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)

A human megakaryoblastic cell line (MEG-01) was successfully transplanted into athymic nude mice. MEG-01 cells (5 x 10(7)) were inoculated subcutaneously in KSN-nu/nu mice, none of which were pretreated with irradiation or chemotherapeutic agents. All mice developed solid tumors at the site of injection after incubation for 10-14 days reaching a size of 200-400 mm2 (product of cross-sectional diameters) after 30 days. These tumors, designated as MEG-01/nu, were transplanted into other nude mice. The transplanted tumors infiltrated the liver and spleen, and leukemic megakaryoblastic cells appeared in the blood of some transplanted mice. Cells resuspended from MEG-01/nu tumors exhibited almost the same megakaryocytic characteristics as the original MEG-01 cells, and underwent in vitro differentiation to a mature form of megakaryocyte upon addition of phorbol diesters. MEG-01/nu was evaluated for sensitivity to cytosine arabinoside, vincristine, and daunorubicin in vitro and in vivo. Daunorubicin exhibited significant anti-tumor activity against MEG-01/nu in vivo, while cytosine arabinoside did so in vitro. Vincristine showed no activity against these cells. This cell line may provide a useful model for testing the in vivo efficacy of anti-tumor agents and immunotoxins, and for studying the pathophysiological mechanisms of human megakaryoblastic leukemia.
Leukemia 1993 Aug
PMID:New xenografts of human megakaryoblastic cell line (MEG-01) for evaluating anti-tumor agents. 835 Jun 28

Ubenimex (Bestatin, Ubx) has been shown to have anti-tumor activity and immuno-modulating activities. Ubx has been used in immuno-therapy in combination with remission maintenance chemotherapy after induction of complete remission for adult acute non-lymphocytic leukemia (ANLL, AML). Daunomycin (DNR), arabinosylcytosine (Ara-C) and 6-mercaptopurine (6-MP) are used for the standard chemotherapy for ANLL. It is, however, believed that emergence of resistant cells to chemotherapy cause minimal residual leukemia resulting in poor prognosis. Ubx has been administered in combination with these chemotherapeutic agents. We examined the combinatorial effect of Ubx with DNR, Ara-C, 6-MP and etoposide on K562 leukemic cell line and the chemotherapeutic agent resistant cells derived from K562 cell line. Ubx showed growth inhibitory effects on these cell lines. A synergistic effect was observed on growth inhibition and with colony formation of parent k562 cell line when DNR and Ubx were used in combination. A combination of Ubx with Ara-C or etoposide showed additional effects on parent cells and other resistant cell lines. The combined growth inhibitory effect of 6-MP and Ubx was stronger than the effect of 6-MP alone. These results show that Ubx has a direct growth inhibitory effect on leukemic cells and additional or synergistic effects are obtained on K562 leukemic cell line and on chemotherapeutic agent resistant cells derived from the K562 cell line when Ubx is used combination with the above chemotherapeutic agents.
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PMID:[Growth inhibitory effects of ubenimex on leukemic cell lines resistant to chemotherapeutic agents]. 903 97

A 17-year-old girl with acute pomyelocytic leukemia (APL) went into complete remission following Daunorubicin, Ara-C and ATRA chemotherapy for 1 month. Unfortunately, prolonged administration of ATRA 6 weeks later caused binocular diplopia with left abducent nerve paresis, which gradually disappeared upon withdrawal of ATRA. We propose that it is ATRA induced pseudotumour cerebri and present this case to discuss the relationship between the ATRA and pseudotumour cerebri.
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PMID:ATRA-induced pseudotumour cerebri--one case report. 951 92

The acid labile derivative of Daunomycin cis-aconityl Daunomycin (cAD), was coupled to an amphoteric polypeptide, poly[Lys-(Glui-DL-Alam)] (EAK), which was selected for conjugation on the basis of its pharmacological and immunological properties. The systemic toxicity of covalently attached Daunomycin was studied by monitoring body weight, life-span, bone marrow and haematological parameters of BDF1 mice. More than 3-fold the lethal dose of free Daunomycin could be applied without serious toxic effect when the drug was attached to EAK. The dose- and time-dependent modulatory effect of free drug and [cAD]-EAK conjugate on the humoral and cellular immune response to sheep red blood cell antigens in mice was studied. The conjugation of Daunomycin to EAK carrier polypeptide compensated for the immunosuppression induced by free Daunomycin. [cAD]-EAK conjugate at Daunomycin doses of 2-10 mg/kg was very effective against L1210 leukaemia producing 66-100% long-term survivors (> 60 days), while Daunomycin in itself increased the mean survival only by 52%, with no long-term survivors. The mixture of free Daunomycin and EAK polypeptide had similar toxicity and antitumour activity as free Daunomycin, indicating the important role of covalent attachment in increased therapeutic efficacy.
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PMID:Low toxicity and high antitumour activity of daunomycin by conjugation to an immunopotential amphoteric branched polypeptide. 962 51

Currently available data regarding the substrate specificity of the multi-drug resistance (MDR) mechanisms P-glycoprotein (Pgp) and MDR-associated protein (MRP1) for idarubicin are inconclusive. A multiparameter flow cytometry method was developed which allows simultaneous quantitative measurement of total cellular fluorescence and the amount of anthracyclines intercalated into the DNA. Anthracycline DNA intercalation was measured by fluorescence resonance energy transfer (FRET) between Hoechst 33342 and anthracyclines. Daunorubicin and idarubicin accumulation were studied and compared in established cell lines expressing Pgp and MRP1. The data demonstrate that daunorubicin DNA intercalation is affected by both Pgp and MRP1 whereas idarubicin DNA intercalation is affected only by MRP1. MRP1 and Pgp function could be blocked completely by 5 microM PAK 104P, while higher concentrations of verapamil, PSC 833 and cyclosporin A were necessary to attain complete blocking of MRP1 compared to Pgp. Daunorubicin DNA intercalation correlates better with cell survival and is more sensitive at physiological MDR expression as observed in hematopoietic progenitors than daunorubicin levels measured by total cellular fluorescence. In conclusion, idarubicin DNA intercalation is reduced by MRP1 but not by Pgp. PAK-104P is an effective modulator for both Pgp and MRP1 and may further improve idarubicin efficacy.
Leukemia 1999 Sep
PMID:Idarubicin DNA intercalation is reduced by MRP1 and not Pgp. 1048 90

We examined the cellular effects of topo II inhibitors in two human myeloid cell lines, HL-60 and KG-1 cells, with the purpose of finding molecular markers for the sensitivity of leukemia cells to topo II inhibitors. These cell lines are widely used, well characterized and they differ in their sensitivities to topo II inhibitors. Despite the fact that HL-60 cells are p53-negative, they are much more sensitive than KG-1 cells. Three different topo II inhibitors with distinct molecular ways of action have been used. Daunorubicin and aclarubicin are DNA intercalators that secondarily interact with topo II; etoposide, on the other hand, directly binds to the enzyme. In contrast to daunorubicin, which induces protein-associated DNA double-strand breaks due to the blockage of topo II action, aclarubicin inhibits the access of DNA by topo II. No correlation could be established between the drug-induced DNA damage and apoptosis. In fact, the amount and pattern of DNA damage examined with the 'comet assay' was characteristic for each drug in both cell lines. The DNA binding of daunorubicin was slightly higher in HL-60 cells, but there was no notable variance between the cell lines for aclarubicin. The most striking difference could be found for the nuclear topo II activity, which was about half in KG-1 cells and, additionally, less than 1% of the nuclear topo II activity was bound to the DNA in KG-1 cells when compared to HL-60 cells. This fraction of topo II interacts with the inhibitors; subsequently these findings might well explain the variance in the cellular sensitivity. Additional factors are alterations of the apoptotic pathways, eg loss of p53 in HL-60 cells. Although we found no differences in the quantity of DNA damage between the cell lines after drug treatment, the quality of DNA damage appeared to be distinct for each topo II inhibitor. The morphological appearance of the comet tails after treatment was characteristic for each drug. Further studies are necessary to decide whether these in vitro data are compatible with the clinical situation.
Leukemia 1999 Nov
PMID:Molecular effects of topoisomerase II inhibitors in AML cell lines: correlation of apoptosis with topoisomerase II activity but not with DNA damage. 1055 63

Daunorubicin and doxorubicin are anthracyclines that have efficacy against malignancies such as breast cancer, lung cancer, lymphoma, and leukemia. Their adverse effects are similar. The most serious is cardiotoxicity, which often limits the total cumulative dose that can be administered. Introduction of a liposomal formulation for both agents allows tumor selectivity by accumulating the drug in tumor tissue, thus increasing the tolerated dose. Liposomal doxorubicin is commonly associated with palmar-plantar erythrodysesthesia syndrome (PPES), although no reports of PPES were found in the literature related to liposomal daunorubicin (L-DNR). Two patients developed PPES while receiving high-dose L-DNR. The symptoms were self-limiting and resolved within a few weeks.
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PMID:Palmar-plantar erythrodysesthesia syndrome associated with liposomal daunorubicin. 1103 47

Multidrug resistance (MDR) lines from a murine T-cell leukemia were selected in increasing vincristine (VCR) or doxorubicin (DOX) concentrations. Daunorubicin (DNR) efflux was evidenced after 25 additional passages with constant 160 ng ml(-1) of either VCR or DOX, an effect that was inhibited by verapamil, cyclosporin-A (CsA) and PSC 833. The expression of Pgp was not evidenced in the resistant cell lines using anti-human Pgp antibodies. Cell proliferation assay showed that cell lines resistant to VCR (LBR-V160) or DOX (LBR-D160) required higher doses of either drug to produce GI50 compared with control cell line obtained after culture in the absence of VCR or DOX. When resistant cell lines were maintained during 60 days in the absence of either VCR or DOX, MDR phenotype reversal was obtained in LBR-D160 while LBR-V160 remained resistant to the drug, as shown by cell proliferation assays and by drug efflux pump functionality. When VCR or DOX were used together with either CsA or PSC 833, the latter was more effective to produce reversal of resistance than the former, whereas CsA presented greater cytotoxic effect than PSC 833 for sensitive and resistant cells. Cross-resistance was found between VCR, DOX and other antineoplasic agents on murine leukemic cell line. VCR was more effective to induce MDR since the resistant cell lines were more stable to the MDR phenotype.
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PMID:Modulator activity of PSC 833 and cyclosporin-A in vincristine and doxorubicin-selected multidrug resistant murine leukemic cells. 1113 65

Leukotriene C(4) synthase (LTC(4) S) is a pivotal enzyme for generation of cysteinyl-leukotrienes (cysLTs). LTC(4) S activity in rat basophilic leukemia-1 (RBL-1) cells increased after culture in the presence of retinoic acid (RA) analogues, which was inhibited by cycloheximide or actinomycin D (ACD). Unexpectedly, the co-addition of a low dose of ACD with RA further potentiated the upregulation of the LTC(4) S activity. Daunorubicin and mitomycin C also had a similar effect. When stimulated with calcium ionophore A23187, control cells did not produce cysLTs, but RA-treated cells generated cysLTs and the co-addition of ACD further increased. While LTC(4) S mRNA and protein increased in the cells treated with RA, the co-addition of ACD further potentiated both in proportion to the LTC(4) S activity. The effect of ACD was considered to enhance the transcription rate of LTC(4) S gene, but not the mRNA-stability. The addition of methylprednisolone (MP) inhibited generation of cysLTs from the cells with A23187-stimulation and also did LTC(4) S activity, but did not inhibit 5-lipoxygenase (5-LOX). The suppression of LTC(4) S with MP showed a dependent manner on the time-point and duration of MP-treatment after RA-addition which was correlated with reduction in LTC(4) S mRNA and protein. The cells cultured with RA plus ACD contained more histamine, chymase activity, and granules in the cytoplasm than the control cells, suggesting differentiation to mature mast cells. In consideration of RA-differentiation therapy, it may be of pathophysiological relevance that the antineoplastic agents potentiate RA-induced, steroid-sensitive, induction of LTC(4) S in RBL-1 cells.
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PMID:Induction of leukotriene C4 synthase after the differentiation of rat basophilic leukemia cells with retinoic acid and a low dose of actinomycin D and its suppression with methylprednisolone. 1276 51

The aim of our study was to characterise, for the first time, the chemo- and radiation sensitivity of seven pediatric acute lymphoblastic leukemias xenotransplanted into immunodeficient NOD/SCID mice and to correlate the findings with the expression of three drug resistance proteins, P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP1) and lung resistance protein (LRP). Mice were treated with single drugs used in clinical protocols: daunorubicin, doxorubicin, cyclophosphamide, vincristine, cytarabine, asparaginase and methotrexate. Two ALL samples, established from primarily diagnosed patients, responded to 5 or 6 of the tested cytostatics, respectively, while 3 out of 5 ALLs from relapse patients were only sensitive towards 2-4 drugs tested. Daunorubicin was more efficient than doxorubicin. The response of xenografted ALL toward vincristine and cyclophosphamide was inversely correlated with the expression of P-gp, LRP and MRP1 (R2 = 0.71, 0.70 and 0.64 for vincristine and 0.44, 0.70 and 0.60 for cyclophosphamide). A good correlation could be detected between the expression of P-gp and LRP (R2 = 0.88), P-gp and MRP1 (R2 = 0.75) and LRP and MRP1 (R2 = 0.90). The highest co-expression of the drug resistance proteins in the leukemia ALL-SCID 6 coincided with a high resistance to radiation and chemotherapy. Prediction of the individual drug resistance profile of a patient on the basis of results from the ALL-SCID xenograft studies was not possible because of the relatively long time necessary and because of the changes in the expression of P-gp, LRP and MRP1 during the murine generations. We conclude that in the drug resistance phenotype of ALL not only the above mentioned proteins but a variety of different molecules are involved.
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PMID:Chemo- and radiation sensitivity of xenografted acute lymphoblastic leukemias--correlation to the expression of multidrug resistance proteins. 1289 54


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