title: Molecular profiling of CD34+ cells in idiopathic myelofibrosis identifies a set of disease-associated genes and reveals the clinical significance of Wilms' tumor gene 1 (WT1).
abstract: This study was aimed at the characterization of a gene expression signature of the pluripotent hematopoietic CD34(+) stem cell in idiopathic myelofibrosis (IM), which would eventually provide novel pathogenetic insights and/or diagnostic/prognostic information. Aberrantly regulated genes were revealed by transcriptome comparative microarray analysis of normal and IM CD34(+) cells; selected genes were also assayed in granulocytes. One-hundred seventy four differentially expressed genes were identified and in part validated by quantitative polymerase chain reaction. Altered gene expression was corroborated by the detection of abnormally high CD9 or CD164, and low CXCR4, membrane protein expression in IM CD34(+) cells. According to class prediction analysis, a set of eight genes (CD9, GAS2, DLK1, CDH1, WT1, NFE2, HMGA2, and CXCR4) properly recognized IM from normal CD34(+) cells. These genes were aberrantly regulated also in IM granulocytes that could be reliably differentiated from control polycythemia vera and essential thrombocythemia granulocytes in 100% and 81% of cases, respectively. Abnormal expression of HMGA2 and CXCR4 in IM granulocytes was dependent on the presence and the mutational status of JAK2(V617F) mutation. The expression levels of both CD9 and DLK1 were associated with the platelet count, whereas higher WT1 expression levels identified IM patients with more active disease, as revealed by elevated CD34(+) cell count and higher severity score. In conclusion, molecular profiling of IM CD34(+) cells uncovered a limited number of genes with altered expression that, beyond their putative role in disease pathogenesis, are associated with patients' clinical characteristics and may have potential prognostic application.
authors.affiliation: Department of Hematology, Azienda Ospedaliera-Universitaria Careggi, University of Florence, Florence, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Guglielmelli
authors.forename: Roberta
authors.initials: R
authors.lastname: Zini
authors.forename: Costanza
authors.initials: C
authors.lastname: Bogani
authors.forename: Simona
authors.initials: S
authors.lastname: Salati
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pancrazzi
authors.forename: Elisa
authors.initials: E
authors.lastname: Bianchi
authors.forename: Francesco
authors.initials: F
authors.lastname: Mannelli
authors.forename: Sergio
authors.initials: S
authors.lastname: Ferrari
authors.forename: Marie-Caroline
authors.initials: MC
authors.lastname: Le Bousse-Kerdilès
authors.forename: Alberto
authors.initials: A
authors.lastname: Bosi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Barosi
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Migliaccio
authors.forename: Rossella
authors.initials: R
authors.lastname: Manfredini
authors.forename: Alessandro M
authors.initials: AM
authors.lastname: Vannucchi
mesh_terms: D000465:Algorithms; D018952:Antigens, CD34 / Q000032:analysis* / Q000235:genetics; D004252:DNA Mutational Analysis; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D015321:Gene Rearrangement; D016162:Genes, Wilms Tumor; D016313:Genes, abl / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000502:physiology*; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D039904:Pluripotent Stem Cells / Q000276:immunology / Q000502:physiology*; D016133:Polymerase Chain Reaction; D055728:Primary Myelofibrosis / Q000235:genetics*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification
chemical_list: D018952:Antigens, CD34; D012313:RNA