Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UMLS:C0023418 (leukemia)
93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of the leukemia inhibitory factor/D factor (LIF) gene in human T-cell leukemia virus type 1 infected T-cell lines was examined. Human T-cell leukemia virus type 1 infected T-cell lines MT-1, MT-2, H89-59, H89-79, and H109 expressed LIF mRNA, but the T-cell lines MOLT-4 and TALL-1 did not. LIF mRNA expression was enhanced by interleukin 2 or 12-O-tetradecanoylphorbol-13-acetate in MT-2 cells. The biological activity of LIF was detected in culture medium enhanced by interleukin 2 in MT-2 cells. The expression of LIF mRNA was suppressed by 1 alpha,25-dihydroxyvitamin D3 and dexamethasone. These results imply that the expression of the LIF gene is involved in the development of hypercalcemia and abnormalities of the immune system observed in patients with adult T-cell leukemia.
...
PMID:Expression and regulation of the leukemia inhibitory factor/D factor gene in human T-cell leukemia virus type 1 infected T-cell lines. 145 88

We studied the effects of ICRF-154 in combination with 11 anticancer agents on four human leukaemia cell lines. Cells were incubated for 3 days in the presence of two drugs (ICRF-154 and one other), and cell growth inhibition was determined by MTT assay. Effects of drug combinations at the ID50 level were analysed using the isobologram method (Steel). In the lymphoblastic leukaemia cell lines, MOLT-3, HSB, and B-ALL, supra-additive effects were observed for ICRF-154 in combination with amsacrine, bleomycin, doxorubicin, and etoposide. Additive effects were observed for its combinations with cisplatin, CPT-11, cytosine arabinoside, 5-fluorouracil, mitomycin C, and vincristine. Sub-additive to protective effects were observed in combination with methotrexate. In an erythroleukaemia cell line, K-562, no drug showed supra-additive effects with ICRF-154, while sub-additive to protective effects were observed for ICRF-154 in combination with cisplatin and methotrexate. The other drugs showed additive effects with ICRF-154. These results indicate that the combined effects of ICRF-154 with other agents vary, depending on the cell line. Against lymphoid malignancies, ICRF-154 would be advantageous when administered simultaneously with many anticancer agents. Of such agents, amsacrine, bleomycin, doxorubicin, and etoposide are the most suitable, while methotrexate is least suitable for such combined treatment.
...
PMID:The effects of ICRF-154 in combination with other anticancer agents in vitro. 150 99

Metabolic effects and mode of cytotoxicity of 5-deazaacyclotetrahydrofolate (5-DACTHF, BW543U76), a glycineamide ribonucleotide transformylase inhibitor, were studied in MOLT-4 cells, a human T-cell leukemia line. 5-DACTHF inhibits purine synthesis with 50% inhibitory concentration values of 0.5 microM and 0.08 microM following 6- or 24-h exposure to drug, respectively. At 6 h, adenine nucleotide synthesis is preferentially inhibited over guanine nucleotide synthesis. A similar effect was observed with another glycineamide ribonucleotide transformylase inhibitor, 5,10-dideazatetrahydrofolate. GTP was depleted to 40% of control and ATP to 10% of control by 5 microM 5-DACTHF. After a transitory increase, UTP and CTP were depleted to 30% of control. Deoxynucleotides were also depleted by the drug; dCTP was depleted to the greatest extent, followed by dATP, dTTP, and dGTP, respectively. MOLT-4 cell growth was inhibited by 5-DACTHF with a 50% inhibitory concentration of 0.066 microM. Complete reversal was effected by hypoxanthine, and there was no reversal by thymidine. The drug was cytotoxic to MOLT-4 cells in the range 0.25 to 5.0 microM, but a minimum of 48 h was required for trypan blue-staining dead cells to appear. The rate and extent of kill with the thymidylate synthase inhibitor 2-methyl-10-propargyl-5,8-dideazafolate was greater than with 5-DACTHF, which indicates that kill by inhibition of thymidylate synthase is more effective than that by inhibition of purine synthesis. Electron microscopy of MOLT-4 cells exposed to 5-DACTHF showed electron-dense mitochondria and nuclear changes reminiscent of apoptosis. These morphological changes were accompanied by the appearance of DNA strand breaks at approximately 180-base pair intervals (internucleosomal breaks). Concomitant proteolysis of nuclear proteins poly(ADP-ribose) polymerase and lamin B was observed.
...
PMID:Metabolic effects and kill of human T-cell leukemia by 5-deazaacyclotetrahydrofolate, a specific inhibitor of glycineamide ribonucleotide transformylase. 151 46

CPT-11, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy camptothecin, is a newly developed water-soluble camptothecin derivative now undergoing phase-II evaluation. In an attempt to establish whether the combination of CPT-11 with other standard anti-cancer agents would be of any benefit, we studied the effects of CPT-11 in combination with 11 other anti-cancer agents on a human T-cell leukemia cell line, MOLT-3, in culture. We used both CPT-11 and SN-38 (active substance of CPT-11 in vivo), for our study. Cells were incubated for 3 days in the presence of 2 drugs (CPT-11 or SN-38 and another drug) and cytotoxic effects were determined by MTT assay. The effects of drug combinations on ID50 were analyzed by an improved isobologram method. Supra-additive and marginal supra-additive effects (synergism) were observed for CPT-11 in combination with cisplatin, cytosine arabinoside and mitomycin C. Additive effects were observed for its combination with amsacrine, bleomycin, doxorubicin, etoposide, 5-fluorouracil, mitoxantrone and vincristine. Alternate sub-additive and protective effects (antagonism) were observed for CPT-11 in combination with methotrexate. Similar tendencies were observed for SN-38 in combination with other agents. These results suggest that CPT-11 in simultaneous administration with a majority of anti-cancer agents has an advantage for cytokilling. Of these agents, cisplatin, cytosine arabinoside and mitomycin C are most suitable for simultaneous administration with CPT-11.
...
PMID:Effects of CPT-11 in combination with other anti-cancer agents in culture. 153 25

N-Acetylserotonin (compound 1) and N-acetyldopamine (compound 7) inhibit bovine adrenal medullary sepiapterin reductase in a manner competitive with the pterin substrate and have Ki values of 0.12 and 0.4 microM, respectively. Molecular modeling suggests that the phenyl rings of the two compounds bind in the pyrimidine pocket of the enzyme with the 3-hydroxyl of dopamine or the 5-hydroxyl of serotonin aligned at the pyrimidine 4-position. Further, the acetyl moieties of the two inhibitors appear to mimic the substrate side chain. Consistent with this analysis, N-acetyl-m-tyramine (compound 13) is also an excellent competitive inhibitor (Ki = 0.13 microM), whereas N-acetyltryptamine (compound 2), N-acetyl-p-tyramine (compound 14) and N-acetylphenylethylamine (compound 15) all bind poorly. Interestingly, restricted-rotation analogs of N-acetyldopamine and N-acetyl-m-tyramine are noncompetitive inhibitors of the enzyme. Modification of N-acetyldopamine to N-chloroacetyldopamine (compound 10) or of N-acetylserotonin to the N-chloroacetyl (5) or N-methoxyacetyl (compound 6) analogs results in greatly increased competitive affinity, with Ki = 0.014 microM for the dopamine analog and 0.006 and 0.008 microM, respectively, for the serotonin analogs. In MOLT-4 T-cell leukemia and MCF-7 breast adenocarcinoma in culture, 0.1 mM N-methoxyacetylserotonin depleted tetrahydrobiopterin by greater than or equal to 97 and greater than 50%, respectively, with no effect upon cell growth. In both cell lines, the GTP cyclohydrolase inhibitor, 2,4-diamino-6-hydroxypyrimidine at 1-5 mM also depleted tetrahydrobiopterin greater than or equal to 97%. In this case, however, modest growth inhibition did occur. Since the growth inhibition could not be reversed upon tetrahydrobiopterin repletion, inhibition was due to other effects of the inhibitor rather than to tetrahydrobiopterin depletion. The results show that there is no effect on cell growth when at least 97% of the tetrahydrobiopterin in these cell lines is depleted. Since the sepiapterin reductase inhibitor depleted tetrahydrobiopterin with fewer nonspecific effects than the cyclohydrolase inhibitor, it will be useful for determining metabolic effects of tetrahydrobiopterin depletion.
...
PMID:New inhibitors of sepiapterin reductase. Lack of an effect of intracellular tetrahydrobiopterin depletion upon in vitro proliferation of two human cell lines. 154 33

It has been reported that high doses of (dl)-5-methyltetrahydrofolate (mTHF) inhibit the growth of leukemic cell lines. We studied the effect of methotrexate (MTX) and mTHF in combination on the lymphoid cell lines BALM 3, CEM, MOLT 4 and P3HR1 by evaluating the clonogenic cell reduction in a limiting dilution assay. Cells were treated with 0.1 mM MTX for 4 h and 1 mM mTHF for 48 h. The growth of the cell lines was inhibited by 1 mM mTHF, with a clonogenic cell reduction of 3.5 log. MTX, following by mTHF after a delay of 8-24 h, caused a substantial killing of lymphoid leukemia cells, greater than the effect of either drug alone. The clonogenic cell reduction caused by the combination MTX-mTHF ranged from about 3.5 to 4.5 log, depending on the cell line studied. Normal hemopoiesis, as evaluated by primitive hematopoietic precursor colonies and granulocyte-macrophage colony-forming units (CFU-GM) was only slightly affected by the MTX-mTHF treatment at a dose and schedule which caused up to 4.5 log reduction of the leukemic cell lines. mTHF-MTX treatment could be useful in vitro for purging bone marrow cells in autologous bone marrow transplantation for acute leukemia.
Leukemia 1992 Feb
PMID:Differential effect of the combination methotrexate/(dl)-5-methyltetrahydrofolate on lymphoid malignant and normal bone marrow cells. 155 44

Chimeric oligodeoxynucleotides with terminal nonionic methylphosphonate analogue sections and internal phosphodiester regions offer several advantages as antisense effectors over either structure alone. These include enhanced biological stability relative to all-phosphodiester molecules, increased activity in directing ribonuclease H mediated destruction of target RNA, increased specificity and reduced non-specific toxicity. However, another important parameter, the ability of these molecules to enter intact mammalian cells, has not previously been investigated. Therefore, oligodeoxynucleotides were tagged at their 5'-termini with fluorescein reporter groups and a detailed study of uptake kinetics in human leukaemia MOLT-4 cells undertaken by calibrated flow cytometry. Baseline measurements with all-phosphodiester and all-methylphosphonate molecules confirmed that uptake of oligodeoxynucleotides by intact cells is a highly inefficient process. The kinetic data were in agreement with previous reports of mechanisms of cell uptake involving receptor mediated endocytosis in the case of phosphodiester molecules and simple diffusion for methylphosphonates. Chimeric oligodeoxynucleotides exhibited saturable cell uptake kinetics similar to all-phosphodiester oligodeoxynucleotides, suggesting that uptake was receptor-mediated and distinct from concentration-dependent uptake of all-methylphosphonate molecules. Similarly, chimeric molecules were apparently confined to the endosomal compartment within cells. These results imply that reversible masking of the negative charges of the phosphodiester sections of chimeric oligodeoxynucleotides may be required to change the uptake mechanism back to simple diffusion and allow intracellular delivery to the site of the target RNA.
...
PMID:The uptake kinetics of chimeric oligodeoxynucleotide analogues in human leukaemia MOLT-4 cells. 157 85

Activation of resting human peripheral blood T lymphocytes by the lectin phytohemagglutinin results in an increase in methionine adenosyltransferase (MAT) activity, accompanied by an increase in the amount of the alpha/alpha' catalytic subunits of the enzyme. In contrast, the amount of the noncatalytic beta subunit remains constant throughout the course of the response. Using both polyclonal antibodies to the holoenzyme and monoclonal antibodies to the alpha/alpha' subunits, we detected a cross-reactive 68-kDa protein, which we refer to as lambda. This protein is present in high abundance in resting T cells but decreases upon cell stimulation, as both MAT activity and the amount of the catalytic alpha/alpha' subunits increase. The decrease in lambda and increase in alpha/alpha' occurs after interleukin-2 production and before DNA synthesis. lambda virtually disappears when the cells are actively dividing. Several continuous T cell lines (HPB-ALL, MOLT-4, and Jurkat) as well as a freshly isolated T cell leukemia (ALL-2) had no detectable lambda. The Km for L-methionine for enzyme from resting peripheral blood mononuclear cells was 19-23 microM, which is 3-8-fold higher than purified MAT from fresh leukemic cells or enzyme from Jurkat cells, both of which have a Km of 3.5-3.8 microM. Kinetic analysis of enzyme activity from activated peripheral blood mononuclear cells suggested the presence of two forms of enzyme catalyzing the synthesis of AdoMet. After separation of lambda from the alpha and beta subunits by hydrophobic chromatography, it was determined that lambda has MAT activity but that it is significantly less active than the form containing the alpha subunit. It therefore appears that in resting T cells MAT is sequestered as a less active form. We hypothesize that lambda is a precursor to the catalytic subunits of human lymphocyte MAT and propose that the transition from lambda to alpha/alpha' may be important in the response of T cells to mitogenic signals.
...
PMID:Changes in the relative amount of subunits of methionine adenosyltransferase in human lymphocytes upon stimulation with a polyclonal T cell mitogen. 158 46

To investigate the effects of mitoxantrone in combination with other anticancer agents, a human T-cell leukemia cell line, MOLT-3, was incubated for 3 days in the presence of two drugs (mitoxantrone and the combined drug) and cell growth inhibition was determined by assay with 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazonium bromide. The effects of drug combinations at doses giving 80% inhibition (ID80) were analyzed by an improved isobologram method. A supra-additive (synergistic) effect was observed for mitoxantrone in combination with amsacrine, cisplatin, or cytosine arabinoside. An additive effect was observed for its combination with bleomycin, doxorubicin, etoposide, 5-fluorouracil, mitomycin C, 6-mercaptopurine, or vincristine. A sub-additive (antagonistic) effect was observed for its combination with methotrexate. These data suggest that mitoxantrone, administered simultaneously with any one of a majority of anticancer agents we studied, is advantageous for cytokilling. Of the anticancer agents tested, amsacrine, cisplatin, and cytosine arabinoside are the most suitable for combination with mitoxantrone, and these combinations are worthy of clinical investigation. Methotrexate in our system is inappropriate for simultaneous administration with mitoxantrone. These data should provide useful information for the establishment of clinical protocols involving mitoxantrone.
Leukemia 1992 May
PMID:Effects of mitoxantrone in combination with other anticancer agents on a human leukemia cell line. 159 9

The effect of prothymosin alpha (ProT alpha) on the survival of DBA/2 mice inoculated with syngeneic tumour cells was studied. DBA/2 mice inoculated intraperitoneally (i.p.) with 2 x 10(5) syngeneic leukaemic L1210 cells developed ascites within 8-12 days and died 10-14 days later. Treatment with ProT alpha consistently inhibited the development of ascites in 20% of the treated animals and prolonged the survival of 40%-60% of the animals up to 70 days. The most effective treatment schedule of ProT alpha was 300 ng/mouse given i.p. at 2-day intervals for 3 weeks followed by a rest period of 7 days, prior to tumour cell inoculation. Peritoneal exudate (PE) cells collected from mice treated with the optimal dose of ProT alpha produced, in the absence of exogenous stimulus, six- to eightfold higher levels of tumour necrosis factor alpha (TNF alpha) than PE cells from control mice. Furthermore these cells exhibited cytotoxic activity against several tumour cell lines including the syngeneic L1210, the TNF-insensitive P815 mastocytoma, the human MOLT-4 lymphoblastic leukaemia, as well as the murine TNF-sensitive L929 fibroblast cell line. Kinetic studies revealed that both production of TNF alpha and tumoricidal activity peaked 7 days after the last injection of ProT alpha and were maintained at high levels over a period of 1 month. Injections with 150 ng ProT alpha slightly improved the survival of mice whereas higher (500 ng and 1000 ng) doses of ProT alpha and a wide range of thymosin alpha 1 doses remained without any effect. PE cells collected from these mice produced extremely low levels of TNF alpha and exhibited negligible tumoricidal activity. Our data demonstrate that ProT alpha has a protective effect in vivo against the growth of adoptively transferred tumour cells and suggest that this effect is, at least in part, mediated by ProT alpha-activated PE cells. These cells were demonstrated to produce high levels of TNF alpha in vitro and to exhibit activity against both TNF-sensitive and TNF-resistant cell lines.
...
PMID:Promotion of murine antitumor activity by prothymosin alpha treatment: I. Induction of tumoricidal peritoneal cells producing high levels of tumour necrosis factor alpha. 159 38


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---