Detection of ALL-1/AF4 fusion transcript by reverse transcription-polymerase chain reaction for diagnosis and monitoring of acute leukemias with the t(4;11) translocation.
The chromosomal breakpoints of t(4;11) translocation of acute lymphoblastic leukemia (ALL) have been recently identified at molecular level and shown to involve the AF4 (FEL) gene on chromosome 4 and the ALL-1 (MLL, Hrx) gene on chromosome 11. The ALL-1/AF4 fusion gene is transcribed into a chimeric mRNA. Using primer sets derived from ALL-1 and AF4 cDNAs by reverse transcription-polymerase chain reaction (RT-PCR), we were able to amplify the breakpoint sites of the fusion transcript of all 15 ALL cases with karyotypic or molecular evidence of the t(4;11). DNA fragments of different size were obtained as the consequence of different breakpoints on chromosome 11 and the presence of alternative splicing of ALL-1 exon 8. The feasibility of monitoring the residual cells carrying the t(4;11) in 2 ALL patients with different clinical outcome was evaluated. Overall, the presented results provide evidence that RT-PCR can be used as a rapid method for detecting this chromosomal abnormality and following the patient's response to therapy.
Biondi
A
A
Clinical Pediatrica Università di Milano, Ospedale San Gerardo, Monza, Italy.
Rambaldi
A
A
Rossi
V
V
Elia
L
L
Caslini
C
C
Basso
G
G
Battista
R
R
Barbui
T
T
Mandelli
F
F
Masera
G
G
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D002648:Child; D002880:Chromosomes, Human, Pair 11; D002894:Chromosomes, Human, Pair 4; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D051788:Myeloid-Lymphoid Leukemia Protein; D009857:Oncogenes; D016133:Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000235:genetics; D014157:Transcription Factors; D014178:Translocation, Genetic
D004268:DNA-Binding Proteins; C497422:KMT2A protein, human; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase