Absence of global hypomethylation in promoter hypermethylated Mixed Lineage Leukaemia-rearranged infant acute lymphoblastic leukaemia

摘要

Background: Mixed Lineage Leukaemia (MLL)-rearranged acute lymphoblastic leukaemia (ALL) in infants represents a highly aggressive type of leukaemia that is often characterised by severe promoter CpG island hypermethylation. Consequently, MLL-rearranged ALL cells respond well to demethylating cytosine analogue drugs. In human cancer cells, enhanced promoter methylation is typically accompanied by global loss of methylation in non-promoter regions of the genome. In turn, global hypomethylation usually leads to geno-mic instability, which may have contributed to cancer development.