DMMC Course: EPIGENETICS: FROM MECHANISMS TO MEDICINES

0940-1030 Tuesday 26 June 2007. O’Reilly Hall, University College Dublin.

Stem cell chromatin patterns - a blueprint for DNA hypermethlation?
Dr Joyce Ellen Ohm (Johns Hopkins University)

Adult cancers may derive from stem or early progenitor cells. Epigenetic modulation of gene expression is essential for normal function of these early cells, but is highly abnormal in cancers, which often exhibit aberrant promoter CpG island hypermethylation and transcriptional silencing of tumor suppressor genes and pro-differentiation factors. Compelling data suggests that bivalent, transcription-ready promoter chromatin patterns mediated by polycomb group proteins may leave these genes vulnerable to aberrant DNA hypermethylation and heritable gene silencing, and result in a directed, instructive program for silencing initiation reflective of a stem/progenitor cell of origin for adult tumors.