Effect of mitoxantrone liposomes on multidrug-resistant breast cancer cells

A major obstacle in efficacy of breast cancer chemotherapy is the emergence of multidrug resistance. We investigated modulation of multidrug resistance by liposome-encapsulated mitoxantrone in a drug resistant human breast MCF7R cell line and the influence of liposome composition. Neutral high phase-transition temperature and anionic low phase-transition temperature phospholipid liposomes, reduced the resistance factor from 142 to 15 and 38, respectively. The higher cytotoxicity obtained with mitoxantrone-encapsulation was not necessarily related to higher intracellular uptake. Our data suggest that liposomes, according to their lipid composition, may alter the P-glycoprotein function by plasma membrane stabilization and modulate multidrug resistance in human cancer.