title: Selective inhibition of STAT3 induces apoptosis and G(1) cell cycle arrest in ALK-positive anaplastic large cell lymphoma.
abstract: Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) is an aberrant fusion gene product expressed in a subset of cases of anaplastic large cell lymphoma (ALCL). It has been shown that NPM-ALK binds to and activates signal transducer and activator of transcription 3 (STAT3) in vitro, and that STAT3 is constitutively active in ALK(+) ALCL cell lines and tumors. In view of the oncogenic potential of STAT3, we further examined its biological significance in ALCL using two ALK(+) ALCL cell lines (Karpas 299 and SU-DHL-1) and an adenoviral vector that carries dominant-negative STAT3 (AdSTAT3DN). Infection by AdSTAT3DN led to the expression of STAT3DN in both ALK(+) ALCL cell lines at a similar efficiency. Subcellular fractionation studies showed that a significant proportion of the expressed STAT3DN protein translocated to the nucleus, despite the fact that STAT3DN has a mutation at residue 705(tyrosine --> phenylalanine), a site that is believed to be crucial for STAT3 activation and nuclear translocation. Introduction of STAT3DN induced apoptosis and G(1) cell cycle arrest. Western blot studies showed that expression of STAT3DN resulted in caspase-3 cleavage, downregulation of Bcl-2, Bcl-xL, cyclin D3, survivin, Mcl-1, c-Myc and suppressor of cytokine signaling 3. These results support the concept that STAT3 activation is pathogenetically important in ALCL cells by deregulating the expression of multiple target proteins that are involved in the control of apoptosis and cell cycle progression.
authors.affiliation: Department of Hematopathology, Box 72, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. hamin@mdanderson.org
authors.forename: Hesham M
authors.initials: HM
authors.lastname: Amin
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: McDonnell
authors.forename: Yupo
authors.initials: Y
authors.lastname: Ma
authors.forename: Quan
authors.initials: Q
authors.lastname: Lin
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Fujio
authors.forename: Keita
authors.initials: K
authors.lastname: Kunisada
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Leventaki
authors.forename: Pamela
authors.initials: P
authors.lastname: Das
authors.forename: George Z
authors.initials: GZ
authors.lastname: Rassidakis
authors.forename: Cathy
authors.initials: C
authors.lastname: Cutler
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.forename: Raymond
authors.initials: R
authors.lastname: Lai
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D016193:G1 Phase / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D050796:STAT3 Transcription Factor; D015534:Trans-Activators / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D014443:Tyrosine / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D014443:Tyrosine; C107023:p80(NPM-ALK) protein; D011505:Protein-Tyrosine Kinases