title: Expression of AML1-ETO fusion transcripts and detection of minimal residual disease in t(8;21)-positive acute myeloid leukemia.
abstract: The t(8;21) translocation breakpoint, which is observed in acute myeloid leukemia (AML), has recently been cloned and a fusion transcript identified. We have now designed primer sets capable of amplifying the breakpoint junction of the fusion transcript by the reverse transcription-polymerase chain reaction (RT-PCR). Primer set 821U/821D1 amplified a 200-bp DNA fragment, and primer set 821U/821D2 amplified a 1.2-kb DNA fragment in all t(8;21)-positive AML tested. Sequence analysis of the amplified DNA fragments demonstrated that all fusion transcripts were fused at exactly the same site, indicating that this translocation breakpoint occurs within a single intron of the AML1 and ETO genes. Forty-five cycles of RT-PCR were used to detect residual t(8;21)-positive leukemia cells in three patients who had been in complete remission for 1, 3 and 5 years. Minimal residual disease was found in all three samples. Northern blot analysis demonstrated that two fusion transcripts of 7 and 10 kb were expressed in the t(8;21)-positive AML and that the ETO gene is not normally expressed in the hematopoietic system. Expression of a normal 5.5-kb ETO mRNA was found in the lung. From these results we concluded that expression of the ETO gene in t(8;21)-positive AML was activated as a result of the translocation.
authors.affiliation: Hematopathology Program, University of Texas M.D. Anderson Cancer Center, Houston 77030.
authors.forename: K S
authors.initials: KS
authors.lastname: Chang
authors.forename: Y H
authors.initials: YH
authors.lastname: Fan
authors.forename: S A
authors.initials: SA
authors.lastname: Stass
authors.forename: E H
authors.initials: EH
authors.lastname: Estey
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.forename: J M
authors.initials: JM
authors.lastname: Trujillo
authors.forename: P
authors.initials: P
authors.lastname: Erickson
authors.forename: H
authors.initials: H
authors.lastname: Drabkin
mesh_terms: D001483:Base Sequence; D002891:Chromosomes, Human, Pair 21; D002898:Chromosomes, Human, Pair 8; D004273:DNA, Neoplasm / Q000032:analysis; D015870:Gene Expression; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000175:diagnosis* / Q000235:genetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D012334:RNA, Neoplasm / Q000235:genetics; D015183:Restriction Mapping; D014178:Translocation, Genetic
chemical_list: D004273:DNA, Neoplasm; D009838:Oligodeoxyribonucleotides; D012334:RNA, Neoplasm