• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.156-156
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• 2001

We have previously shown that H-ras, but N-ras, induces an invasiveness and cell motility in human breast epithelial cells (MCFl0A), while both H-ras and N-ras induce transformed phenotype. It has been recently shown that phosphatidylinositol 3-kinase (PI3K) plays an important role on cell migration. In the present study, we wished to investigate the functional role of PI3K in H-ras-induced invasive phenotype in MCF10A cells.(omitted)

• Toxicological Research
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• v.14 no.4
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• pp.569-575
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• 1998

One of the most frequent dejects in human cancer is the uncontrolled activation of the ms-signaling pathways. Significant evidence has accumulated to directly implicate members of the matrix metalloproteinases (MMPs) in tumor invasion and metastasis formation. We have previously shown that MMP-9 expression was significantly enhanced in the ras-tranfected HT1080 human fibrosarcoma cells at the mRNA level. In the present study, we investigated the roles of MMP-2 and -9 on the H-ras-induced invasive phenotypes of MCF 10A human breast epithelial cells and HT 1080 human fibrosarcoma cells. We show that H-ras is able to induce or enhance a signaling pathway leading to the enhancement of an invasive phenotype in both MCF10A and HT1080 cells as determined by matrigel invasion assay. We then examined the effect of H-ras activation on the expression of MMP-2 and -9 by measuring enzymatic activities and mRNA levels. Our data clearly demonstrated that H-ras prominently induces expression of MMP-2 in MCF10A cells, while it efficiently up regulates MMP-9 in HT1080 cells. Taken together, these findings suggest that the correlation between ras-mediated invasiveness and enhanced expression of MMPs may be cell type-specific: MMP-9 is closely associated with the invasive phenotype induced by ras activation in fibrosarcoma cells, whereas MMP-2 is more likely associated with it in epithelial cells.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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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)

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1111-1113
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• 2012

The ER-/PR+ breast tumor may be the result of a false ER negative result. The aim of this study was to investigate whether there is a difference in patient and tumor characteristics of the ER-/PR+ phenotype in an Asian setting. A total of 2629 breast cancer patients were categorized on the basis of their age, ethnicity, tumor hormonal receptor phenotype, grade and histological type. There were 1230 (46.8%) ER+/PR+, 306 (11.6%) ER+/PR-, 122 (4.6%) ER-/PR+ and 972 (37%) ER-/PR-. ER-/PR+ tumors were 2.5 times more likely to be younger than 50 years at diagnosis (OR: 2.52; 95% CI: 1.72-3.67). Compared to ER+/PR+ tumors, the ER-/PR+ phenotype was twice more likely to be associated with grade 3 tumors (OR:2.02; 95%CI: 1.00-4.10). In contrast, compared to ER-/PR- tumors, the ER-/PR+ phenotype was 90% less likely to be associated with a grade 3 tumor (OR: 0.12; 95%CI:0.05-0.26), and more likely to have invasive lobular than invasive ductal histology (OR: 3.66; 95%CI: 1.47-9.11). These results show that the ER-/PR+ phenotype occurs in a younger age group and is associated with intermediate histopathological characteristics compared to ER+/PR+ and ER-/PR- tumors. This may imply that it is a distinct entity and not a technical artifact.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.165.1-165.1
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• 2003

Transforming growth factor (TGF)-$\beta$, a hormonally active polypeptide found in normal and transformed tissue, is a potent regulator of cell growth and differentiation. In this study, we examined the effect of TGF-$\beta$ on invasion and motility of MCF10A human breast epithelial cells. TGF-$\beta$-induced migration and invasive phenotype of the parental MCF10A cells in a dose-dependent manner. Activity of MMP-2 promoter was increased by TGF-b, suggesting that the TGF-$\beta$-induced invasive phenotype may possibly be mediated by MMP-2 rather than MMP-9. (omitted)

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.234-234
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• 2002

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.214.2-215
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• 2001

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.156-156
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• 2001

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.200.1-200.1
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• 2000

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.174.1-174.1
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• 2002