Related Experiment Video

Updated: Jul 17, 2026

In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice
07:02

In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice

Published on: August 23, 2019

Reciprocal negative regulation between thyrotropin/3',5'-cyclic adenosine monophosphate-mediated proliferation and

Maria José Costa1, Maximin Senou, Fabienne Van Rode

  • 1Institut de Recherche Interdisciplinaire, Campus Erasme, Université Libre de Bruxelles, 808 Route de Lennik, Building C, 1070 Brussels, Belgium.

Molecular Endocrinology (Baltimore, Md.)
|January 5, 2007
PubMed

Insights

Thyroid adenoma involves reduced caveolins. Chronic TSH/cAMP stimulation in thyrocytes down-regulates caveolin-1 expression at the mRNA level, impacting cell proliferation and linking to disease.

Area of Science:

  • Endocrinology
  • Molecular Biology
  • Oncology

Background:

  • Caveolins are down-regulated in human thyroid autonomous adenomas.
  • The specific cell type and mechanism responsible for this down-regulation in thyrocytes remained unclear.
  • Understanding this process is crucial for comprehending thyroid tumor development.

Purpose of the Study:

  • To investigate whether thyrocytes exhibit caveolin down-regulation.
  • To elucidate the molecular mechanisms and functional significance of caveolin down-regulation in the context of thyroid tumors.
  • To determine the role of the TSH/cAMP pathway in regulating caveolin expression.

Main Methods:

  • Prolonged stimulation of isolated human thyrocytes with TSH/cAMP/cAMP-dependent protein kinase.
  • Analysis of caveolin expression at both mRNA and protein levels.
  • Investigation of mRNA stability and translation processes.
  • Assessment of thyrocyte proliferation in caveolin-1 knockout mice.

Main Results:

  • Prolonged TSH/cAMP stimulation specifically inhibits caveolin expression in human thyrocytes.
  • Down-regulation of caveolin-1 occurs at the mRNA level, leading to decreased protein levels.
  • TSH/cAMP induces transcription-dependent, translation-independent destabilization of caveolin-1 mRNA.
  • Caveolin-1 knockout mouse thyrocytes exhibit enhanced proliferation in vivo.

Conclusions:

  • Down-regulation of caveolin expression in autonomous adenomas is a direct consequence of chronic TSH/cAMP pathway activation in thyrocytes.
  • The TSH/cAMP pathway regulates caveolin-1 expression by destabilizing its mRNA.
  • Reduced caveolin-1 expression contributes to thyrocyte proliferation, highlighting its role in thyroid tumorigenesis.

More Related Videos

An Ex vivo Culture System to Study Thyroid Development08:33

An Ex vivo Culture System to Study Thyroid Development

Published on: June 6, 2014

Related Concept Videos

Synthesis and Regulation of Thyroid Hormones01:20

Synthesis and Regulation of Thyroid Hormones

Low blood levels of the thyroid hormones — triiodothyronine (T3) and thyroxine (T4) — signal the hypothalamus to release the thyrotropin-releasing hormone (TRH). TRH then reaches the pituitary gland and stimulates the release of thyroid-stimulating hormone(TSH) into the bloodstream.
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
Functions of Thyroid Hormones01:18

Functions of Thyroid Hormones

The thyroid hormone (TH) plays a pivotal role in the intricate orchestration of physiological processes, exerting profound effects on development, metabolism, and homeostasis throughout different life stages.
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
Hormones and Bone Tissue01:17

Hormones and Bone Tissue

The endocrine system produces and secretes hormones, which interact with the skeletal system. These hormones control bone growth, maintain bone once it is formed, and remodel it.
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...