• BMB Reports
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• 제32권2호
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• pp.173-180
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• 1999

The effects of agmatine on the enzymes responsible for the biosynthesis of polyamines, the resultant levels of polyamines, and their effect on the growth of DU145 human prostate tumor cells were investigated. When agmatine was added to the medium, ornithine decarboxylase (ODC, EC 4.1.1.17) activity was substantially reduced, but S-adenosylmethionine decarboxylase (SAMDC, EC 4.1.1.50) activity increased markedly. These changes in ODC and SAMDC activities were the result of an induction of ODC-antizyme and a decreased turnover rate of SAMDC in the presence of agmatine. Accordingly, there was a decrease in the intracellular levels of putrescine and spermidine but an increase in the intracellular level of spermine. Cell growth was markedly inhibited by agmatine treatment and this inhibition was not recovered by the addition of putrescine or spermidine. Our results suggest that agmatine alters the intracellular amounts of polyamine in the cells, closely related to the inhibition of cell growth.

• Toxicological Research
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• 제11권2호
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• pp.169-173
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• 1995

The effects of tumor necrosis factor alpha $(TNF-{\alpha})$ on growth and tubular formation of bovine aortic endothelial cells were examined using an in vitro angiogenesis model system. The growth of endothelial cells was enhanced in a dose-dependent manner when the cells were cultured with $TNF-{\alpha}$ for 3 days, but $TNF-{\alpha}$, at the concentration of 1 nM or higher, produced a growth inhibition of endothelial cells when the cells were cultured for 8 days. The endothelial cells incubated with $TNF-{\alpha}$ for 48-h exhibited a typical morphologic change. Then, they showed a fibroblastoid organization of overlapping, elongated, and spindle-shaped cells. $TNF-{\alpha}$, at the concentration of O. 1 nM or higher, inhibited the tubular formation of vascular endothelial cells in an in vitro anglogenesis model using a 3-dimensional culture system.

• 약학회지
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• 제38권5호
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• pp.579-585
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• 1994

Antitumor activity was tested by administration of reaction mixture of green onion extract and chitin to mice bearing sarcoma-180 cells. An intraperitoneal injection of mixture(20 mg/kg/day) to mice Have an 52% inhibition of tumor growth. Inhibition of tumor growth was found to be dose-dependent. When eighty miligrams of the mixture were administered, the weight of tumor was reduced significantly. HPLC analysis indicated the mixture was composed of N-acetyl-D-glucosamine, N-acetylchitobiose and N-acetylchitotriose.

• 한국식품과학회지
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• 제36권1호
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• pp.141-146
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• 2004

여러 발표에서 버섯추출물의 간접적 항종양효과에 대해 보고 되고 있다. 본 연구는 표고버섯의 직접적인 종양세포주 성장억제효과를 탐지하기 위하여 휴먼자궁경부암바이러스 타입 16의 종양유전자가 발현된 동물종양세포주(TC-1)를 이용하였다. 여러 추출용매 중 물을 이용한 추출액에서 TC-1 세포주의 성장억제효과를 탐지할 수 있었다. 이들 세포성장저해는 추출물첨가농도에 상응하며 $IC_{50}$는 $800\;{\mu}g/mL$로 계산되었다. 또한, 표고버섯 물 추출물은 휴먼자궁경부암세포주(CaSki and HeLa)에서도 유사한 세포성장억제효과를 보여 주었다. 첨가농도가 1.5 mg/mL에서는 첨가후 6시간째에 벌써 완전한 종양세포주(TC-1)의 성장억제가 탐지되었다. 이들 추출물을 열처리시 종양세포주성장억제가 소실되었으나 pH의 변화에서는 그대로 종양세포주성장억제효과가 탐지되었다. 이는 표고버섯 물 추출물 내에 있는 항종양물질이 열에 민감함을 의미한다. Annexin V 및 propidium iodide 염색에 의해 이들 TC-1종양세포주의 성장 억제효과는 apoptosis에 의해 매개됨을 보여 주었다 동물실험에서 표고버섯 물 추출물의 구강투여시 TC-1유래 종양의 성장 및 생성에 아무 효과를 주지 못하였다. 반면, 형성된 종양에 직접 주사시 종양크기의 감소가 탐지되었다. 요약하면 이들 연구에서 표고버섯 물 추출물에 존재하는 항암물질은 열에 민감하며 apoptosis에 의해 휴먼자궁경부암종양유전자에 의해 종양화된 세포주의 세포성장을 직접 억제하는 기능이 있음을 증명한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권2호
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• pp.66-73
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• 2009

Tumor angiogenesis is a process leading to formation of blood vessels within tumors and is crucial for maintaining a supply of oxygen and nutrients to support tumor growth and metastasis. Vascular endothelial growth factor(VEGF) plays a key role in tumor angiogenesis including induction of endothelial cell proliferation, migration, survival and capillary tube formation. VEGF binds to two distinct receptors on endothelial cells. VEGFR-2 is considered to be the dominant signaling receptor for endothelial cell permeability, proliferation, and differentiation. Bevacizumab(Avastin, Genetech, USA) is a monoclonal antibody against vascular endothelial growth factor. It is used in the treatment of cancer, where it inhibits tumor growth by blocking the formation of new blood vessels. The goal of this study is to identify the anti-tumor effect of Bevacizumab(Avastin) for oral squamous cell carcinoma cell lines. Human squamous cell carcinoma cell line(HN4) was used in this study. We examined the sensitivity of HN4 cell line to Bevacizumab(Avastin) by using in vitro proliferation assays. The results were as follows. 1. In the result of MTT assay according to concentration of Bevacizumab(Avastin), antiproliferative effect for oral squamous cell carcinoma cell lines was observed. 2. The growth curve of cell line showed the gradual growth inhibition of oral squamous cell carcinoma cell lines after exposure of Bevacizumab(Avastin). 3. In the apoptotic index, groups inoculated Bevacizumab(Avastin) were higher than control groups. 4. In condition of serum starvation, VEGFR-2 did not show any detectable autophosphorylation, whereas the addition of VEGF activated the receptor. Suppression of phosphorylated VEGFR-2 and phosphorylated MAPK was observed following treatment with Bevacizumab(Avastin) in a dose-dependent manner. 5. In TEM view, dispersed nuclear membrane, scattered many cytoplasmic vacuoles and localized chromosomal margination after Bevacizumab(Avastin) treatment were observed. These findings suggest that Bevacizumab(Avastin) has the potential to inhibit MAPK pathway in proliferation of oral squamous cell carcinoma cell lines via inhibition of VEGF-dependent tumor growth.

• 셀메드
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• 제1권1호
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• pp.5.1-5.3
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• 2011

Molecular events that cause tumor formation enhance a number of HOX genes, called switch genes, coding for RNApolymeraseII transcription factors. Thus, in tumor cells, RNApolymeraseII is more active than in other somatic cells. Amanita phalloides contains amanitin which inhibits RNApolymeraseII. Partial inhibition with amanitin influences tumor cell - but not normal cell - activity. To widen the treatment spectrum, dilutions of Amanita phalloides, containing amanitin, are applied to a patient with mammary duct cancer. For monitoring tumormarkers, different doses of amanitin are applied. The former duplication time of tumor growth represented three months; however within a period of 18 months the patient can be stabilized without further growth of the tumor. There are also no severe symptoms, no liver damage and no continuous erythrocyte deprivation. This new principle of tumor therapy shows high potential to provide a medical treatment.

• BMB Reports
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• 제50권12호
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• pp.599-600
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• 2017

Many studies have focused on the tumor suppressive role of $TGF-{\beta}$ signaling during the early stages of tumorigenesis by activating the target genes involved in cytostasis and apoptosis. We investigated the effects of $TGF-{\beta}$ inhibition on early tumorigenesis in the liver, by employing diverse inhibitory methods. Strikingly, $TGF-{\beta}$ inhibition consistently suppressed hepatic tumorigenesis that was induced either by activated RAS plus p53 downregulation or by the co-activation of RAS and TAZ signaling; this demonstrates the requirements for canonical $TGF-{\beta}$ signaling in tumorigenesis. Moreover, we found that Snail is the target gene of the $TGF-{\beta}$ signaling pathway that promotes hepatic carcinogenesis. The knockdown of Snail suppressed the early tumorigenesis in the liver, as did the $TGF-{\beta}$ inhibition, while the ectopic expression of Snail restored tumorigenesis that was suppressed by the $TGF-{\beta}$ inhibition. Our findings establish the oncogenic $TGF-{\beta}$-Smad-Snail signaling axis during the early tumorigenesis in the liver.

• BMB Reports
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• 제51권9호
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• pp.425-426
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• 2018

As highly conserved signaling cascades of multicellular organisms, Wnt and Hippo pathways control a wide range of cellular activities, including cell adhesion, fate determination, cell cycle, motility, polarity, and metabolism. Dysregulation of those pathways are implicated in many human diseases, including cancer. Similarly to ${\beta}-catenin$ in the Wnt pathway, the YAP transcription co-activator is a major player in Hippo. Although the intracellular dynamics of YAP are well-known to largely depend on phosphorylation by LATS and AMPK kinases, the molecular effector of YAP cytosolic translocation remains unidentified. Recently, we reported that the Dishevelled (DVL), a key scaffolding protein between canonical and non-canonical Wnt pathway, is responsible for nuclear export of phosphorylated YAP. The DVL is also required for YAP intracellular trafficking induced by E-cadherin, ${\alpha}-catenin$, or metabolic stress. Note that the p53/LATS2 and LKB1/AMPK tumor suppressor axes, commonly inactivated in human cancer, govern the reciprocal inhibition between DVL and YAP. Conversely, loss of the tumor suppressor allows co-activation of YAP and Wnt independent of epithelial polarity or contact inhibition in human cancer. These observations provide novel mechanistic insight into (1) a tight molecular connection merging the Wnt and Hippo pathways, and (2) the importance of tumor suppressor contexts with respect to controlled proliferation and epithelial polarity regulated by cell adhesion.

• Journal of Ginseng Research
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• 제14권2호
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• pp.244-252
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• 1990

Antitumor polyacetylenic alcohol, panaxytriol (Cl7 H26O3), was isolated and purified from a powder of the root of Pnnnx tin.1.encl C.A. Meyer. Panaxytriol possesses unusual property of being soluble in both water and organic solvents. Panaxytriol inhibited the growth of various kinds of human cultured cell lines in dose-dependent fashion in vitro. The in vivo effects of panaxytriol were tested against C57BL/6 mice transplanted with Bl6 melanomas. Panaxytriol (8 and 40 mg/kg) administered intra-muscularly(im) produced significant tumor growth delays in mice. Although a detailed mechanism of growth inhibition by panaxytriol is unknown, preliminary results appear to implicates a surface membrane site of action. And its action seems to be more dose-dependent than time-dependent. Finally, panaxytriol pharmacokinetics was evaluated in mice given single 8 mg/kg doses intraperitoneally (ip) or im. Serum panaxytriol content was measured using both tumor growth inhibitory assay and a gas chromatographic method. The maximum serum panaxytriol content after ip and im administration was 35.0 and 1.6 $\mu$g/ml respectively. These results indicate that the compound may act as cytotoxic substance even in patients.

• Natural Product Sciences
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• 제10권6호
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• pp.284-288
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• 2004

We have recently reported that red ginseng acidic polysaccharide (RGAP), isolated from Korean red ginseng (Panax ginseng C. A. Meyer), showed immunomodulatory antitumor activities, mainly mediated by nitric oxide (NO) production by macrophage. In this study, we examined the effect of RGAP on anticancer activity using lung carcinoma 3LL, sarcoma 180 and adenocarcinoma JC tumor cells transplanted into mice as well as antimetastatic activity using B16-F10 melanoma. When RGAP (300 mg/kg) were treated to mice implanted with one of the three kinds of tumor cells, the tumor weight significantly decreased compared with control mice. Tumor inhibition ratios of RGAP (300 mg/kg) in mice transplanted with lung carcinoma 3LL, sarcoma 180 and adenocarcinoma JC cells were 26.8%, 29.3% and 31.6%, respectively. Hundred mg/kg of RGAP did not cause a significant decrease in tumor weight compared with control group. When RGAP was administered i.p. with the dose of 100 and 300 mg/kg in B16-F10 melanoma-bearing mice, lung metastasis were reduced significantly in mice. Corrected phagocytic index was also remarkably increased by RGAP. These results suggest that stimulation of phagocytic activity of macrophages may be a mechanism for in vivo anticancer and antimetastasis activities of RGAP.