Figure 3

Interrogation of paediatric AML by clinically defined cytogenetic and FAB subtypes alongside DLEU2 promoter methylation. Paediatric AML diagnostic cytogenetic and subtyping analyses were specifically investigated, including those with known gene abnormalities and CN-AML cases. We investigate here the DNA Methylation of DLEU2/Alt1 promoter region to 95% CI. DNA methylation values range from 0.0 (0% no detected methylation) to 1.0 (100% fully methylated). The leukaemic group refers to diagnostic bone marrow from paediatric patients. Non-leukaemic group consists of CD sorted cell populations (CD19+, CD33+, CD34+, CD45+) and patient remission specimens. A. DNA methylation for DLEU2 HM450 probes (cg12883980, cg20529344, cg5394800) according to cytogenetic type, showing heterogeneous DNA methylation outcomes. Of note, a subset of patients with observable chromosome 11 and trisomy 8 abnormalities have a reduced DNA methylation compared to all other AML abnormalities. B. A subset of DLEU2 DNA methylation results for paediatric AML chromosome 11 and trisomy 8 abnormality patients from Figure 3A fall into a range akin to non-leukaemic specimens. Grouping these patients, regardless of clinical subtyping (M5a, M5b or M1/M2/M4), forms an additional sub-group, denoted here as ‘t(11)/+8’. The DNA methylation values obtained for probe cg12883980 are depicted, as an indication of the methylation at the DLEU2 promoter. t(11)/+8 are not differentially methylated compared to non-leukaemic specimens (t(11)/+8 sub-group Mean Methylation (MM) = 0.38, non-leukaemic MM = 0.32. p = 0.22). M5a, M5b and M1/M2/M4 AMLs (with the removal of t(11)/+8 patients) have become increasingly hypermethylated compared to non-leukaemic methylation (M5a MM = 0.81, M5b MM = 0.78, M1/M2/M4 MM = 0.87. p < 0.0001), and significantly different from t(11)/+8 (M5a/b p < 0.05; M1/M2/M4 p < 0.0001).