Background Cardiac glycosides are approved for the treatment of heart failure as Na + /K + pump inhibitors. Their repurposing in oncology is currently investigated in preclinical and clinical studies. However, the identification of a specific cancer type defined by a molecular signature to design targeted clinical trials with cardiac glycosides remains to be characterized. Here, we demonstrate that cardiac glycoside proscillaridin A specifically targets MYC overexpressing leukemia cells and leukemia stem cells by causing MYC degradation, epigenetic reprogramming and leukemia differentiation through loss of lysine acetylation. Methods Proscillaridin A anticancer activity was investigated against a panel of human leukemia and solid tumor cell lines with different MYC expression levels, overexpression in vitro systems and leukemia stem cells. RNA-sequencing and differentiation studies were used to characterize transcriptional and phenotypic changes. Drug-induced epigenetic changes were studied by chromatin post-translational modification analysis, expression of chromatin regulators, chromatin immunoprecipitation, and mass-spectrometry. Results At a clinically relevant dose, proscillaridin A rapidly altered MYC protein half-life causing MYC degradation and growth inhibition. Transcriptomic profile of leukemic cells after treatment showed a downregulation of genes involved in MYC pathways, cell replication and an upregulation of hematopoietic differentiation genes. Functional studies confirmed cell cycle inhibition and the onset of leukemia differentiation even after drug removal. Proscillaridin A induced a significant loss of lysine acetylation in histone H3 (at lysine 9, 14, 18 and 27) and in non-histone proteins such as MYC itself, MYC target proteins, and a series of histone acetylation regulators. Global loss of acetylation correlated with the rapid downregulation of histone acetyltransferases. Importantly, proscillaridin A demonstrated anticancer activity against lymphoid and myeloid stem cell populations characterized by MYC overexpression. Conclusion Overall, these results strongly support the repurposing of proscillaridin A in MYC overexpressing leukemia. Electronic supplementary material The online version of this article (10.1186/s13046-019-1242-8) contains supplementary material, which is available to authorized users.

Exposure to alcohol during in-utero development can permanently change the developmental programming of physiological responses, thereby increasing the risk of neurological illnesses during childhood and later adverse health outcomes associated with fetal alcohol spectrum disorder (FASD). There is an increasing body of evidence indicating that exposure to alcohol during gestation triggers lasting epigenetic alterations in offspring, long after the initial insult; together, these studies support the role of epigenetics in FASD etiology. However, we still have little information about how ethanol interferes with the fundamental epigenetic reprogramming wave (e.g., erasure and re-establishment of DNA methylation marks) that characterizes pre-implantation embryo development. This review examines key epigenetic processes that occur during pre-implantation development and especially focus on the current knowledge regarding how prenatal exposure to alcohol during this period could affect the developmental programming of the early stage pre-implantation embryo. We will also outline the current limitations of studies examining the in-vivo and in-vitro effects of alcohol exposure on embryos and underline the next critical steps to be taken if we want to better understand the implicated mechanisms to strengthen the translational potential for epigenetic markers for non-invasive early detection, and the treatment of newborns that have higher risk of developing FASD.

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