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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This report describes the first observation of a direct mitogenic effect of androgens on isolated osteoblastic cells in serum-free culture. [3H]thymidine incorporation into DNA and cell counts were used as measures of cell proliferation. The percentage of cells that stained for alkaline phosphatase was used as a measure of differentiation. Dihydrotestosterone (DHT) enhanced mouse osteoblastic cell proliferation in a dose dependent manner over a wide range of doses (10(-8) to 10(-11) molar), and was maximally active at 10(-9) M. DHT also stimulated proliferation in human osteoblast cell cultures and in cultures of the human osteosarcoma cell line, TE89. Testosterone, fluoxymesterone (a synthetic androgenic steroid) and methenolone (an anabolic steroid) were also mitogenic in the mouse bone cell system. The mitogenic effect of DHT on bone cells was inhibited by antiandrogens (hydroxyflutamide and cyproterone acetate) which compete for binding to the androgen receptor. In addition to effects on cell proliferation, DHT increased the percentage of alkaline phosphatase (ALP) positive cells in all three bone cell systems tested, and this effect was inhibited by antiandrogens. We conclude that androgens can stimulate human and murine osteoblastic cell proliferation in vitro, and induce expression of the osteoblast-line differentiation marker ALP, presumably by an androgen receptor mediated mechanism.
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PMID:Androgens directly stimulate proliferation of bone cells in vitro. 252 24

Although numerous clinical studies have demonstrated the beneficial effect of preventing postmenopausal bone loss in elder women by long-term estrogen administration, effects of estrogen at the cellular level still remain unclear. Efforts to determine the precise role of bone cells in estrogen-mediated pathways are often hampered by the lack of suitable cell culture models. Presuming that sex steroids have a direct, stimulating effect on bone cells in vitro, we investigated the influence of 17beta-estradiol, testosterone and 1,25(OH)2D, on cell proliferation and differentiation using four established human osteosarcoma (HOS) cell lines of different gender of the donors (male origin: MG 63, HOS 58; female origin: SaOS 2, TE 85). These cell lines are believed to represent different stages of osteogenic maturation. Thus, the aim of this study was to clarify if possible responses to sex steroids are related to gender or osteogenic commitment of the individual cell culture. HOS cells were cultured in six-well plates and underwent hormone treatment (1 nM and 10 nM 17beta-estradiol. 0.1 nM and I nM testosterone and 1 microM 1,25(OH)2D3) for 48 h hours. Cell proliferation was determined by measuring total cell numbers. Cell function was studied by measuring alkaline phosphatase activity and secreted osteocalcin. In this study, estrogen significantly increased proliferation of both one male (MG 63) and one female (SaOS 2) cell line, but decreased proliferation of the female HOS TE 85 cell line significantly. Testosterone treatment had a positive effect on proliferation of only one female cell line (SaOS 2). A significant increase of alkaline phosphatase activity in SaOS 2 and HOS 58 cells and of osteocalcin levels in SaOS 2 cells was detected following estrogen treatment. Administration of 1.25(OH)2D3 was followed by an increased cell proliferation in HOS 58, MG 63 and SaOS 2. Significant gender-related differences could not be demonstrated. In conclusion, response to hormonal treatment with sex steroids is not related to the gender of the osteosarcoma cell line, but rather depends on its osteoblastic commitment.
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PMID:Sex steroids and bone metabolism: comparison of in vitro effects of 17beta-estradiol and testosterone on human osteosarcoma cell lines of various gender and differentiation. 1102 55

Bone matrix proteins are being identified in mineralized foci in several different pathological states. Irrespective of how these proteins become localized it is of great interest to further define what endocrine factors are necessary for triggering the release of bone matrix proteins. MG63 cells (Osteosarcoma cell line) were seeded at a density of 1 x 10(5) cells/ml onto two 24 well tissue culture plates. The wells were divided into 8 groups of 6 wells/group. Cells in group 1 were provided with media alone and served as a control. Cells in group II, IV, and VI were supplemented with Insulin Like Growth factor-1 (IGF-1), Testosterone (T), or Growth Hormone (GH), respectively. Cells in groups III, V and VII were supplemented with TCPL capsules containing IGF-1, Test or GH, respectively. Cells in group VIII were incubated with sham TCPL and served as vehicle control. Cells were incubated in the presence or absence of hormones for 24, 48 and 72 hours. At the end of each phase, cell damage, cell morphology, cell number and cellular protein concentrations were determined. The results showed a significant increase in MDA initially in all groups, followed by a drop in MDA levels by the 48-hour phase, and thereafter remaining lower than the control. Results also demonstrated a decrease in total cellular protein following administration of hormones by conventional means. Sustained delivery of the hormones by TCPL resulted in only a slight increase in protein levels. Cell count data showed an initial decrease in all groups, followed by a significant increase in cell number at the end of 48 hours and, finally, reaching control levels at the 72 hour period. Morphological evaluation revealed major structural changes associated with sustained delivery as compared to conventional delivery of hormones. For example, sustained delivery of IGF-1 and T resulted in an increase in mitotic figures, swelling, and aggregate formation. Cluster cellular formation were observed on cells exposed to IGF-1 and T by conventional routes.
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PMID:The effects of sustained delivery of growth promoting hormones on the proliferation of MG63 cells in culture. 1134 1