| Research Abstract |
We investigated influence of EPA and DHA to breast carcinogenesis. On the other hand, EPA and DHA are known as inhibitors of cyclooxygenase (COX) : enzyme, which regulated resolution of arachidonic acids. Recently, expressions of COX were reported in the tissue of breast cancer, gastric cancer, and colon cencer. Then, we studied significance of COX expression in breast cancer cell and relation to invasiveness of cancer cells in vitro. When cancer cells invade to capillary vessles or lymphatics, matrix metalloproteinases (MMPs) which resolve constructive protein of basement membrane and connective tissue are necessary. At present ten and few spices were isolated as MMPs product by ancer cells. MMP-2 and MMP-9 were known as showing enzyme activity resolve gelatin and type IV collagen, and the relation to breast cancer wes reported. However, there was no report that the relation between MMP and COX was evaluated, Therefore, we evaluated the relation between MMP-9 expression and COX using Hs578T,human breast cancer cell line. Hs578T cells showed induction of COX activity by addition of TPA to the culture medium. By Western blot analysis, COX-2 was overexpressed in the Hs578T cells. Gelatin zymography revealed expression of MMP-9 after addition of TPA.MMP-9 expression was reduced by indomethacin (IM) : inhibitor of COX.In conclusion, COX-2 activity plays an important role in expression of MMP-9.
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