Thyrotropin and cyclic AMP regulation of ras proto-oncogene expression in cultured thyroid cells.
We examined the effect of thyrotropin (TSH) on intracellular levels of c-ras mRNA in a line of differentiated rat thyroid cells obtained from normal Fischer rat thyroids. These cells are totally dependent on TSH for growth. TSH stimulation of quiescent cells increased c-ras mRNA content, with a maximal response (730% of basal) after 6 h, and a decline towards basal levels after 24 h. Dibutyryl cAMP and forskolin mimicked this stimulatory effect of TSH on c-ras, but did not enhance beta-actin mRNA content. This study demonstrates hormonal and cyclic nucleotide control of c-ras expression in a well-differentiated, non-tumorogenic mammalian cell.
D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000494:pharmacology*; D005786:Gene Expression Regulation; D011519:Proto-Oncogenes / Q000187:drug effects*; D051381:Rats; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013972:Thyrotropin / Q000494:pharmacology*
D013972:Thyrotropin; D000242:Cyclic AMP