scholarly journals Role of thyroglobulin on negative feedback autoregulation of thyroid follicular function and growth

2011 ◽  
Vol 209 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Koichi Suzuki ◽  
Akira Kawashima ◽  
Aya Yoshihara ◽  
Takeshi Akama ◽  
Mariko Sue ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Growth ◽  
Thyroid Function ◽  
Negative Feedback ◽  
Specific Gene ◽  
Thyroid Cell ◽  
Follicular Cells ◽  
Thyroid Follicular Cells ◽  
Feedback Regulator

Thyroid function is tightly regulated by TSH. Although individual follicles are exposed to the same blood supply of TSH and express relatively homogenous levels of the TSH receptor, the function of individual follicles is variable. It was shown that thyroglobulin (Tg), stored in the follicular lumen, is a potent negative feedback regulator of follicular function. Thus, physiological concentrations of Tg significantly suppress thyroid-specific gene expression and antagonize the TSH-mediated stimulation that induces expression of thyroid-specific genes. Tg coordinately regulates both basal and apical iodide transporters in thyroid follicular cells. Recently, it was also reported that Tg could induce thyroid cell growth in the absence of TSH. These results indicate that Tg is an essential autocrine regulator of physiological thyroid follicular function that counteracts the effects of TSH.

scholarly journals Thyroglobulin Suppresses Thyroid-Specific Gene Expression in Cultures of Normal But Not Neoplastic Human Thyroid Follicular Cells

2014 ◽  
Vol 99 (4) ◽  
pp. E694-E702 ◽  
Author(s):  
Yuko Ishido ◽  
Kazuko Yamazaki ◽  
Makoto Kammori ◽  
Yoshiyuki Sugishita ◽  
Yuqian Luo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Thyroid ◽  
Specific Gene ◽  
Follicular Cells ◽  
Specific Gene Expression ◽  
Thyroid Follicular Cells

scholarly journals Role of Estrogen in Thyroid Function and Growth Regulation

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Ana Paula Santin ◽  
Tania Weber Furlanetto
Keyword(s):  
Thyroid Function ◽  
Growth Regulation ◽  
Thyroid Tissue ◽  
Thyroid Diseases ◽  
Follicular Cells ◽  
Direct Role ◽  
Thyroid Cells ◽  
Thyroid Follicular Cells ◽  
And Function

Thyroid diseases are more prevalent in women, particularly between puberty and menopause. It is wellknown that estrogen (E) has indirect effects on the thyroid economy. Direct effects of this steroid hormone on thyroid cells have been described more recently; so, the aim of the present paper was to review the evidences of these effects on thyroid function and growth regulation, and its mechanisms. The expression and ratios of the two E receptors,αandβ, that mediate the genomic effects of E on normal and abnormal thyroid tissue were also reviewed, as well as nongenomic, distinct molecular pathways. Several evidences support the hypothesis that E has a direct role in thyroid follicular cells; understanding its influence on the growth and function of the thyroid in normal and abnormal conditions can potentially provide new targets for the treatment of thyroid diseases.

Inhibitory effect of dihydrotestosterone on human thyroid cell growth

1996 ◽  
Vol 151 (2) ◽  
pp. 185-194 ◽  
Author(s):  
R Rossi ◽  
M C Zatelli ◽  
P Franceschetti ◽  
I Maestri ◽  
E Magri ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Primary Cultures ◽  
Inhibitory Effect ◽  
Human Thyroid ◽  
Growth Fraction ◽  
Thyroid Cell ◽  
Mrna Levels ◽  
Follicular Cells ◽  
Thyroid Follicular Cells

Abstract Sex steroid-binding activities have been identified by several authors in normal and pathological thyroids and the expression of the canonic androgen receptor (AR) has recently been demonstrated in human thyroid follicular cells. In order to assess what influence, if any, androgen exposure has on thyroid cell growth, the effect of dihydrotestosterone (DHT) on [3H]thymidine (thy) incorporation and cell proliferation was investigated in thyroid follicular cells in vitro. In a primary culture of goitrous cells, DHT induced a significant reduction of [3H]thy incorporation at concentrations ranging from 10−12 to 10−8 m, with a more pronounced effect at 10−9 m. At this concentration, the inhibitory effect was evident after both 24 and 48 h of treatment and in various types of primary thyroid cell cultures. In goitrous cells, the DHT-induced decrease of [3H]thy was associated with a reduction of expression of the proliferation-associated nuclear Ki-67 antigen, a protein commonly used to assess cell growth fraction. In TPC cells, an AR-positive thyroid papillary carcinoma cell line, DHT at concentrations between 10−12 and 10−8 m significantly decreased the growth rate. DHT (10−9 m) produced an approximately 50–60% inhibition of cell proliferation and the antiandrogen cyproterone acetate was capable of reversing such effects. The DHT-induced reduction of TPC cell proliferation was associated with a significant reduction of c-myc RNA levels. Thyroperoxidase mRNA levels and thyroglobulin production were not reduced by androgen in primary cultures of goitrous cells. In conclusion, our results indicated that androgens may have a role in this gland by reducing the proliferation, but not the function, of follicular cells. Journal of Endocrinology (1996) 151, 185–194

scholarly journals Role of cyclic AMP in the control of cell-specific gene expression

1993 ◽  
Vol 4 (6) ◽  
pp. 204-209 ◽  
Author(s):  
Wolfgang Schmid ◽  
Doris Nitsch ◽  
Michael Boshart ◽  
Günther Schütz
Keyword(s):  
Gene Expression ◽  
Cyclic Amp ◽  
Specific Gene ◽  
Specific Gene Expression

scholarly journals Notch Signaling Is Involved in Expression of Thyrocyte Differentiation Markers and Is Down-Regulated in Thyroid Tumors

2008 ◽  
Vol 93 (10) ◽  
pp. 4080-4087 ◽  
Author(s):  
E. Ferretti ◽  
E. Tosi ◽  
A. Po ◽  
A. Scipioni ◽  
R. Morisi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thyroid Cancer ◽  
Notch Signaling ◽  
Notch Pathway ◽  
Human Thyroid ◽  
Thyroid Tumors ◽  
Follicular Cells ◽  
Differentiation Markers ◽  
Thyroid Follicular Cells ◽  
Thyroid Cancer Cells

Context: Notch genes encode receptors for a signaling pathway that regulates cell growth and differentiation in various contexts, but the role of Notch signaling in thyroid follicular cells has never been fully published. Objective: The objective of the study was to characterize the expression of Notch pathway components in thyroid follicular cells and Notch signaling activities in normal and transformed thyrocytes. Design/Setting and Patients: Expression of Notch pathway components and key markers of thyrocyte differentiation was analyzed in murine and human thyroid tissues (normal and tumoral) by quantitative RT-PCR and immunohistochemistry. The effects of Notch overexpression in human thyroid cancer cells and FTRL-5 cells were explored with analysis of gene expression, proliferation assays, and experiments involving transfection of a luciferase reporter construct containing human NIS promoter regions. Results: Notch receptors are expressed during the development of murine thyrocytes, and their expression levels parallel those of thyroid differentiation markers. Notch signaling characterized also normal adult thyrocytes and is regulated by TSH. Notch pathway components are variably expressed in human normal thyroid tissue and thyroid tumors, but expression levels are clearly reduced in undifferentiated tumors. Overexpression of Notch-1 in thyroid cancer cells restores differentiation, reduces cell growth rates, and stimulates NIS expression via a direct action on the NIS promoter. Conclusion: Notch signaling is involved in the determination of thyroid cell fate and is a direct regulator of thyroid-specific gene expression. Its deregulation may contribute to the loss of differentiation associated with thyroid tumorigenesis.

scholarly journals Oestrogen receptors and antioestrogen treatment of hormone-dependent tumours

2018 ◽  
Vol 49 (2) ◽  
pp. 91
Author(s):  
N. G. KOSTOMITSOPOULOS (Ν.Γ. ΚΩΣΤΟΜΗΤΣΟΠΟΥΛΟΣ)
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Dna Sequences ◽  
Human Breast Cancer ◽  
Oestrogen Receptor ◽  
Specific Gene ◽  
Oestrogen Receptors ◽  
Human Breast ◽  
Potential Use

The oestrogen receptor is a ligand-activated transcription factor that modulates specific gene expression by binding to short DNA sequences. The study of the role of oestrogen receptor on the expression of the mitogenic actionof oestrogens and oncogenesis lead biomedical research in new approaches of the treatment of oestrogen-dependent tumors by using antioestrogens. Main mechanism of action of antioestrogens is the prevention of oestrogen action by blocking the binding of oestradiol to the oestrogen receptor. Tamoxifen, the most wellknown antioestrogen, is widely used as adjuvant therapy in all stages of human breast cancer. Recently interest is focused on the potential use of "pure" antioestrogens. The use of antioestrogens in veterinary oncology is also under discussion.

scholarly journals Tunable stiffness of graphene oxide/polyacrylamide composite scaffolds regulates cytoskeleton assembly

2018 ◽  
Vol 9 (31) ◽  
pp. 6516-6522 ◽  
Author(s):  
Yupeng Sun ◽  
Kaixiang Zhang ◽  
Ruijie Deng ◽  
Xiaojun Ren ◽  
Can Wu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Extracellular Matrix ◽  
Graphene Oxide ◽  
Cell Growth ◽  
Specific Gene ◽  
Composite Scaffolds ◽  
Specific Gene Expression ◽  
Tunable Stiffness

Graphene oxide/polyacrylamide composite scaffolds with tunable stiffness are designed and fabricated to investigate the effect of extracellular matrix (ECM) stiffness on cytoskeleton assembly and specific gene expression during cell growth.

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