Expression of insulin-like growth factor I (IGF-I) gene and of genes for IGF-binding proteins 1, 2, 3, 4 (IGFBP-1-IGFBP-4) in non-neoplastic human thyroid cells and in certain human thyroid cancers. Effect of exogenous IGF-I on this expression.
OBJECTIVE
The aim of this study was to examine the expression of the IGF-I gene and of genes for IGFBP-1, -2, -3, and -4 in cells from nodular goiters (NG), and from different human thyroid carcinomas (papillary--PTC, anaplastic--ATC, and medullary--MTC), cultured in monolayers. The influence, exerted by exogenous IGF-I on the expression of these genes, was also investigated.


METHODS
Thyroid tissue specimens were obtained from 65 patients during subtotal or total thyroidectomies. After approximately 2-3 weeks of culture, thyroid cells were incubated for 24 hours with IGF-I in concentrations of: 0, 1, 10 and 100 ng/ml. The total mRNA was isolated according to the method described by Chomczyński and Sacchi with our own modifications. Afterwards, mRNA encoding IGF-I, IGFBP-1-IGFBP-4 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), were amplified, using the reverse transcription-polymerase chain reaction (RT-PCR); GAPDH gene served as a control gene. PCR products were electrophoresed and then submitted to densitometric analysis.


CONCLUSIONS
Our study has shown that in carcinoma cells (ATC, PTC, MTC), IGF-I reveals a stimulatory influence on the expression of its own gene, that effect being most distinctive in ATC cells. These facts indicate an important role of IGF-I in the pathogenesis and invasiveness of the analyzed malignant neoplasms.
Lewiński
Andrzej
A
Department of Thyroidology, Institute of Endocrinology, Medical University of Lodź, Lodź, Poland. alewin@csk.am.lodz.pl
Marcinkowska
Magdalena
M
Brzeziańska
Ewa
E
Jeziorowska
Anna
A
Włoch
Jan
J
Brzeziński
Jan
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000096:biosynthesis* / Q000235:genetics; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis* / Q000235:genetics; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000096:biosynthesis* / Q000235:genetics; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000096:biosynthesis* / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D018974:Insulin-Like Growth Factor Binding Protein 4; D007334:Insulin-Like Growth Factor I