Overexpression of ovine insulin-like growth factor-I stimulates autonomous autocrine or paracrine growth in bovine mammary-derived epithelial cells
| Autor: | Eric A. Wong, T B McFadden, P L Boyle, Donato F. Romagnolo, J. D. Turner, R. M. Akers |
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| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_specialty
Recombinant Fusion Proteins medicine.medical_treatment Biology Transfection Models Biological Dexamethasone Epithelium Paracrine signalling Mammary Glands Animal Endocrinology Internal medicine medicine Animals Insulin-Like Growth Factor I Protein Precursors Autocrine signalling Molecular Biology Cells Cultured Mammary tumor Sheep Growth factor General Medicine Somatomedin Stimulation Chemical Cell biology Cell culture Cattle Female Clone (B-cell biology) Cell Division |
| Zdroj: | Molecular Endocrinology. 6:1774-1780 |
| ISSN: | 1944-9917 0888-8809 |
| Popis: | To test the hypothesis that insulin-like growth factor-I (IGF-I) affects the growth of bovine mammary epithelial cells through an autocrine and/or paracrine pathway, a cell line (MD-IGF-I) was originated from MAC-T cells by cotransfection with a construct containing the cDNA for an ovine exon 2-encoded prepro-IGF-I under control of the mouse mammary tumor virus-long terminal repeat promoter. Clone MD-IGF-I contained multiple copies of the plasmid integrated into the genome, expressed the highest level of IGF-I mRNA, and secreted radioimmunoactive IGF-I into the medium. The mitogenic activity of MD-IGF-I cells was stimulated 80% by dexamethasone (DEX). The total DNA in MD-IGF-I cells was 2.5-fold higher than that in parental MAC-T cells in the presence of DEX. Conditioned medium from MD-IGF-I cells, induced with DEX, stimulated [3H]thymidine incorporation into DNA of MAC-T cells and uninduced MD-IGF-I cells. These data provide evidence that IGF-I was secreted into medium by MD-IGF-I cells. It is suggested that IGF-I can stimulate the growth of mammary epithelial cells by an autocrine and/or paracrine mode of action. The MD-IGF-I cell line may be a suitable system to study translational and posttranslational modifications of IGF-I peptides. |
| Databáze: | OpenAIRE |
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