Epidermal growth factor receptor induced apoptosis: potentiation by inhibition of Ras signaling.
Previous studies have shown that certain tumor cell lines which naturally express high levels of the epidermal growth factor receptor (EGFR) undergo apoptosis when exposed to epidermal growth factor. Whether this phenomenon is a direct result of receptor overexpression or some other genetic alteration renders these cells sensitive to apoptosis is yet to be established. We show that experimentally increasing the level of EGFR expression predictably leads to apoptosis in a variety of cell types which requires an active tyrosine kinase but not EGFR autophosphorylation sites. Expression of a dominant negative Ras mutant in EGFR overexpressing cells results in a significant potentiation of EGFR induced apoptosis suggesting that Ras activation is a key survival signal generated by the EGFR. We propose that potentiation of EGFR induced apoptosis by dominant negative Ras results, at least in part, by a block of Akt activation.
Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Boston, MA 02115, USA.
T
T
Högnason
S
S
Chatterjee
T
T
Vartanian
R R
RR
Ratan
K M
KM
Ernewein
A A
AA
Habib
D017209:Apoptosis; D015153:Blotting, Western; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D005799:Genes, Dominant; D006801:Humans; D009154:Mutation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D011518:Proto-Oncogene Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)