Abstract Body: Introduction: Doxorubicin is a highly effective chemotherapy drug whose therapeutic utility is significantly hampered by its life-threatening adverse cardiac effects. The need for strategies to mitigate these cardiotoxic effects without diminishing its efficacy against cancer is critical in cardio-oncology.
Hypothesis: We hypothesize that through an integrated drug discovery pipeline, utilizing patient iPSC-derived cardiomyocytes (iCMs) and CRISPRi/a bidirectional pooled screens combined with small molecule screening and molecular docking, we can identify therapeutic targets that ameliorate doxorubicin-induced cardiotoxicity (DIC) while preserving its anticancer efficacy.
Methods: Our approach included patient iPSC-derived cardiomyocytes (iCMs), CRISPRi/a bidirectional pooled screens targeting druggable genome (~2000 genes) to identify candidate genes implicated in DIC, and small molecule screening alongside molecular docking to find potential inhibitors. Notably, carbonic anhydrase 12 (CA12) was identified as a primary hit for its role in DIC.
Results: The CRISPRi/a screens revealed several novel genes, including CA12, as potential contributors to DIC. Genetic inhibition of CA12 in iCMs enhanced cell survival, preserved sarcomere structure, and improved contractile function and calcium handling, effectively protecting against DIC. Furthermore, we discovered that a CA12 antagonist significantly attenuates DIC in both iCMs and mouse models. Mechanistic studies suggested that doxorubicin triggers CA12 activation, leading to a metabolic change towards glycolysis in cardiomyocytes, thereby exacerbating DIC by disrupting cellular metabolism and cardiac functions.
Conclusions: Our findings propose a novel therapeutic avenue to safeguard against doxorubicin-induced cardiotoxicity through the targeting of CA12, offering new direction for the development of more refined anticancer therapies that minimize cardiotoxic risk. This study sets the stage of combining CRISPRi/a screen with iPSC technology for future drug discovery endeavors aimed at eliminating off-target cardiotoxicities of chemotherapy agents.