Published in:
01-03-2010 | Original Paper
Expression of multidrug resistance-associated ABC transporters in B-CLL is independent of ZAP70 status
Authors:
Alexander Hoellein, Thomas Decker, Christian Bogner, Madlen Oelsner, Stefanie Hauswald, Christian Peschel, Ulrich Keller, Thomas Licht
Published in:
Journal of Cancer Research and Clinical Oncology
|
Issue 3/2010
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Abstract
Purpose
To assess whether the poor prognosis of ZAP70-positive B-cell chronic lymphocytic leukemia (CLL) is associated with the overexpression of ABC transporter genes that are responsible for pleiotropic drug resistance.
Materials and methods
The transcript level of ten drug transporters was analyzed using semiquantitative and quantitative RT-PCR in control hematopoietic cells, in 41 CLL patient samples and in 5 lymphoma cell lines. ZAP70 status was determined by immunoblotting.
Results
Of all analyzed transporters, MDR1, MDR2, MRP1, MRP4, MRP5, and MRP7 were expressed at a significantly higher level in B lymphocytes when compared with other hematopoietic cells in peripheral blood. A subgroup of 41 CLL patient samples showed similar or higher expression of these genes than control B cells, and CLL cells exhibited high expression when compared with multiple lymphoma cell lines. No significant correlation between ZAP70 expression and ABC transporter expression was observed.
Conclusion
The ZAP70 status is independent of the multidrug resistance phenotype in CLL.