Amelioration of Doxorubicin-Induced Cardiotoxicity by an

Doxorubicin (DOX) is a drug commonly used for the treatment of cancer. The development of resistance to DOX is common, and high cumulative doses cause potentially lethal cardiac side ef- fects. HO-3867 (3,5-bis(4-fluorobenzylidene)-1-[(2,2,5,5-tetra- methyl-2,5-dihydro-1-hydroxy-pyrrol-3-yl)methyl]piperidin-4-one), a synthetic curcumin analog, has been shown to exhibit both anticancer and cardioprotective effects. However, its cardio- protection in the setting of a conventional cancer therapy has not been established. This work investigated the use of HO- 3867 and DOX to achieve a complementary outcome, i.e., increased toxicity toward cancer cells, and reduced cardiac toxicity. Combination treatment was investigated using DOX- resistant MCF-7 breast cancer cells [MCF-7 multidrug-resistant (MDR)] and BALB/c mice. Lower doses of HO-3867 and DOX (5 and 2.5 ? M, respectively) reduced viability of MCF-7 MDR cells to an extent significantly greater than that when either drug was used alone, an effect equivalent to that induced by exposure to 50 ? M DOX. In normal cardiac cells, the loss of viability from combination treatment was significantly lower than that in- duced by 50 ? M DOX. Increases in apoptotic markers, e.g., cleaved caspase-3, and decreases in fatty acid synthase and pAkt expressions were observed by Western blotting. Mice treated with both HO-3867 and DOX showed significant im- provement in cardiac functional parameters compared with mice treated with DOX alone. Reduced expression of Bcl-2 and pAkt was observed in mice treated with DOX alone, whereas mice given combination treatment showed levels similar to control. The study indicates that combination treatment of HO- 3867 and DOX is a viable option for treatment of cancer with reduced cardiotoxic side effects.