Antisense Strategies for Redirection of Drug Metabolism: Using Paclitaxel as a Model

The concept of metabolic redirection involves shifting the metabolism of a substrate away from one biochemical pathway to another (1 ). There are numerous instances in biological systems of a single substrate being metabolized by more than one enzyme with differing rates and activities, resulting in substantially different products. While an extremely large number of compounds are substrates for these enzymes, the types of reactions catalyzed are finite. This chapter focuses on Taxol�(paclitaxel; Fig. 1 ), an important antineoplastic agent that is used extensively in treating several types of malignancies including ovarian, breast, and lung, as well as melanomas (2 –5 ).