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Larsson R - - 1989
The effects of 12-O-tetradecanoylphorbol-13 acetate (TPA) on DNA synthesis, phenotypic expression, cytoplasmic Ca2+ (Ca2+i), intracellular pH (pHi) and membrane potential were studied in the monoblastic U-937 and the erythroleukemic K-562 cells. In both cell lines DNA synthesis was inhibited and in the U-937 cells this was accompanied by the appearance ...
Aylsworth C F - - 1989
The effects of TPA and/or DDT and oleic acid and/or DDT on gap junction-mediated intercellular communication (i.e. metabolic cooperation) between Chinese hamster V79 cells was examined. Addition of TPA, DDT or oleic acid alone to cocultures of 6-thioguanine-resistant (6-TGR) and 6-thioguanine-sensitive (6-TGS) V79 cells significantly increased the recovery of 6-TGR ...
Morikawa K - - 1989
Bestatin, an inhibitor of aminopeptidase B, was examined for its effect on B-cell activation. Small, dense B-cells from human tonsil samples were isolated by Percoll density gradients from non-rosetted (E-) cells and were used as target cells. Although bestatin was not cytotoxic towards B-cells, it inhibited the proliferative response of ...
Glasø M - - 1989
The nature and significance of so-called dark keratinocytes in the epidermis during chemical carcinogenesis is still a matter of concern and debate. Based on ultrastructural observations it has been suggested that dark cells most often are shrunken cells. Reports on skin carcinogenesis, however, claim that dark cells are a sign ...
Wilson V L - - 1988
The terminal squamous differentiation of epithelial cells involves a number of cellular changes. However, the mechanisms underlying this differentiation process are unknown. The present study demonstrates that 5-azacytidine, 12-O-tetradecanoylphorbol-13-acetate (TPA) and type beta-transforming growth factor (TGF-beta) significantly diminish the genomic 5-methyldeoxycytidine (5mdC) content of normal human bronchial epithelial cells concomitantly ...
Rao K M - - 1988
We used the promyelocytic leukemic cell line HL-60 to explore the molecular mechanisms regulating stimulus-induced actin polymerization in myeloid cells. HL-60 cells express very few chemotactic peptide receptors in their undifferentiated state and fail to undergo actin polymerization when stimulated with the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP). However, when the cells ...
Kumagai N - - 1988
Cyclosporin A (CsA) is a potent inhibitor of T lymphocyte proliferation induced by Ag and mitogens. In an attempt to further delineate the mechanism of action of CsA, we have examined its effects on T cell proliferation induced by the combination of the phorbol ester, phorbol 12,13-dibutyrate (PDB), and the ...
Tsang S S - - 1988
Cultured C3H/10T1/2 cells transfected with the plasmid pdBPV-1 were used as targets, and the frequency of transformed colonies as the endpoint to test the enhancing capacity of four promoters: 12-O-tetradecanoylphorbol-13-acetate (TPA), 4-O-methyl-tetradecanoylphorbol-13-acetate (4-O-methyl-TPA), mezerein and phorbol-12-retinoate-13-acetate (PRA). The frequency of the transfected C3H/10T1/2 cells to form transformed colonies was enhanced ...
Chida K - - 1988
The activities of protein kinase C (PKC) and the bindings to phorbol-12,13-dibutyrate (PDBu) of 41 cell lines were measured. The activities of PKC varied from 0.2 to 37 mU/10(6) cells in different cell lines, and in general were high in normal or untransformed cells and low in malignant, or transformed ...
Chanson M - - 1988
Second messengers have been implicated in the control of communication between cells of various tissues and of a number of cell lines. To assess whether protein kinase C (PKC) is involved in the regulation of gap junctions between primary differentiated cells, we studied the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on PKC ...
Hogans B B - - 1988
To determine whether activation of protein kinase C is involved in the proliferation of interleukin-3 (IL-3) -dependent cells, we examined the effect of tumor-promoting phorbol esters on the in vitro proliferation of the IL-3-dependent cell lines FD and DA-1. The viability of FD and DA-1 cells cultured for 24 hours ...
Sears R - - 1988
In previous work, we found that the phorbol ester drug 12-O-tetradecanoyl phorbol acetate (TPA) reversed the developmental restriction of melanogenesis that normally occurs in neural crest-derived Schwann cell precursors around embryonic Day 5 of quail development. That is, TPA treatment of dorsal root ganglia (DRG) from 7-day quail embryos caused ...
Rochette-Egly C - - 1988
The effects of a protein kinase C activator, 12-O-tetradecanoylphorbol-13-acetate (TPA), and of a calmodulin antagonist calmidazolium (CZ), on a human colonic cancer cell line HT-29 were analyzed. HT-29 cells are undifferentiated in standard culture conditions (HT-29 G+) and display an enterocytic differentiation when cultured in glucose-deprived medium (HT-29 G-). Early ...
Dorner A J - - 1988
GRP78 is localized in the endoplasmic reticulum and associates with improperly folded or underglycosylated proteins. The role of GRP78 in secretion was studied in Chinese hamster ovary cells expressing a tissue plasminogen activator (tPA) variant which lacks potential N-linked glycosylation site sequences because of mutagenesis. The expression of variant tPA ...
Essani N - - 1988
Pretreatment of EL4 cells with 12-O-tetradecanoyl phorbol-13-acetate (TPA) for 30 min renders them resistant to lysis by activated macrophages (M phi). This resistance was augmented two to three-fold when TPA-treated EL4 cells were incubated for 2-6 hr prior to co-culture with M phi. Preincubation of TPA-treated cells for 24 hr ...
Furlong A M - - 1988
A baculovirus expression vector was constructed with the tissue plasminogen activator (TPA) cDNA under the control of the viral polyhedrin promoter. After infection of insect cells with the recombinant baculovirus, active TPA was secreted into the medium in which these cells were grown. TPA was isolated from the conditioned media ...
Drexler H G - - 1988
Cells from 3 patients with B-chronic lymphocytic leukaemia (B-CLL) and 1 with B-prolymphocytic leukaemia (B-PLL) were treated in vitro with the phorbol ester 12-0-tetradecanoylphorbol (TPA), the calcium ionophore A23187, or a combination of TPA and A23187. TPA induced the cells to adhere to the culture flask or to clump in ...
Baxter C S - - 1988
Repeated twice-weekly applications of promoting doses of 12-O-tetradecanoylphorbol-13-acetate (TPA) to the dorsal skin of female adult SENCAR mice led to a reduction in numbers per unit area of epidermal Thy-1+ dendritic cells. Although no parallel effect was observed on Ia+ Langerhans cells, a concurrent reduction of dendritic morphology of both ...
Ase K - - 1988
The down-regulation of protein kinase C (PKC) subspecies in KM3 cells (a pre-B, pre-T cell line) has been examined. The PKC from KM3 cells was resolved into two subspecies, type II (mainly beta II) and type III (alpha), upon hydroxyapatite column chromatography. Biochemical and immunocytochemical analysis revealed that, when these ...
Forsbeck K - - 1988
12-O-tetradecanoylphorbol-13-acetate (TPA)-induced changes in cytoplasmic pH, cytoplasmic Ca2+-concentration, rate of DNA synthesis, and concentration and activity of protein kinase C (PKC) were studied in human monoblastoid cell lines. The cell line U-937 GTB was compared to the subline U-937 RES (adapted to growth in the presence of 10(-9) M TPA) ...
Langlois D - - 1988
Y-1 adrenal cells contain specific vasopressin (VP) binding sites (27,000 +/- 2,000 sites/cell) of high affinity (KD = 2.2 +/- 0.5 X 10(-9) M). VP which alone has no effect on cAMP production inhibited in a dose-dependent manner (ID50 = 3.5 +/- 0.7 X 10(-11) M) the ACTH-induced cAMP production ...
Lord J M - - 1988
The human promyeloid cell line HL60 differentiates toward monocytes when treated with TPA. We have analyzed, by two-dimensional gel electrophoresis, the phosphoprotein patterns within HL60 cells, labeled to equilibrium with [32P]orthophosphate when cells were treated with suboptimal (1 nM), optimal (5 and 10 nM), and supraoptimal (40 and 100 nM) ...
Platts E A - - 1988
Luteinizing-hormone (LH)-stimulated cyclic AMP production in rat testis Leydig cells was desensitized by both LH and 12-O-tetradecanoylphorbol 13-acetate (TPA). However, TPA, but not LH, enhanced the subsequent response to cholera toxin. Treatment of the cells with pertussis toxin potentiated cyclic AMP production in both control and LH-desensitized cells, but did ...
Szallasi A - - 1988
The effects of methotrexate (MTX) and N-phosphonacetyl L-aspartate (PALA) with and without 12-O-tetradecanoylphorbol-13-acetate (TPA) have been tested on the cell-cycle traverse of mouse 3T6 and Chinese hamster V79 cell lines. MTX, whether administered with or without TPA, had very little effect on the cell cycle of the V79 Chinese hamster ...
Takada K - - 1988
In quiescent rat thyroid (FRTL-5) cells, phorbol-12-myristate-13-acetate (PMA) inhibited DNA synthesis induced by a combination of insulin and thyrotropin (TSH) or dibutyryl cyclic AMP (Bt2cAMP). This inhibitory effect of PMA was observed even when PMA was added after addition of these growth factors, and was maximal when PMA was added ...
Takimoto T - - 1988
After four days of treatment with 10(-8) M TPA, differentiation of the human T-lymphoblastoid cell line MOLT-4 was induced along the T cell lineage, confirmed by a fall in adenosine deaminase and 5'-ectonucleotidase and a rise in purine nucleoside phosphorylase activity. TPA-treated cells became resistant to the cytotoxic effects of ...
Geny B - - 1988
Phorbol 12-myristate 13-acetate (PMA) induces the differentiation of the human promyelocytic cell line, HL60, towards adherent macrophage-like cells within 2 days. We have examined the early effects of PMA on inositol phosphates and on diacylglycerol production, two second messengers derived from inositol lipids. In proliferating HL60 cells, PMA induced a ...
Einarsson M - - 1988
The mechanism of uptake of tissue plasminogen activator (tPA) in rat liver was studied. Radio-iodinated tPA was removed from the circulation after intravenous administration in a biphasic mode. The initial half life, t1/2(alpha), and the terminal phase, t1/2 (beta), were determined to be 0.5 min and 7.5 min, resp. Separation ...
Aquino A - - 1988
In response to phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate (TPA), HL-60 cells differentiate to macrophage-like cells and exhibit the ability to phosphorylate vinculin in vitro. Adriamycin-resistant HL-60 (HL-60/ADR) cells similarly demonstrate this characteristic without prior treatment with TPA. Since protein kinase C (PK-C) is a cellular TPA receptor, we have examined ...
Okuno T - - 1988
HL-60 cells can be induced to differentiate into macrophage-like cells by treatment with 12-O-tetra-decanoylphorbol-13-acetate (TPA). The relationship between virus replication and cell differentiation was investigated using HL-60 cells that had been induced to differentiate by TPA (dHL-60 cells) and undifferentiated cells (udHL-60 cells). On infection of these cells with cell-free ...
Hsu S M - - 1988
We compared the proliferation of mononuclear and multinuclear cells in four Hodgkin's cell lines, HDLM-1, HDLM-1d, L-428, and KM-H2, by examining their capacity to incorporate bromodeoxyuridine (BrdUrd) into nuclei. Approximately 5% of all cells in HDLM-1 cultures had two or more nuclei, a characteristic of Reed-Sternberg (RS) cells. Unlike mononuclear ...
Svenson M - - 1988
We investigated whether urine from normal individuals contains inhibitors of interleukin 1 (IL-1). Diafiltered urine from normal afebrile donors suppressed IL-1-induced interleukin 2 (IL-2) activity of mouse thymocyte supernatants. These supernatants, however, strongly suppressed IL-2-induced [3H]thymidine incorporation into the IL-2-sensitive cell line CTLL-2, whereas the urine preparations did not. This ...
Rothstein T L - - 1988
B cells obtained by irrigation of the peritoneal cavity differ from splenic B cells in signaling requirements for the initiation of DNA synthesis. Splenic B cells are stimulated to enter S phase by phorbol esters in conjunction with a second signal provided by calcium ionophore; however, splenic B cells are ...
Giroldi L - - 1988
Induced differentiation of Friend erythroleukemia cells can be continuously and reversibly inhibited by phorbol ester tumor promoters, e.g. 12-O-tetradecanoylphorbol-13-acetate (TPA), for many years, allowing us to study the mechanisms of differentiation and its inhibition by TPA. We previously identified two steps in the differentiation process, which can be inhibited by ...
Tsuda H - - 1988
Terminal cell differentiation usually results in an irreversible arrest in the G1 phase of the cell cycle and loss of cell renewal ability. Human promyelocytic leukemia HL-60 cells induced with 12-o-tetradecanoylphorbol-13-acetate (TPA) differentiate into monocytes/macrophages and accumulate in G1. We determined the effect of TPA on the growth kinetics of ...
Carter L J - - 1988
Chemical agents including 5-iodo-2'-deoxyuridine (IUdR), 4-O-methyl 12-O-tetradecanoyl phorbol-13-acetate (TPA), phorbol, and the tumor promoters teleocidin and TPA were tested for their ability to induce Human T-cell leukemia-lymphoma virus Type I (HTLV-I) expression in the low-virus producer MT-1 cell line and in the non-virus producer C63/CRII-2 cell line, which contains at ...
Kinzel V - - 1988
The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) has been shown previously to mimic X-irradiation in altering cell cycle parameters in Hela cells [Kinzel, V., Richards, J., and Stöhr, M., Science (Wash. DC), 210: 429-431, 1980]. These changes include a delay in G2 phase from which cells recover in the presence of TPA, ...
Kano-Sueoka T - - 1988
Mammalian cells in culture can be classified as either ethanolamine (Etn)-responsive or Etn-nonresponsive with regard to their growth. Epithelial cells and some of their transformed derivatives are the Etn-responsive type. When these cells are grown without Etn, the content of membrane phospholipid becomes significantly altered. Namely, the content of phosphatidylethanolamine ...
Macfarlane D E - - 1988
The promyelocytic leukaemia cell line HL-60 differentiates to a macrophage-like cell when exposed to the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) and other agents which activate protein kinase C. To investigate this phenomenon we developed an HL-60 variant which does not differentiate when exposed to TPA. HL-60 cells were exposed to ...
Malvoisin E - - 1988
We have examined the sterol composition and metabolism of promyelocytic leukaemia cell lines (HL-60) after treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA). A variant cell line (Blast II cells) which is resistant to TPA was used as control. Analysis of the sterols of TPA-sensitive cells radiolabelled with [3H]leucine, [14C]acetate or [14C]pyruvate showed ...
Knecht M - - 1988
Follicle-stimulating hormone (FSH) increases the activity of a cell-associated, tissue-type plasminogen activator (tPA) during the initial hours of granulosa cell development. In order to determine the cellular localization of tPA, granulosa cells were labeled with [35S]methionine for 4 h and detergent-solubilized proteins were immunoprecipitated and analyzed by polyacrylamide gel electrophoresis. ...
Kitajima Y - - 1988
The present study was performed to investigate involvement of protein kinase C in the biphasic effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on cell morphology in low calcium (0.07 mM)-grown cells of a human epidermal squamous cell carcinoma cell line. The low calcium-grown cells formed no desmosomal cell-cell contact and showed roughly circular ...
O'Brien T G - - 1988
The identity of the genetic defect(s) in Swiss 3T3 TNR-2 and TNR-9 that confers nonresponsiveness to the proliferative effect of 12-0-tetradecanoylphorbol-13-acetate (TPA) is not known. In BALB/c 3T3 cells, loss (via mutation) of a specific membrane ion transport system, the furosemide-sensitive Na+K+Cl- cotransporter, is associated with decreased responsiveness to TPA. ...
Nakamura Y - - 1988
Evidence has been obtained that implicates the generation of reactive oxygen species as an early and critical event in the promotion of neoplastic transformation in mouse JB6 cells. The time courses for specific inhibition by CuZn-superoxide dismutase (CuZn-SOD) of the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced promotion of neoplastic transformation in JB6 cells and ...
Kessler F K - - 1988
Guinea pig alveolar cells were obtained in situ via bronchoalveolar lavage. The cells were 86% macrophages (GPAM), (greater than 97% viability) with the remainder of the population comprised of lymphocytes and eosinophils. The following battery of functional assays were studied in GPAM: chemotaxis was stimulated by N-formyl-methionyl-leucine-phenylalanine (FMLP) and by ...
Hiraoka A - - 1988
Cells derived from human germ cell tumors (HGCT) are potential models for the study of human embryonic differentiation. Differentiation in four HGCT-derived lines (1618K, 833KE, 1777Ndif, 2806B) was examined by light and electron microscopy, after exposure of cells to dimethyl sulfoxide (DMSO) and 12-O-tetradecanoyl phorbol-13-acetate (TPA). In line 1618K, the ...
Böhmer R M - - 1988
Tumor-promoting phorbol ester derivatives are known to stimulate as well as inhibit the cell cycle traverse of many kinds of cells, but it is not known whether or how these effects are related to tumor promotion. It is shown here that the potency of the phorbol diester PMA (phorbol myristate ...
Kolset S O - - 1988
The monocytic cell line U-937 was cultured in vitro in the absence or presence of phorbol myristate acetate, and agent known to induce differentiation of these cells along the monocyte/macrophage lineage. The cells were fixed, prepared for, and subjected to transmission scanning electron microscopy. The intracellular structures of the cells ...
Rana S V - - 1988
Previously, unstimulated cells of the human monocytic tumor cell line U937 have been shown to possess a negligible cell-surface tissue factor (TF) activity, and to secrete a small amount of factor VIIa/tissue factor (VIIa/TF) inhibitor activity. On stimulation with endotoxin or with phorbol myristate acetate (PMA), TF of these cells ...
Tragni E - - 1988
The established mouse epidermis-derived cell line HEL/30 was incubated in the presence of 3H arachidonic acid (AA) for 1 h. After medium removal, cells were reincubated with fresh medium in the presence or absence of the calcium ionophore A23187 and tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA). The AA metabolites formed were extracted ...
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