• Journal of Nutrition and Health
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• v.38 no.7
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• pp.512-520
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• 2005

Phytoestrogens, especially Yak-kong or soybean-derived isoflavones have been traditionally used as a supplement of estrogen for preventing postmenopausal osteoporosis in oriental folk medicine. In a previous study, we demonstrated that as Yak-kong and soybean increased MG-63 human osteoblastic cell proliferation, the expression of estrogen receptor $\alpha\;and\;beta\;(ER\;\alpha:\;ER\;\beta$) both were increased. However, the increased level of ER $\alpha$ is much higher than that of ER$\beta$. To determine whether the altered level of ER $\alpha$ expression affects Yak-kong or soybean induced MG-63 cell proliferation, we established cell lines stably expressing either ER $\alpha$ or antisense ER $\alpha$ RNAs. Increased expression of ER a in MG- 63 cells (ER $\alpha$-MG63) enhanced Yak-kong or soybean induced proliferation which paralleled with the enhanced expression of IGF-I. Inhibition of ER $\alpha$ expression by antisense $ER\;\alpha\;RNAs\;(As-ER\;\alpha-MG63$) caused these cells to insensitize Yak- kong or soybean induced proliferation and IGF-I expression. Furthermore, the comparable effects between Yak-kong and the combined treatment of genistein and daidzein at $0.5\;{\times}\;10^{-8}M$, which is a concentration of these two isoflavones similar to Yak-kong at 0.001 mg/ml, on cell proliferation and IGF-I expression in $ER\;\alpha-MG63\;or\;As-ER\;\alpha-MG63$ cells demonstrate that ER $\alpha$ plays an important, active role in MG-63 cell proliferation induced by phytoestrogens, especially Yak-kong or soybean derived isoflavones.

• Nutritional Sciences
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• v.8 no.3
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• pp.159-168
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• 2005

Phytoestrogens, especially Yak-kong or soybean-derived isoflavones have been traditionally used as a supplement of estrogen for preventing postmemopausal osteoporosis in oriental folk medicine. In our previous study, the treatment of Yak-kong and soybean increased estrogen receptor-a (ERa) expression and proliferation of MG-63 osteoblastic cells. In contrast, the increase of estrogen receptor-$\beta$ (ER$\beta$) expression in proliferating MG-63 cells with Yak-kong and soybean treatment was less pronounced, which suggested that ER$\beta$ may play a role rather in the regulation of bone cell differentiation To determine the role of ER$\beta$ in Yak-kong or soybean mediated regulation of bone cell differentiation, we established MG-63 cell lines stably expressing either ER$\beta$ or antisense ER$\beta$ RNAs. Increased expression of ER$\beta$ did not affect ERa expression and proliferation of MG-63 cells. However, increased expression of ER$\beta$ in MG-63 cells (ER$\beta$-MG63 cells) selectively enhanced Yak-kong or soybean induced expression of osteoprotegerin (OPG), a novel soluble glycoprotein which is secreted from osteoblasts and mediates the signal for osteoclast differentiation. Inhibition of ER$\beta$ expression by antisense ER$\beta$ RNAs (As-ER$\beta$-MG63) caused these cells to insensitize Yak-kong or soybean induced expression of OPG but increased MG-63 cell proliferation. Furthermore, the comparable effects between Yak-kong and the combined treatment of genistein and daidzein at $0.5{\times}l0^{-8}$ M, which is a concentration of these two isoflavones similar to Yak-kong at 0.001 mg/mL, on OPG expression in ER$\beta$-MG63 cell demonstrate that the enhanced expression of OPG with Yak-kong treatment is mediated by the synergistic effect of low leveled isoflavones in the extracts. Together, coupled with low level of ER expression in osteoclasts, our data demonstrate that ER$\beta$ in osteoblasts plays an important role in Yak-kong and soybean mediated inhibition of osteoclast differentiation indirectly by enhancing the expression of OPG.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.26 no.2
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• pp.121-132
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• 1996

The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chemotherapy. For this study, cell surviving curves were obtained for human osteosarcoma MG-63 cell line using semiautomated MTT assay. 2,4, 6, 8, 10Gy were irradiated at a dose rate of 210cGy/min using /sup 60/Co Irradiator ALDORADO 8. After irradiation, MG-63 cell lines(3×10⁴ cells/ml) were exposed to bleomycin and cisplatin at concentration of 0.2, 2, 20㎍/㎖ for 1 hour respectively. The viable cells were determined for each radiation dose and/or each concentration of drug. And they were compared to control values. The obtained results were as follows : 1. There was significant difference of surviving fraction at 4, 6, 8, 10Gy on MG-63 cell line(p<0.05). 2. There was significant difference of cytotoxicity of bleomycin or cisplatin at all concentration of 0.2, 2, 20㎍/㎖ (p<0.05) on MG-63 cell line. The cytotoxicity of cisplatin was more effective than bleomycin at concentration of 20㎍/㎖ on MG-63 cell line. 3. There was significant difference of cytotoxicity of bleomycin or cisplatin at all concentration after irradiation of 2Gy on MG-63 cell line. 4. There was significant difference of cytotoxicity of bloemycin or cisplatin at concentration of 20㎍/㎖ after irradiation than that of irradiation alone(p<0.01). But there was no significant difference of cytotoxicity of bleomycin at concentration of 20㎍/㎖ after irradiation of l0Gy than that of irradiation alone.

• Molecules and Cells
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• v.37 no.2
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• pp.118-125
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• 2014

Osteosarcoma is the most common primary malignant bone tumor with a very poor prognosis. Treating osteosarcoma remains a challenge due to its high transitivity. Tenascin-C, with large molecular weight variants including different combinations of its alternative spliced FNIII repeats, is specifically over expressed in tumor tissues. This study examined the expression of Tenascin-C FNIIIA1 in osteosarcoma tissues, and estimated the effect of mechanical stimulation on A1 expression in MG-63 cells. Through immunohistochemical analysis, we found that the A1 protein was expressed at a higher level in osteosarcoma tissues than in adjacent normal tissues. By cell migration assay, we observed that there was a significant correlation between A1 expression and MG-63 cell migration. The relation is that Tenascin-C FNIIIA1 can promote MG-63 cell migration. According to our further study into the effect of mechanical stimulation on A1 expression in MG-63 cells, the mRNA and protein levels of A1 were significantly up-regulated under mechanical stress with the mTOR molecule proving indispensable. Meanwhile, 4E-BP1 and S6K1 (downstream molecule of mTOR) are necessary for A1 normal expression in MG-63 cells whether or not mechanical stress has been encountered. We found that Tenascin-C FNIIIA1 is over-expressed in osteosar-coma tissues and can promote MG-63 cell migration. Furthermore, mechanical stress can facilitate MG-63 cell migration though facilitating A1 overexpression with the necessary molecules (mTOR, 4E-BP1 and S6K1). In con-clusion, high expression of A1 may promote the meta-stasis of osteosarcoma by facilitating MG-63 cell migration. Tenascin-C FNIIIA1 could be used as an indicator in metastatic osteosarcoma patients.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.3
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• pp.261-266
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• 2004

Statement of problem. The effects of surface roughness have not or insufficiently been analyzed on earlier events such as cell adhesion though cell behavior most germane to implant performance is cell adhesion. Purpose. The purpose of this study was to evaluate cell adhesion of osteoblast-like cells (MG63) onto three types of titanium disks with varying roughness using the Elisa assay. Materials and methods. Representative disks from each group (SLA, HA, machined) were subjected to surface analysis and surface roughness was measured by the optical interferometer (Accura 2000, Intekplus Co., Seoul, Korea). Following this, MG63 cells were cultured on the titanium disks and released. Cell adhesion measurements using the Elisa assay were performed specifically at three points: after 24, 48, and 72 hours of culture. Results. Among the 3 types of surface analyzed, the SLA surface was the roughest with a Ra value of $1.114{\mu}m$ followed by HA coated surface and machined surface, consecutively. The optical density values for the SLA surface group was significantly higher than that of the machined and HA coated surface groups following 24 and 48 hours of culture. The cell culture on HA coated surface showed significantly higher values compared to the machined surface following 24, 48 and 72 hours of culture. Conclusion. The results suggest that surface treatment of titanium surfaces enhanced cell adhesion of human osteoblast-like cells (MG63).

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.249-260
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• 1994

The purpose of this study was to aid in the radiation therapy of head and neck cancer patients. For this study, radiation survival curves were generated for Bl6, MG-63 and YAC-l cell lines using semiautomated MTT assay and Dye Exclusion Assay. Irradiation of 2, 4, 6, 8, 10Gy were delivered at room temperature at a dose rate of 210.2cGy/min using / sup 60/Co γ-ray Irradiator ALOORAOO 8. The viable cells were determined for each radiation dose and compared to control values. The obtained results were as follows: 1. There was significantly different absorbance at 10Gy on B16 cell line in MTT assay(P<0.05). 2. There was significantly different absorbance at 4, 6, 8, 10Gy on MG-63 cell line in MTT assay(P<0.05). 3. YAC-l cell line was more sensitive than B16 or MG-63 cell line to all doses of radiation(P<0.05). 4. There was significantly different absorbance among all tumor cell lines except between B16 and MG-63 cell line at ZGy in MTT assay(P<0.05). 5. Good correlation was obtained between MTT assay and DEA(P<0.05). The efficient of correlation of B16, MG-63 and YAC-l cell line was 0.845, 0.824 and 0.906, respectively.

• International Journal of Oral Biology
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• v.46 no.1
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• pp.23-29
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• 2021

Demethoxycurcumin (DMC), which is a curcuminoid found in turmeric, has anti-proliferative effects on cancer cells. However, the effect of DMC on osteosarcoma has not been established. The aim of this study was to examine the effects of DMC on cell growth and apoptosis induction in MG-63 human osteosarcoma cells. This study was investigated using 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromid assay, Live/Dead cell assay, 4', 6-diamidino-2-phenylindole staining, and immunoblotting in MG-63 cells. DMC induced MG-63 cell death in a dose-dependent manner, with an estimated IC50 value of 54.4 µM. DMC treatment resulted in nuclear condensation in MG-63 cells. DMC-induced apoptosis in MG-63 cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting results showed that Bcl-2 and Bcl-xL were downregulated, while Bax and Bad were upregulated by DMC in MG-63 cells. These results indicated that DMC inhibits cell proliferation and induces apoptotic cell death in MG-63 human osteosarcoma cells via the death receptor-mediated extrinsic apoptotic pathway and mitochondria-mediated intrinsic apoptotic pathway.

• Journal of Society of Preventive Korean Medicine
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• v.11 no.1
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• pp.9-21
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• 2007

This study was performed to evaluate the effect of Carthami tinctorius(HH) on osteoblast function and gene expression. The osteoblasts separated from the rat calvariae were cultivated to evaluate the cell function, and MG-63 cell was also cultivated for the test of mRNA synthesis. In this experiments, cell proliferation of rat calvarial cells was increased by HH. PKC activity, intracellular free calcium level and collgen synthesis from calvarial cells were increased by HH, but not PKA activity. And the mRNA of $PLA_2$, COX-2, and $PGE_2$ synthase from MG-63 were decreased by HH, but the mRNA of prostacyclin synthase was increased. It is concluded that HH might increase the proliferation of calvarial cell resulted from augumentation of osteoblast activity and its mRNA synthesis.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.1
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• pp.39-43
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• 2013

Carthamus tinctorius L. and Eucommia umoides Oliver are often used in traditional herbal medicines for reducing damage to the liver, kidney, bone and muscle. In the present study, we investigated cell viability and alkaline phosphatase activity in the human osteoblast-like MG-63 cell line with methanol extracts of Carthami Semen (CS) and Eucommiae Cortex (EC) alone or in a mixture (CS+EC). Osteoblast cell viability was evaluated using the MTS assay and alkaline phosphatase activity assays. The cell viability and alkaline phosphatase activity significantly increased in MG-63 osteoblast cells treated with the CS+EC mixture. These findings suggest the CS+EC mixture may have beneficial effects on bone health through the proliferation of osteoblast cells.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.162-173
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• 2006

The water-extracts of Scutellaria barbata Don (SBDE) were isolated from Chinese medicinal plant sources. The extracts showed strong growth-inhibitory activity and cancer chemopreventive activity on the growth and DNA incorporation of MG63 human osteosarcoma and K562 human leukemia cell lines. The growth of human cancer cells was inhibited in the presence of the extracts (20, 50 and 100 ${\mu}$g/ml), and the effects were concentration-dependent and incubation time-dependent up to 8 days. When 50 ${\mu}$g/ml of the extracts was added to the media of MG63 and K562, cell growth after 8 days or 6 days of incubation was retarded by 93.2 to 97.3% of the control group. Morphological changes of MG63 and K562 cell lines were observed. As the concentration of the extracts increased up to 50 ${\mu}$g/ml, degree of cell aggregation decreased. Moreover, the DNA incorporation of the cells which were labeled with [3H] thymidine was significantly reduced after 3 days of incubation at $37^{\circ}C$ with the extract. Therefore, it is suggested that the extract is highly effective on inhibition of cancer cell growth. The extract also inhibited gene expression of IGF-II in transcriptional level. Since IGF-II works as a mitogenic effector on MG63 and K562 cell lines, these results suggest that the growth inhibition is in part mediated through the inhibition of IGF-II gene expression.