Carfilzomib triggers cardiotoxicity by suppressing SENP1-mediated deSUMOylation of DDX17.

Carfilzomib (Cfz) is a second-generation proteasome inhibitor approved for the treatment of relapsed/refractory multiple myeloma (RRMM). Previous studies have shown that Cfz is associated with a higher incidence of severe adverse cardiac effects than bortezomib (Btz); however, the underlying mechanisms remain to be elucidated. The aim of this study is to identify key regulators of cardiotoxicity induced by Cfz and to investigate the mechanisms by which these factors exert their effects. We establish a mouse model of cardiac toxicity induced by Cfz and confirm the phenotype through cardiac functional analysis, morphology assessment, myocardial fibrosis, and apoptosis analysis. We subsequently perform RNA sequencing to identify differentially expressed genes (DEGs) and further validate their functions and mechanisms. We find that Cfz induces myocardial hypertrophy and myocardial injury, along with the suppression of SENP1 expression in mouse heart tissues and <i>in vitro</i> cultured neonatal rat cardiomyocytes. Suppression of SENP1 exacerbates Cfz-induced injury and remodeling in cardiomyocytes by directly binding to and deconjugating the SUMO1-mediated SUMOylation of the RNA helicase DDX17. This process leads to a reduction in K-48 ubiquitin-linked polyubiquitination and degradation of DDX17, resulting in increased expressions of anti-apoptotic genes and maintenance of mitochondrial homeostasis. Therefore, the overexpression of SENP1 using AAV vectors alleviates Cfz-induced cardiotoxicity in mice. In summary, our findings reveal a previously unknown role of the SENP1-DDX17 axis in protecting against cardiotoxicity induced by Cfz, providing a potential foundation for developing therapeutic strategies to mitigate cardiac side effects in the clinical management of MM patients.