Caveolin-1 inhibits anoikis and promotes survival signaling in cancer cells.

IntroductionThe cell biology of caveolaeCaveolae have garnered a great deal of attention during the last decade, as they appearto mediate multiple cellular functions, including clathrin-independent endocytosis,cholesterol efflux and regulation of intracellular signaling pathways (Razani et al., 2002;Parton, 2003). Defined as non-clathrin-coated, flask-shaped invaginations of the plasmamembrane, caveolae sometime appear also as juxtamembrane vesicles that occur singly orin clusters and are fairly uniform in size (50–100nm in diameter) (Anderson, 1998).Caveolae are related to membrane microdomains called lipid rafts, with which they sharean unusual lipid composition that differs from that of bulk cellular membranes in beingenriched with cholesterol and sphingolipids. Therefore, caveolae may be considered asubset of lipid rafts. Because of their unique lipid composition, membranes of lipid raftsand caveolae exhibit a liquid-ordered phase behavior that is intermediate in propertiesbetween the liquid crystalline phase of bulk cellular membranes and the gel phase of simplelipid bilayers composed of one or more saturated phospholipid species (Brown andLondon, 1997). The liquid-ordered phase of rafts and caveolar membranes turned out tobe quite useful, as it confers upon the membranes an insolubility in certain non-ionicdetergents at 4