Background microRNAs (miRNAs) are a class of non-coding, single-stranded RNA molecules which are crucial regulators of gene expression at the posttranscriptional level.Methyl-CpG binding domain proteins (MBPs) are transcription repressors through binding to methylated gene promoters.Recent studies have displayed that the effect of miRNAs on DNA methylation by targeting DNA methyltransferase or MBPs plays important role in various human cancers.