Seed in soil, with an epigenetic view

it is becoming increasingly evident that discrete genetic alterations in neoplastic cells alone cannot explain multistep carcinogenesis whereby tumor cells are able to express diverse phenotypes during the complex phases of tumor development and progression. The epigenetic model posits that the host microenvironment exerts an initial, inhibitory constraint on tumor growth that is followed by acceleration of tumor progression through complex cell-matrix interactions. This review emphasizes the epigenetic aspects of breast cancer development in light of such interactions between epithelial cells (seed) and the tumor microenvironment (soil). Our recent research findings suggest that epigenetic perturbations induced by the tumor microenvironment may play a causal role in promoting breast cancer development. It is believed that abrogation of these initiators could offer a promising therapeutic strategy. (C) 2008 Elsevier B.V. All rights reserved.