WT1 overexpression affecting clinical outcome in non-hodgkin lymphomas and adult acute lymphoblastic leukemia.

The Wilms tumor 1 (WT1) gene has a complex role as a transcriptional regulator, acting as tumor suppressor or oncogene in different malignancies. The prognostic role of its overexpression has been well-studied in leukemias, especially acute myeloid leukemia (AML), but not in lymphomas. For the first time to our knowledge, we present a study demonstrating the correlation of WT1 expression and survival in various non-Hodgkin lymphomas. We also studied the prognostic implications of WT1 overexpression in adult acute lymphoblastic leukemia (ALL). In our sample of 53 patients--25 with diffuse large B-cell lymphoma (DLBCL), 8 with mantle cell lymphoma (MCL), 9 with peripheral T-cell lymphoma (PTCL), 2 with Burkitt's lymphoma, 2 with mucosa-associated lymphoid tissue (MALT) lymphoma, and 7 with B-cell ALL--, we measured WT1 mRNA from blood samples by quantitative RT-PCR, and divided the patients into subgroups based on the level of expression. Kaplan-Meier survival curves were drawn and compared using the logrank test. In the sample of DLBCL patients, the difference in overall and disease-free survival between WT1-positive and negative subgroups was significant (p = 0.0475 and p = 0.0004, respectively), and in a few observed cases, a sudden increase in WT1 expression signified a relapse soon followed by death. Disease-free survival curves in MCL and ALL were similarly suggestive of a potential role played by WT1. In PTCL, though WT1-positivity was detected in 4 out of 9 cases, it did not seem to affect survival. The few cases of MALT and Burkitt's lymphoma all proved to be WT1-negative.