title: Early hematopoietic zinc finger protein prevents tumor cell recognition by natural killer cells.
abstract: Early hematopoietic zinc finger/zinc finger protein 521 (EHZF/ZNF521) is a novel zinc finger protein expressed in hematopoietic stem and progenitor cells and is down-regulated during their differentiation. Its transcript is also abundant in some hematopoietic malignancies. Analysis of the changes in the antigenic profile of cells transfected with EHZF cDNA revealed up-regulation of HLA class I cell surface expression. This phenotypic change was associated with an increased level of HLA class I H chain, in absence of detectable changes in the expression of other Ag-processing machinery components. Enhanced resistance of target cells to NK cell-mediated cytotoxicity was induced by enforced expression of EHZF in the cervical carcinoma cell line HeLa and in the B lymphoblastoid cell line IM9. Preincubation of transfected cells with HLA class I Ag-specific mAb restored target cell susceptibility to NK cell-mediated lysis, indicating a specific role for HLA class I Ag up-regulation in the NK resistance induced by EHZF. A potential clinical significance of these findings is further suggested by the inverse correlation between EHZF and MHC class I expression levels, and autologous NK susceptibility of freshly explanted multiple myeloma cells.
authors.affiliation: Department of Experimental and Clinical Medicine G Salvatore, University of Catanzaro Magna Graecia, Catanzaro, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: La Rocca
authors.forename: Mariateresa
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authors.lastname: Fulciniti
authors.forename: Tadepally
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authors.lastname: Lakshmikanth
authors.forename: Maria
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authors.lastname: Mesuraca
authors.forename: Talib Hassan
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authors.lastname: Ali
authors.forename: Valerio
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authors.lastname: Mazzei
authors.forename: Nicola
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authors.lastname: Amodio
authors.forename: Lucio
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authors.lastname: Catalano
authors.forename: Bruno
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authors.lastname: Rotoli
authors.forename: Ouathek
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authors.lastname: Ouerfelli
authors.forename: Michele
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authors.lastname: Grieco
authors.forename: Elio
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authors.lastname: Gulletta
authors.forename: Heather M
authors.initials: HM
authors.lastname: Bond
authors.forename: Giovanni
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authors.lastname: Morrone
authors.forename: Soldano
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authors.lastname: Ferrone
authors.forename: Ennio
authors.initials: E
authors.lastname: Carbone