Elevation of the thyroid hormone receptor erb A-alpha 2 mRNA in transformed rodent cells is due to increased message stability.
Previously, the authors reported an elevation of erb A-alpha 2 mRNAs in transformed rodent cells when compared with their non-transformed counterparts (Cancer Res., 52(1992) 2186-2190). To investigate this phenomenon further the rates of gene transcription and the effects of translation/transcription inhibition on erb A-alpha 2 mRNA expression were examined. The present study found no difference between non-transformed and transformed cells in erb A-alpha 2 gene transcription rate, nor an effect of cycloheximide on erb A-alpha 2 mRNA expression. However, a significant difference was obtained with actinomycin D. With this inhibitor, the half-life of erb A-alpha 2 mRNAs in nontransformed rodent cells was determined to be approximately 8 h. In contrast, the alpha 2 transcripts in their transformed counterparts showed no decay during this period, suggesting that the elevation of erb A-alpha 2 mRNAs in transformed rodent cells was due to increased transcript stability.
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Department of Pathology, Faculty of Medicine, Dalhousie University, Halilax, Nova Scotia, Canada.
Guernsey
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D000818:Animals; D015152:Blotting, Northern; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic; D002999:Clone Cells; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008809:Mice, Inbred C3H; D018774:Oncogene Proteins v-erbA; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000302:isolation & purification; D051381:Rats; D011916:Rats, Inbred F344; D011988:Receptors, Thyroid Hormone / Q000235:genetics / Q000378:metabolism; D015682:Retroviridae Proteins, Oncogenic / Q000096:biosynthesis* / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D014158:Transcription, Genetic
D018774:Oncogene Proteins v-erbA; D012333:RNA, Messenger; D011988:Receptors, Thyroid Hormone; D015682:Retroviridae Proteins, Oncogenic; D014157:Transcription Factors; D003609:Dactinomycin; D003513:Cycloheximide