Forskolin and a tumor promoter are able to induce c-fos and c-myc expression in normal, but not in a v-ras-transformed rat thyroid cell line.
The rat thyroid cell line (FRTL5) is dependent on thyrotropic hormone (TSH) for its growth. c-fos and c-myc oncogenes expression was measured in these cells after addition of their specific growth factor TSH and after treatment with either forskolin, an activator of adenylate cyclase or with a tumor promoter, TPA. Transient expression of oncogenes coding for nuclear products and a slight increase in ras-h oncogene expression were observed in normal rat thyroid cells after all treatments. In contrast, in v-ras-transformed rat thyroid cells, which express very high levels of p21, treatment with either TSH, forskolin or TPA does not induce c-fos gene expression, while c-myc expression was constitutive. Normal unstimulated cells show no c-myc expression.
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Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università degli Studi di Napoli, Italy.
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D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral; D005576:Colforsin / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D005786:Gene Expression Regulation; D011905:Genes, ras; D009857:Oncogenes; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013954:Thyroglobulin / Q000235:genetics; D013961:Thyroid Gland / Q000502:physiology*; D013972:Thyrotropin / Q000494:pharmacology
D011518:Proto-Oncogene Proteins; D005576:Colforsin; D013972:Thyrotropin; D004247:DNA; D013954:Thyroglobulin; D013755:Tetradecanoylphorbol Acetate