Altered response to growth factors in rat epithelial liver cells overexpressing human c-Fos protein.
Human c-fos cDNA was transfected into normal rat liver epithelial (REL) cells to identify cellular modifications associated with high expression of c-Fos protein. Responses to EGF and TGF beta were examined in the different cell lines, under anchorage-dependent and -independent conditions. Sensitivity to both factors was modified in transfected cells. While parental cells in monolayer did not respond to EGF, c-fos containing cells growth was stimulated by this factor. Overexpression of c-Fos protein led to an enhanced TGF beta-induced growth inhibition under anchorage dependent conditions, and TGF beta abolished spontaneous growth in soft agar of the cell lines containing c-fos oncogene. The mechanisms underlying the increased sensitivity to TGF beta in c-fos transfected cells are still to be determined.
Lagarrigue
S
S
Laboratoire de Nutrition et de Sécurité Alimentaire, INRA, Jouy en Josas, France.
Seillan-Heberden
C
C
Martel
P
P
Gaillard-Sanchez
I
I
D000818:Animals; D015139:Blotting, Southern; D002455:Cell Division; D002460:Cell Line; D004815:Epidermal Growth Factor / Q000502:physiology*; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000502:physiology*; D051381:Rats; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000502:physiology*
D016760:Proto-Oncogene Proteins c-fos; D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor