title: BCL-6 gene product, a 92- to 98-kD nuclear phosphoprotein, is highly expressed in germinal center B cells and their neoplastic counterparts.
abstract: The BCL-6 gene is known to be located on chromosome 3q27, at the breakpoint of the 3q27-associated translocations that occur frequently in human non-Hodgkin's lymphomas (NHLs). To identify the BCL-6 protein, two antibodies that recognized distinct domains of this protein were raised in rabbits. Immunoprecipitation and immunoblotting of lysates of BCL-6-expressing cells using both antibodies showed a broad 92- to 98-kD band. Dephosphorylation of BCL-6 protein reduced the size of this band to 87 kD, suggesting that BCL-6 may be expressed in a phosphorylated form. Immunostaining with both antibodies showed that BCL-6 protein was localized in the nuclei of most of the germinal center B cells and a small number of marginal zone B cells. Furthermore, BCL-6 protein was expressed in follicular, Burkitt's, and diffuse large B-cell lymphomas. These results suggest that the BCL-6 protein, expressed in B cells of the germinal centers which are important in the maturation of immune responses, may play some physiological role(s) in the germinal center B cells.
authors.affiliation: Department of Pathology, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Onizuka
authors.forename: M
authors.initials: M
authors.lastname: Moriyama
authors.forename: T
authors.initials: T
authors.lastname: Yamochi
authors.forename: T
authors.initials: T
authors.lastname: Kuroda
authors.forename: A
authors.initials: A
authors.lastname: Kazama
authors.forename: N
authors.initials: N
authors.lastname: Kanazawa
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Kato
authors.forename: H
authors.initials: H
authors.lastname: Ota
authors.forename: S
authors.initials: S
authors.lastname: Mori
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D016175:B-Lymphocyte Subsets / Q000378:metabolism*; D001483:Base Sequence; D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002051:Burkitt Lymphoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D015973:Gene Expression Regulation, Leukemic; D015972:Gene Expression Regulation, Neoplastic; D007938:Leukemia / Q000235:genetics / Q000378:metabolism; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000378:metabolism; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics / Q000378:metabolism; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D012516:Osteosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D014066:Palatine Tonsil / Q000166:cytology*; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D051560:Proto-Oncogene Proteins c-bcl-6; D011817:Rabbits; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D014407:Tumor Cells, Cultured; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors; D014415:Tunicamycin