title: Immunohistochemical detection of E2F-1 in non-Hodgkin's lymphomas: a survey of 124 cases.
abstract: E2F-1 is a transcription factor that mediates cell cycle progression from the G1 to S phase and is normally regulated by a group of proteins, including cyclin D1. Although deregulation of E2F-1 is implicated in neoplastic transformation, in situ examination of this protein has not been performed to date. Using an immunohistochemical technique applied to routinely fixed, paraffin-embedded tissue sections, we evaluated E2F-1 expression in reactive lymphoid tissues and in 124 cases of non-Hodgkin's lymphoma (NHL) of various types. In reactive lymphoid tissues, E2F-1 was expressed predominantly by large noncleaved cells in germinal centers and by a small subset of cortical thymocytes. Mantle zones and splenic marginal zones were negative. Among the NHLs, four types had a relatively high percentage (> 20%) of E2F-1-positive cells: mantle cell lymphoma (19 of 19), lymphoblastic lymphoma (5 of 5), small noncleaved cell lymphoma (4 of 6), and hepatosplenic gammadelta T-cell lymphoma (3 of 3). The consistent detection of many E2F-1-positive cells in mantle cell lymphoma is in contrast to other small B-cell NHLs (n = 29), which had relatively few (< 10%) E2F-1-positive cells. This finding suggests that immunohistochemical staining for E2F-1 as a supplement to the existing markers, such as cyclin D1, might be useful in the differential diagnosis of NHLs composed of small B cells.
authors.affiliation: Division of Pathology, City of Hope National Medical Center, Duarte, California, USA.
authors.forename: R
authors.initials: R
authors.lastname: Lai
authors.forename: L J
authors.initials: LJ
authors.lastname: Medeiros
authors.forename: R
authors.initials: R
authors.lastname: Coupland
authors.forename: A
authors.initials: A
authors.lastname: McCourty
authors.forename: R K
authors.initials: RK
authors.lastname: Brynes
mesh_terms: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008221:Lymphoid Tissue / Q000378:metabolism / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000378:metabolism / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000378:metabolism* / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000378:metabolism / Q000473:pathology; D012016:Reference Values; D056465:Retinoblastoma-Binding Protein 1; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D019394:Ki-67 Antigen; D056465:Retinoblastoma-Binding Protein 1; D050680:Transcription Factor DP1; D014157:Transcription Factors