Obstacles and solutions to the use of cationic antimicrobial peptides in the treatment of cancer

Cationic antimicrobial peptides (CAPs) are cytotoxic agents that show promise for use in conjunction with current anti-cancer therapies to improve the specific killing of cancer cells. CAPs are small peptides that constitute an important innate defense mechanism against microbial pathogens in many different species. CAPs that are selectively cytotoxic for cancer cells, regardless of their growth rate or expression of multidrug-resistance proteins, show considerable promise as an alternative to conventional chemotherapy. Murine models of cancer indicate that many CAPs can target and kill cancer cells without causing undue harm to normal tissues. In order for an anti-cancer CAP to be clinically useful, the CAP must be specific for cancer cells, stable in serum, cost effective, and minimally immunogenic. Herein, obstacles and possible strategies to using CAPs in the treatment of cancer are discussed. Thus far, preclinical studies provide a strong rationale for the possible clinical use of CAPs in cancer patients.