Novel 5' exonuclease-based real-time PCR assay for the detection of t(14;18)(q32;q21) in patients with follicular lymphoma.
The exonuclease-based real-time polymerase chain reaction (PCR) exploits 5'-->3' exonuclease activity of Taq polymerase and measures PCR product accumulation as the reaction proceeds through a dual-labeled fluorogenic probe. The utility of this exonuclease-based PCR assay as a rapid alternative to conventional PCR for follicular lymphoma-associated t(14;18)(q32;q21) was evaluated in this study. The specificity of the assay for t(14;18) involving bcl-2 and immunoglobulin heavy-chain joining region (JH) genes was assessed by analyzing DNA from 53 patients (38 B-cell non-Hodgkin's lymphomas and 15 nonneoplastic proliferations) and correlating the exonuclease PCR data with conventional PCR results. bcl-2/JH fusion sequences were detected by exonuclease-based PCR in 24 of 25 cases shown to be bcl-2 rearranged by conventional PCR. Fusion sequences were not detected in patients who were negative by conventional PCR. The overall concordance between the two assays was 98% (52 of 53 cases concordant positive or negative). In a serial dilution study using t(14;18)-positive cell line DNA, exonuclease-based PCR detected fusion sequences at DNA concentrations of 5 pg, equivalent to 0.6 to 0.8 genomes per reaction. Thus, this study demonstrated that exonuclease-based PCR for t(14;18) is both specific and highly sensitive. The elimination of the post-PCR amplicon detection steps and the ability to quantitate the input target DNA sequences make this assay ideal for routine diagnostics and monitoring minimal residual disease.
Luthra
R
R
Department of Pathology, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
McBride
J A
JA
Cabanillas
F
F
Sarris
A
A
D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D005092:Exonucleases; D006801:Humans; D008224:Lymphoma, Follicular / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D014178:Translocation, Genetic
D005092:Exonucleases