Download Epigenetics: Biologic Targets, Biomarkers and Role in Disease

Epigenetics: Biologic targets, Biomarkers and role in disease
Epigenetics refers to the heritable changes in gene expression which are not associated with sequence
changes. While genetic differences explain variation between species, and to some extent, the variation
between individuals of each species, epigenetic variation accounts for the vast differences in function
and appearance of tissues in each multicellular organism. Epigenetic regulation includes chromatin
organization and modification of histone tails to provide a “code” for the expression or silencing of
genes during differentiation. These states, unlike genetic alterations, are potentially reversible, and
thus, epigenetic programing is a target for modulation. Specific epigenetic changes may be marks for
normal phenotypes (stem cells vs. committed lineages), and may be used to define the differentiation of
cellular state. Epigenetic alterations are associated with disease states, and in the case of aging and
cancer, may be causally involved. The specific epigenetic alterations which are found in an individual
tumor may define that tumor’s phenotype for prognosis and for sensitivity to specific therapies.