Effect of Chromatin Structure on the Extent and Distribution of DNA Double Strand Breaks Produced by Ionizing Radiation; Comparative Study of hESC and Differentiated Cells Lines.

Chromatin structure affects the extent of DNA damage and repair. Thus, it has been shown that heterochromatin is more protective against DNA double strand breaks (DSB) formation by ionizing radiation (IR); and that DNA DSB repair may proceed differently in hetero- and euchromatin regions. Human embryonic stem cells (hESC) have a more open chromatin structure than differentiated cells.

PPG peptide nucleic acids that promote DNA guanine quadruplexes.

Recent studies have shown that guanine-rich (G-rich) sequences with the potential to form quadruplexes might play a role in normal transcription as well as overexpression of oncogenes. Chemical tools that allow examination of the specific roles of G-quadruplex formation in vivo, and their association with gene regulation will be essential to understanding the functions of these quadruplexes and might lead to beneficial therapies. Properly designed peptide nucleic acids (PNAs) can invade G-rich DNA duplexes and induce the formation of a G-quadruplex in the free DNA strand.