• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.119-120
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• 2003

One of the most frequent defects in human cancer is the uncontrolled activation of the ras-signaling pathways. Elevated p21 ras expression is associated with tumor aggressiveness in breast cancer including the extent of invasion into fat tissues. infiltration into lymphatic vessels and tumor recurrence, We demonstrate that H-ras, but not N-ras, upregulates matrix metalloproteinase(MMP)-2 expression and induces invasive phenotype in MCF10A human breast epithelial cells. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.165.2-165.2
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• 2003

Phosphatidylinositol 3-kinase (PI3K) and Rac play important roles that regulate cellular functions including cell survival and migration. In the present study, we investigated the functional roles of PI3K and Rac1 pathways in H-ras-induced invasive phenotype and motility of MCF10A cells. Akt, a downstream molecule of PI3K, was effectively activated not only by H-ras but also by N-ras, suggesting that the activation of PI3K pathway is not sufficient to induce metastatic potential of MCF10A cells. (omitted)

• BMB Reports
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• 제29권5호
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• pp.484-487
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• 1996

The matrix metalloproteinases (MMPs) are members of a unique family of proteolytic enzymes that degrade components of the extracellular matrix. Significant evidence has accumulated to directly implicate members of the MMPs in tumor invasion and metastasis formation. To investigate the correlation between ras oncogene and MMP gene expression in various tumor cells, we detected mRNAs for the ras, MMP-2 and MMP-9 (72 kD and 92 kD type IV collagenases, respectively) genes in nine human tumor cell lines. The ras gene was expressed in seven cell lines; MMP-2 in three; MMP-9 in two cell lines tested. There was no direct correlation between the ras oncogene and MMP expression. A clear difference in the mRNA expression between MMP-2 and MMP-9 was observed among the cell lines. As an approach to study the effect of the ras oncogene on metastasis, we examined the expressions of MMP-2 and MMP-9 in HT1080 cells transfected with the v-H-ras gene. MMP-9 expression was Significantly enhanced in the ras-transfected HT1080 cells compared with the nontransfectants while ras transfection did not affect the expression of MMP-2. These results suggest the possible inducing effect of the ras oncogene on the metastasis by activation of the MMP-9 gene in HT1080.

• Toxicological Research
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• 제17권
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• pp.293-297
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• 2001

The international pharmaceutical and regulatory communities had been recognizing the limited utility of conventional rodent carcinogenicity study particularly on the second species, mouse, after intense investigation of carcinogenicity data base worldwide, and a new scheme for carcinogenicity testing for pharmaceuticals was proposed at the Expert Working Group on Safety in the International Conference on Harmonization (ICH) in 1996. CB6F 1-Tg rasH2 mouse carrying human prototype c-Ha-ras gene with its own promoter/enhancer is one oj the new carcinogenicity assay model for human cancer risk assessment. Studies have been conducted since 1992 to validate the transgenic (Tg) mice for rapid carcinogenicity test-ing, short term (26 weeks) studies with genotoxic (by Salmonella), non-genotoxic carcinogens, genotoxic non-carcinogens, non-genotoxic non-carcinogens revealed relatively high concordance oj the response of the Tg mouse with classical bioassay across classes of carcinogenic agents. Mechanistic basis for carcinogensis in the model are being elucidated in terms of the role of overexpression and/or point mutation of the transgene. This report review the initial studies of validation of the model and preliminary results of on-going ILSI HESI ACT project will be presented.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.154-155
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• 2001

Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of proinflammatory agents and cytokines. COX-2 expression has been shown to be elevated in several different types of human cancer. The presence of oncogenic ras has been associated with constitutive induction of COX-2 in certain H-ras transformed cells, and COX-2 overexpression confers resistance to apoptosis.(omitted)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.141-141
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• 2002

Transforming growth factor-${\beta}$ (TGF-${\beta}$), a hormonally active polypeptide found in normal and transformed tissues, regulates cellular growth and phenotyphic plasticity. We have previously shown that H-ras, but not N-ras, induces invasive phenotype in MCF10A human breast epithelial cells.(omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.153.2-154
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• 2003

Extracts of Artemisia asiatica Nakai (Asteraceae) possess anti-inflammatory and anti-oxidative activities. Eupatilin (5,7-dihydroxy-3,4,6-tri-methoxy-flavone), one of the pharmacologically active ingredients derived from Artemisia asiatica, was shown to induce apoptosis in human promyelocytic leukemia (HL-60) cells (H.-J. Seo and Y.-J. Surh, Mutat. Res., 496, 191-198, 2001). In the present study, we examined the cytostatic effects of eupatilin in H-ras-transformed human breast epithelial (MCF10A-ras) cells. (omitted)

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.106-106
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• 2001

Matrix metalloproteases (MMPs) 는 다양한 세포에서 전이와 침윤성에 중요한 역할을 한다. MMP의 내인성 저해제인 tissue inhibitor of motalloprotease-2 (TIMP-2) 는 MMP-2에 높은 특이성을 지닌다. MMP-2와 TIMP-2사이의 불균형은 침윤성과 전이와 같은 병리학적 과정과 관계되는 extracellular matrix (ECM)의 퇴화를 일으킨다. TIMPs는 분비되는 분자이기 때문에 특정한 암의 유전자 치료에 사용될 가능성을 지닌다. 본 연구에서는 MMP-2가 H-ras에 의해 유도된 침윤성에 책임지는 것으로 보여지는 H-ras MCF10A 세포에 TIMP-2 유전자를 함유하는 retrovirus를 이용하여 연구하였다. TIMP-2 유전자를 함유하는 재조합 retrovirus는 PG13 세포를 infection 시키는데 사용되었다. H-ras MCF10A 세포는 PGl3 세포의 conditioned media로 처리되었을 때, gelatin zymography에서 MMP-2의 분비가 농도의존적으로 저해되었다. 또한 retrovirus에 의한 TIMP-2의 과잉 발현은 농도의존적으로 H-ras MCF10A 세포의 침윤성과 이동성을 상당히 감소시킨다. 이와 같은 실험 결과는 TIMP-2가 H-ras MCF10A 세포에서 MMP-2 분비와 세포의 침윤성, 이동성을 감소시키는 역할을 지닌다는 것과 TIMP-2 유전자를 함유하는 retrovirus가 효과적으로 MMP-2 분비, 세포 침윤성, 세포 이동성을 감소시켰다는 것을 보여 준다. 이는 암의 예방과 치료를 위한 유전자 치료법의 적용에 상당한 가능성을 제시한다.

• 한국수의병리학회:학술대회논문집
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• 한국수의병리학회 2001년도 추계학술대회 및 정기총회
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• pp.13-15
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• 2001

발암성시험연구에 사용되고 있는 형질전환 동물들은 랫드와 마우스 등이 있는데, 그 중 c-Ha-ras proto-oncogene 마우스 (ras H2 mice), v-Ha-ras 형질전환 마우스 (Tg.AC mice), pim-1 형질전환 마우스 및 p53 knockout 마우스 등이 발암유발물질에 감수성이 높아 현재 중기발암성시험에 이용되고 있다. (중략)

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.142-142
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• 2002