Human Induced Pluripotent Stem Cells Recapitulate Breast Cancer Patients’ Predilection to Doxorubicin-Induced Cardiotoxicity

Doxorubicin (Adriamycin) is an anthracycline chemotherapy agent effective in treating a wide range of malignancies1 with a well-established dose-response cardiotoxic side-effect that can lead to heart failure2-4. Even at relatively low cumulative doses of 200–250 mg/m2, the risk of cardiotoxicity is estimated at 7.8% to 8.8%4,5. Doxorubicin-induced cardiotoxicity (DIC) can range from asymptomatic reductions in left ventricular ejection fraction (LVEF) to highly symptomatic heart failure6,7. At present, it is not possible to predict which patients will be affected by DIC or adequately protect patients who are at risk for suffering this devastating side-effect8. Here we demonstrate that patient-specific human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) can recapitulate individual patients’ predilection to DIC at the single cell level. hiPSC-CMs derived from breast cancer patients who suffered clinical DIC are consistently more sensitive to doxorubicin toxicity, demonstrating decreased cell viability, mitochondrial/metabolic function, calcium handling, and antioxidant pathway gene expression, along with increased reactive oxygen species (ROS) production compared to hiPSC-CMs from patients who did not experience DIC. Together, our data indicate that hiPSC-CMs are a suitable platform for identifying and verifying the genetic basis and molecular mechanisms of DIC.