BCR-ABL, ABL-BCR, BCR, and ABL genes are all expressed in individual granulocyte-macrophage colony-forming unit colonies derived from blood of patients with chronic myeloid leukemia.
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.
Diamond
J
J
Department of Haematology, Royal Postgraduate Medical School, London, UK.
Goldman
J M
JM
Melo
J V
JV
D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D002999:Clone Cells / Q000378:metabolism* / Q000473:pathology; D016044:Fusion Proteins, bcr-abl / Q000096:biosynthesis* / Q000235:genetics; D015973:Gene Expression Regulation, Leukemic; D006098:Granulocytes / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000097:blood / Q000473:pathology*; D054438:Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative / Q000097:blood / Q000473:pathology; D015466:Leukemia, Myeloid, Chronic-Phase / Q000097:blood / Q000473:pathology*; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D015513:Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D010677:Philadelphia Chromosome; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D016315:Proto-Oncogene Proteins c-abl / Q000096:biosynthesis* / Q000235:genetics; D051562:Proto-Oncogene Proteins c-bcr; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics; D014410:Tumor Stem Cell Assay
D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl; D016315:Proto-Oncogene Proteins c-abl; C496613:BCR protein, human; D051562:Proto-Oncogene Proteins c-bcr