Histone modification profiling in normal and transformed human embryonic stem cells using micro chromatin...

Comparing normal human embryonic stem cells (hESCs) to those that have acquired cellular properties of neoplasm provides a unique opportunity to study the distinguishing molecular features of human cellular transformation. As global alterations in the epigenetic landscape are a common feature of cancer, we sought to investigate the loci-specific and global differences between normal and transformed hESCs using ChIP-PCR and ChIP-microarray (also known as ChIP-chip). Here, specific emphasis was placed on optimizing ChIP for low cell numbers (termed micro-ChIP; μChIP) towards applications where the target population is rare, such as the case for somatic human tumors containing a low frequency of cancer stem cell populations and for single-colony analysis of embryonic and induced pluripotent stem cells emerging from initial derivation. Using these methods, we suggest that μChIP-PCR and microarray analysis is thus a powerful technology for epigenetic profiling of cell populations relevant to developmental biology, cancer, and regenerative medicine where target populations regulating the biological process can only be isolated in small numbers.