Detection of major bcr-abl gene expression at a very low level in blood cells of some healthy individuals.
The major bcr-abl fusion gene is presently seen as the hallmark of chronic myeloid leukemia (CML) and presumably as the cause of its development. Accordingly, long-term disappearance of bcr-abl after intensive therapy is considered to be a probable cure of CML. The nested reverse transcriptase-polymerase chain reaction (RT-PCR) provides a powerful tool for minimal residual CML detection. The RT-PCR was optimized by (1) increasing the amount of total RNA involved in the reverse transcription reaction to correspond to total RNA extracted from 10(8) cells, (2) using a specific abl primer in this reverse reaction, and (3) reamplifying 10% of the RT-PCR product in nested amplification. This optimized RT-PCR permitted us to detect up to 1 copy of RNA bcr-abl synthesised in vitro, mixed with yeast RNA in an equivalent quantity to 10(8) white blood cells (WBCs). Using this highly sensitive RT-PCR during the follow-up of CML patients, a signal was unexpectedly found in healthy controls. Therefore, a systematic study of the possible expression of bcr-abl RNA in the WBCs of healthy adults and children and in umbilical cord blood was undertaken. It showed the presence of bcr-abl transcript in the blood of 22 of 73 healthy adults and in the blood of 1 of 22 children but not in 22 samples of umbilical cord blood.
Biernaux
C
C
Laboratory of Biological Chemistry (Rhode-St-Genèse), Université Libre de Bruxelles, Belgium.
Loos
M
M
Sels
A
A
Huez
G
G
Stryckmans
P
P
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D005312:Fetal Blood / Q000378:metabolism; D016044:Fusion Proteins, bcr-abl / Q000097:blood* / Q000235:genetics; D005786:Gene Expression Regulation; D016313:Genes, abl; D006801:Humans; D007223:Infant; D007962:Leukocytes / Q000378:metabolism; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012016:Reference Values; D012680:Sensitivity and Specificity
D016044:Fusion Proteins, bcr-abl