Induction of c-fos/c-myc expression by epidermal growth factor decreases with alteration of their gene binding proteins in senescent fibroblasts.
OBJECTIVE
To observe the changes of proto-oncogene c-fos/c-myc expression and its relation to specific transcription factors in human senescent fibroblast after epidermal growth factor (EGF) addition.


METHODS
The c-fos/c-myc expression were analysed by Northern blot. Transcription factors were analysed by Southwestern blot.


RESULTS
(1) The expression of c-fos/c-myc was less susceptible to induction by EGF as the cells aged. (2) EGF increased the binding of protein P91 to c-fos with regulatory sequence and P80 to c-myc with regulatory sequence, but the increased levels of both proteins were significantly reduced in senescent cells.


CONCLUSIONS
Inability of c-fos/c-myc gene induction by EGF in senescent cells might be correlated with some DNA-binding proteins.
Mao
Z
Z
Department of Biochemistry and Molecular Biology, Beijing Medical University, China.
Zhang
Z
Z
Tong
T
T
D016922:Cellular Senescence / Q000235:genetics; D004268:DNA-Binding Proteins / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000502:physiology*; D005260:Female; D005333:Fetus; D005347:Fibroblasts / Q000166:cytology*; D016762:Genes, fos; D016259:Genes, myc; D006801:Humans; D000090063:Proto-Oncogene Mas; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis*; D018808:Transcription Factor AP-1 / Q000502:physiology
D004268:DNA-Binding Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D018808:Transcription Factor AP-1; D004815:Epidermal Growth Factor