Skeletal alkaline phosphatase specific activity is an index of the osteoblastic phenotype in subpopulations of the human osteosarcoma cell line SaOS-2
| Autor: | Nanine M. Tarbaux, Sandra Herring, John R. Farley, Toshikitsu Matsuyama, Susan L. Hall, Jon E. Wergedal |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
musculoskeletal diseases
medicine.medical_specialty Endocrinology Diabetes and Metabolism Population Parathyroid hormone Bone and Bones chemistry.chemical_compound Fluorides Endocrinology stomatognathic system Internal medicine medicine Cyclic AMP Tumor Cells Cultured Humans Cyclic adenosine monophosphate education education.field_of_study Osteosarcoma Osteoblasts biology Cell growth Histocytochemistry musculoskeletal neural and ocular physiology Acid phosphatase Alkaline Phosphatase Microbial Collagenase Phenotype chemistry Cell culture Parathyroid Hormone Protein Biosynthesis biology.protein Alkaline phosphatase Specific activity Thymidine |
| Zdroj: | Metabolism: clinical and experimental. 40(7) |
| ISSN: | 0026-0495 |
| Popis: | During continuous culture with serial passage, the human osteosarcoma cell line SaOS-2 showed a time-dependent decrease in skeletal alkaline phosphatase (ALP) activity. Because this was indicative of heterogeneity, subpopulations of SaOS-2 cells were isolated from replicate low-density cultures. The subpopulations were less heterogeneous and more stable (with respect to ALP) than the parent population. ALP specific activity in the subpopulations ranged from 0.05 to 2.3 U/mg protein, and cytochemical analyses indicated multiple steady-state levels of ALP activity per cell. The amount of ALP activity in SaOS-2 subpopulations was proportional to collagen production ([3H]proline incorporation into collagenase-digestible protein; r = .84, P less than .005), and to parathyroid hormone (PTH)-linked synthesis of cyclic adenosine monophosphate (cAMP) (r = .88, P less than .01). From these data, we inferred that ALP activity in SaOS-2 cells can provide a useful index of the osteoblastic phenotype, and that ALP activity, collagen production, and PTH-linked adenylate cyclase were coordinately regulated in these osteoblast-like osteosarcoma cells (ie, selection of subpopulations for ALP activity coselected for collagen synthesis and PTH-linked synthesis of cAMP). Further comparative studies showed that micromolar fluoride concentrations stimulated cell proliferation ([3H]thymidine incorporation into DNA) in low-ALP SaOS-2 subpopulations, but not in high-ALP cells (P less than .001), and that this differential sensitivity to fluoride was associated with an inverse correlation between fluoride-sensitive acid phosphatase and ALP activities (r = -.91, P less than .001). |
| Databáze: | OpenAIRE |
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