Back to Search
Start Over
Dexamethasone differentially affects the levels of calcitonin and calcitonin gene-related peptide mRNAs expressed in a human medullary thyroid carcinoma cell line
- Source :
- Journal of Biological Chemistry. 261:15524-15528
- Publication Year :
- 1986
- Publisher :
- Elsevier BV, 1986.
-
Abstract
- The TT cells are a continuous line of human C-cells derived from a medullary thyroid carcinoma. These cells produce large quantities of calcitonin and calcitonin gene-related peptide (CGRP) by the differential splicing of a single calcitonin gene transcript. We have used specific cDNA probes for calcitonin and CGRP to study the regulation of the calcitonin gene by dexamethasone, a synthetic glucocorticoid. Northern blot analysis of total cellular RNA isolated from the TT cells showed hybridization of the calcitonin probe to 3600- and 1000-base RNA species. The CGRP probe hybridized to 3600- and 1050-base RNA species. Dexamethasone treatment (10(-9) to 10(-5) M) of TT cells (for 6 days) caused a dosage-dependent increase in calcitonin mRNA levels and a decrease in CGRP mRNA levels. These findings were confirmed in time course studies where dexamethasone treatment (10(-6) M) caused a 2-13-fold increase in calcitonin mRNA and a 40-60% decrease in CGRP mRNA between 4 and 6 days of treatment; the effect was reversible after dexamethasone withdrawal. After excluding an effect of dexamethasone on calcitonin and CGRP mRNA stability, we have concluded that dexamethasone affects the splicing mechanism to favor production of calcitonin mRNA over CGRP mRNA.
- Subjects :
- medicine.medical_specialty
Messenger RNA
Thyroid
Cell Biology
Calcitonin gene-related peptide
Biology
Peptide hormone
Biochemistry
medicine.anatomical_structure
Endocrinology
Calcitonin
Internal medicine
Gene expression
medicine
Northern blot
Molecular Biology
hormones, hormone substitutes, and hormone antagonists
Dexamethasone
medicine.drug
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 261
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi...........33a7730037040537eb330ae24bf370b9