New study unveils how cancer drug causes heart failure

A drug that kills cancer by damaging DNA also attacks heart muscle, which for some patients leads to heart failure, a new study by U.S. scientists shows. Scientists at the University of Texas MD Anderson Cancer Center and Texas Heart Institute at St. Luke's Episcopal Hospital have discovered how the drug, doxorubicin, attacks the heart, opening potential new options to prevent or minimize the drug's life- threatening side effects, according to the online edition of Texas Medical Center News released Thursday. Doxorubicin, brand names Adriamycin and Rubex, is a 50-year-old chemotherapy drug still widely used against a variety of cancers, including breast, ovarian, lung and bladder cancers as well as leukemia and lymphoma. "However, its use is limited by its cardiotoxicity. We're excited because we've identified the molecular basis for doxorubicin's damage to the heart," said Edward T.H., chair of MD Anderson's cardiology department and senior author of the study. Understanding the steps the drug takes when attacking the heart can help researchers identify those patients who are sensitive to heart damage by doxorubicin, Yeh was quoted as saying. "Once identified, those patients can be placed on alternative cancer drugs, or on special drugs to protect the heart," Yeh added. Yeh and his colleagues showed that when a protein known as Top2b was eliminated in the heart muscles of laboratory mice, the mice were protected against and avoided heart damage from the toxic side effects of doxorubicin. This finding suggests that Top2b triggers the drug's effect on cancer patients, said Yeh. "This is obviously a significant finding," he said, "and one with the potential to help scientists develop a blood test to predict patients' sensitivity to this drug, and to completely eliminate its dreaded side effects." Researchers from the Shanghai Jiao Tong University School of Medicine in China and the Robert Wood Johnson Medical School in New Jersey also participated in the study, said the report.