The activated anaplastic lymphoma kinase increases cellular proliferation and oncogene up-regulation in rat 1a fibroblasts.
More than 60% of anaplastic large-cell lymphomas (Ki-1 lymphoma) are associated with a t(2;5)(p23;q35) translocation that produces an 80 kDa hyperphosphorylated chimeric protein (p80) derived from the fusion of the anaplastic lymphoma kinase (ALK) with nucleophosmin (NPM). The NPM-ALK chimeric gene is an activated tyrosine kinase that has been shown to be a potent oncogene. We have developed a cellular model for the study of p80 action in rat 1a fibroblasts. Expression of cDNA's encoding NPM-ALK (p80) in rat 1a fibroblasts induces anchorage-independent growth in soft agar and promotes foci formation in culture. Cells expressing exogenous p80 showed significantly increased proliferation characterized by accelerated cell cycle entry into S-phase. Consistent with increased G0/G1 to S-phase transition, there is also marked up-regulation of cyclin A and cyclin D1 expression. In addition, p80 transformed cells showed elevated expression of several immediate early genes involved in cellular proliferation, including fos, jun, and c-myc. DNA binding analysis of nuclear extracts prepared from p80 transformed cells reveal marked up-regulation of AP-1 DNA binding activity. Functional AP-1-specific transfection assays also show up-regulation of AP-1-dependent transcriptional activation. These finding demonstrate that p80 transformed rat 1a fibroblast can be a highly useful model system for the molecular and biochemical characterization of the mechanisms of action of this interesting new oncogene.
Wellmann
A
A
Laboratory of Pathology, National Institutes of Health, Bethesda, Maryland 20892-1500, USA.
Doseeva
V
V
Butscher
W
W
Raffeld
M
M
Fukushima
P
P
Stetler-Stevenson
M
M
Gardner
K
K
D000077548:Anaplastic Lymphoma Kinase; D000818:Animals; D019677:Artificial Gene Fusion; D002455:Cell Division; D002460:Cell Line; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic; D002889:Chromosomes, Human, Pair 2; D002895:Chromosomes, Human, Pair 5; D005347:Fibroblasts; D016762:Genes, fos; D016758:Genes, jun; D016259:Genes, myc; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics; D000090243:Nucleophosmin; D009857:Oncogenes; D016366:Open Reading Frames; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured
C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D018808:Transcription Factor AP-1; D000090243:Nucleophosmin; C000626173:ALK protein, human; C000626175:Alk protein, rat; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases