Abstract 227: Cardiomyocytes from Human Pluripotent Stem Cells Predict Chemotherapy-Induced Cardiotoxicity

Abstract

The potential of human pluripotent stem cells-derived cardiomyocytes (hPSC-CM) to mimic human cardiac toxicity tests is largely unknown. Here we investigate the interaction between the chemotherapeutic agents Doxorubicin (DOX) and Lapatinib (LAP) and the protective effect of beta2 adrenergic signalling in hPSC-CM and murine myocytes. We hypothesized that death and survival pathways in hPSC-CM differ from those in animal-derived myocytes and thereby may predict better clinical outcome of chemotherapeutics. Human induced pluripotent or embryonic stem cell H7 cell lines were differentiated into cardiomyocytes (hiPSC-CM and hESC-CM, respectively), treated with drugs and stained with fluorescent dyes (Hoechst 33342, mitochondrial probes, effector caspases activation and impermeant nuclear dyes). Cell death profile was generated from high content screening and analysis (Cellomics). In isolated hPSC-CM, the anthracycline DOX induced apoptosis in a concentration-dependent manner (1-100µM), whereas LAP did not produce any toxicity. However, the combination of the two chemotherapeutic agents worsened the toxicity profile compared to DOX alone (p<0.001, n=12), consistent with clinical observations. In contrast, rat neonates were sensitive to LAP and showed a different cell death profile in DOX and drug combination experiments. Activation of apoptotic caspases in hESC-CM clusters was coincident with the dissipation of the mitochondrial membrane potential, while the potential was preserved in isolated cells during this phase. Beta2 adrenergic stimulation did not reverse DOX pro-apoptotic effect but modified toxicity-related nuclear events. In conclusion, we have shown that hPSC-CM reproduce the clinical adverse cardiac effects after treatment with anti-cancer drugs, making these cells a more relevant system for future drug development than animal-derived cells. However, our data suggest that cell death pathways involved may depend on culture condition for cardiomyocytes.