Stimulation of calcitonin/CGRP-I and CGRP-II gene expression by dibutyryl cAMP in a human medullary thyroid carcinoma (TT) cell line.
In a human medullary thyroid carcinoma (TT) cell line, expression of the calcitonin (CT)/CT gene-related peptide (CGRP-I) gene (CALC-I or alpha) at the level of mRNA and of encoded peptides is higher than that of the closely related CGRP-II gene (CALC-II or beta). In response to 1 mM dibutyryl cAMP ((Bu)2cAMP), mature CGRP-II mRNA and intact cellular CGRP-II were raised 65- and 10-fold, respectively, at 72 h. Also at 72 h, 1 mM sodium butyrate enhanced CGRP-II mRNA only 9-fold and cellular CGRP-II 2-fold; stimulation of CGRP-I and CT mRNA and of cellular CGRP-I and CT by both (Bu)2cAMP and sodium butyrate was similarly low. During the same incubation time period secreted CGRP-II was raised 44-fold in response to (Bu)2cAMP, and CGRP-I and CT 8- and 42-fold, respectively. In conclusion, gene products of CALC-I (CGRP-I and CT) are present in higher amounts in TT cells than those of CALC-II (CGRP II). Yet (Bu)2cAMP predominantly stimulates the expression of CALC-II.
Laboratory for Physiological Chemistry, University of Utrecht, Netherlands.
J C
JC
Wind
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W
Born
A
A
Rijnsent
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Boer
J A
JA
Fischer
D003994:Bucladesine / Q000494:pharmacology*; D002087:Butyrates / Q000494:pharmacology; D020148:Butyric Acid; D002116:Calcitonin / Q000096:biosynthesis* / Q000235:genetics; D015740:Calcitonin Gene-Related Peptide / Q000096:biosynthesis* / Q000235:genetics; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D003609:Dactinomycin / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D013268:Stimulation, Chemical; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured / Q000187:drug effects
D002087:Butyrates; D009363:Neoplasm Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D020148:Butyric Acid; D003609:Dactinomycin; D003994:Bucladesine; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide