Simple screening method for differentially methylated regions of the genome using a small number of cells

Novel tools for unbiased DNA differential methylation screening

DNA differential methylation screening approaches may be hypothesis driven (preselection of the loci to screen) or unbiased (screening precedes mapping of differentially methylated loci). The latter allow for the identification of sequences demonstrating ‘nonclassical’ methylation behavior in cancer and, thus, widen our concept of tumor biology. Extensive employment of unbiased screening methods is hampered by the troublesome procedures involved in physically mapping the identified differentially methylated DNA fragments. In this special report, we describe a positive experience of optimizing two screening methods, methylation-sensitive arbitrarily primed PCR and amplification of intermethylated sites, with a special focus on simplification, or even exclusion, of sequencing procedures. With our modifications, unbiased screening of DNA differential methylation acquires an easy-to-use workflow, including sophisticated experimental design, high-resolution analysis and simple genomic mapping of the fragments of interest.

Changing modified regions in the genome in hematopoietic stem cell differentiation

In the process of hematopoietic stem cell (CD133+ cell) differentiation, a drastic change in gene expression occurs which must be regulated by epigenetic mechanisms. One strategy for CD133+ cell differentiation analysis is to identify genomic DNA regions that have been modified in the process of differentiation. However, it is difficult to obtain large amounts of genomic DNA from uniform CD133+ cells. Based on this situation, we screened genomic DNA regions where modifications change during the process of differentiation in human CD133+ cells using differential methylation site scanning (DMSS), which is a method of identifying differentially methylated regions of the genome from a small number of cells. As a result, we cloned three DNA fragments which corresponded to centrosomal protein 68kDA (Cep68), TRIO and F-actin binding protein (TRIOBP), and AMP-activated protein kinase beta (AMPKb).