A novel non-invasive monitoring assay of 5-azacitidine efficacy using global DNA methylation of peripheral blood in myelodysplastic syndrome

Abstract

Purpose:

Monitoring response and resistance to 5-azacitidine (AZA) is essential when treating patients with myelodysplastic syndrome (MDS). To quantify methylated DNA not only in the promoter region but also in the gene body, we established a single-molecule methylation assay (SMMA).

Patients and methods:

We first investigated the methylation extent (expressed as methylation index [MI]) by SMMA among 28 MDS and 6 post-MDS acute myeloid leukemia patients. We then analyzed the MI in 13 AZA-treated patients.

Results:

Whole-blood DNA from all 34 patients had low MI values compared with healthy volunteers (P<0.0001). DNA hypomethylation in MDS patients was more evident in neutrophils (P=0.0008) than in peripheral mononuclear cells (P=0.0713). No consistent pattern of genome-wide DNA hypomethylation was found among MDS subtypes or revised International Prognostic Scoring System (IPSS-R) categories; however, we found that the MI was significantly increased for patients at very high risk who were separated by the new cytogenetic scoring system for IPSS-R (P=0.0398). There was no significant difference in MI before AZA, regardless of the response to AZA (P=0.8689); however, sequential measurement of MI in peripheral blood demonstrated that AZA non-responders did not have normalized MI at the time of next course of AZA (P=0.0352).

Conclusion:

Our results suggest that sequential SMMA of peripheral blood after AZA may represent a non-invasive monitoring marker for AZA efficacy in MDS patients.

Keywords:

• myelodysplastic syndrome
• azacytidine
• peripheral blood
• methylation index

Acknowledgments

This research is supported by the Platform Project for Practical Research for Innovative Cancer Control from the Japan Agency for Medical Research and Development (AMED) (#15Ack0106073h0002) (K.O.), the Private University Strategic Research-Based Support Project (S1311016) (J.H.O., K.O.), and JSPS KAKENHI (grant no. 24501344 (J.H.O.) and 16K19186 (S.I.)). We thank Clare Cox, PhD, from Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.

Disclosure

Prof. Dr. Kazuma Ohyashiki reports personal fees from Celegene KK personal fees from Nippon Shinyaku Co., Ltd, during the conduct of the study; and personal fees from Novartis Pharma KK, personal fees from Janssen Pharmaceutical K.K, personal fees from Kirin Brewery KK, personal fees from Chugai KK, personal fees from Bristrol Myere Squib KK, and personal fees from Dainipon Sumitomo, outside the submitted work. The authors report no other conflicts of interest in this work.

Supplementary material

Table S1 Mutation analysis using the GeneRead DNAseq Targeted Panel V2 (Human Myeloid Neoplasms Panel; Qiagen)