title: PRAME is a membrane and cytoplasmic protein aberrantly expressed in chronic lymphocytic leukemia and mantle cell lymphoma.
abstract: The preferentially expressed antigen in melanoma (PRAME) gene is aberrantly expressed in chronic lymphoproliferative disorders (CLD). We produced and characterized an anti-PRAME monoclonal antibody (MoAb), which was then applied in a quantitative flow cytometric (QFC) method to evaluate PRAME expression in leukemic cells from the peripheral blood (PB) of 47 patients with chronic lymphocytic leukemia and seven with mantle cell lymphoma as well as in the PB mononuclear cells (PBMCs) and B lymphocytes from 15 healthy subjects. Approximately 90% of CLD, but none of the normal samples, presented more than 20% of PRAME+ lymphocytes. Moreover, the intensity of PRAME expression was significantly higher in CLD cells compared to normal B lymphocytes and PBMCs. By immunofluorescence microscopy and by permeabilized flow cytometry we demonstrated that PRAME is a membrane antigen and a cytoplasmic protein aberrantly expressed in malignant CLD. Our results suggest that the analysis of PRAME protein may contribute for the distinction between normal and leukemic cells in CLD, and that PRAME may be a potential target for therapy.
authors.affiliation: Hematology Division and Center for Cell Based Therapy, Medical School of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Proto-Siqueira
authors.forename: Lorena L
authors.initials: LL
authors.lastname: Figueiredo-Pontes
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Panepucci
authors.forename: Aglair B
authors.initials: AB
authors.lastname: Garcia
authors.forename: Edgar G
authors.initials: EG
authors.lastname: Rizzatti
authors.forename: Fabio M
authors.initials: FM
authors.lastname: Nascimento
authors.forename: Hellen C F
authors.initials: HC
authors.lastname: Ishikawa
authors.forename: Roy E
authors.initials: RE
authors.lastname: Larson
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Falcão
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Simpson
authors.forename: Ivan
authors.initials: I
authors.lastname: Gout
authors.forename: Valery
authors.initials: V
authors.lastname: Filonenko
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Rego
authors.forename: Marco A
authors.initials: MA
authors.lastname: Zago
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D045744:Cell Line, Tumor; D005434:Flow Cytometry / Q000379:methods; D005455:Fluorescent Antibody Technique / Q000379:methods; D020869:Gene Expression Profiling; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics*; D020522:Lymphoma, Mantle-Cell / Q000235:genetics*; D008232:Lymphoproliferative Disorders / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; C404944:PRAME protein, human