In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 30, No. 15_suppl ( 2012-05-20), p. 6581-6581
Abstract:
6581 Background: Intracellular ZAP-70 protein was recently recognized as prognostic marker in chronic lymphocytic leukemia (CLL). The specific objective of this study was to develop a simple and sensitive assay, for the quantitative detection of ZAP-70 protein in leukemic cells. Methods: Components of the assay system include sample preparation, immunomagnetic fluorescence assay, Signalyte-II spectrofluorometer. The leukemic cells were isolated from CLL patient blood samples and lysed to release the intracellular ZAP-70 protein. ZAP-70 protein was captured by magnetic beads coated with anti-ZAP70 capture antibody, and recognized by a fluorescent detector antibody, forming an immuno-sandwich complex. This complex was dissociated for measurement of the fluorescence signal, which was proportional to ZAP-70 concentration, using the spectrofluorometer. Results: The assay conditions were extensively optimized by selecting an optimal pair of capture/detector antibodies, conjugation of fluorescence dye, cell lysis condition and excitation/emission wavelengths. The protocol was further validated with two positive controls, Jurkat cell lysate and recombinant ZAP70 protein (rZAP70). The limit of detection was determined to be lower than 125 Jurkat cells and 39 pg of rZAP70 protein. The signal response was linear over a wide range of concentration, from 625 to 40,000 Jurkat cells per test (R 2 =0.9987) and from 0 to 40,000 pg rZAP70 protein per test (R 2 =0.9928). The results from 20 CLL patients correlated strongly with flow cytometry analysis. The concordance between the two methods for positive and negative results was 100% (7/7) and 92% (12/13), respectively, while the overall concordance between the two methods was 95%. Conclusions: The assay is a simple, reliable, and reproducible method for quantitative detection of ZAP-70 in patient leukemic cells, without the need for cell fixation or permeabilization. The entire assay could be completed in 5.5 hours. The ZAP-70 signal was linear over a wide dynamic range, which we believe enables quantitative assessment of small changes in ZAP-70 expression over the course of the disease and in response to therapeutic intervention.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2012.30.15_suppl.6581
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2012
detail.hit.zdb_id:
2005181-5
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