Progress towards the use of HIV protease inhibitors in cancer therapy.

Approaches to targeting the signaling pathways responsible for tumor survival are currently under intense investigation and there is ongoing rapid development of novel agents to target various signaling components that mediate tumor growth and survival. The development of agents as viable clinical interventions is, however, a relatively slow process when starting from novel compounds not previously tested in humans. An approach that could circumvent this delay in the development of molecular targeting agents for cancer therapy is to adopt drugs currently in clinical use for other diseases that have the desired effects on cell signaling and to test these for anti-cancer effects. This process is currently being followed with anti-retroviral drugs that inhibit AKT activation as candidates for the treatment of cancer in general, and is being pursued in particular for developing these agent as new means of sensitizing tumors to radiation.(1,2) Although such drugs have been approved for patient use, it is unclear whether or not these drugs can be safely combined with cytotoxic modalities such as radiation. It is this point that Plasteras et al. address in the current issue of Cancer Biology & Therapy, by examining the effects of combined treatment with radiation and HIV protease inhibitors.(3).