Exploring carbohydrates to design blood-brain barrier–penetrating, brain tumor-targeting anthracyclines

CARB 14

Waldemar Priebe, wp@wt.net, Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Unit 0422, Houston, TX 77030-1402
Doxorubicin and other clinically useful anthracycline antibiotics contain a rare amino sugar called daunosamine. This minor groove–binding daunosamine moiety is linked via an alpha glycosidic bond to an intercalating moiety (adriamycinone) to form doxorubicin, a 3-base-pair DNA-binding agent. The presence of a sugar moiety is essential for antitumor activity, and modifications of that sugar produce pronounced biological effects.

Development of chemotherapeutic strategies effective against brain tumors has been limited in part by the inaccessibility of the central nervous system to pharmacologic interventions. To identify new agents effective against brain tumors in vivo, we have developed an innovative approach incorporating our modular design of DNA-binding agents, allowing the creation of unique carbohydrate moiety–based libraries of DNA binders and potential topoisomerase II poisons. By systematically screening such libraries, we have identified highly apoptotic compounds that can circumvent P-glycoprotein- and MRP1-mediated resistance mechanisms, suggesting that such compounds will be potent cytotoxins against brain tumors as well as being able to cross the blood-brain barrier.

We discuss the design, synthesis, screening, selection, and unique properties of a lead compound, WP744, currently in phase I clinical studies in humans.