Translation of ODC mRNA and polyamine transport are suppressed in ras-transformed CREF cells by depleting translation initiation factor 4E

Jeremy R. Graff, Arrigo De Benedetti, Jack W. Olson, Pamela Tamez, Robert A Casero, Stephen G. Zimmer

Research output: Contribution to journalArticle

Abstract

Rapid tumor growth and metastasis require in. creased polyamine metabolism, which is coordinately regulated by ornithine decarboxylase (ODC) and the polyamine transporter. Both activities are stimulated by ras signalling and are dependent upon protein biosynthesis. T24(ras) oncogene expression in rat embryo fibroblasts (CREFT24) induces cellular transformation and malignancy, in part, by stimulating the rate-limiting translation initiation factor, eIF-4E. CREFT24 expressing antisense RNA to eIF-4E (AS4E) have markedly decreased tumor growth rates and metastatic capacity, without altered monolayer growth rates. Herein, we demonstrate that in AS4E, ODC is translationally suppressed resulting in decreased ODC activity. Additionally, exogenous polyamine uptake is suppressed in AS4E cells indicating that AS4E can neither generate nor import the polyamines necessary to support rapid tumor growth. These data provide evidence that eIF-4E is the link between ras-induced malignancy and increased polyamine metabolism and support the hypothesis that eIF-4E plays a pivotal role in mediating ras-induced malignancy.

Original languageEnglish (US)
Pages (from-to)15-20
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume240
Issue number1
DOIs
Publication statusPublished - Nov 7 1997

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ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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