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)

Deuterium oxide (D2O), which is known to stimulate microtubule aggregation, enhanced the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in rat basophilic leukemia cells (RBL-2H3) in the same dose-dependent manner (up to 90% (v/v]. We compared the interaction between D2O and a variety of groups of pharmacological agents. A microtubule depolymerizing agent, demecolcine, which inhibited the IgE-mediated (14C)-arachidonic acid and histamine release without affecting 45Ca2+ influx, was counteracted by 45% D2O. Taxol, a microtubule stabilizing agent, which had an inhibitory effect on the above three steps, was also reversed by 45% D2O. These results would support the previous data on the interaction between D2O and microtubules and would further suggest that the status of microtubule aggregation may be related to the secretory process. Calmodulin inhibitors (W-7, trifluoperazine) blocked the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in the same dose-dependent manner, but were counteracted by 45% D2O. In contrast, the effects of proteinase inhibitors (TPCK, TLCK), an adenylate cyclase inhibitor (ddAdo), a phosphodiesterase inhibitor (aminophylline), a phospholipid methylation inhibitor (DZA + Hcy) and microfilament blockers (cytochalasin B and D) were not counteracted by 45% D2O. These results would suggest that D2O may be associated with calmodulin directly or indirectly possibly through some relationship between calmodulin and microtubules.
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PMID:Effect of deuterium oxide (D2O) on the IgE-mediated Ca2+ influx, arachidonic acid and histamine release in rat basophilic leukemia cells. 247 27

Taxol, a novel antimicrotubule agent that enhances tubulin polymerization and microtubule stability, was administered to adults with refractory leukemias as a 24-h i.v. infusion in a Phase I study. The primary objectives were to determine the maximum tolerated dose of taxol administered on this schedule to patients with acute leukemias and describe the nonhematological toxicities which became dose limiting. The starting dose, 200 mg/m2, was based on the maximum tolerated dose in solid tumor trials, in which myelosuppression precluded dose escalation. Seventeen patients received 28 evaluable courses at 200, 250, 315, and 390 mg/m2. Severe mucositis limited further dose escalation. Other nonhematological effects included peripheral neuropathy, alopecia, myalgias, arthralgias, nausea, vomiting, diarrhea, and an acute pulmonary reaction that was presumptively due to taxol's Cremophor vehicle. Mean peak taxol plasma concentrations at all dose levels were in the range of concentrations that were previously demonstrated to induce microtubule bundles, a morphological effect associated with cytotoxicity, in leukemia cells in vitro. Pretreatment blasts from 12 patients were incubated with taxol ex vivo. Taxol-induced microtubule bundles were apparent in the blasts of eight patients who also had cytoreduction of tumor, and sensitivity to bundle formation was related to the magnitude of antitumor activity. In contrast, taxol did not induce microtubule bundles ex vivo in the blasts of the other four total nonresponders. Based on this study, the maximum tolerated doses and recommended Phase II doses for taxol, limited by nonhematological toxicity and administered as a 24-h i.v. infusion to patients with refractory leukemias, are 390 and 315 mg/m2. Phase II trials at these myelosuppressive doses are required to determine taxol's activity in the treatment of leukemias. In addition, further evaluation of microtubule bundle formation ex vivo in Phase II studies is necessary to determine the ultimate utility of this assay in assessing tumor sensitivity to taxol.
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PMID:Phase I and pharmacodynamic study of taxol in refractory acute leukemias. 256 75

Taxol, a diterpenoid plant product that enhances the polymerization of tubulin, is currently entering clinical trials in the treatment of human leukemia. In order to develop an in vitro assay to predict tumor sensitivity to taxol, human leukemic cell lines were exposed to clinically achievable concentrations of taxol for relevant exposure periods. Changes in microtubules visualized by indirect immunofluorescence were compared to drug sensitivity measured by a clonogenic assay. Taxol produced either multiple mitotic asters in G2/M or microtubule bundling throughout the cell cycle. In cells that were relatively resistant to taxol, microtubule bundling was reversible while microtubule bundling in relatively sensitive cells persisted in the presence or absence of taxol. In contrast, aster formation was unrelated to cytotoxicity in any cell line. In the future, these microtubule effects may be useful in predicting the chemotherapeutic efficacy of taxol.
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PMID:Microtubule changes and cytotoxicity in leukemic cell lines treated with taxol. 289 89

By suppressing apoptosis, hemopoietic growth factors (HGFs) promote the survival of CD34+, HLA-DR+ marrow cells that are enriched for hemopoietic progenitor cells (HPC). In the present studies, we have examined the effects of pIXY321, a genetically engineered fusion protein of GM-CSF and IL-3 (GM-CSF/IL-3), on high-dose Ara-C (HIDAC) and taxol-induced apoptosis and survival of a multilineage HPC, the CFU-GEMM. Exposure to 1.0 mumol/l taxol for 24 h or HIDAC > or = 10 mumol/l for 4 h induced internucleosomal DNA fragmentation and the morphologic features of apoptosis in CD34+, HLA-DR+ cells. These treatments were associated with > or = 50% inhibition of the assayable CFU-GEMM colony numbers. Incubation in serum-free medium (SFM) alone for 24 h also induced apoptosis of CD34+, HLA-DR+ cells, which was associated with reduced intracellular levels of the bcl-2 gene product p26BCL-2. Co-treatment with pIXY321 (10 ng/ml) inhibited apoptosis of CD34+, HLA-DR+ cells incubated in SFM, without significantly increasing the intracellular p26BCL-2 levels. Furthermore, co-treatment with pIXY321 significantly reduced taxol- and Ara-C-induced apoptosis and promoted the survival of CFU-GEMM (P < 0.05). Taxol and Ara-C mediated apoptosis of CD34+, HLA-DR+ cells, and its inhibition by pIXY321, was not accompanied by any significant alteration in the intracellular p26BCL-2 levels. By demonstrating that co-treatment with pIXY321 confers significant protection against apoptosis of CD34+, HLA-DR+ cells as well as promotes survival of normal HPC exposed to clinically relevant schedules and concentrations of taxol of Ara-C, these results support the design of chemotherapy regimens incorporating pIXY321 plus taxol and/or high-dose Ara-C for solid tumors and/or acute leukemias. It is hoped that the use of such a cytokine might maintain normal HPC numbers following chemotherapy, therefore avoiding prolonged suppression.
Leukemia 1995 Nov
PMID:pIXY321 protects against Ara-C or taxol-induced apoptosis and loss of clonogenic survival of normal human bone marrow progenitor cells. 747 74

Taxol (paclitaxel, Bristol-Myers Squibb Company, Princeton, NJ), a drug extracted from the stem bark of the western yew, shows great promise as an antineoplastic agent for ovarian, breast, nonsmall cell lung, and head and neck cancers; melanoma; and leukemia. Although Taxol first was isolated in 1971, completion of many phase I studies was delayed until 1988, primarily because the drug caused severe hypersensitivity reactions. Other side effects of Taxol include cardiotoxicity, nausea and vomiting, diarrhea, mucositis, myelosuppression, tingling and numbness of the hands and feet, myalgia and arthralgia, alopecia, fatigue, headache, irritation at the injection site, and taste changes. Nursing care includes measures for preventing or minimizing side effects, close assessment and monitoring of potential side effects, patient education, and support. Because of the environmental impact of harvesting the western yew for Taxol, semisynthetic preparations such as taxotere are being explored.
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PMID:Taxol: a promising new drug of the '90s. 790 60

Taxol-resistant sublines of HL-60 myeloid leukemia cells (HL-60/TAX100 and HL-60/TAX1000) have been isolated in vitro by subculturing in progressively higher concentrations of taxol. HL-60/TAX100 and HL-60/TAX1000 cells are capable of continuous growth in the presence of 0.1 microM and 1.0 microM taxol, respectively, and the IC50 (50% growth inhibitory dose) values for taxol for the two sublines are 0.34 and 2.44 microM as compared to 3.1 nM for the parent HL-60 cells. HL-60/TAX100 and HL-60/TAX1000 cells display a variable degree of cross-resistance to taxotere, vincristine and doxorubicin, but are sensitive to the antimetabolite Ara-C. Both HL-60/TAX100 and HL-60/TAX1000 cells over-express MDR-1 m-RNA and the membrane efflux multidrug transporter P-glycoprotein (PGP), as determined by Western blot and immunofluorescence labeling with anti-PGP antibodies. Consequently, exposure of the taxol-resistant cells to [3H]taxol or daunomycin results in the accumulation of significantly lower levels of the two drugs. Co-treatment with cyclosporine (0.5 microgram/ml) or verapamil (10 microM) partially overcomes taxol resistance in HL-60/TAX1000 cells. Following treatment with clinically relevant concentration of taxol (1.0 microM for 24 h), HL-60 but not HL-60/TAX1000 cells display intracellular microtubular bundling, markedly enhanced accumulation of the cells in G2/M phase of cell-cycle and internucleosomal DNA fragmentation associated with apoptosis which is independent of bcl-2 gene expression. These taxol-resistant myeloid leukemia cells may serve as in vitro experimental models for examinating strategies which may have potential applicability for overcoming taxol resistance.
Leukemia 1994 Mar
PMID:Characterization of a human myeloid leukemia cell line highly resistant to taxol. 790 95

Taxol, a diterpene alkaloid isolated from the bark of Taxus brevifolia, has a unique mechanism of action. The drug promotes the formation of microtubule polymers in a cell, by reversibly and specifically binding the beta-subunit of tubulin. Taxol is administered intravenously by a 3-24-hour infusion at 3-week intervals. Myelosuppression, especially neutropenia, appears to be the dose limiting toxicity in solid tumours at 200-250 mg/m2. Furthermore, side effects such as sensory neurotoxicity (with typical numbness, tingling and painful paraesthesiae in the extremities), diarrhoea and alopecia appear frequently. Mucositis appears to be the non-haematological dose limiting side effect at 390 mg/m2 that has been determined in patients with leukaemia. Hypersensitivity reactions, which have been fatal in individual cases, might be schedule dependent. Furthermore, antiallergic prophylaxis must be given, although this precaution might not be considered to be fully protective. Phase I studies performed with combinations of taxol and cisplatin, doxorubicin or cyclophosphamide have indicated the feasibility of these regimens and show promise for future investigations. Addition of granulocyte-colony stimulating factor (G-CSF), aimed at modulating myelosuppressive toxicity, showed in Phase I studies that the taxol dose could be increased to 250 mg/m2, with peripheral neuropathy as the dose limiting toxicity. In Phase II studies, taxol has been shown to be effective, including producing complete tumour remission, in advanced drug refractory ovarian carcinoma (19%-36% response rate), previously treated patients with metastatic breast carcinoma (27%-62% response rate), advanced non-small lung cancer (21%-24% response rate), advanced small cell lung cancer (37% response rate) and advanced head and neck cancer (34% response rate).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical, toxicological and pharmaceutical aspects of the antineoplastic drug taxol: a review. 790 88

The apoptosis-associated DNA strand breaks were detected in situ, in individual leukemic cells in peripheral blood and bone marrow of over 110 patients with different types of leukemia (ALL, AML, CML in blastic crisis, APL), prior to and during routine chemotherapy. The DNA strand breaks were labeled with digoxigenin- or biotin-conjugated dUTP in the reaction catalyzed by exogenous terminal deoxynucleotidyl transferase, and the cells, counterstained for DNA, were analyzed by bivariate flow cytometry. The proportion of cells with DNA strand breaks prior to therapy, most likely reflecting spontaneous apoptosis, varied from 0.1 to 16%, but in the large majority of cases was below 3%. Administration of drugs of different classes, which included DNA topoisomerase I (Topotecan) and II (mitoxantrone, VP-16) inhibitors, antimetabolite (ara-C) or microtubule poison (Taxol), all triggered the appearance of cells with extensive DNA breakage, typical of apoptosis, to up to 80%. The peak of the response, measured as maximal percent of cells with DNA strand breaks, which varied between individual patients by as much as factor 10, was generally seen between 8 to 24 h after the initial administration of DNA topoisomerase inhibitors, and somewhat later (48-72 h) during the response to Taxol or ara-C. Thus, the data show that the response to treatment with a variety of drugs, in terms of induction of apoptosis, can be conveniently measured by the present method. The prognostic value of the apoptotic index, before, as well as during treatment, is being estimated for each type of leukemia, in the ongoing prospective studies.
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PMID:Apoptotic cell death during treatment of leukemias. 807 83

The present results demonstrate that the exposure of human myeloid leukemia HL-60 and KG-1 cells to clinically achievable concentrations of taxol produced internucleosomal DNA fragmentation of approximately 200 base-pair multiples, and the morphologic changes characteristic of cells undergoing programmed cell death (PCD) or apoptosis. Taxol-induced PCD was associated with a marked inhibition of suspension culture growth and clonogenic survival of HL-60 cells. In addition, taxol treatment decreased BCL-2 oncogene expression, which is known to block PCD. The exposure to taxol moderately decreased c-myc expression, but did not induce c-jun expression--which has been previously noted for a variety of DNA interactive, antileukemic drugs. These findings indicate that taxol may induce leukemic cell death partly by the alternative but gene-directed and active mechanism of PCD.
Leukemia 1993 Apr
PMID:Taxol induces internucleosomal DNA fragmentation associated with programmed cell death in human myeloid leukemia cells. 809 57

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is an effective drug in the treatment of metastatic breast cancer (MBC). In the salvage setting, 5-fluorouracil (5-FU) and folinic acid have proved to be effective against MBC as well. Recent preclinical data suggest that paclitaxel plus 5-FU has additive cytotoxicity. Given these observations, we initiated a phase II trial in which 38 women with MBC have been treated with a combination of all three drugs. All patients are currently evaluable for toxicity and 34 are evaluable for response. All women had histologically proven and assessable disease. Patients with prior exposure to paclitaxel were ineligible. Patient characteristics include a median age of 51 years (age range, 31 to 73 years) and a median performance status of 1 (range, 0 to 2). Thirty-three patients have received prior chemotherapy, of whom 23 had adjuvant chemotherapy only. Fifty-eight percent of the patients (22 of 38) had received prior doxorubicin or mitoxantrone; four patients had only hormonal therapy. Four patients had bone-only disease, and three patients had lymphangitic spread or cytologically positive pleural effusion as the only evaluable disease. Treatment consisted of paclitaxel 175 mg/m2 over 3 hours (day 1 only), followed by folinic acid 300 mg over 1 hour, followed by 5-FU 350 mg/m2 on days 1 to 3. Patients received standard paclitaxel premedications. To date, 175 cycles have been administered (median cycle length, 29 days; median number of cycles per patient, five). Toxicities included grade 3/4 infections in nine cycles (5%), grade 3/4 mucositis in three cycles, grade 3/4 nausea/vomiting in three cycles, grade 1 paresthesias in 12 patients (32%), alopecia 100%, and 17 cycles (10%) associated with dose reduction. Based on Cancer and Leukemia Group B toxicity criteria, arthralgia/myalgias were modest and graded mild (32 cycles), moderate (nine cycles), or severe (two cycles). There were two major hypersensitivity reactions, prompting removal of those patients from further protocol treatment. Four patients are unassessable for response due to hypersensitivity reactions (two) and unevaluable disease (two). Among the 34 patients evaluable for response, there were three complete responses, 18 partial responses, one minor response, nine stable disease, and three progressive disease (response rate, 62%). Responses were seen in patients who had received prior doxorubicin or mitoxantrone (11 of 22 patients) and in anthracycline/naive patients (10 of 16 patients). Responses were observed in all metastatic sites: soft tissue, viscera, and bone. Paclitaxel/5-FU/folinic acid appears to be an effective and well-tolerated outpatient regimen for women with MBC, even after failure of anthracycline-containing therapy.
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PMID:Paclitaxel and 5-fluorouracil in metastatic breast cancer: the US experience. 862 38


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