ZAP-70 is highly expressed in most cases of childhood pre-B cell acute lymphoblastic leukemia.
The tyrosine kinase ZAP-70 plays a critical role in signal transduction in T cells and NK cells but has limited expression in primary human B cells. ZAP-70 is, however, expressed in adult B cell chronic lymphocytic leukemia where it correlates with a poor prognosis. We wished to determine if ZAP-70 is also expressed in pediatric B cell malignancy. A quantitative PCR assay for ZAP-70 expression was established and ZAP-70 expression in a range of human B cell lines was compared with expression in the Jurkat T cell line. ZAP-70 expression was then determined in bone marrow lymphoblasts obtained from 12 patients with pre-B cell acute lymphoblastic leukemia (ALL). ZAP-70 expression was not detected in mature B cell lines but was detected in pre-B cell lines at a level comparable to that seen in T cells. ZAP-70 expression was strongly expressed in nine of the 12 cases of primary pre-B cell lymphoblastic leukemia. The T cell-associated protein kinase ZAP-70 is highly expressed in pre-B lineage cells and most cases of pre-B acute lymphoblastic leukemia. ZAP-70 expression may hold prognostic value for pre-B ALL and raises the prospect of a novel therapeutic target.
Wandroo
F
F
Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham, UK.
Bell
A
A
Darbyshire
P
P
Pratt
G
G
Stankovic
T
T
Gordon
J
J
Lawson
S
S
Moss
P
P
D000293:Adolescent; D001402:B-Lymphocytes / Q000378:metabolism*; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000378:metabolism; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D019169:Jurkat Cells; D008297:Male; D016133:Polymerase Chain Reaction; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000378:metabolism*; D054448:Precursor Cells, B-Lymphoid / Q000378:metabolism*; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000235:genetics / Q000378:metabolism*
D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human