Abstract
Wilms tumor gene (WT1) expression occurs in various malignancies including adult leukemia. WT1 expression was studied in children with acute leukemia according to morphological types and immunophenotypes. RT-PCR was used to examine relative level of WT1 transcripts from the peripheral blood of 15 children diagnosed with acute leukemia: 12 acute lymphoblastic leukemias (ALLs) and 3 acute myelogenous leukemias (AMLs); 8 ALLs newly diagnosed, 2 ALLs in first marrow relapse, 2 ALLs in remission over 2 years, 2 AMLs newly diagnosed, and 1 AML in second marrow relapse. Six healthy adult volunteers were studied for controls. WT1 was detectable in 7 out of 10 ALLs and all 3 AMLs, but not in 2 ALLs in remission and the controls. The expression levels were higher for AMLs than for ALLs. According to the types of ALL, WT1 was detectable in 2 out of 2 non-T group II, 4 out of 6 non-T group III, but not in one CD20+ non-T group IV, while one T-ALL showed a relatively high level. WT1 expression was detectable more frequently in ALL-L2 than in ALL-L1 and with higher levels for ALL-L2. WT1 expression was frequently noted in children with acute leukemia. The results suggest that WT1 transcripts may prove to be a significant tumor marker, possibly as an MRD monitor in evaluating remission status and early relapse, and may also prove to be useful in predicting outcomes in acute leukemia in children.