Functional analysis of the EWS/ETS target gene uridine phosphorylase.
The EWS/ETS fusion proteins associated with Ewings family tumors (EFTs) are thought to promote oncogenesis by acting as aberrant transcription factors. Uridine phosphorylase is a gene that is up-regulated by structurally distinct EWS/ETS fusions. Ectopic expression of uridine phosphorylase was able to support anchorage-independent cell growth, indicating that it plays an active role in the oncogenic process. Transcriptional up-regulation of uridine phosphorylase is shown to be mediated in a DNA binding-dependent manner, and reporter gene assays demonstrated that EWS/FLI1 and RAS mediate activation through a single activator protein 1/ETS site located in the uridine phosphorylase promoter. Chromatin immunoprecipitation assays reveal that EWS/FLI1 directly associates with the uridine phosphorylase promoter in vivo. Up-regulation of uridine phosphorylase by EWS/FLI1 sensitizes cells to growth inhibition by the pyrimidine analogue, 5'-deoxy-5'fluorouridine, both in tissue culture and in vivo model systems.
Deneen
Benjamin
B
Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90024, USA.
Hamidi
Habib
H
Denny
Christopher T
CT
D016475:3T3 Cells; D000818:Animals; D004247:DNA / Q000378:metabolism; D005467:Floxuridine / Q000494:pharmacology; D006801:Humans; D051379:Mice; D015514:Oncogene Proteins, Fusion / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D050783:Proto-Oncogene Proteins c-ets; D034802:RNA-Binding Protein EWS / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection; D015854:Up-Regulation; D014543:Uridine Phosphorylase / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D018631:ras Proteins / Q000502:physiology
C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D034802:RNA-Binding Protein EWS; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D005467:Floxuridine; D004247:DNA; D014543:Uridine Phosphorylase; D018631:ras Proteins; C025034:doxifluridine