Hypoxia-induced pathways in breast cancer.

Hypoxia, a common consequence of solid tumor growth in breast cancer and other cancers, serves to propagate a cascade of molecular pathways which include angiogenesis, glycolysis, and alterations in microenvironmental pH. Hypoxia-inducible factors, heterodimeric DNA binding complexes composed of two subunits, provide critical regulation of this response. This review presents a synopsis of the genes induced by hypoxia in the context of breast cancer and discusses how upregulation of HIF-1 activity, and the homologous factor HIF-2, are not only fundamental for the adaptation to hypoxia but also may be critical for tumor progression. Copyright 2002 Wiley-Liss, Inc.