Enhancement of c-erbA proto-oncogene expression by glucocorticoid hormones in S49.1 lymphoma cells.
The modifications of the mRNA levels of the c-myc and c-erbA proto-oncogenes during the dexamethasone-induced decrease of S49.1 cell proliferation have been studied. The levels of c-myc mRNA decreased significantly between 3 and 18 h after dexamethasone (1 microM) treatment. In contrast, a significant increase in the levels of a 2.6 kb c-erbA mRNA was observed between 6 and 18 h after hormone treatment. Cycloheximide treatment of S49.1 cells increased the levels of c-erbA RNA and overcome the enhancing effect of dexamethasone on the expression of this proto-oncogene, suggesting that ongoing protein synthesis is necessary to elicit this hormone effect. The associated decrease of cell proliferation and changes in c-myc and c-erbA mRNA levels after dexamethasone treatment suggest that such oncogenes might be involved in the dexamethasone-mediated control of lymphoid cell growth.
Maroder
M
M
Department of Experimental Medicine, University La Sapienza, Rome, Italy.
Vacca
A
A
Screpanti
I
I
Petrangeli
E
E
Frati
L
L
Gulino
A
A
D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D007700:Kinetics; D051379:Mice; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000235:genetics; D011988:Receptors, Thyroid Hormone / Q000235:genetics; D014407:Tumor Cells, Cultured
D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D011988:Receptors, Thyroid Hormone; D003907:Dexamethasone; D003513:Cycloheximide