PARACRINE AUTOCRINE REGULATION OF BREAST-CANCER BY THE INSULIN-LIKE GROWTH-FACTORS/

focal environmental signals regulate the growth and development of bot h normal and malignant breast epithelium. Members of the insulin-like growth factor (IGF) family Likely influence both of these processes. T he localization of IGF2 to stroma specifically surrounding malignant b reast epithelium indicates that this growth factor may play a critical role in the genesis or maintenance of this transformed phenotype. Rec ent studies have sought to understand the mechanism by which IGF2 expr essing fibroblasts are localized to the periphery of malignant breast cancer cells. In addition, the consequences of the expression of IGF-s ignaling components Likely expand beyond their direct effects on mitog enesis. Indirect effects predominantly associated with the IGF2 recept or could also influence the invasive potential of breast tumor cells.