Poloxamer 188 enhances apoptosis in a human leukemia cell line.

Poloxamer block copolymers have been studied in multiple applications as drug delivery systems (DDS). These A-B-A amphiphilic block copolymers up-regulate the expression of selected genes in cells and alter genetic responses to antineoplastic agents in cancer. One example is poloxamer 188, also known as pluronic F68, which may be promising as a carrier in DDS. To clarify the possible mechanistic role of pluronic F68 in several leukemia cell lines, we examined whether pluronic F68-inducible factors were capable of causing apoptosis. The influence of pluronic F68 on the cell lines was examined using a comprehensive analysis. It was found that treatment of K562 cells with 6% pluronic F68 resulted in G2/M phase arrest of the cell cycle, followed by caspase activation and the accumulation of apoptotic cells. When used as a carrier in a DDS, pluronic F68 may provide a synergistic effect on the drug of interest. Although the mechanisms behind the function of pluronic F68 are not fully understood, the results suggests that pluronic F68 may act as a useful carrier in DDS for the purpose of leukemia therapy.