WT1 and GATA1 expression in myelodysplastic syndrome and acute leukemia

The Wilms' tumor protein, WT1, represses transcription from several growth factor genes. WT1 transcription is regulated in erythroid and myeloid lineages by the transcription factor GATA-1. Using a sensitive, isotopic duplex RT-PCR procedure amplifying WT1 or GATA-1 together with p-actin as the internal control in a single reaction mix, we quantitated the expression of WT1 and GATA-1 mRNA of 16 patients with myelodysplastic syndrome (MDS), 56 with acute myeloid leukemia (AML) and 22 with acute lymphoblastic leukemia (ALL). K562 was used as reference positive control for this cell line expresses both WT1 and GATA-1. Among MDS patients, increased WT1 expression was found in refractory anemia with excess blast (RAEB) and RAEB in transformation (RAEB-T) subtypes compared to the normal controls, whereas WT1 expression in refractory anemia (RA) was not different from the normal control level. All of AML cases of subtypes M0, M1, M2 and M3 expressed WT1 more than three times the normal WT1 level. Subtypes M4 to M7 showed significantly lower WT1 levels than M1 to M3 and AML cases with CD14⁺ expressed less WT1 than CD14^-. Higher than normal WT1 levels were also expressed in cases of ALL.