Differential expression of WT1 gene product in non-Hodgkin lymphomas.
The tumor suppressor gene wt1 (Wilms tumor 1) encodes a zinc finger transcription factor reported to be expressed in many tumors, including mesotheliomas, carcinomas, and acute leukemias. However, WT1 expression in non-Hodgkin lymphomas (NHLs) has not been studied. The authors assessed for WT1 expression in six lymphoma/leukemia cell lines using Western blot methods after subcellular fractionation. We also assessed for WT1 expression in 167 NHLs using immunohistochemical methods. The B-cell NHLs analyzed were 18 diffuse large B-cell lymphomas, 13 marginal zone B-cell lymphomas, 9 small lymphocytic lymphomas, (DLBCLs), 8 follicular lymphomas, 6 mantle cell lymphomas, 5 Burkitt lymphomas, 3 lymphoplasmacytic lymphomas, and 2 B-cell lymphoblastic lymphomas. The T-cell NHLs analyzed were 43 anaplastic large cell lymphomas (ALCLs), 26 peripheral T-cell lymphomas unspecified, 13 angioimmunoblastic T-cell lymphomas, 6 cutaneous ALCLs, 6 cases of mycosis fungoides, 5 extranodal NK/T-cell lymphomas of nasal type, and 4 T-cell lymphoblastic lymphomas. WT1 levels were higher in cytoplasmic extracts than in nuclear extracts of the Karpas 299 and SU-DHL-1 lymphoma cell lines but were higher in nuclear extracts than in the cytoplasmic extracts of the Jurkat, HH, U-937, and K562 leukemia cell lines. In NHLs, WT1 was positive in 4 of 5 (80%) Burkitt lymphomas, 9 of 12 (75%) ALK-positive ALCLs, 3 of 6 (50%) lymphoblastic lymphomas (2 of 4 T-cell, 1 of 2 B-cell), 14 of 31 (45%) ALK-negative ALCLs, 6 of 18 (33%) DLBCLs, and 1 of 6 (17%) cutaneous ALCLs. WT1 was negative in all other NHLs tested. WT1 immunoreactivity was primarily cytoplasmic in all positive NHLs except T-cell lymphoblastic lymphoma. In conclusion, WT1 protein is frequently detected in the cytoplasm of a subset of high-grade NHLs.
Drakos
Elias
E
Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Rassidakis
George Z
GZ
Tsioli
Panagiota
P
Lai
Raymond
R
Jones
Dan
D
Medeiros
L Jeffrey
LJ
D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics* / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D025721:WT1 Proteins / Q000096:biosynthesis / Q000235:genetics*
D025721:WT1 Proteins