Our data show that in hamster fibroblasts transformed by Rous sarcoma virus (RSV), the phosphoinositide 3'-kinase (PI-3K)/Akt/glycogen synthase kinase 3 antiapoptotic pathway is upregulated and involved in increased protein synthesis through activation of initiation factor eIF2B. Upon inhibition of PI-3K by wortmannin, phosphorylation of 70-kDa ribosomal protein S6 kinase (p70 S6k) and its physiological substrate, ribosomal protein S6, decreased in the non-transformed cells but not in RSV-transformed cells. Thus PI-3K, which is thought to be involved in regulation of p70 S6k, signals to p70 S6k in normal fibroblasts, but it does not appear to be an upstream effector of p70 S6k in fibroblasts transformed by v-src oncogene, suggesting that changes in the PI-3K signalling pathway upstream of p70 S6k are induced by RSV transformation.
- MeSH
- Enzyme Activation MeSH
- Androstadienes pharmacology MeSH
- Cell Line MeSH
- Eukaryotic Initiation Factor-2B physiology MeSH
- Phosphatidylinositol 3-Kinases metabolism MeSH
- Enzyme Inhibitors pharmacology MeSH
- Phosphoinositide-3 Kinase Inhibitors MeSH
- Glycogen Synthase Kinase 3 metabolism MeSH
- Ribosomal Protein S6 Kinases, 70-kDa physiology MeSH
- Cricetinae MeSH
- Oncogene Protein pp60(v-src) genetics MeSH
- Protein Serine-Threonine Kinases * MeSH
- Proto-Oncogene Proteins c-akt MeSH
- Proto-Oncogene Proteins metabolism MeSH
- Signal Transduction * MeSH
- Cell Line, Transformed MeSH
- Cell Transformation, Viral MeSH
- Avian Sarcoma Viruses genetics pathogenicity MeSH
- Wortmannin MeSH
- Animals MeSH
- Check Tag
- Cricetinae MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Androstadienes MeSH
- Eukaryotic Initiation Factor-2B MeSH
- Enzyme Inhibitors MeSH
- Phosphoinositide-3 Kinase Inhibitors MeSH
- Glycogen Synthase Kinase 3 MeSH
- Ribosomal Protein S6 Kinases, 70-kDa MeSH
- Oncogene Protein pp60(v-src) MeSH
- Protein Serine-Threonine Kinases * MeSH
- Proto-Oncogene Proteins c-akt MeSH
- Proto-Oncogene Proteins MeSH
- Wortmannin MeSH
