Knock-down of FOXO3, GATA2, NFE2L2 and AHR promotes doxorubicin-induced cardiotoxicity in human cardiomyocytes

Recent advances in cancer therapy have substantially increased survival rates among patients, yet the prolonged effect of current treatment regimens with anthracyclines (ACs) often include severe long-term complications, notably in the form of anthracycline-induced cardiotoxicity (AIC). Despite known associations between AC treatment and AIC, a comprehensive understanding of the underlying molecular pathways remains elusive. This gap is highlighted by the scarcity of reliable therapeutic interventions, with dexrazoxane being the sole FDA-approved drug to mitigate AIC risks. This study aims at elucidating the transcriptional response of human cardiomyocytes (hCMs) to AC exposure by analyzing a previously generated RNA-sequencing dataset of cardiac spheroids subjected to clinically relevant doses of ACs. The analysis revealed a robust transcriptional response identified across various time points. We aimed at identifying important transcription factors (TFs) mediating AIC by employing predictive algorithms to highlight key TFs for further experimental validation. Using shRNA constructs, we further assessed the impact of these TFs on hCM response to doxorubicin (DOX) and revealed that these TFs had a notable impact on hCM survival upon DOX exposure. TFs FOXO3, GATA2, AHR and NFE2L2 were further investigated for their role in AIC including cell viability, DOX uptake, DNA damage repair and induction of apoptosis through Cleaved-Caspase 3. Our study demonstrated that eliminating FOXO3 and GATA2 made hCMs more vulnerable to DOX and the lack of GATA2, NFE2L2 and AHR led to significantly higher intracellular levels of DOX. Additionally, FOXO3 played a role in the repair of hCM DNA damage as we observed markedly enhanced levels of CDKN1A. We also noted significant increases in DNA damage through COMET-assays when FOXO3, GATA2, NFE2L2 and AHR were absent. Furthermore, we investigated the clinical relevance by comparing our results with those from a study based on hiPSC-CMs derived from patients with doxorubicin-induced cardiotoxicity, identifying overlapping TFs and their regulatory roles in critical cellular processes like the cell cycle and DNA repair. This approach not only advances the understanding of the molecular mechanisms behind AIC but also opens possible windows for new therapeutic approaches to mitigate the negative side-effects from patient AC treatment.