title: Overexpression of heterogeneous nuclear ribonucleoprotein B1 in lymphoproliferative disorders: high expression in cells of follicular center origin.
abstract: It is reported that overexpression of hnRNP A2 and B1 proteins is useful for detecting early cancers, and that B1, a splicing minor isoform of A2, is more specific than A2. The B1 expression is still undetermined in human lymphoid tissues. We quantitatively studied the B1 expression in 85 lymph node specimens, comprising reactive lymphoid hyperplasia (RLH; n=8), B-cell lymphoma (n=23), T-cell lymphoma (n=22), and metastatic carcinoma (n=32). Immunostaining and immunoblotting analyses with an anti-B1 monoclonal antibody, 2B2 were performed, and the two sets of results correlated with each other (p<0.05). In RLH specimens, B1 expression rate was significantly higher in follicular centers (FC; 44%) than in mantle zone (MZ; 15%) and paracortex (16%) (p<0.01). B1 expression was statistically higher in B-cell lymphoma than in T-cell lymphoma (p<0.01). In B-cell lymphomas, B1 expression rates were 51% in diffuse large B-cell lymphoma (DLBL; n=5) and 45% in follicular lymphoma (FL; n=16), and they were almost the same as that of the FC. Especially in DLBLs, CD10+ FC-origin lymphomas expressed greater amount of B1 than CD10- non-FC-origin lymphomas. B1 expression rate was low in mantle cell lymphoma (MCL; n=2) and similar to that of MZ in RLH. These results suggest that B1 expression is associated with differentiation in lymphoid tissue rather than transformation. B1 expression increases during the process of B-cell differentiation in the FC, and that high B1 expression is maintained in B-cell lymphomagenesis, especially in cells of FC-origin DLBL.
authors.affiliation: Department of Pathology, School of Medicine, Fukuoka University, Nanakuma 7-45-1, Jonan-ku, Fukuoka 814-0133, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tani
authors.forename: Koichi
authors.initials: K
authors.lastname: Ohshima
authors.forename: Seiji
authors.initials: S
authors.lastname: Haraoka
authors.forename: Makoto
authors.initials: M
authors.lastname: Hamasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamma
authors.forename: Seiyo
authors.initials: S
authors.lastname: Ikeda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002454:Cell Differentiation; D002648:Child; D002675:Child, Preschool; D005260:Female; D034502:Heterogeneous-Nuclear Ribonucleoprotein D / Q000032:analysis; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000032:analysis*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000378:metabolism / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000032:analysis
chemical_list: D034502:Heterogeneous-Nuclear Ribonucleoprotein D; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; C439768:hnRNP A2; D015260:Neprilysin