Quantification of minimal residual disease in T-lineage acute lymphoblastic leukemia with the TAL-1 deletion using a standardized real-time PCR assay

Abstract

Hematologic relapse remains the greatest obstacle to the cure of children with acute lymphoblastic leukemia (ALL). Recent studies have shown that patients with increased risk of relapse can be identified by measuring residual leukemic cells, called minimal residual disease (MRD), during clinical remission. Current PCR methods, however, for measuring MRD are cumbersome and time-consuming. To improve and simplify MRD assessment, we developed a real-time quantitative PCR (RQ-PCR) assay for detection of leukemic cells that harbor the TAL-1 deletion. We studied serial dilutions of leukemic DNA and found the assay had a sensitivity of detection of one leukemic cell among 100 000 normal cells. We then investigated 23 samples from eight children with ALL in clinical remission. We quantified residual leukemic cells by using the TAL-1 RQ-PCR assay and by using limiting dilution analysis. In 17 samples, both methods detected MRD levels у0.001%. The percentages of leukemic cells measured by the two methods correlated well (r 2 ‫؍‬ 0.926). In the remaining six samples, both methods detected fewer than 0.001% leukemic cells. We conclude the TAL-1 RQ-PCR assay can be used for rapid, sensitive and accurate assessment of MRD in T-lineage ALL with the TAL-1 deletion. Leukemia (2001) 15, 166-170.

Comparative analysis of flow cytometry and polymerase chain reaction for the detection of minimal residual disease in childhood acute lymphoblastic leukemia

“…The quantity and integrity of the DNA was checked by TaqMan analysis of the RAS gene. 34 The results of the RAS gene in the various DNA samples differed less than a factor of two.…”

A zinc-finger transcriptional activator designed to interact with the γ-globin gene promoters enhances fetal hemoglobin production in primary human adult erythroblasts

“…The average VCN was calculated by establishing a standard curve of K562 DNA containing a single copy of the HIV vector genome serially diluted with native K562 DNA to yield mixtures containing 1, 0.5, 0.25, 0.1, and 0.01 vector copies where DNA was normalized using primers and a probe specific for human N-RAS. 26 The final VCN of each sample was adjusted by dividing the copy number by 1.5 based on the triploid nature of the K562 cell line genome.…”

Standardization and quality control studies of ‘real-time’ quantitative reverse transcriptase polymerase chain reaction of fusion gene transcripts for residual disease detection in leukemia – A Europe Against Cancer Program

“…134 The detection of TAL1 deletions at the DNA level has already been described. [143][144][145] A recent report described a TaqManbased RQ-PCR method for the detection of TAL1 deletions at the DNA level in T-ALL patients. 145 In that report, the forward primer and probe were positioned in SIL exon 1b (and part of the following intron) and the reverse primer was located in TAL1 exon 1b.…”

“…[143][144][145] A recent report described a TaqManbased RQ-PCR method for the detection of TAL1 deletions at the DNA level in T-ALL patients. 145 In that report, the forward primer and probe were positioned in SIL exon 1b (and part of the following intron) and the reverse primer was located in TAL1 exon 1b. Using the CEM cell line, a sensitivity of 10 À5 could be obtained, which is equivalent to a single leukemic genome.…”