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

Two main types of therapy-related acute myeloid leukemias (tAML) and myelodysplastic syndromes (tMDS) have been described. The first classical type typically occurs late after use of alkylating agents and presents as MDS with -7/del 7q and/or -5/del5q. The second form occurs early after the use of agents targeted at topoisomerase II, and presents as AML with 11q23 or other rearrangements of de novo AML. Recently, we and others reported, in AML and MDS, a strong correlation between cytogenetic rearrangements leading to 17p deletion, a specific type of dysgranulopoiesis and p53 mutation; several of those cases of 17p- syndrome were therapy-related. Over the last 15 years, we observed 25 cases of tAML and tMDS with 17p deletion, which represented 36% of the AML and MDS with 17p deletion diagnosed during that period. Median age was 59 years. Twenty-one patients had tMDS and four tAML. Typical dysgranulopoiesis and p53 mutation and/or overexpression were seen in 22 of 24 and 16 of 19 evaluable patients, respectively. 17p deletion resulted from unbalanced translocations involving 17p (18 cases), monosomy 17 (five cases), i(17q) (one case) or del 17p (one case). Twenty-one patients also had -5/del 5q, and/or -7/del 7q. Median interval from treatment of the first tumor of tAML and tMDS was 94 months (range 19-252). Median survival was only 7 months. Based on primary tumor and antineoplastic agents used, patients could be relatively well divided into two groups: a first group of 11 cases, occurring mainly after a lymphoid neoplasm (eight cases) treated by chemotherapy with an alkylating agent (10 cases), and a second group of 14 cases occurring after essential thrombocythemia (ET) or polycythemia vera (PV) treated mainly by hydroxyurea (10 cases), pipobroman (eight cases), 32P (six cases) but rarely by alkylating agents (two cases). -7/del 7q was found in 10 of the 11 patients in the first group, as compared to three of the 14 patients of the second group (P = 0.0001). Therefore, therapy-related cases represent a high proportion of AML and MDS with the 17p- syndrome. They have many features in common with classical tMDS and tAML, including long interval from the first tumor, a usual preleukemic phase, and frequent occurrence of -5/del 5q. About one half of them, in addition, occur after alkylating agents and generally carry -7/del 7q. The other half, however, occur mainly after ET or PV treated by hydroxyurea or other non-alkylating agents, and usually have no -7/del 7q. These findings bring further support to a possible relationship between prior drugs used and cytogenetic rearrangements in tAML and tMDS.
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PMID:Therapy-related myelodysplastic syndrome and acute myeloid leukemia with 17p deletion. A report on 25 cases. 1002 99

The inhibition of topoisomerase II (topo II) is a very powerful principle of chemotherapy and topo II inhibiting drugs are the backbone of most chemotherapeutic strategies. However, secondary malignomas can occur after treatment. Typically, secondary acute myeloid leukemia (t-AML) after treatment with topo II inhibitors has a shorter latency period than t-AML following alkylator therapy. Fragments originating from chromosome breakage as well as whole chromosomes which are not correctly distributed during mitosis give rise to micronuclei in the next interphase. Micronucleus formation has become an important endpoint in genotoxicity testing. In an effort to test the suitability of the micronucleus assay for predictive purposes, we have analyzed three human tumor cell lines for cell growth as well as micronucleus induction after treatment with four clinically used topo II inhibitors. Micronuclei were induced at levels of low toxicity by etoposide, mitoxantrone, daunorubicin and idarubicin. The induction of micronuclei was a more sensitive indicator of drug effects than reduction in cell growth. Thus, micronucleus induction may assist in the prediction of the potency of a chemotherapeutic agent for induction of secondary malignomas.
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PMID:Are topoisomerase II inhibitor-induced micronuclei in vitro a predictive marker for the compounds' ability to cause secondary leukemias after treatment? 1004 55

The oral antitumor drugs against hematological malignancies are summarized. Sobuzoxane, a topoisomerase II inhibitor, is useful for the treatment of lymphoma, especially adult T cell leukemia/lymphoma. Sobuzoxane has an effect to protect against doxorubicin cardiotoxicity. Cytarabine ocfosfate, a derivative of cytosine arabinoside, is a useful agent against acute leukemia and MDS, especially RAEB, RAEB in T, CMMoL. The JALSG AML 92 study for APL with all-trans retinoic acid resulted in a 89% CR rate in 196 and 64% 4-year DFS in CR cases. Hydroxycarbamide is can control the WBC in CML. This agent is also effective for other myeloproliferative disorders, such as acute leukemia and MDS. Oral administration of 50 mg etoposide daily showed a good outcome in old patients with malignant lymphoma. For old patients and those with refractory hematological malignancies, oral administration of these agents can offer a new form of palliative therapy to allow them to remain at home while maintaining a high quality of life.
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PMID:[Oral antitumor drugs for hematological malignancies]. 1006 91

Prolonged exposure to a topoisomerase I inhibitor may increase expression of topoisomerase II, making cells more susceptible inhibitors of that enzyme. This study was undertaken to establish the maximum tolerated dose (MTD) of a topotecan/topoisomerase II inhibitor sequential combination that may be active in acute leukemia, and to evaluate the effects of in vivo exposure to topotecan on topoisomerase II levels in leukemic blast cells as measured by image cytometry. Patients who were eligible for this phase I study had relapsed or refractory acute myeloid leukemia (< or = 2 prior regimens) or CML blast crisis (0 or 1 prior regimen). Topotecan was given as a 5 day continuous i.v. infusion and was to be escalated through three levels (1.5, 1.75 and 2.0 mg/m2 day), followed by etoposide at two dose levels (100 and 150 mg/m2) i.v. bolus days 6, 7 and 8. Topoisomerase IIalpha levels in leukemic blasts from bone marrow were measured by image cytometry prior to starting treatment, on day 5 of topotecan infusion and on day 28; and daily during topotecan in peripheral blood blasts. Dose-limiting toxicity was seen in two of six patients at the first dose level (topotecan 1.5 mg/m2/day, etoposide 100 mg/m2/day; > or = grade 3 mucositis in both cases). This cohort was expanded to 10 patients; no further non-hematologic dose-limiting toxicity was observed, but given the extent of toxicity seen, further dose escalation was judged not to be feasible. Topo IIalpha levels increased in peripheral blood blasts during the first 72 h of topotecan infusion and returned to near baseline by day 5, whereas levels appeared to decrease in bone marrow blasts by day 5 compared to pretreatment. One complete hematologic and cytogenetic remission in a patient with CML blast crisis was observed in the 10 patients evaluable for response. The sequential administration of topotecan 1.5 mg/m2/day continuous infusion for 5 days followed by etoposide 100 mg/m2/day x 3 is the recommended phase II dose for this schedule. Topotecan increases topo IIalpha expression in vivo in leukemia cells, but levels of the enzyme are cell cycle dependent. Pharmacodynamic evaluation of the sequential or combination administration of novel antileukemic agents may help improve treatment strategies in acute leukemia.
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PMID:Phase I trial of sequential topotecan followed by etoposide in adults with myeloid leukemia: a National Cancer Institute of Canada Clinical Trials Group Study. 1008 24

Increased levels of DNA-protein cross-links (DNAPC) have been observed in vitro and in vivo following treatment with a number of chemotherapeutic alkylating agents and topoisomerase II inhibitors, that is, agents that have also been associated with the development of bone marrow depression and acute myelogenous leukemia. The current studies were undertaken to examine the effect of benzene, a bone marrow toxin and human leukemogen, on DNAPC levels in mouse bone marrow cells. Using a K+/sodium dodecyl sulfate (SDS) precipitation assay for DNAPC determination, the results indicate increased DNA-protein cross-link levels in mouse bone marrow cells at 2 and 4 but not 8 h after a single ip injection of 440 mg/kg benzene. Following the administration of multiple hematotoxic benzene doses (440 or 880 mg/kg, 2x/d for 2 d), increases in DNA-protein cross-link levels were either slight or not present. These results suggest that DNAPC induced by benzene are neither cumulative nor persistent lesions. The toxicity of benzene is mediated by a number of number of ring-hydroxylated and ring-opened compounds; therefore the present studies also examined DNAPC levels in mice administered trans,trans-muconaldehyde (MUC), a ring-opened hematotoxic and genotoxic metabolite of benzene. No marked increases in DNAPC levels were observed in CD- mouse bone marrow cells 1-12 h following a single ip injection of 3 mg/kg muconaldehyde. It is possible that multiple doses of MUC are required to induce elevated DNAPC levels in bone marrow cells of mice, since multiple doses are required for MUC-induced hematotoxicity. Other reactive metabolites and/or an interaction of reactive intermediates may also be involved in DNAPC induced by benzene.
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PMID:DNA-protein cross-link levels in bone marrow cells of mice treated with benzene or trans,trans-muconaldehyde. 1009 61

MLL (ALL1, Htrx, HRX), which is located on chromosome band 11q23, frequently is rearranged in patients with therapy-related acute myeloid leukemia who previously were treated with DNA topoisomerase II inhibitors. In this study, we have identified a fusion partner of MLL in a 10-year-old female who developed therapy-related acute myeloid leukemia 17 months after treatment for Hodgkin's disease. Leukemia cells of this patient had a t(11;17)(q23;q25), which involved MLL as demonstrated by Southern blot analysis. The partner gene was cloned from cDNA of the leukemia cells by use of a combination of adapter reverse transcriptase-PCR, rapid amplification of 5' cDNA ends, and BLAST database analysis to identify expressed sequence tags. The full-length cDNA of 2.8 kb was found to be an additional member of the septin family, therefore it was named MSF (MLL septin-like fusion). Members of the septin family conserve the GTP binding domain, localize in the cytoplasm, and interact with cytoskeletal filaments. A major 4-kb transcript of MSF was expressed ubiquitously; a 1.7-kb transcript was found in most tissues. An additional 3-kb transcript was found only in hematopoietic tissues. By amplification with MLL exon 5 forward primer and reverse primers in MSF, the appropriately sized products were obtained. MSF is highly homologous to hCDCrel-1, which is a partner gene of MLL in leukemias with a t(11;22)(q23;q11.2). Further analysis of MSF may help to delineate the function of MLL partner genes in leukemia, particularly in therapy-related leukemia.
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PMID:MSF (MLL septin-like fusion), a fusion partner gene of MLL, in a therapy-related acute myeloid leukemia with a t(11;17)(q23;q25). 1033 4

Acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) in infants have in common a high incidence of translocations of the MLL gene at chromosome band 11q23. Similar translocations occur in leukemias associated with chemotherapies that target DNA topoisomerase II. MLL has numerous different partner genes. The role of the many MLL fusion proteins in leukemogenesis is not yet understood. The t(4;11) translocation, the most common translocation in infant ALL, adversely affects the outcome. Additional genetic changes, especially Ikaros alterations, are found in infant ALL. Other forms of myeloid leukemia in infants present as myelodysplastic and myeloproliferative syndromes, which may be associated with constitutional disorders. This review will consider all leukemia in infants, but will focus on leukemias with MLL gene translocations.
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PMID:Leukemia in infants. 1039 90

NAD(P)H:quinone oxidoreductase (NQO1) converts benzene-derived quinones to less toxic hydroquinones and has been implicated in benzene-associated hematotoxicity. A point mutation in codon 187 (Pro to Ser) results in complete loss of enzyme activity in homozygous subjects, whereas those with 2 wild-type alleles have normal activity. The frequency of homozygosity for the mutant allele among Caucasians and African Americans is 4% to 5% but is higher in Hispanics and Asians. Using an unambiguous polymerase chain reaction (PCR) method, we assayed nonmalignant lymphoblastoid cell lines derived from 104 patients with myeloid leukemias; 56 had therapy-related acute myeloid leukemia (t-AML), 30 had a primary myelodysplastic syndrome (MDS), 9 had AML de novo, and 9 had chronic myelogenous leukemia (CML). All patients had their leukemia cells karyotyped. Eleven percent of the t-AML patients were homozygous and 41% were heterozygous for the NQO1 polymorphism; these proportions were significantly higher than those expected in a population of the same ethnic mix (P =.036). Of the 45 leukemia patients who had clonal abnormalities of chromosomes 5 and/or 7, 7 (16%) were homozygous for the inactivating polymorphism, 17 (38%) were heterozygous, and 21 (47%) had 2 wild-type alleles for NQO1. Thus, NQO1 mutations were significantly increased compared with the expected proportions: 5%, 34%, and 61%, respectively (P =.002). An abnormal chromosome no. 5 or 7 was observed in 7 of 8 (88%) homozygotes, 17 of 45 (38%) heterozygotes, and 21 of 51 (41%) patients with 2 wild-type alleles. Among 33 patients with balanced translocations [14 involving bands 11q23 or 21q22, 10 with inv(16) or t(15;17), and 9 with t(9;22)], there were no homozygotes, 15 (45%) heterozygotes, and 18 (55%) with 2 wild-type alleles. Whereas fewer than 3 homozygotes were expected among the 56 t-AML patients, 6 were observed; 19 heterozygotes were expected, but 23 were observed. The gene frequency for the inactivating polymorphism (0. 31) was increased approximately 1.4-fold among the 56 t-AML patients. This increase was observed within each of the following overlapping cohorts of t-AML patients: the 43 who had received an alkylating agent, the 27 who had received a topoisomerase II inhibitor, and the 37 who had received any radiotherapy. Thus, the frequency of an inactivating polymorphism in NQO1 appears to be increased in this cohort of myeloid leukemias, especially among those with t-AML or an abnormality of chromosomes 5 and/or 7. Homozygotes and heterozygotes (who are at risk for treatment-induced mutation or loss of the remaining wild-type allele in their hematopoietic stem cells) may be particularly vulnerable to leukemogenic changes induced by carcinogens.
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PMID:Prevalence of the inactivating 609C-->T polymorphism in the NAD(P)H:quinone oxidoreductase (NQO1) gene in patients with primary and therapy-related myeloid leukemia. 1039 48

Combination chemotherapy and radiation therapy have contributed to the successful treatment of various cancer patients. But the development of second malignancies is an inevitable complication of long-term cytotoxic treatment. The most serious and frequent of such complications is acute myelogenous leukemia (AML). Therapy-related leukemia is generally fatal. Since the number of patients exposed to chemotherapy is increasing each year, the clinical significance of this entity cannot be underestimated. There have been many investigations of therapy-related leukemia, but in Korea published reports are rare. We describe four such cases, involving one older female with lung cancer and three children with acute lymphoblastic leukemia (ALL) and malignant lymphoma. Alkylating agents were used for chemotherapy, and in one case, topoisomerase II inhibitor. Irrespective of the causative agents, the latency periods were relatively short, and despite induction chemotherapy in two, all survived for only a few months. During the follow-up of patients treated for primary malignancies, the possibility of therapy-related leukemia should always be borne in mind.
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PMID:Four cases of therapy-related leukemia. 1040 78

Drug resistant cells often have an increased capacity to repair their DNA after damage by cytotoxic agents. Aphidicolin can inhibit this DNA repair. We describe a study of the effect of aphidicolin to modulate the sensitivity to cytotoxic drugs of blast cells from 13 patients with AML, 11 with de novo disease on presentation and 2 secondary to MDS. Three patients had relapsed following previous therapy and samples were received from 1 patient both on presentation and relapse. Blast cells were exposed to anthracyclines, antimetabolites or etoposide +/- aphidicolin (15 microM) for 48 hours. The MTT assay was used to measure cell survival and the LC50 (concentration of drug required for 50% cell kill) was calculated. Overall, there was a significant increase in sensitivity to ara-C on co-incubation with aphidicolin in 12/14 samples (p = 0.007). The median increase in sensitivity was 3.88-fold (range 1.26- to 80-fold). Interestingly, when patients were grouped according to in vitro sensitivity to ara-C, cells from resistant patients demonstrated the greatest increase in sensitivity (median 14-fold compared to 2-fold for the sensitive group, p = 0.02). Despite the documented evidence for altered DNA repair as a mechanism of resistance to the topoisomerase II inhibitors, we found no significant increase in sensitivity to daunorubicin, doxorubicin or etoposide on co-incubation with aphidicolin. Nevertheless, we believe the unparalleled modulation of ara-C warrants further investigation.
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PMID:Aphidicolin markedly increases the in vitro sensitivity to ara-C of blast cells from patients with AML. 1050 Aug 35


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