Effect of growth factors on the expression of proto-oncogenes c-fos and c-myc in FRTL-5 cell line.
This study was performed to prove the hypothesis that oncogene expressions would have the same patterns with those of cellular growth to growth factors in FRTL-5 cells. Ribonucleic acids of FRTL-5 were extracted at 15', 30', 60' and 120' after administration of growth factors to quiescent FRTL-5, and blotted to the nitrocellulose membrane. They were hybridized with radiolabelled c-fos, c-myc and beta-actin probes. Hybridized dot blots were autoradiographed and the amount of radioactivity was measured by densitometry. Densitometric readings were used as the indices of oncogene expressions. Expressions of c-fos and c-myc were more prominent in combined administrations of TSH (10 mU/ml) and IGF-I (100 ng/ml) or IgG of Graves' disease (Graves' IgG; 1 mg/ml) and IGF-I than in combined administration of TSH and Graves' IgG. IgG of primary myxedema suppressed oncogene expressions by TSH or Graves' IgG, but not by IGF-I. From the above results, it was suggested that expressions of c-fos and c-myc to growth factors would have similar patterns with those of cell growth to growth factors in FRTL-5, and the actions of TSH and Graves' IgG would be manifested through same signal transduction system, but IGF-I would be manifested by its own.
Department of Surgery and Internal Medicine, Seoul National University College of Medicine, Korea.
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Yoo
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Oh
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Yi
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Cho
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Koh
D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D002460:Cell Line / Q000166:cytology / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D006111:Graves Disease / Q000276:immunology; D006133:Growth Substances / Q000235:genetics / Q000494:pharmacology*; D007074:Immunoglobulin G / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D009230:Myxedema / Q000276:immunology; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D012313:RNA / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D013961:Thyroid Gland / Q000166:cytology; D013972:Thyrotropin / Q000494:pharmacology; D013997:Time Factors
D006133:Growth Substances; D007074:Immunoglobulin G; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D012313:RNA; D007334:Insulin-Like Growth Factor I; D013972:Thyrotropin