title: Cyclin D1 protein expression in mantle cell lymphoma.
abstract: BACKGROUND
  The t(11;14)(q13;q32) is a chromosomal abnormality usually associated with mantle cell (centrocytic) lymphomas, although it has occasionally been reported in other chronic lymphoproliferative disorders such as chronic lymphocytic leukemia, prolymphocytic leukemia, splenic lymphoma with villous lymphocytes, and multiple myeloma. This abnormality results in the translocation of the bcl-1 oncogene from chromosome 11 to the immunoglobulin heavy chain locus on chromosome 14. The bcl-1 oncogene is a member of the cyclin gene family, and high levels of cyclin D1 mRNA are consistently found in malignant B cell proliferations with t(11;14).
  
  
  METHODS
  We examined cyclin D1 protein expression in 33 patients with low grade lymphoproliferative disorders and 2 patients with reactive hyperplasias by Western blot analysis using a polyclonal antibody.
  
  
  RESULTS
  8/11 mantle cell lymphomas, 0/11 chronic lymphocytic leukemias, 0/4 hairy cell leukemias, 0/2 Sezary syndrome, 0/2 monocytoid B-cell lymphomas, 0/3 follicular lymphomas, and 0/2 reactive hyperplasias had overexpression of cyclin D1. Cytogenetic analysis was performed in four cases of mantle cell lymphoma; three of these cases had the t(11;14), one of which was hypotetraploid with two copies of t(11;14). Immunophenotypically, all cases of mantle cell lymphoma and chronic lymphocytic leukemia had coexpression of CD5 and CD20.
  
  
  CONCLUSIONS
  Mantle cell lymphoma may be difficult to discriminate from chronic lymphocytic leukemia, a more indolent disease, on morphologic and immunophenotypic grounds. Our findings suggest that analysis of cyclin D1 protein expression may be helpful in differentiating mantle cell lymphomas from other low grade lymphoproliferative disorders.
authors.affiliation: Department of Pathology, University of South Florida, H. Lee Moffitt Cancer Center, Tampa, USA.
authors.forename: S
authors.initials: S
authors.lastname: Alkan
authors.forename: B
authors.initials: B
authors.lastname: Schnitzer
authors.forename: J L
authors.initials: JL
authors.lastname: Thompson
authors.forename: L C
authors.initials: LC
authors.lastname: Moscinski
authors.forename: C W
authors.initials: CW
authors.lastname: Ross
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis; D015153:Blotting, Western; D019938:Cyclin D1; D016213:Cyclins / Q000096:biosynthesis*; D003937:Diagnosis, Differential; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015513:Oncogene Proteins / Q000096:biosynthesis*; D012189:Retrospective Studies
chemical_list: D000951:Antigens, Neoplasm; D016213:Cyclins; D015513:Oncogene Proteins; D019938:Cyclin D1