Abstract
It has been suggested that the BCR-ABL gene of chronic myeloid leukemia (CML) is not uniformly expressed in Philadelphia (Ph)-positive cells, and that BCR-ABL gene expression precludes transcription of the normal BCR or ABL genes. Therefore, we have analyzed granulocyte-macrophage colony-forming unit (CFU-GM) colonies derived from peripheral blood of 11 CML patients by cytogenetic and by reverse transcriptase-polymerase chain reaction (PCR) amplification of BCR-ABL, ABL-BCR, BCR, and ABL. All CFU-GM colonies with analyzable metaphases were found to contain a Ph chromosome. In 2 patients, the initial PCR screening failed to detect BCR-ABL transcripts in 2 of 11 and 1 of 7 Ph-positive colonies. However, when amplification for BCR-ABL was repeated in quintuplicate, all but 1 colony from a single patient showed one or more positive results. Amplifications of the four genes in each colony showed that BCR-ABL, ABL-BCR, and the normal BCR and ABL were simultaneously expressed in the majority of CFU-GM colonies. Replicate PCR tests for BCR and for ABL in colonies initially scored as negative also uncovered previously undetected positive amplifications. We conclude that BCR-ABL expression does not suppress transcription from the normal BCR and ABL genes, and that Ph-positive, BCR-ABL-negative colonies derived from peripheral blood CFU-GM are rare or nonexistent.
MeSH terms
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Base Sequence
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Biomarkers, Tumor / biosynthesis*
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Biomarkers, Tumor / genetics
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Clone Cells / metabolism*
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Clone Cells / pathology
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Fusion Proteins, bcr-abl / biosynthesis*
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Fusion Proteins, bcr-abl / genetics
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Gene Expression Regulation, Leukemic*
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Granulocytes / metabolism*
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Granulocytes / pathology
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Humans
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Leukemia, Myelogenous, Chronic, BCR-ABL Positive / blood
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Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology*
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Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative / blood
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Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative / pathology
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Leukemia, Myeloid, Chronic-Phase / blood
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Leukemia, Myeloid, Chronic-Phase / pathology*
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Macrophages / metabolism*
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Macrophages / pathology
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Molecular Sequence Data
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Neoplasm Proteins / biosynthesis*
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Neoplasm Proteins / genetics
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Neoplastic Stem Cells / metabolism*
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Oncogene Proteins / biosynthesis*
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Oncogene Proteins / genetics
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Philadelphia Chromosome
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Polymerase Chain Reaction
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Protein-Tyrosine Kinases*
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Proto-Oncogene Proteins c-abl / biosynthesis*
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Proto-Oncogene Proteins c-abl / genetics
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Proto-Oncogene Proteins c-bcr
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Proto-Oncogene Proteins*
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RNA, Messenger / analysis
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RNA, Messenger / genetics
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RNA, Neoplasm / analysis
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RNA, Neoplasm / genetics
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Tumor Stem Cell Assay
Substances
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Biomarkers, Tumor
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Neoplasm Proteins
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Oncogene Proteins
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Proto-Oncogene Proteins
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RNA, Messenger
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RNA, Neoplasm
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Protein-Tyrosine Kinases
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Fusion Proteins, bcr-abl
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Proto-Oncogene Proteins c-abl
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BCR protein, human
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Proto-Oncogene Proteins c-bcr