title: Persistence of multipotent progenitors expressing AML1/ETO transcripts in long-term remission patients with t(8;21) acute myelogenous leukemia.
abstract: The leukemia-specific AML1/ETO fusion gene has been shown to be detected by reverse transcriptase polymerase chain reaction (RT-PCR) analysis in patients with t(8;21) acute myelogenous leukemia (AML) in long-term remission. In the present study, the AML1/ETO mRNA could be detected by RT-PCR in bone marrow (BM) and/or peripheral blood (PB) samples from all 18 patients who had been maintaining complete remission for 12 to 150 months (median, 45 months) following chemotherapy or PB stem cell transplantation (PBSCT), whereas it could not be detected in four patients who had been maintaining remission for more than 30 months following allogeneic BM transplantation (BMT). We surveyed the expression of AML1/ETO mRNA in clonogenic progenitors from BM in these cases. Notably, 51 of 2,469 colonies from clonogenic progenitors (2.1%) expressed the AML1/ETO mRNA in 18 cases who were RT-PCR+ in BM and/or PB samples. Expression was observed in various clonogenic progenitors, including granulocyte-macrophage colonies, mixed colonies, erythroid colonies, and megakaryocyte colonies. Furthermore, we analyzed the clonality of these progenitors by X-chromosome inactivation patterns of the phosphoglycerate kinase (PGK) gene in four female patients. The AML1/ETO mRNA+ progenitors showed the PGK allele identical to that detected in the leukemic blasts from the time of initial diagnosis. Normal constitutive hematopoiesis was sustained by polyclonal BM reconstitution in these patients. Accordingly, these committed progenitor cells that express AML1/ETO mRNA during remission likely have arisen from common t(8;21)+ pluripotent progenitor cells with at least trilineage differentiation potential. These data strongly suggest that the origin of the clonogenic leukemic progenitors of t(8;21) AML may be multipotent hematopoietic progenitors that acquired the t(8;21) chromosomal abnormality.
authors.affiliation: First Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Miyamoto
authors.forename: K
authors.initials: K
authors.lastname: Nagafuji
authors.forename: K
authors.initials: K
authors.lastname: Akashi
authors.forename: M
authors.initials: M
authors.lastname: Harada
authors.forename: T
authors.initials: T
authors.lastname: Kyo
authors.forename: T
authors.initials: T
authors.lastname: Akashi
authors.forename: K
authors.initials: K
authors.lastname: Takenaka
authors.forename: S
authors.initials: S
authors.lastname: Mizuno
authors.forename: H
authors.initials: H
authors.lastname: Gondo
authors.forename: T
authors.initials: T
authors.lastname: Okamura
authors.forename: H
authors.initials: H
authors.lastname: Dohy
authors.forename: Y
authors.initials: Y
authors.lastname: Niho
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000032:analysis*; D001853:Bone Marrow / Q000473:pathology; D019070:Cell Lineage; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics / Q000648:ultrastructure*; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics / Q000648:ultrastructure*; D002999:Clone Cells / Q000378:metabolism / Q000473:pathology; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D005260:Female; D015973:Gene Expression Regulation, Leukemic; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000097:blood / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D018365:Neoplasm, Residual; D014411:Neoplastic Stem Cells / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000096:biosynthesis / Q000235:genetics*; D009857:Oncogenes; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D000075142:RUNX1 Translocation Partner 1 Protein; D012074:Remission Induction; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D014178:Translocation, Genetic; D014410:Tumor Stem Cell Assay
chemical_list: D014408:Biomarkers, Tumor; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D000075142:RUNX1 Translocation Partner 1 Protein; C493728:RUNX1 protein, human; C082222:RUNX1T1 protein, human; D014157:Transcription Factors