Over-expression of Wilm's Tumor Gene 1 (WT1) in Iranian Patients with Acute Myeloblastic Leukemia

Background: The Wilm's tumor gene 1 (WT1) encodes a zinc finger transcription factor that is inactivated in a subset of Wilm 's tumors. It plays a crucial role in growth, proliferation and development of some embryonic and adult organs. WT1 is expressed as a tumor associated antigen (TAA) in various types of solid and hemato- poietic malignancies and can be employed as a useful marker for targeted immuno- therapy and monitoring of minimal residual disease (MRD). Objective: To investi- gate the profile of WT1 gene expression in Iranian patients with acute myeloblastic leukemia. Methods: RT-PCR method was used to determine the WT1 gene expres- sion in bone marrow (BM) and/or peripheral blood (PB) samples from 11 patients with AML and PB samples of 36 normal subjects. Isolated cells from all patients were immunophenotyped by flow cytometry. Results: The leukemic cells from 10 patients (91%) were found moderately or strongly positive for WT1 expression whereas only 3 out of 36 normal subjects expressed WT1 at very low levels. A highly significant correlation was observed for WT1 expression between paired BM and PB samples of the AML patients. Conclusion: Our results indicate that WT1 is expressed in the majority of Iranian AML patients and may be employed for screen- ing and monitoring of minimal residual disease in these patients.