Conditioned medium from ras oncogene-transformed nih 3T3 cells induces bone resorption in vitro
| Autor: | Nancy S. Krieger, Vikas P. Sukhatme, David A. Bushinsky |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
medicine.medical_specialty
Osteolysis Cathepsin L Endocrinology Diabetes and Metabolism chemistry.chemical_element Calcium Biology 3T3 cells Bone resorption Mice Organ Culture Techniques Internal medicine Endopeptidases medicine Animals Orthopedics and Sports Medicine Secretion Bone Resorption Cell Line Transformed Cathepsin Skull Blotting Northern medicine.disease Cathepsins Molecular biology In vitro Culture Media Cysteine Endopeptidases Genes ras medicine.anatomical_structure Endocrinology chemistry biology.protein |
| Zdroj: | Journal of Bone and Mineral Research. 5:159-164 |
| ISSN: | 0884-0431 |
| DOI: | 10.1002/jbmr.5650050209 |
| Popis: | Tumor-associated hypercalcemia is due, in part, to enhanced osteoclastic bone resorption induced by soluble factors elaborated from malignant cells. ras transformation of NIH 3T3 cells results in a 50-fold induction of cathepsin L mRNA and secretion of the corresponding protein. Since cathepsin L is an acid proteinase we asked whether conditioned medium from these cells would directly increase calcium release from bone in vitro. We tested conditioned medium obtained after 72 h culture of NIH 3T3 ras-transformed cells (DT) or nontransformed NIH 3T3 cells (3T3) and identical medium not exposed to cells (Ctl). Incubation of either live or dead neonatal mouse calvaria for 48 h in DT-conditioned medium increased calcium release compared to bones incubated with 3T3 medium. In both states the increased calcium release with DT medium was blocked by 0.25 mM E-64, a general cysteine proteinase inhibitor, and 1 microM Z-Phe-Ala-CH2F, a specific inhibitor of cathepsin L activity. Thus, conditioned medium from ras-transformed cells enhances calcium release in both live and dead bone. Since cathepsin L is the major protein secreted by these cells and the effect of DT-conditioned medium is blocked by a specific inhibitor of cathepsin L, these studies suggest that this acid proteinase acts directly on bone mineral to enhance net calcium release. |
| Databáze: | OpenAIRE |
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