Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostaglandin E2 (PGE2) induced differentiation of human monoblastic leukemia U-937 cells into cells with macrophage characteristics. PGE2 synergistically increased the differentiation, of U-937, ML-1 and HL-60 cells when combined with TNF. PGE1 and PGF2 also induced differentiation of U-937 cells; however, PGD2, deoxy-delta 9,12-13, 14-dihydro-PGD2 (delta 12-PGJ2), and PGI2 did not induce differentiation, either alone or in combination with TNF. PGE2 changed the dissociation constant of TNF for its receptors on U-937 cells only marginally, but it approximately doubled the number of binding sites.
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PMID:Synergism of prostaglandin E2 plus TNF in induction of differentiation of human monocytoid leukemic U-937 cells. 254 32

The regulation of prostaglandin stimulated cAMP accumulation in cells of the human T-cell leukemia line Jurkat was examined. Pretreatment with PGE2 (0.1-10 nM) for 2 hour caused a concentration dependent desensitization of the prostaglandin receptor. Tumor promoting phorbol esters (1-1000 nM) could also inhibit PGE2 stimulated cAMP production dose dependently. Inhibition of tubulin polymerization with colchicine or nocodazole (1 microM) eliminated prostaglandin but not phorbol ester induced desensitization of the receptor. It is concluded that agonist and phorbol ester induced desensitization are mediated by two distinct mechanisms and that tubulin polymerization appear to be required only for agonist induced desensitization of the prostaglandin receptor.
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PMID:Agonist but not phorbol ester induced desensitization of human lymphocyte prostaglandin receptor is dependent on tubulin polymerization. 284 28

The human promyelocytic leukemia cell line HL-60 and monoblastic leukemia cell line U937 undergo differentiation when induced by lymphokine and cytokine preparations. Growth inhibition, acquisition of immunoglobulin Fc receptors, increased expression of monocyte-related surface antigens, and an increase in lysosomal enzyme contents accompany maturation induced by gamma-interferon and other cytokine factors tested. Additionally, increased receptors for chemotactic peptide (fMLPR), increased hydrogen peroxide release in response to phorbol myristic acetate stimulation, and the release of prostaglandins (PGE2 and 6-keto-PGF1a) follow exposure to lymphokine and cell line sources of myeloid colony-stimulating activity (CSA). Gamma-Interferon (gamma-IFN) induced fMLPR in HL-60 (only at 1000 units/ml) but not in U937. Additionally, gamma-IFN did not induce prostaglandin release in either cell line. These myeloid colony-stimulating activity-associated differentiation-inducing factors were obtained from the human hepatoma++ cell line SK-Hep and bladder carcinoma cell line 5637, which were free of interferon activity. The 2-day phytohemagglutinin-induced lymphokine contained no detectable CSA and was a good source of differentiation activity. A simple, rapid assay for a new human CSA with pluripotent hematopoietic stimulating activity (pluripoietin) is described based on stimulation of [3H]glucosamine incorporation. Cell line conditioned media containing pluripoietin, purified pluripoietin, and gamma-IFN are active in this assay. These myeloid leukemia cell line differentiation factors are thus different from interferon and conventional CSA. These results suggest that endogenous human cytokines may have a role in the differentiation of leukemic as well as normal myeloid cells.
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PMID:Distinct differentiation-inducing activities of gamma-interferon and cytokine factors acting on the human promyelocytic leukemia cell line HL-60. 298 60

The immunosuppressive effect of feline leukemia virus (FeLV) and its 15,000 dalton envelope protein (p15E) were studied to determine if the mechanism of action was due to an increase in prostaglandin production. We examined the effects of exogenous PGE1 and PGE2 on the normal Con A response of feline peripheral blood lymphocytes (PBL) and found them to be inhibitory. The addition of the cyclooxygenase inhibitor indomethacin to cells incubated with FeLV or FeLV p15E and Con A completely abrogated the viral suppressive effects. This reversal was titratable and time-dependent. Other non-steroidal anti-inflammatory (NSAI) drugs were found to have similar actions. Indomethacin was also able to increase the suppressed Con A response of PBL from FeLV-infected cats. Upon measurement of PGE2 levels from PBL cultured with FeLV, we found a decrease in PGE2 accumulation associated with FeLV presence during the first 24 h of culture. These findings indicate that FeLV does not cause its immunosuppressive effects by increasing PG production and suggests that indomethacin and the other tested NSAI drugs do not produce their effect by PG inhibition.
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PMID:Reversal of feline retroviral suppression by indomethacin. 300 36

Intraperitoneal inoculation of L1210 murine leukemia cell vaccine increased I-Ad antigen-positive and -negative macrophages in the peritoneal cavity of histocompatible mice. Mitomycin C, a poor producer of I-Ad antigen-positive macrophages, selectively augmented the production of I-Ad antigen-positive macrophages in L1210 vaccine-primed mice, since it did not augment the production of non-macrophage cells. Since our previous study showed that the priming of mice with L1210 vaccine and mitomycin C induced augmented antitumor response, we tested the feasibility of the association of mitomycin C-augmented I-Ad antigen-positive macrophages with the augmented antitumor response. Prostaglandin E2 suppressed the antitumor response in L1210 vaccine- and mitomycin C-primed mice and, consistent with this, it inhibited the production of I-Ad antigen-positive macrophages, although it inhibited the production of non-macrophage cells as well. This hypothesis was further tested by the use of silica. When L1210 vaccine- and mitomycin C-primed mice were further given silica on the day of and one day after live L1210 inoculation, their antitumor response was strongly suppressed, while a kinetic analysis of the cellularity of peritoneal cells showed that administration of silica resulted in a decrease of I-Ad antigen-positive macrophages, but not I-Ad antigen-negative macrophages or non-macrophage cells in these mice. These results strongly suggest, though they do not prove, the association of mitomycin C-augmented production of I-Ad antigen-positive macrophages with the antitumor response in L1210 vaccine- and mitomycin C-primed mice.
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PMID:Mitomycin C-augmented production of I-A antigen-positive macrophages in tumor vaccine-primed mice. 300 73

The effects of various compounds were studied quantitatively on the growth of human immunodeficiency virus (HIV). For this we used a human T-cell leukemia virus type I carrying cell line, MT-4 which is most permissive for HIV infection. The results are summarized as follows: 1) Prostaglandin E2 and 12-0-tetradecanoylphorbol-13-acetate enhanced the production of HIV significantly in MT-4 cells as well as a continuous HIV producer Molt-4/HTLV-III cells. 2) Interferon gamma, retinoic acid and 3'-azido-3'-deoxythymidine inhibited the replication of HIV at the concentrations which were not cytotoxic. Mechanism of action of these compounds and its clinical implications are discussed.
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PMID:Substances affecting the infection and replication of human immunodeficiency virus (HIV). 303 Mar 46

When L-1210 murine leukemia cells were incubated with 60 microM PGE2 in culture medium containing fetal calf serum for various time, cell proliferation was inhibited dependent on incubation time. However, when the medium containing PGE2 was changed every 6 h during 24 h exposure to cells, growth inhibition became much weaker. Moreover, when the medium containing PGE2 was aged by preincubating without cells at 37 degrees C, growth inhibitory effect of the medium was enhanced with preincubation time, suggesting that active growth inhibitory compound(s) accumulated during preincubation. In culture medium containing fetal calf serum, PGE2 degraded time-dependently and the major product was identified as PGA2 by HPLC. Furthermore, when cells were incubated with the medium containing 60 microM[3H]PGE2 or the same medium aged by preincubation, we observed that the radioactivity was taken up by the cells time-dependently, and identified the incorporated radioactivity as PGA2. This uptake was closely correlated with decrease in viable cell number during incubation. These results suggested that growth inhibitory effect of PGE2 was due to the metabolic dehydration of PGE2 to PGA2, and PGA2, after taken up by cells, exerted cell growth inhibition.
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PMID:Metabolic dehydration of prostaglandin E2 and cellular uptake of the dehydration product: correlation with prostaglandin E2-induced growth inhibition. 346 77

Cyclopentenone prostaglandins (PGs) such as PGA2 or 9-deoxy-delta 9,12-13,14-dihydro-PGD2 (delta 12-PGJ2) induce growth inhibition of various lines of cultured cells. Action sites of these PGs were studied by incubating them with L-1210 murine leukemia cells. L-1210 cells accumulated both PGs in a time-dependent manner at 37 degrees C. When the uptake was analyzed with various concentrations of delta 12-PGJ2, the Michaelis-Menten type of kinetics was obtained, and the Km and Vmax were 250 microM and 2.5 nmol/min/10(6) cells, suggesting that the uptake was a carrier-mediated active transport. Competition studies with [3H]delta 12-PGJ2 showed that PGA2 was transported by the same carrier with a similar affinity. PGs without growth inhibitory activity such as PGD2, PGE2 and PGF2 alpha were neither taken up by the cells nor interfered the uptake. Subcellular distribution studies with sucrose density gradient centrifugation showed that transported delta 12-PGJ2 was present mainly in cytoplasm and nuclei without metabolism. Accumulation of the PG was attenuated greatly by preincubation of the cells at 37 degrees C for 30 min. When the effect of delta 12-PGJ2 was examined in the control and attenuated cells, a clear correlation was observed between the accumulation of the PG and its growth inhibitory effect. These results suggested that uptake and intracellular accumulation of cyclopentenone PGs are responsible for their growth inhibitory activity.
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PMID:Site and mechanism of growth inhibition by prostaglandins. I. Active transport and intracellular accumulation of cyclopentenone prostaglandins, a reaction leading to growth inhibition. 377 4

Rat basophil leukemia cells (RBL-1), when grown in monolayer, synthesize from endogenous substrates the prostaglandins (PG) E2, F2 alpha, and I2 (measured as 6-keto-PGF1 alpha) and 6-sulfidopeptide-containing leukotrienes (SRS), as well as materials that react serologically with anti-12-hydroxyeicosatetraenoic acid (HETE). The non-steroidal anti-inflammatory drugs indomethacin and aspirin inhibited PGE2 synthesis by RBL-1 cells, which had been stimulated with the calcium ionophore A-23187, in a dose-dependent manner with an IC50 of 0.7 and 7.8 microM respectively. Indomethacin, when used at higher concentrations, also inhibited iSRS synthesis with an IC50 of 230 microM. Benoxaprofen, also a non-steroidal anti-inflammatory drug, inhibited both PGE2 and iSRS production in a dose-dependent manner, but inhibition of the iSRS biosynthesis was three times more effective than inhibition of PGE2 production. The anti-oxidants gossypol, butylated hydroxyanisole (BHA), nordihydroguariatic acid (NDGA), and 3-amino-1-[m-(trifluoromethyl)phenyl]-2-pyrazoline (BW755c) also inhibited iSRS synthesis more effectively than PGE2 biosynthesis. The IC50 values for inhibition of iSRS production were 0.2 microM (gossypol), 0.5 microM (BW755c), 0.6 microM (BHA), and 0.6 microM (NDGA) compared to 2.8 microM (gossypol), 2.0 microM (BW755c), 4.8 microM (BHA) and 2.6 microM (NDGA) for inhibition of PGE2 synthesis. Gossypol, BW755C, BHA, and NDGA, as well as benoxaprofen, inhibited i12-HETE-biosynthesis (IC50 for gossypol, 0.32 microM; and for benoxaprofen, 0.5 microM). Two calcium channel blockers, verapamil and nifedipine, inhibited PGE2, iSRS and i12-HETE synthesis in a dose-dependent manner. The calcium channel blockers inhibited iSRS synthesis ten times more effectively than PGE2 production.
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PMID:Inhibition of the A-23187-stimulated leukotriene and prostaglandin biosynthesis of rat basophil leukemia (RBL-1) cells by nonsteroidal anti-inflammatory drugs, antioxidants, and calcium channel blockers. 631 14

The behaviour of phagocytosis and that of PGE1 and PGE2 in the circulating granulocytes of normal and leukaemic subjects was investigated by the comparison of latex particles and the PAP (peroxidase-antiperoxidase) immuno-enzymatic method respectively. Generally speaking, it was found that chronic myeloid leukaemia and acute myeloblastic leukaemia were accompanied by a marked reduction in phagocyting capacity, whereas this is apparently normal in CLL and ALL. PCE values, on the other hand, were well down in lymphatic leukaemia, AML and AMML, but not in CML, where high PGE (especially PGE2) was noted both basally and after phagocytosis. That the PGE take part in phagocytosis is shown by their redistribution in phagocyting cells, with elective accumulation in the membrane and around the engulfed material.
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PMID:[Behavior of PGE1 and PGE2 in the granulocytes of normal and leukemic subjects during phagocytosis in vitro]. 695 84


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