title: CD34+ cells from AML with mutated NPM1 harbor cytoplasmic mutated nucleophosmin and generate leukemia in immunocompromised mice.
abstract: Acute myeloid leukemia (AML) with mutated NPM1 shows distinctive biologic and clinical features, including absent/low CD34 expression, the significance of which remains unclear. Therefore, we analyzed CD34(+) cells from 41 NPM1-mutated AML. At flow cytometry, 31 of 41 samples contained less than 10% cells showing low intensity CD34 positivity and variable expression of CD38. Mutational analysis and/or Western blotting of purified CD34(+) cells from 17 patients revealed NPM1-mutated gene and/or protein in all. Immunohistochemistry of trephine bone marrow biopsies and/or flow cytometry proved CD34(+) leukemia cells from NPM1-mutated AML had aberrant nucleophosmin expression in cytoplasm. NPM1-mutated gene and/or protein was also confirmed in a CD34(+) subfraction exhibiting the phenotype (CD34(+)/CD38(-)/CD123(+)/CD33(+)/CD90(-)) of leukemic stem cells. When transplanted into immunocompromised mice, CD34(+) cells generated a leukemia recapitulating, both morphologically and immunohistochemically (aberrant cytoplasmic nucleophosmin, CD34 negativity), the original patient's disease. These results indicate that the CD34(+) fraction in NPM1-mutated AML belongs to the leukemic clone and contains NPM1-mutated cells exhibiting properties typical of leukemia-initiating cells. CD34(-) cells from few cases (2/15) also showed significant leukemia-initiating cell potential in immunocompromised mice. This study provides further evidence that NPM1 mutation is a founder genetic lesion and has potential implications for the cell-of-origin and targeted therapy of NPM1-mutated AML.
authors.affiliation: Institute of Hematology and Clinical Immunology, University of Perugia, Perugia, Italy.
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Martelli
authors.forename: Valentina
authors.initials: V
authors.lastname: Pettirossi
authors.forename: Christian
authors.initials: C
authors.lastname: Thiede
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Bonifacio
authors.forename: Federica
authors.initials: F
authors.lastname: Mezzasoma
authors.forename: Debora
authors.initials: D
authors.lastname: Cecchini
authors.forename: Roberta
authors.initials: R
authors.lastname: Pacini
authors.forename: Alessia
authors.initials: A
authors.lastname: Tabarrini
authors.forename: Raffaella
authors.initials: R
authors.lastname: Ciurnelli
authors.forename: Ilaria
authors.initials: I
authors.lastname: Gionfriddo
authors.forename: Nicla
authors.initials: N
authors.lastname: Manes
authors.forename: Roberta
authors.initials: R
authors.lastname: Rossi
authors.forename: Linda
authors.initials: L
authors.lastname: Giunchi
authors.forename: Uta
authors.initials: U
authors.lastname: Oelschlägel
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Brunetti
authors.forename: Marica
authors.initials: M
authors.lastname: Gemei
authors.forename: Mario
authors.initials: M
authors.lastname: Delia
authors.forename: Giorgina
authors.initials: G
authors.lastname: Specchia
authors.forename: Arcangelo
authors.initials: A
authors.lastname: Liso
authors.forename: Mauro
authors.initials: M
authors.lastname: Di Ianni
authors.forename: Francesco
authors.initials: F
authors.lastname: Di Raimondo
authors.forename: Franca
authors.initials: F
authors.lastname: Falzetti
authors.forename: Luigi
authors.initials: L
authors.lastname: Del Vecchio
authors.forename: Massimo F
authors.initials: MF
authors.lastname: Martelli
authors.forename: Brunangelo
authors.initials: B
authors.lastname: Falini
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D050505:Mutant Proteins / Q000235:genetics* / Q000378:metabolism; D009368:Neoplasm Transplantation; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D000090243:Nucleophosmin; D014183:Transplantation, Heterologous
chemical_list: D018952:Antigens, CD34; D008562:Membrane Glycoproteins; D050505:Mutant Proteins; C000716967:NPM1 protein, human; C000715570:Npm1 protein, mouse; D009687:Nuclear Proteins; D000090243:Nucleophosmin; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1