Amelioration of doxorubicin-induced cardiotoxicity by an anticancer-antioxidant dual-function compound, HO-3867

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 effects. HO-3867 (3,5-bis(4-fluorobenzylidene)-1-[(2,2,5,5-tetramethyl-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 cardioprotection 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 μM, 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 μM DOX. In normal cardiac cells, the loss of viability from combination treatment was significantly lower than that induced by 50 μM 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 improvement 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.