Targeting autophagy with SAR405 alleviates doxorubicin-induced cardiotoxicity

Anthracycline antitumor agents, such as doxorubicin (DOX), are effective in the treatment of solid tumors and hematological malignancies, but anthracycline-induced cardiotoxicity (AIC) limits their application as chemotherapeutics. Dexrazoxane (DEX) has been adopted to prevent AIC. Using a chronic AIC mouse model, we demonstrated that DEX is insufficient to reverse DOX-induced cardiotoxicity. Although therapies targeting autophagy have been explored to prevent AIC, but whether novel autophagy inhibitors could alleviate or prevent AIC in clinically relevant models needs further investigation. Here, we show that genetic ablation of Atg7, a key regulator in the early phase of autophagy, protected mice against AIC. We further demonstrated that SAR405, a novel autophagy inhibitor, attenuated DOX-induced cytotoxicity. Intriguingly, the combination of DEX and SAR405 protected cells against DOX-induced cardiotoxicity in vivo. Using the cardiomyocyte cell lines AC16 and H9c2, we determined that autophagy was initiated during AIC. Our results suggest that inhibition of autophagy at its early phase with SAR405 combined with DEX represents an effective therapeutic strategy to prevent AIC.