NRF2-related transcriptomic alterations as a long-term effect of doxorubicin treatment for childhood acute lymphoblastic leukemia

The use of doxorubicin is associated with an increased risk of acute and long-term cardiomyopathy. Despite that the number of cancer survivors is growing constantly, little is known about the transcriptional mechanisms which progress in time leading to severe cardiac outcome. It is also unclear whether long-term transcriptomic alterations are related to an acute response to doxorubicin. We have sequenced miRNA from total plasma and extracellular vesicles (EVs) from 66 acute lymphoblastic leukemia (ALL) survivors treated with doxorubicin and 61 healthy controls (254 samples in total). We identified 94 and 33 TFs regulating differentially expressed miRNA in plasma and EVs compartments, respectively. For total plasma we found: HEY1, NRF2, HIF1A, NOTCH1, and for EVs: TGFB, ZEB1, ASCL2, PELP1, SIP1, TWIST1. Analysis of the data from patients with dilated and idiopathic cardiomyopathy revealed similarities with our data from EVs, especially in the activity of TFs related to epithelial-to-mesenchymal transition (EMT). To verify if similarities exist between acute and long-term response to doxorubicin, we performed experiments on cultured as well as we studied the role of NRF2, previously considered as an important player in acute response, in transcriptomic network upon doxorubicin treatment). KEGG analysis of miRNA targets for EVs indicates development of cardiomyopathy, whereas among GO process we found terms related to cardiac septum. In vitro experiments revealed that NRF2 is co-regulated with NOTCH effectors from HEY family, with known role in muscle regeneration. NRF2 and doxorubicin treatment contribute also to the dysregulation of TWIST family, important for the process of EMT.