Studies with Insulin and Insulin-Like Growth Factor-I Show that the Increased Labeling of Phosphatidylinositol-3,4-Bisphosphate Is not Sufficient to Elicit the Diverse Actions of Epidermal Growth Factor on MA-10 Leydig Tumor Cells
| Autor: | Omar Pedro Pignataro, Mario Ascoli |
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| Rok vydání: | 1990 |
| Předmět: |
Male
medicine.medical_specialty Phosphatidylinositol 3 4-bisphosphate medicine.medical_treatment Biology Phosphatidylinositols Insulin-like growth factor chemistry.chemical_compound Endocrinology Phosphatidylinositol Phosphates Testicular Neoplasms Epidermal growth factor Internal medicine Tumor Cells Cultured medicine Animals Insulin Inositol Phosphatidylinositol Insulin-Like Growth Factor I Molecular Biology Epidermal Growth Factor Leydig cell General Medicine medicine.anatomical_structure chemistry Leydig Cell Tumor Transforming growth factor |
| Zdroj: | Molecular Endocrinology. 4:758-765 |
| ISSN: | 1944-9917 0888-8809 |
| Popis: | In a recent publication we showed that addition of mouse epidermal growth factor (mEGF) to MA-10 Leydig tumor cells rapidly leads to an increase in the incorporation of [3H]inositol-derived radioactivity into an unusual lipid that was identified as phosphatidylinositol-3,4-bisphosphate (PI-3,4-P2). Other ligands that are known to bind to MA-10 cells, such as hCG and arginine vasopressin, however, did not elicit this effect. Inasmuch as mEGF modulates the differentiated functions of MA-10 cells in a number of ways, our findings raised the possibility that PI-3,4-P2 may be an intracellular mediator of these actions of mEGF. In an attempt to answer this question, we set out to determine if other ligands increase the labeling of PI-3,4-P2 in MA-10 cells prelabeled with [3H]inositol, and if such ligands mimic the diverse biological actions of mEGF on these cells. The experiments presented herein show that insulin, insulin-like growth factor-I, and transforming growth factor-alpha increase the labeling of PI-3,4-P2 in MA-10 cells, but only transforming growth factor-alpha mimics the actions of mEGF on the differentiated functions of MA-10 cells. We conclude that an increase in the labeling of PI-3,4-P2 is not sufficient to elicit these actions of mEGF. |
| Databáze: | OpenAIRE |
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