• The Korean Journal of Physiology and Pharmacology
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• 제4권4호
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• pp.283-289
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• 2000

Natriuretic peptides comprise a family of three structurally related peptides; atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). The present study was performed to investigate the effect of ANP on the proliferation and activity of ROS17/2.8 and HOS cells which are well-characterized osteoblastic cell lines. ANP dose-dependently decreased the number of ROS17/2.8 and HOS cells after 48-hour treatment. ANP generally increased the alkaline phosphatase activity of ROS17/2.8 and HOS cells after 48 hr treatment, regardless of the fact that basal activity of alkaline phosphatase was much lower in HOS cells compared to that of ROS17/1.8 cells. ANP increased the NBT reduction by ROS17/2.8 and HOS cells. ANP showed the variable but no significant effect on the nitric oxide production by ROS17/2.8 and HOS cells. ROS17/2.8 and HOS cells produced and secreted gelatinase into culture medium, and this enzyme was thought to be the gelatinase A type with the molecular weight determination. The gelatinase activity produced by ROS17/2.8 cells was increased by the treatment of ANP. However, the enzyme activity was not affected by ANP treatment in the HOS cell culture. In summary, ANP decreased the proliferation and increased the alkaline phosphatase activity and NBT reduction of osteoblasts. These results indicate that ANP is one of the important regulators of bone metabolism.

• Journal of Oral Medicine and Pain
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• 제26권4호
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• pp.319-329
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• 2001

Endothelin-1 (ET-1) is a recently discovered potent vasoconstrictive peptide. It was first identified in vascular endothelial cells. ET-1 is a 21-amino acid peptide and elicits systemic effects such as stimulation of the production of atrial natriuretic peptide and release of aldosterone and corticosterone. In this study, to examine the role of ET-1 in the bone metabolism, effect of ET-1 on the proliferation and activity of osteoblastic cells was studied using HOS cells as osteoblast model. ET-1 dose-dependently increased the cell proliferation as determined by cell counting and MTT reduction assay after 48hr treatment. Alkaline phosphatase activity was inhibited by ET-1 and showed significant inhibition by 50 and 100 nM ET-1. ET-1 increased NBT reduction by HOS cells dose-dependently showing that ET-1 may increase the superoxide production by osteoblasts. Nitrite concentration in the media of HOS cell culture without cytokine stimulation was negligible and unaffected by ET-1 after 48hr treatment. Finally, after collection and concentration of conditioned media, gelatinase activity produced by HOS cells was determined by zymography. HOS cells can produce and secrete the gelatinase (gelatinase A type as determined by molecular weight of about 65,000) into culture media, however, ET-1 had no effect on the gelatinase activity. These findings suggest that ET-1 may have diverse effects on the proliferation and differentiation of osteoblasts, therefore, it may play an important role in bone metabolism.

• Archives of Pharmacal Research
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• 제29권5호
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• pp.363-368
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• 2006

EGCG [(-)-epigallocatechin-3-gallate], a major component of green tea has been considered as a major antioxidant constituent. In addition to having been considered for cancer treatment as a chemopreventive and chemotherapeutic agent, EGCG has recently been attributed an anti-proliferative effect. We re-examined the latter finding in this study and added specific focus on the ability of EGCG to induce apoptosis in human osteogenic sarcoma (HOS) cells. Antiproliferative action of EGCG $(IC_{50}=35.3{\pm}6.0{\mu}g/mL)$ appeared to be linked to apoptotic cell death based on morphological changes, chromosomal DNA degradation, and an increase in the $sub-G_1$ apoptotic cell population. Treatment of HOS cells with EGCG gradually activated caspase-3, an established inducer of apoptotic cell death.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권1호
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• pp.20-27
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• 2007

Eugenol is commonly used in dentistry for the sedation of toothache, pulpitis, and dental hyperalgesia. This study was performed to investigate the apoptotic effect of eugenol to human osteosarcoma (HOS) cells and the potential use of this compound in osteosarcoma cells. Eugenol showed the apoptotic effect in HOS cells in dose- and time-dependent manner. Fragmentation and condensation of DNA were showed by TUNEL assay, Hemacolor stain and Hoechst stain. In the DNA electrophoresis analysis, cells showed DNA degradation characteristic of apoptosis with a ladder pattern of DNA fragments. Apoptosis-related factors were analyzed by western blotting. Cells treated with eugenol showed caspase-3, PARP, lamin A and DFF-45 cleavage. Eugenol treatment induced caspase-3 cleavage and activation. Cleavages of PARP, DFF-45 and lamin A were accompanied with activation of caspase triggered by eugenol in HOS cells. Though this study needs more investigations, these results suggest that eugenol induce apoptosis via caspase dependent pathway in HOS cells and eugenol may constitute a potential antitumor compound against osteosarcoma cells.

• International Journal of Oral Biology
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• 제30권4호
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• pp.111-116
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• 2005

Resveratrol (3,4',5-trihydroxy-trans-stilbene), a naturally occuring polyphenol compound which present in the skin of grapes and red wine has been considered to posses chemopreventive and antioxidant properties. However, little is known about the cellular actions by which resveratrol mediates its therapeutic effects. In this study, the effect of resveratrol on cell proliferation and induction of apoptosis in human osteogenic sarcoma (HOS) cells was investigated. $IC_{50}$ value was determined to be approximately $6.0{\mu}g/ml$. Chromosomal DNA framgmentation analysis showed the appearance degraded DNA in time-and dose-dependent manner upon treatment of resveratrol. In order to observe the molecular mechanism involved in resveratrol-induced apoptosis, Western blot analysis was performed. We observed the decrease in the level of procaspase-3, the zymogen form of active caspase-3 in resveratrol-treated cells. This result implies that caspase-3 is activated upon treatment of resveratrol. The activation of caspase-3 was confirmed by the cleavage of poly(ADP-ribose) polymerase. Taken together, our data demonstrate that resveratrol has anti-proliferative effect on HOS cells and induced apoptosis through activation of caspase-3 and PARP cleavage.

• International Journal of Oral Biology
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• 제32권4호
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• pp.135-141
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• 2007

Anti-proliferation of methanol extract of Curcuma rhizome on oral squamous cell carcinoma (KB) and osteosarcoma (HOS) cells were investigated. In order to elucidate the involvement of telomerase inhibitory activity as a part of anti-proliferative effect of Curcuma rhizome on cancer cells, we measured telomerase activity in Curcuma rhizome extract-treated cancer cells. The concentration inhibited cell proliferation to 50% $(IC_{50})$ of the methanol extract of Curcuma rhizome against oral squamous cell carcinoma (KB) cells and osteosarcoma (HOS) cells were 21.30 ${\mu}g/ml$ and 39.3${\mu}g/ml$, respectively. The methanol extract of Curcuma rhizome showed inhibitory telomerase inhibitory effect which is required for cancer cell immortality. Therefore, it seems that the anticancer effect of methanol extract of Curcuma rhizome is at least partially due to telomerase inhibitory effect. Five fraction samples were prepared according to its polarity differences and analyzed anti-proliferative effects of each fraction samples on oral squamous cell carcinoma and osteosarcoma cells. Anticancer effect was observed in dichloromethane, and ethylacetate fractions. The highest anticancer effect was found in dichloromethane fraction which had $IC_{50}$ value of 23.3 ${\mu}g/ml$ and 10.5${\mu}g/ml$ against oral squamous cell carcinoma (KB) cells and osteosarcoma (HOS) cells, respectively.

• Natural Product Sciences
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• 제11권1호
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• pp.45-49
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• 2005

Previously, a flavonoid fraction, which consisted mainly of protocatechuic acid, fustin, fisetin, sulfuretin, and butein, here named RCMF [${\underline{R}}hus$ verniciflua Stokes (RVS) ${\underline{c}}hloroform-{\underline{m}}ethanol\;{\underline{f}}raction$], was prepared from a crude acetone extract of RVS which is traditionally used as a food additive and as an herbal medicine. In the present study, we investigated the effects of $TNF-{\alpha}$ on RCMF-induced growth inhibition and apoptosis induction using human osteosarcoma (HOS) cells. The results from tritium uptake and MTT assays showed that $TNF-{\alpha}$ treatment itself (10 ng/ml) did not induce any cytotoxicity, but it actively accelerated RCMF-mediated cytotoxicity of HOS cells. RCMF-induced cytotoxicity and its facilitation by $TNF-{\alpha}$ was verified to be apoptotic, based on the increased DNA fragmentation and low fluorescence intensity in nuclei after propidium iodide (PI) staining of HOS cells. This speculation was further demonstrated by monitoring the Annexin V/PI double staining which could discriminate the difference between apoptotic and necrotic deaths. Collectively, our findings indicate that $TNF-{\alpha}$ accelerates RCMF-induced cytotoxicity in HOS cells.

• Journal of Oral Medicine and Pain
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• 제24권4호
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• pp.361-374
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• 1999

F. nucleatum is a gram-negative obligate anaerobe which is the principal and most frequent cause of gingival inflammation and is the predominant pathogen isolated in subsequent periodontal breakdown. It is also one of the most numerous bacteria found in subgingival plaque samples from healthy sites; its numbers are about 10-fold greater in plaque from periodontally diseased sites. The purpose of this study is to examine the effects of outer membrane(OM), outer membrane vesicle(OMV), and lipopolysaccharide(LPS) from F. nucleatum ATCC 25586 strain on the growth of human gingival fibroblasts and HOS 941 cells, and on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes. For the examination of cytotoxic effects, $TNF-{\alpha}$ production and $TNF-{\alpha}$ mRNA expression, the MTT assay, the ELISA and the RT-PCR were performed, respectively. All extracts of F. nucleatum tested were cytotoxic to both of human gingival fibroblasts and HOS 941 cells, and the significant difference of cytotoxic activity among the extracts was not observed. In the effects of these extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes, all extracts of F. nucleatum tested also stimulated the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression, but the effects of the OM extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression were higher than those of the OMV and the LPS extracts. The pattern of the $TNF-{\alpha}$ mRNA expression was similar to that of the $TNF-{\alpha}$ production. These results indicate that F. nucleatum seems to contribute to the pathogenesis of periodontal diseases at least by its cytotoxicity, directly and its $TNF-{\alpha}$ production, indirectly.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권6호
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• pp.509-515
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• 2004

광역동치료(PDT)는 갖가지 고형 종양의 치료를 위한 임상적시도로 시작되어 화학요법 및 방사선 요법에 내성이 있는 종양의 대체 치료법의 하나로 제시되고 있다. PDT는 전신적 또는 국소적으로 투여하여 유해한 조직에 선택적으로 농축되도록 한 광증감제와 이를 활성화하는 적절한 파장과 에너지를 가진 레이저광의 조합에 기초한다. 이 연구에서는, 인체 골육종 세포(HOS)에 미치는 레이저 EIT 21의 광독성 효과에 대해 알아보았으며, 그런 광독성 효과가 세포고사를 유발하는가를 규명하고자 하였다. 본 연구는 레이저 EIT 21이 HOS 세포에 대해 광독성을 효과를 가진다는 것을 증명했다. 세포 죽음이 세포괴사에 의해 유발되는지 아니면 세포고사에 의해 유발되는지를 알아보기 위해 세포 고사를 평가 하는 여러 실험 기법을 이용하였다. TUNEL 분석은 극소수만이 응축된 핵의 양성반응을 보여주었다. Hemacolor와 AO/EB 염색 또한 대부분의 세포가 괴사로 죽는 것을 보여주었다. 레이저 EIT로 조사된 HOS 세포에서 응축되거나 분절된 핵을 발견하는 것은 어려웠다. DNA 전기영동에서, 세포고사에서 보여지는 DNA 분절의 전형적인 특징인 사다리형 절편 형태(ladder fragmentation pattern)가 나타나지 않았다. Western blotting에 의한 분석에서 p53의 발현은 일정하게 나타났고 레이저로 조사된 세포는 caspase-3과 PARP의 분열을 나타내지 않는 것으로 보아 레이저 유도 세포 죽음(laser-induced cell death)은 p53과는 관련이 없는 것 같다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권4호
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• pp.281-288
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• 2001

Anticancer effect of methanol extract of Caesalpinia sappan L. on oral carcinoma (KB) and osteosarcoma (HOS) cells were investigated in this study. In order to elucidate the anticancer mechanism of Caesalpinia sappan L, we analyzed telomerase inhibitory effect of the methanol extract of Caesalpinia sappan L. In addition we prepared 5 fraction samples according to its polarity differences and analyzed anticancer effects on oral carcinoma and osteosarcoma cells. Following results are obtained in this study. 1. 50% cell proliferation inhibitory value ($IC_{50}$) of the methanol extract of Caesalpinia sappan L. against oral carcinoma (KB) cells and osteosarcoma (HOS) cells were $9.0{\mu}g/ml$ and $10.9{\mu}g/ml$, respectively. 2. The methanol extract of Caesalpinia sappan L. showed inhibitory effect of telomerase which is required for cancer cell immortality. Therefore, it seems that the anticancer effect of methanol extract of Caesalpinia sappan is at least partially due to telomerase inhibitory effect. 3. Five fraction samples were prepared according to its polarity and 88.7% of ingredient of total methanol extract was transferred to ethylacetate fraction. Thin layer chromatography analysis showed that dichloromethane fraction contained ingredient with relatively high polarity and ethylacetate fraction contained similar ingredient found in total methanol extract. 4. Anticancer effect was observed in n-hexane, dichloromethane, and ethylacetate fractions. The highest anticancer effect was found in dichloromethane fraction which had $IC_{50}$ value of 4.4 and $>4.0{\mu}g/ml$ against oral carcinoma (KB) cells and osteosarcoma (HOS) cells, respectively.