Myeloid Leukemia

WT1 Expression in AML and MDS 199
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WT1 Overexpression in Acute Myeloid Leukemia
and Myelodysplastic Syndromes
Daniela Cilloni, Enrico Gottardi, and Giuseppe Saglio
Summary
The Wilms tumor gene was identified as a tumor suppressor gene responsible for a particular
type of kidney tumor. Several years ago, it was demonstrated that it is also overexpressed in
acute and chronic leukemias. Although the exact role of this gene in the hematopoietic system
is still quite completely obscure, it represents a reliable marker for the detection of the presence
of leukemic cells. WT1 quantitative assessment may therefore represent a useful tool for the
diagnosis and follow up of leukemia patients. In this chapter, we describe the method for the
quantification of WT1 transcript by real-time polymerase chain reaction.
Key Words: WT1; myelodysplastic syndrome; acute leukemia; minimal residual disease;
real-time PCR.
1. Introduction
The applicability of molecular techniques for the diagnosis and monitoring
of minimal residual disease (MRD) in acute leukemia has been limited to those
patients whose leukemia is characterized by genetic markers amenable to sensitive
detection by polymerase chain reaction (PCR). Genetic markers such as
fusion genes derived from chromosome translocations (1,2) are ideally suited
to such an approach. At present, more than 50% of acute leukemia patients,
and in particular most cases of acute myeloid leukemia (AML), lack known
genetic lesions or markers of clonality that are suitable for MRD monitoring.
Moreover, several hematological malignancies present particular difficulties
in terms of differential diagnosis. This is the situation for many patients affected
by myelodysplastic syndromes (MDS), which are rarely characterized by the
presence of cytogenetic abnormalities (3). In this setting, the Wilms tumor gene
(WT1) has gained a central role as a universal molecular marker of leukemia
(4–6).
From: Methods in Molecular Medicine, Vol. 125: Myeloid Leukemia: Methods and Protocols
Edited by: H. Iland, M. Hertzberg, and P. Marlton © Humana Press Inc., Totowa, NJ
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