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ABSTRACT (Maximum 200 Words)The goal of DAMD17-98-1-8502 Idea Development Award is to investigate the role of 12-lipoxygenase (LOX) and its arachidonate product, 12(S)-hydroxyeicosatetraenoic acid (HETE), in human prostate cancer angiogenesis. The research progress during the funding period confirms the role of 12-LOX as a novel "angiogenic switch" governing prostate cancer angiogenesis and tumor growth. We found that 12-LOX increased the angiogenic potential of PCa cells by stimulating the production of VEGF, in addition to its arachidonate product 12(S)-HETE. The link between 12-LOX, a free fatty acid metabolizing enzyme, and VEGF, a putative angiogenic factor, is both novel and exciting, providing significant insights into our understanding of the regulation of VEGF expression during PCa progression. The study also found that 12-LOX and its lipid product, 12(S)-HETE, regulate VEGF expression at transcriptional level. The study also demonstrated the plausibility of using 12-LOX inhibitors such as BMD188 to inhibit prostate tumor angiogenesis and growth.14. SUBJECT
INTRODUCTIONThe goal of DAMD17-98-1-8502 Idea Development Award is to investigate the role of 12-lipoxygenäse (LOX) and its arachidonate product, 12(S)-hydroxyeicosatetraenoic acid (HETE), in human prostate cancer angiogenesis. In the first 18-month funding period, we found that 12-LOX, when constitutively expressed in PC-3 cells, increased the ability of cancer cells to stimulate endothelial cell migration in vitro and angiogenesis in vivo and the ability to form larger, rapidly growing tumors in an animal model. Further it was found that 12-LOX functions as an "angiogenic switch" in PCa cells by stimulating the production of 12(S)-HETE and vascular endothelial growth factor (VEGF). 12(S)-HETE activates p42/44 MAP kinase in endothelial cells and stimulates endothelial cell migration. Further, 12(S)-HETE enhances the secretion of VEGF in PC-3 cells. Increased VEGF gene expression in 12-LOX transfected PC-3 cells was confirmed by ELISA measurement of VEGF levels, Northern Blot and VEGF promoter activity analysis. These observations, made in the first 18-month of funding, support our hypothesis that 12-LOX play a contributory role in prostate cancer angiogenesis. The findings also significantly further our understanding of prostate cancer angiogenesis in general and lipid regulation of angiogenesis in particular. The finding...