title: BCR-ABL expression in different subpopulations of functionally characterized Ph+ CD34+ cells from patients with chronic myeloid leukemia.
abstract: In patients with chronic myeloid leukemia (CML), the leukemic (BCR-ABL+/Ph+) clone typically includes cells belonging to all of the myeloid lineages and frequently some B cells. From such observations it has been inferred that the initial BCR-ABL gene rearrangement event occurs in a pluripotent hematopoietic stem cell and that the clone subsequently generated is maintained by a subpopulation of neoplastic, BCR-ABL-expressing cells that retain at least some of the defining properties of normal hematopoietic stem cells. To test this hypothesis directly, we isolated various subpopulations of CD34+ cells from fresh or cryopreserved samples of peripheral blood from 5 CML patients with high white blood cell counts, 4 of which were selected because of their exclusive content of Ph+ progenitors (both colony-forming cells and long-term culture-initiating cells [LTC-IC]). Cells in each of the CD34+ subpopulations isolated were examined for the presence of BCR-ABL mRNA using a reverse transcriptase-polymerase chain reaction technique that reproducibly gave a positive signal from single K562 cells. BCR-ABL mRNA was detected in 117 of 147 samples (80%) in which actin mRNA was demonstrable. This included 60% to 90% of a large number of individually analyzed CD34+ cells including 46 single CD34+CD71-CD38- cells and 27 single CD34+CD71+CD38+ cells from 3 patients. In 2 of these cases, the same populations also contained a very high frequency of Ph+ LTC-IC. Our findings demonstrate BCR-ABL gene expression in neoplastic cells with functional as well as surface marker characteristics of very primitive normal hematopoietic cells. This implicates the BCR-ABL gene product directly in the acquisition by these cells of properties that alter their interactions with the microenvironment and deregulate their proliferation control.
authors.affiliation: Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Maguer-Satta
authors.forename: A L
authors.initials: AL
authors.lastname: Petzer
authors.forename: A C
authors.initials: AC
authors.lastname: Eaves
authors.forename: C J
authors.initials: CJ
authors.lastname: Eaves
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D000943:Antigens, Differentiation / Q000032:analysis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D001483:Base Sequence; D002469:Cell Separation; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000096:biosynthesis* / Q000235:genetics; D015973:Gene Expression Regulation, Leukemic; D006684:HLA-DR Antigens / Q000032:analysis; D006412:Hematopoietic Stem Cells / Q000145:classification / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics* / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases / Q000032:analysis; D014411:Neoplastic Stem Cells / Q000145:classification* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D011990:Receptors, Transferrin; D018800:Thy-1 Antigens / Q000032:analysis
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; C068126:CD71 antigen; D006684:HLA-DR Antigens; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011990:Receptors, Transferrin; D018800:Thy-1 Antigens; D016044:Fusion Proteins, bcr-abl; D009699:N-Glycosyl Hydrolases; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1