Analysis of acute leukemias with MLL/ENL fusion transcripts: identification of two novel breakpoints in ENL.
t(11;19)(q23;p13.3); is one of the common chromosomal translocations in acute leukemias involving MLL rearrangements. This translocation generates MLL/ENL fusion transcripts. In a study of acute leukemias, 148 patients were identified to have MLL rearrangements by Southern blot analysis. Reverse transcriptase-polymerase chain reaction (RT-PCR) assay, using primer sets covering the 2 previously described breakpoints at exons 2 and 7 of ENL detected 11 samples harboring MLL/ENL. complementary DNA panhandle PCR further identified 4 additional cases with novel breakpoints in ENL at exon 4 or 6. Sequencing analysis showed that all novel fusion transcripts were in-frame. The conventional cytogenetic analysis failed to detect t(11;19) in 6 of 13 cases. Of 15 patients with MLL/ENL, 7 had precursor B-cell acute lymphoblastic leukemia, 4 had T-cell acute lymphoblastic leukemia, and 4 had acute myeloid leukemia. The present study showed that PCR-based techniques are more sensitive than conventional karyotyping for detecting MLL/ENL fusions and an extra antisense primer at exon 6 of ENL should be included in RT-PCR assay to ensure complete detection of all MLL/ENL fusion transcripts.
Fu
Jen-Fen
JF
Department of Medical Research, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
Liang
Der-Cherng
DC
Shih
Lee-Yung
LY
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics; D005260:Female; D015321:Gene Rearrangement; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007951:Leukemia, Myeloid / Q000235:genetics*; D008297:Male; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics*; D050596:Oncogene Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics*; D016896:Treatment Outcome
C497422:KMT2A protein, human; C081448:MLLT1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase