Vascular Endothelial Growth Factor and Receptors in Breast Cancer

Experiments completed in the past year were designed to characterize the role of Vascular Endothelial Growth Factor VEGF and its receptors VEGFr in the progression of breast cancer. VEGF and VEGFr are known to be involved in tumor angiogenesis and many other vascular proliferative disorders. Since VEGF and VEGFr are intimately involved in generating the vascular invasion in tumors, they are likely to be important prognostic indicators. VEGF mRNA is alternatively spliced into 4 isoforms, while there are 2 high affinity receptors for VEGF. The relative roles and involvements of each isoform and receptor in cancer is unknown. Since VEGF can be regulated by estrogen, we have grown tumors human MDA-MB-231 and murine MXT-OVEX in ovariectomized mice implanted with either estradiol or placebo pellets. We proposed to study the effect of estrogen on the expression of the VEGF isoforms and receptors in the normal mammary gland and in breast cancers in ovariectomized animals.