphological studies were combined with immunofluorescence investigations of cytoskeletal elements and their rearrangements by various agents. ...
Potdar P D - - 1999
The development and characterization of normal hamster tracheal epithelial (HTE) cell system and its initiated subline is described in the present study. Normal HTE cells grew in a monolayer, had a stable diploid karyotype, were anchorage dependent and non-tumorigenic. The presence of desmosomal attachments and keratin filaments confirmed the epithelial ...
Song X D - - 1999
One of the objectives of treatment for patients with acute promyelocytic leukemia (APL) is to induce tumor cell differentiation and block cell proliferation. Acute promyelocytic leukemia cells (NB4) responded to the combination treatment of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] plus phorbol 12-myristate 13-acetate (PMA) and differentiated into monocyte/macrophage-like cells, as well as ...
Passalacqua M - - 1999
In this study we provide evidence that the protein kinase C (PKC)-straight theta isoenzyme is recruited on to the mitotic spindle in dividing murine erythroleukaemia (MEL) cells and associates specifically with centrosome and kinetochore structures. None of the other PKC isoenzymes (-alpha, -delta, -epsilon, -mu and -zeta) expressed by MEL ...
Katayama H - - 1998
The rat AIM-1 gene encoding an Aurora- and Ipl1-like midbody-associated protein serine/threonine kinase has a mitotic regulator function playing a key role in the onset of cytokinesis during mitosis. This report presents a cDNA sequence and megakaryocytic differentiation-dependent expression profile of the human AIM-1 gene. The nucleotide sequences of the ...
Vaudry D - - 1998
In vitro studies have shown that PACAP promotes cell survival and neurite outgrowth in immature cerebellar granule cells. In the present study, we have examined the transduction pathways involved in the neurotrophic activity of PACAP. Incubation of cultured granule cells with graded concentrations of PACAP produced a dose-dependent increase in ...
Aten R F - - 1998
Luteal regression is associated with the generation of reactive oxygen species (ROS). To determine the nature of the ROS generator, cells isolated from luteinized rat ovaries were examined for ROS production using luminol-amplified chemiluminescence (LCL). Cells cultured for 2-48 h exhibited minimal LCL, but there was a significant (30- to ...
Ishino K - - 1998
We investigated the possible negative regulation of the cell cycle by protein kinase C (PKC) isoforms in synchronously grown BALB/MK-2 mouse keratinocytes, in which PKC isoforms were overexpressed by using the adenovirus vector Ax. Cells at the G1/S boundary of the cell cycle were the most sensitive to the inhibitory ...
Lehman N L - - 1998
Atrial natriuretic peptide (ANP) stimulates aqueous humor formation in primates, but the membrane-bound receptors which mediate this effect have not been well studied in the eye. Endocytosis of [125I]ANP bound to natriuretic peptide C receptors was characterized in fetal human nonpigmented ciliary epithelial (NPE) cells. [125I]ANP which bound to cells ...
Peers C - - 1998
1. Whole-cell patch clamp recordings were used to investigate the effects of protein kinase C (PKC) activation on K+ and Ca2+ currents in type I cells isolated from the rat carotid body. 2. Pretreatment of cells for 10 min at 37 C with 4alpha-phorbol 12,13-didecanoate (4alpha-PDD, 200 nM), a phorbol ...
La Porta C A - - 1998
Phorbol esters, known activators of c- and n-protein kinase C (PKC) isoforms, play a pivotal role in tumor promotion. In order to better understand the relationships between PKC activation, the metastatic potential and the proliferative capacity, we have analyzed the effect of 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment on the proliferative as well ...
El Sayed Khalid A. - - 1998
Sarcophytol A (1) and B (2) (see Chart 1) are cembrane-type diterpenes known to inhibit tumor promotion. Indicative of this inhibitory response, we currently report sarcophytol A (1) mediates dose-dependent diminution of 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced transformation of JB6 cells. Moreover, a structurally related furanocembrane diterpene, sarcophine (3), isolated in good ...
Resnick M S - - 1998
Sensitive EL4 mouse thymoma cells (s-EL4) respond to phorbol esters with growth inhibition, adherence to substrate, and production of cytokines including interleukin 2. Since these cells express several of the phorbol ester-sensitive protein kinase C (PKC) isozymes, the function of each isozyme remains unclear. Previous studies demonstrated that s-EL4 cells ...
Pierzchalska M - - 1998
Local anaesthetics block action potentials in the membranes of excitable cells but their effects on non-excitable cells are less well known. Some local anaesthetics are applied directly onto the skin, and for this reason the effect of procaine (p-aminobenzoic acid diethylamino-etyl ester hydrochloride) and tetracaine (4-[butylamino]benzoic acid 2-[dimethylamino]ethyl ester) upon ...
Nie J - - 1998
The human leukemia U937 cells differentiate into monocyte/macrophage-like cells when treated with 12-O-tetradecanoylphorbol-13-acetate (TPA). We observed that during this process, both protein and mRNA levels for PARS markedly decreased in U937 cells. Through deletion analysis of the PARS regulatory gene, we found that the sequence within the first intron region ...
Thorsen V A - - 1998
We have shown that 12-O-tetradecanoylphorbol 13-acetate (TPA) increases protein kinase C (PKC)-mediated choline transport, incorporation of choline into phosphatidylcholine (PtdCho) and PtdCho degradation by phospholipase D (PLD) in C3H10T1/2 Cl 8 cells. Dual prelabeling experiment using [3H]/[14C]choline indicated that intracellular choline generated from the PLD reaction was not directly recycled ...
Hibino S - - 1998
Tenascin (TN) is an extracellular matrix protein which interferes with fibronectin (FN)-dependent cell attachment and activation as a natural antagonist to FN action. In this study, we examined the inhibitory effect of TN on T cell proliferation induced by immobilized anti-CD3 Ab combined with various costimulators in a serum-free condition. ...
Sasaki K - - 1998
Simian virus 40-immortalized human milk epithelial cells (HuMI) are anchorage dependent and non-tumorigenic but can spontaneously progress to anchorage-independent and tumorigenic cells. To see whether HuMI cells can be transformed into anchorage-independent cells by chemical carcinogens, we treated them with 3-methylcholanthrene (MCA, 10 microg/mL). After 7-8 wk of culture, none ...
Lim K - - 1998
DNA topoisomerase II is a marker for the proliferation state of mammalian cells in culture, and the protein levels are markedly higher in exponentially growing cells than quiescent cells and can be downregulated by growth of the cells at high density and serum starvation. Correlation between ATF and TPA-repressed DNA ...
Kaneki H - - 1998
To determine the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on phospholipase D (PLD) activity in osteoblast-like UMR-106 cells, we used cells prelabeled with [3H] myristic acid or [3H] arachidonic acid, which were preferentially incorporated to phosphatidylcholine. The treatment of [3H] myristate-labeled cells with TPA in the presence of 1% ethanol caused a ...
Takasaka N - - 1998
We characterized the expression of Epstein-Barr virus (EBV) on two epithelial cell lines, GT38 and GT39, derived from human gastric tissues. The EBV nuclear antigen (EBNA) was detected in all cells of both cell lines. The EBV immediate-early BZLF 1 protein (ZEBRA), the early antigen diffuse component (EA-D), and one ...
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