Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The risk for induction of epipodophyllotoxin-related acute myeloid leukemia (AML) depends largely on the schedule of drug administration and, to a lesser degree, the cumulative dose. Concomitant use of other genotoxic drugs, such as alkylating agents and cisplatin, can increase the hazard further. We have treated 154 consecutive higher-risk cases of acute lymphoblastic leukemia in our recent Total Therapy Study XIII with an intensive post-remission regimen of chemotherapy that included etoposide given every other week or less often-a schedule associated with a relatively low cumulative incidence of secondary AML in our Study XI. Unexpectedly, four patients have developed secondary AML at 12 to 23 months from the start of treatment (median, 16 months). The 2-year cumulative risk estimate significantly exceeds that for 185 historical controls in Study XI whose continuation regimen included epipodophyllotoxins every other week: 5.4% (95% confidence interval, 0-11%) compared with 1.1% (0-2.6%), P = 0.046. Compared to patients treated in Study XI, those enrolled in Study XIII receive fewer scheduled doses of epipodophyllotoxin (48 (all etoposide) vs 63 (30 etoposide, 33 teniposide)) but 16 to 19 additional doses of L-asparaginase and eight additional doses of high-dose methotrexate, all within the week preceding etoposide treatment. We attribute the apparently increased rate of secondary AML in Study XIII to the use of L-asparaginase immediately before etoposide administration. On this schedule, the enzyme could increase systemic exposure to etoposide or its catechol metabolites and reduce the ability of cells to repair DNA damage.
 ...
PMID:L-asparaginase may potentiate the leukemogenic effect of the epipodophyllotoxins. 756 9

In preparation for a clinical trial using GM-CSF on days 4-10 of sequential high-dose cytarabine (ara-C) and asparaginase (ASNase) on days 1-3 and 8-10, potential interactions between the protein synthesis inhibitor ASNase and GM-CSF were evaluated. Granulocyte-macrophage colony-stimulating factor (GM-CSF) can stimulate acute myeloid leukemia (AML) cells to proliferate in vitro and in vivo. Log phase HL-60 cells were exposed to ara-C (10 microM x 3 h) and/or ASNase (10 U/ml during the last 2 h of ara-C). Ara-C and/or ASNase was removed and cells were incubated with or without GM-CSF (10 ng/ml). After 24, 48 and 72 h of GM-CSF there was no significant difference in the S phase fraction of cells exposed to ASNase prior to GM-CSF. Soft agar cloning efficiency was determined after retreatment with ara-C +/- ASNase 24 h into the GM-CSF incubation. GM-CSF enhanced cytotoxicity for all combinations, although this effect was of borderline significance (P = 0.0621); addition of ASNase to the treatment regimen significantly (P = 0.0229) enhanced cytotoxicity without any evidence of a negative interaction with GM-CSF. In addition, ara-C metabolism was assessed during simultaneous exposure to ara-C (10 microM x 3 h) +/- ASNase (10 U/ml the last 2 h) +/- GM-CSF (10 ng/ml beginning 24 h prior to ara-C). Ara-C incorporated into DNA (P = 0.0302) and ara-CTP formation (P = 0.0084 and P = 0.0003 at 2 and 3 h timepoints, respectively) were both increased significantly by GM-CSF, with modest non-significant increases with ASNase exposures. Neither ASNase nor GM-CSF inhibited the effects of the other in this in vitro model. Therefore, when appropriately scheduled, both GM-CSF and ASNase may potentiate ara-C cytotoxicity.
 ...
PMID:GM-CSF and asparaginase potentiate ara-C cytotoxicity in HL-60 cells. 788 38

The response to chemotherapy is determined essentially by two factors: first, pharmacokinetic factors, determining which concentration of drug reaches the malignant cells, and second, cellular drug resistance of these cells, determining how many of them will be killed by that concentration of drug. The study of cellular drug resistance has been stimulated by the development of short-term 'total cell kill' assays, such as the MTT assay, for use on patient samples. The drug resistance profiles differed markedly between ALL and ANLL, between immunophenotypic and karyotypic subgroups within ALL, and between initial and relapsed ALL. The results of the MTT assay showed a significant relation between the antileukemic activity of prednisolone in vitro and the clinical response to systemic monotherapy with that drug. At multivariate analysis including several well-known prognostic factors (WBC, age, immunophenotype) only the in vitro resistance to prednisolone, dexamethasone, L-asparaginase, and daunorubicin was significantly related to clinical outcome. At multiple regression analysis, combination of the results for prednisolone, L-asparaginase, and vincristine made it possible to distinguish between three patient groups with increasing levels of drug resistance and markedly different probabilities of 2-year disease-free survival: 100%, 83%, and 60%. These results show that in vitro drug resistance testing can give a correct prediction of prognosis, superior to that of currently used prognostic factors. Stratification of prognostic groups based on the results of drug resistance testing is feasible and should be introduced into new clinical trials. Many questions now remaining could be answered within carefully designed preclinical and clinical studies.
 ...
PMID:Cellular drug resistance in childhood leukemia. 806 Nov 9

L-asparaginase is an enzyme which hydrolyses asparagine. Since the 1960s it has been known that some leukemic cells are deficient in asparagine synthetase and therefore cannot manufacture sufficient quantities of this essential amino acid to maintain cell viability. L-asparaginase is predominantly useful in acute lymphocytic leukemia (ALL) although responses have been noted in patients with acute myeloid leukemia, lymphoma, and rarely other tumors. L-asparaginase has been used in conjunction with methotrexate and ara-C in combination programs in leukemia. The major side-effect limiting the usefulness of L-asparaginase is allergic reactions. In addition, it is probable that neutralizing antibodies develop which shorten the half life of the drug so that the goal of depletion of plasma levels of asparagine cannot be attained or maintained. Polyethylene glycol (M.W. 5000) can be conjugated to L-asparaginase at sites not involving the active site of the enzyme. This enables free access of a small molecule, asparagine, to the active site of the enzyme but prevents uptake by the reticuloendothelial system, greatly decreasing the probability of developing antibodies against the asparaginase and prolongs the circulating half life of the drug. In a phase I/II study conducted at the M.D. Anderson Cancer Center, 37 heavily pretreated patients with refractory hematologic malignancy were treated. The age range from 15 to 73 years, median 49 years. Nineteen patients had ALL, 15 lymphoma, two myeloma, and one Hodgkin's disease. The dose levels of PEG L-asparaginase varied from 250 IU/m2 up to 8000 IU/m2. The pharmacokinetic profile demonstrated a monophasic half life consistent with a one compartment model with a single elimination phase.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:L-asparaginase and PEG asparaginase--past, present, and future. 848 65

A case of successful pregnancy after BMT in a 24-year-old woman with ALL, conditioned with CY, L-asparaginase, methylprednisolone and total body irradiation (TBI) is reported. A second case of two spontaneously aborted pregnancies in a woman transplanted for ALL at the age of 29 years using CY and TBI conditioning and a third case, this time a successful pregnancy in a woman transplanted for AML at age 27 years using CY and TBI conditioning are also described. There are now 6 successful live births after TBI reports of, versus 16 following regimens in which no TBI is used. This is the first report of a successful pregnancy reported in a female transplanted when older than 25 years using any TBI-containing regimen.
 ...
PMID:Pregnancy after BMT: three case reports. 850 78

To define better the risk of epipodophyllotoxin-related acute myeloid leukemia (AML) after extended follow-up and to assess responses to intensive salvage therapy, all patients who developed this complication after treatment for acute lymphoblastic leukemia (ALL) or non-Hodgkin lymphoma (NHL) in consecutive clinical trials at St Jude Children's Research Hospital from 1979 to 1994 were studied. Cases with 'lineage switch' or 'clonal selection' were excluded. Epipodophyllotoxin-related AML developed in 32 of 1140 patients treated for ALL and in three of 332 treated for NHL; it was a first adverse event in 25 and two cases, respectively. The complication was diagnosed at 12-130 months (median 34 months) after the initiation of treatment with epipodophyllotoxins; all but one of the cases occurred within 73 months, indicating that the risk is negligible after 6 years. The predominant karyotypic feature was 11q23 translocations (71% of cases); 21q22 rearrangements were rare. In a stepwise Cox regression analysis, two factors increased the risk of this complication: weekly or twice weekly administration of epipodophyllotoxins (P < 0.001); and the administration of asparaginase immediately before epipodophyllotoxin therapy (P < 0.001). Initial responses to salvage therapy were comparable to those reported for de novo AML: 92% of the evaluable patients entered complete remission after combination treatment. Single-agent therapy with 2-chlorodeoxyadenosine induced complete or partial remissions in one-half of the patients treated. The long-term survival rate was dismal. Of the 17 evaluable patients treated exclusively with chemotherapy, only one is alive at 84 months, compared to three of 16 patients who underwent bone marrow transplantation (alive at 10, 23 and 73 months). Cases of epipodophyllotoxin-related AML constitute a unique clinical syndrome that will require innovative strategies for cure.
 ...
PMID:Epipodophyllotoxin-related acute myeloid leukemia: a study of 35 cases. 860 7

In the last two decades complete remission [CR] rates for adults with acute leukemia has increased to 60 to 80%. In acute myelogenous leukemia [AML], this is due to the application of intensive induction therapies, comprising an anthracycline and a cytarabine. In acute lymphoblastic leukemia [ALL], the introduction of intensive early consolidation and CNS prophylaxis played an additional important role. These myeloablative treatments became feasible because of considerable improvements in the management of infectious and bleeding complications. The standard induction for AML further on remains the '3 + 7' schedule [daunorubicin 45 to 60 mg/m2/day x 3, I.V. and Ara-C 100 to 200 mg/m2/day x 7, 24-h infusion]. In ALL, prednisone, vincristine, L-asparaginase and an anthracyeline are the backbone of the induction therapy. Unfortunately, there has been less improvement for overall long-term survival, which is about 15 to 20% in AML and 20 to 35% in ALL beyond 5 years. More intensive post-remission regimens which include high-dose Ara-C in AML and intermediate-dose methotrexate and cyclophosphamide in ALL seem to improve these results to some extent. Allogeneic bone marrow transplantation has the most powerful anti-leukemic potential; however, because of the high peritransplant mortality [20 to 25%], its use in first CR tends to be restricted to patients with adverse prognostic features predicting early relapse, while good-risk patients are transplanted at the first signs of relapse or in second CR. In both AML and ALL, the optimal form of post-remission treatment needs to be defined.
 ...
PMID:[Current status of therapy and prognosis in acute adult leukemia]. 862 60

The objective of this study was to compare allogeneic bone marrow transplantation (BMT) with high-dose cytarabine containing chemotherapy in children with acute myeloid leukemia (AML) in first complete remission (CR). One hundred and seventy-one children were enrolled on the LAME89/91 protocol. Induction chemotherapy was a combination of cytarabine and mitoxantrone. After achieving CR, patients who had an HLA-identical sibling donor underwent allogeneic BMT. Children not eligible for BMT received post remission chemotherapy which included two consolidation courses, the second consolidation consisting of high-dose cytarabine with amsacrine and asparaginase. CR was achieved in 149 children (87%). Thirty-two had an HLA-identical sibling donor and were eligible for BMT. These 32 patients, as well as an additional child who had a one antigen HLA-mismatched father, received BMT during first CR. Consequently, 33 patients were analyzed in the BMT group and 116 in the chemotherapy group. The 4-year probability of relapse was 26 +/- 15% in the BMT group and 47 +/- 10% in the chemotherapy group (P = 0.04). The risk of therapy-related death was 3% for BMT and 7.7% for chemotherapy. Disease-free survival (DFS) was 72 +/- 15% in the BMT group and 48 +/- 10% in the chemotherapy group (p = 0.02). We conclude that allogeneic BMT from a matched sibling donor is the treatment of choice for reducing the relapse risk and for increasing DFS in children with AML in first CR.
 ...
PMID:Allogeneic bone marrow transplantation vs aggressive post-remission chemotherapy for children with acute myeloid leukemia in first complete remission. A prospective study from the French Society of Pediatric Hematology and Immunology (SHIP). 864 Jan 65

Cytosine arabinoside (Ara-C) has earned its recognition as the most important antileukaemic drug currently available for the treatment of acute myeloid leukaemia. Approximately 60-80% of patients less than 60 years of age can be expected to enter complete remission if treated with standard-dose Ara-C (100-200 mg/m2) in combination with an anthracycline. The efficacy of Ara-C appears clinically to be dose and schedule dependent. A 15-30 fold dose escalation in Ara-C can elicit a therapeutic response in patients who have previously failed treatment with standard-dose Ara-C or other anti-leukaemic drugs. The use of high-dose cytosine arabinoside (HDAC 3 gm/m2) appears rational based on cytosine pharmacology. Drug-scheduling is used to exploit drug synergy when HDAC is given in combination with asparaginase or fludarabine (+/- G-CSF) in a schedule-dependent fashion. Toxicity following Ara-C is also dose- and schedule-dependent. Central nervous system toxicity--particularly cerebellar dysfunction--although rare, is particularly serious because it may preclude further use of the drug. Older patients are particularly susceptible. This article will describe the rationale for and the value of HDAC alone or in combination with other cytotoxics in the treatment of acute myeloid leukaemia.
 ...
PMID:High-dose cytosine arabinoside in the treatment of acute myeloid leukaemia. 921 5

Cellular drug resistance is related to a poor prognosis in childhood leukemia, but little is known about the underlying mechanisms. We studied the expression of P-glycoprotein (P-gp), multidrug resistance (MDR)-associated protein (MRP), and major vault protein/lung resistance protein (LRP) in 141 children with acute lymphoblastic leukemia (ALL) and 27 with acute myeloid leukemia (AML) by flow cytometry. The expression was compared between different types of leukemia and was studied in relation with clinical risk indicators and in vitro cytotoxicity of the MDR-related drugs daunorubicin (DNR), vincristine (VCR), and etoposide (VP16) and the non-MDR-related drugs prednisolone (PRD) and L-asparaginase (ASP). In ALL, P-gp, MRP, and LRP expression did not differ between 112 initial and 29 unrelated relapse samples nor between paired initial and relapse samples from 9 patients. In multiple relapse samples, LRP expression was 1.6-fold higher compared with both initial (P = .026) and first relapse samples (P = .050), which was not observed for P-gp and MRP. LRP expression was weakly but significantly related to in vitro resistance to DNR (Spearman's rank correlation coefficient 0.25, P = .016) but not to VCR, VP16, PRD, and ASP. No significant correlations were found between P-gp or MRP expression and in vitro drug resistance. Samples with a marked expression of two or three resistance proteins did not show increased resistance to the tested drugs compared with the remaining samples. The expression of P-gp, MRP, and LRP was not higher in initial ALL patients with prognostically unfavorable immunophenotype, white blood cell count, or age. The expression of P-gp and MRP in 20 initial AML samples did not differ or was even lower compared with 112 initial ALL samples. However, LRP expression was twofold higher in the AML samples (P < .001), which are more resistant to a variety of drugs compared with ALL samples. In conclusion, P-gp and MRP are unlikely to be involved in drug resistance in childhood leukemia. LRP might contribute to drug resistance but only in specific subsets of children with leukemia.
 ...
PMID:Relationship between major vault protein/lung resistance protein, multidrug resistance-associated protein, P-glycoprotein expression, and drug resistance in childhood leukemia. 949 Jun 95


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