Examining the role of microvesicles to develop prognostic and diagnostic assays

early disease detection is a logical, imperative goal necessary to improve dramatically the patient's odds for successful treatment strategies, survival and overall increase the quality of life. Given the continuous increase in health care cost mostly due to therapy focused on end stage sequelae of diseases rather than prevention and early detection, it has become increasingly clear that existing methods are limited and falling short of these goals. Therefore, there is urgent need to develop new prognostic and diagnostic assays that can detect initial stages of disease, predict accurately high and low risk patients as well as early patient response to therapy. The increased knowledge of microvesicle biology and the ability of microvesicles to enrich tissue-specific biomarkers, both in normal and pathological conditions suggest that they may provide a valuable avenue to identify diagnostic signatures, develop new diagnostic assays and help guide therapeutic approaches. Microvesicle formation is part of constitutive biological processes, such as turnover of intracellular and surface membranes during endocytosis and exocytosis, and normal cellular response to complement attack. Microvesicles are found in significant amounts in plasma, urine, cerebrospinal fluid and broncho-alveolar lavage fluid. Fragile molecules such as RNA molecules show resistance to degradation by RNAases in body fluids when packaged within microvesicles. For years identified as useless cellular debris, recent data seem to challenge the accepted dogma proposing a novel role for microvesicles, as conveyors of information among cells, tissues and even organs through horizontal transfer of proteins, lipids, and nucleic acids. As microvesicles are gaining increasing attention in the basic science circles as an alternative means of intercellular communication, they might also offer a novel way to think about disease detection and treatment. The variety of nucleic acids, proteins and lipids present in microvesicles has the potential to yield signature molecular patterns informative of the state of the human physiology or disease condition. Indeed, it has been recently shown that certain tumors shed microvesicles, which are rich in signaling molecules, second messengers, and genetic material that together constitute a unique, specific, and readily identifiable signature. Subsequently, microvesicles have been proposed as a novel biomarker source for various examining the role of microvesicles to develop prognostic and diagnostic assays