Implication of cancer stem cells in cancer drug development and drug delivery

Abstract

Conventional therapy against cancer by chemotherapy and radiation therapy has proven successful at decreasing bulk tumor size when cancer is diagnosed early enough. These therapeutic approaches, however, often result in recurrence years later. A number of studies have begun to identify a subpopulation of tumor-initiating cells that may be critical to early tumorigenesis and subsequent recurrence. These cells have been termed cancer stem cells (CSCs) and have been demonstrated to have properties of self-renewal, differentiation into other tumor cell types, and enhanced drug resistance. Given the growing body of evidence that CSCs play a key role in tumor biology in many cancer types, it is important to take into account the properties of these cells when developing novel cancer drugs and designing enhanced methods of drug delivery. This review covers some of the mechanisms by which CSCs escape conventional therapy as well as the potential approaches to targeting CSCs that may be used during cancer drug development. © 2013 Society for Laboratory Automation and Screening.