Chemosensitization of solid tumor cells by alteration of their susceptibility to apoptosis.

Chemosensitization strategies use the administration of one drug or agent to render cancer cells more susceptible to a second agent. Usually this involves enhanced drug metabolism, improvement of drug uptake or blockage of resistance mechanisms. Alteration of the susceptibility of cancer cells to apoptosis, the process of individual cell death by which many chemotherapeutic drugs act, shows particular promise for therapy in the future, and is the focus of this review. The dependence of cancer cells on non-neoplastic cells to form solid tumors allows anti-angiogenic therapy to be used in conjunction with chemotherapy to increase the therapeutic index. Chemosensitization strategies are set to become increasingly important in cancer therapy, allowing rational design of synergistic drug combinations at an earlier stage in drug development.