Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This report describes a precise molecular analysis of a rare case of Philadelphia chromosome (Ph) positive acute myeloid leukemia (AML) (FAB classification M2). Phenotypic markers were positive for cells of the myeloid lineage, but negative for B cell and T cell lineage. The leukemic cells carried a Philadelphia chromosome. Major breakpoint cluster region (M-BCR) rearrangement was detected by the Southern blot analysis. Reverse transcriptase polymerase chain reaction analysis revealed the presence of b3a2 BCR/ABL mRNA transcripts. The patient achieved complete remission by conventional remission induction therapy for acute myeloid leukemia. M-BCR rearrangement could not be detected during complete remission. After hematological remission of an 8-month duration, the patient relapsed and died of respiratory distress due to pneumonia. Our case indicate Ph-positive AML with M-BCR rearrangement actually exists. Ph-positive AML carries either M-BCR rearrangement expressing the P210 BCR-ABL or minor breakpoint cluster region (m-BCR) rearrangement producing the P190 BCR-ABL. Therefore, additional other factor (s) apart from the Ph chromosome must be responsible for the acute malignant transformation.
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PMID:Molecular analysis of a case of Philadelphia chromosome-positive acute myeloid leukemia. 906 90

A case of Philadelphia (Ph)-positive acute lymphoblastic leukemia (ALL) with multiple subclones including duplication of the BCR-ABL1 fusion gene and of the Abelson oncogene (ABL1) is reported. Cytogenetically, two different rearrangements of chromosome 9 not involved in the t(9;22) were found in two subclones. In one subclone the normal 9 was lost and replaced by an acrocentric marker, which contained an additional copy of the BCR-ABL1 fusion gene. Reverse transcriptase polymerase chain reaction detected the fusion transcripts p210 (e13a2 junction) and p190 (e1a2 junction), whereas fluorescence in situ hybridization showed the major BCR-ABL1 junction in both Ph chromosomes, strongly suggesting that the presence of the p210 and p190 proteins in this case was due to mechanisms of alternative or mis-splicing at the transcriptional level. The second subclone showed the classic t(9;22) plus an add(9)(p24) containing two copies of the ABL1 gene. Other molecular events involving chromosome 9 were a monoallelic loss of JAK2 in both subclones and an additional loss of P15/P16 in the subclone with the acrocentric marker bearing the extra Ph chromosome.
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PMID:Philadelphia-positive acute lymphoblastic leukemia with multiple subclones including duplication of the Philadelphia chromosome and Abelson oncogene. 1180 8

The Philadelphia chromosome (Ph) as a secondary cytogenetic abnormality is a rare event. It is observed mostly as an additional, late-appearing cytogenetic change during the evolution of acute leukemia and its presentation as a secondary change at the onset of disease is much rarer. We describe here a patient with acute myelogenous leukemia (AML) who had Ph as a secondary chromosome abnormality at diagnosis. Cytogenetic analysis showed an abnormal karyotype, 45,XY,inv(3)(q21q26),-7[4]/45,idem, t(9;22)(q34;q11.2). The p190 variety of BCR-ABL rearrangements was confirmed by a real-time reverse-transcriptase polymerase chain reaction using fluorescent probes. To our knowledge, the minor BCR-ABL fusion gene involving a secondary Ph superimposed on inv(3) and monosomy 7 has not been reported in AML at diagnosis. Along with the identification of more cases, it will be possible to understand the exact role of this secondary Ph in a multistep leukemogenesis.
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PMID:The Philadelphia chromosome as a secondary abnormality in inv(3)(q21q26) acute myeloid leukemia at diagnosis: confirmation of p190 BCR-ABL mRNA by real-time quantitative polymerase chain reaction. 1649 May 99