Calcitonin acutely increases net 45Ca uptake and alters alkaline phosphatase specific activity in human osteosarcoma cells

Farley, John R.; Hall, Susan L.; Herring, Sandra

doi:10.1016/0026-0495(93)90179-r

Cited by 28 publications

(17 citation statements)

References 38 publications

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“…This effect of CGRP on intracellular calcium is not mediated via a G protein linked to the cAMP pathway (10). In human osteosarcoma cells, CT acutely increases net 45 Ca uptake (12). On osteoclasts, CT-induced quiescence and cell retraction involve increased cytosolic free calcium concentrations (2,40).…”

Section: Discussionmentioning

confidence: 99%

Human osteoblast-like cell proliferation induced by calcitonin-related peptides involves PKC activity

Villa¹,

Fiume²,

Maestroni

et al. 2003

American Journal of Physiology-Endocrinology and Metabolism

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The calcitonin peptides [calcitonin (CT), calcitonin gene-related peptide (CGRP), amylin] share many biological actions, including activity on bone cells. In the present study, CT (10−11 to 10−9 M) stimulated [3H]thymidine incorporation in primary cultures of human osteoblasts (hOB), as already demonstrated for CGRP and amylin. RT-PCR analysis showed that the calcitonin receptor and the calcitonin receptor-like receptor are both expressed in hOB. In these cells, CT (10−10 M) and amylin (10−9 M), in contrast to CGRP (10−8 M), did not increase cAMP production. All three peptides stimulated protein kinase C (PKC) activity. To evaluate PKC involvement in hOB proliferation, cells were incubated with phorbol 12,13-dibutyrate, a stimulator of PKC activity; cell proliferation was increased in a dose-dependent manner (EC50 = 3.4 × 10−8 M). Staurosporine (10−9 M), a PKC inhibitor, blocked phorbol 12,13-dibutyrate-induced PKC activity and cell proliferation. Inhibition of PKC by staurosporine also counteracted the stimulatory effect of CT, CGRP, and amylin on hOB proliferation. From these data, it is deduced that the activation of PKC is important for hOB proliferation and that it is involved in the anabolic effect of CT peptides on bone.

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Section: Discussionmentioning

confidence: 99%

Human osteoblast-like cell proliferation induced by calcitonin-related peptides involves PKC activity

Villa¹,

Fiume²,

Maestroni

et al. 2003

American Journal of Physiology-Endocrinology and Metabolism

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“…The maximum net 45Ca uptake observed in these studies represented 2.2% of the total 45Ca in the 0.6 ml volume of serum-free BGJ b. In prior applications of this assay [39], we determined that (I) the rate of net 45Ca uptake was dependent on the Pi concentration in the medium; (2) the time course of net 45Ca uptake was usually hyperbolic, with a first-order linear increase to a maximum steady-state level that was relatively constant between 60 and 240 minutes; and (3) normalizing net 45Ca uptake to cell layer protein did not eliminate effects of variation in cell density, so that all studies need to be conducted at constant cell density (i.e., -+20%) to avoid such variation.…”

Section: Farley Et Al: Fluoride Increases Net 45ca Uptake By Saos-2 mentioning

confidence: 96%

“…This protocol was adapted from previous methods [38] and has been described in detail [39]. The maximum net 45Ca uptake observed in these studies represented 2.2% of the total 45Ca in the 0.6 ml volume of serum-free BGJ b.…”

Section: Farley Et Al: Fluoride Increases Net 45ca Uptake By Saos-2 mentioning

confidence: 99%

Fluoride increases net45Ca uptake by SaOS-2 cells: The effect is phosphate dependent

et al. 1993

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Previous in vitro studies have shown that the effect of fluoride to increase avian osteoblast-like cell proliferation was dependent on the phosphate concentration. In vitro studies have further revealed that fluoride could also have direct effects on osteoblast-like cells to increase phosphate uptake and transiently increase cytosolic calcium. The current studies were intended to determine whether fluoride could increase net 45Ca uptake by human osteosarcoma (SaOS-2) cells and, if so, whether those effects would also be phosphate dependent. The results of these studies indicate that fluoride increased net 45Ca uptake by SaOS-2 cells, with biphasic dose and time dependencies. After 30 minutes of exposure, net 45Ca uptake was increased to a greater extent by 50 microM fluoride (217 +/- 16% of control, P < 0.001) than by 200 microM fluoride; and the stimulatory effect of 100 microM fluoride on net 45Ca uptake was greater after 20 minutes (187 +/- 22% of control, P < 0.001) than after 60 minutes (122 +/- 7% of control, P < 0.05). These effects of fluoride to increase net 45Ca uptake were dependent on the phosphate concentration in the medium. Fluoride had no effect on net 45Ca uptake in medium containing 0.4 mM phosphate, but increased net 45Ca uptake in medium containing 1.2 or 2.0 mM phosphate (P < 0.005). As the phosphate concentration was increased, the biphasic fluoride dose-response curve was shifted to a lower range of fluoride concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…45Ca2+ uptake by cells was performed following a procedure described by Farley et al [29]. Briefly, the cells were removed from the CO2 incubator and washed twice with 4 ml/well of Tris-BSS pH 7.4 (10 mM Tris-HCl, 140 mM NaCI, 0.8 mM MgCI2, 5.3 mM KCI, 1 mM CaCI2, pH 7.4), at room temperature.…”

Section: Calcium Uptake Determinationmentioning

confidence: 99%

Quantitative study of calcium uptake by tumorigenic bone (TE‐85) and neuroblastoma × glioma (NG108‐15) cells exposed to extremely‐low‐frequency (ELF) electric fields

et al. 1997

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These results suggested that serum deprivation may be a requirement for a frequency dependent increase in proliferation in TE-85 cells but is not necessary for the electric field induced increase in 4~Ca 2+ uptake in both TE-85 and NG108 cells. The present study also represents the first demonstration of increased 45Ca 2+ uptake by neuroblastoma and/or glioma cells in response to an electric field exposure.

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Calcitonin acutely increases net 45Ca uptake and alters alkaline phosphatase specific activity in human osteosarcoma cells

Cited by 28 publications

References 38 publications

Human osteoblast-like cell proliferation induced by calcitonin-related peptides involves PKC activity

Human osteoblast-like cell proliferation induced by calcitonin-related peptides involves PKC activity

Fluoride increases net45Ca uptake by SaOS-2 cells: The effect is phosphate dependent

Quantitative study of calcium uptake by tumorigenic bone (TE‐85) and neuroblastoma × glioma (NG108‐15) cells exposed to extremely‐low‐frequency (ELF) electric fields

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