SHP-1 expression by malignant small B-cell lymphomas reflects the maturation stage of their normal B-cell counterparts.
SHP-1 is a protein phosphotyrosine phosphatase that plays an important role in modulating intracellular signaling, which regulates cell activation, proliferation, differentiation, and migration. It is a negative regulator of signal transduction induced by a number of cell receptors. Our immunohistochemical examination of paraffin-embedded reactive lymph nodes and lymphoid tissues revealed that B lymphocytes in follicle germinal centers do not express SHP-1. A weak staining of the B cells in the germinal center light zones was detected when an ultrasensitive amplification system was used. In contrast, normal B cells in mantle and marginal zones as well as interfollicular B lymphocytes and plasma cells displayed strong immunoreactivity. This pattern of SHP-1 expression was repeated in small B-cell lymphomas. All cases of mantle cell lymphoma (12 of 12), marginal zone lymphoma (10 of 10), and chronic lymphocytic leukemia/small lymphocytic lymphoma (13 of 13) expressed SHP-1 protein. However, only 1 of 30 cases of grade 1 follicle center cell lymphoma expressed SHP-1. Our observations highlight the biologic functions of SHP-1 and demonstrate that the SHP-1 expression pattern by small B-cell lymphomas reflects the maturation stage of their normal cell counterparts. These results indicate that determination of SHP-1 expression may help in the differential diagnosis of small B-cell lymphomas.
Kossev
P M
PM
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. pkossev@mail.med.upenn.edu
Raghunath
P N
PN
Bagg
A
A
Schuster
S
S
Tomaszewski
J E
JE
Wasik
M A
MA
D001402:B-Lymphocytes / Q000502:physiology*; D016922:Cellular Senescence; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D047908:Intracellular Signaling Peptides and Proteins; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism* / Q000473:pathology; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008221:Lymphoid Tissue / Q000378:metabolism / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000378:metabolism* / Q000473:pathology; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D012016:Reference Values; D013194:Staining and Labeling / Q000379:methods
D047908:Intracellular Signaling Peptides and Proteins; C509249:PTPN6 protein, human; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases