5-Azacytidine modulates CpG methylation levels of EZH2 and NOTCH1 in myelodysplastic syndromes
Molecular mechanisms of response to hypomethylating agents in patients with myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) still remain largely unknown. Therefore, the effects of 5-Azacytidine (Aza) on clonal architecture and DNA methylation were investigated in this study.
Using next-generation sequencing (NGS), 30 myeloid leukemia-associated genes were analyzed in 15 MDS/CMML patients with excellent response to Aza. Effects on methylation levels were analyzed by quantitative methylation analysis using pyrosequencing for the global methylation marker LINE-1 in patients and myeloid cell lines. Various myeloid cell lines and a healthy cohort were screened for methylation levels in 23 genes. Selected targets were verified on the MDS/CMML cohort.
The study presented here showed a stable variant allele frequency and stable global methylation levels in responding patients. A significant demethylation of EZH2 and NOTCH1 was revealed in patients with Aza response.
A response to Aza is not associated with eradication of malignant clones, but rather with a stabilization of the clonal architecture. We suggest changes in CpG methylation levels of EZH2 and NOTCH1 as potential targets of epigenetic response to Aza treatment which may also serve as useful biomarkers after clinical evaluation.
Keywords5-Azacytidine Azacitidine Myelodysplastic syndromes CpG methylation EZH2 NOTCH1
This study was funded by the Interdisciplinary Center for Clinical Research (IZKF), Universitätsklinikum Jena, Germany.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
- Fenaux P, Mufti GJ, Hellstrom-Lindberg E, Santini V, Finelli C, Giagounidis A et al (2009) Efficacy of azacitidine compared with that of conventional care regimens in the treatment of higher-risk myelodysplastic syndromes: a randomised, open-label, phase III study. Lancet Oncol 10(3):223–232CrossRefGoogle Scholar
- European Medicines Agency (2018) EMA/450923/2016 – Vidaza, Annex I, summary of product characteristics. https://www.ema.europa.eu/en/medicines/human/EPAR/vidaza