Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phenotypic conversion from acute myeloid leukemia (AML) to acute lymphoblastic leukemia (ALL) is rare. A 38-year-old man was initially diagnosed as having AML (FAB-M2) associated with the t(8;21)(q22;q22) chromosomal abnormality. The blasts showed myeloperoxidase (MPO) activity and CD13 antigen expression. He showed complete remission after standard chemotherapy for AML. However, the patient relapsed with blasts showing ALL morphology (FAB-L1), MPO negativity, and CD19 antigen expression 33 months after cessation of AML therapy. Cytogenetic analysis at relapse was unsuccessful. Molecular analysis of ALL blasts revealed immunoglobulin heavy-chain gene and MLL gene rearrangements but no AML1 gene. MLL gene rearrangement or the 11q23 chromosomal abnormality has been associated with therapy-related leukemia. The subsequent ALL in our patient may have been induced by the chemotherapy including daunorubicin, known as a topoisomerase II inhibitor.
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PMID:Phenotypic conversion from t(8;21) acute myeloid leukemia to MLL gene rearrangement-positive acute lymphoblastic leukemia. 984 25

We report here a 73-year old female who was admitted for hematomas, dyspnea, and fever. Hematological data showed pancytopenia with 9% blast cells positive for CD13, CD33, CD34, HLAD2, and myeloperoxydase. A diagnosis of acute myeloid leukemia (AML) type 2 (FAB classification) was made. Banding cytogenetic techniques performed on bone marrow cells showed a 48,XX,+8,+9,del(9)(q22q33)x2 ,t(16;21)(q24;q22)[20]/46,XX[2] karyotype. Fluorescence in situ hybridization (FISH) with BACs covering the RUNX1 (alias AML1) (band 21q22) and MTG16 (band 16q24) gene showed a fusion of both genes. The t(16;21)(q24;q22) has been described in 16 AML cases, including ours. Eleven patients had received chemotherapy for a previous cancer, most of them were been treated with DNA-topoisomerase II inhibitors known to be associated with chromosomal translocations involving the RUNX1 gene. The significant homology between MGT16 and MTG8 suggests that the RUNX1-MTG16 fusion gene induced by the t(16;21)(q24;q22) is a variant of the RUNX1-MTG8 that shares similar activity.
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PMID:RUNX1-MTG16 fusion gene in acute myeloblastic leukemia with t(16;21)(q24;q22): case report and review of the literature. 1865 94

We describe here a new case of therapy-related acute leukemia with t(1;21)(p36;q22). A 25-year-old man was admitted because of anemia and thrombocytopenia. Four years before, he had received combination chemotherapy including etoposide for seminoma. Bone marrow was hypercellular, with 49% myeloperoxidase (MPO) staining-negative blasts. Chromosome analysis showed 46,XY,t(1;21)(p36.3;q22)[11]/49,sl,+8,+16,+20[9]. Fluorescence in situ hybridization demonstrated that RUNX1 signals at 21q22 were split onto the der(1)t(1;21) and der(21)t(1;21). Immunophenotypic analyses revealed that blasts were positive for CD19, CD79a, and cytCD22, as well as MPO, CD13, and CD33, fulfilling the diagnostic criteria of mixed phenotype acute leukemia, B/myeloid. The patient died of disease progression after 10 months. Thus, acute leukemia with t(1;21) and RUNX1 rearrangement could be associated with B/myeloid mixed phenotype as well as previous topoisomerase II inhibitor therapy and poor prognoses.
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PMID:Therapy-related, mixed phenotype acute leukemia with t(1;21)(p36;q22) and RUNX1 rearrangement. 2068 97