Multidrug-Resistance Transporters

Abstract

Approximately half of the one million new cancer cases annually in the United States will be treated with systemic chemotherapy. Unfortunately, this therapy will fail for the majority of these patients due to resistance of the tumors to the drugs. There are numerous mechanisms through which tumors become resistant to drugs; this chapter is limited to the action of a set of proteins known as the multidrug resistance (MDR) transporters. Following a brief discussion of the structure and function of the multidrug resistance transporters, this chapter focuses on the role of these proteins in the absorption and disposition of drugs and the potential consequences of modification of their function.