Estrogen-mediated epigenetic repression of large chromosomal regions through DNA looping.
Genome Res
; 20(6): 733-44, 2010 Jun.
Article
in En
| MEDLINE
| ID: mdl-20442245
ABSTRACT
The current concept of epigenetic repression is based on one repressor unit corresponding to one silent gene. This notion, however, cannot adequately explain concurrent silencing of multiple loci observed in large chromosome regions. The long-range epigenetic silencing (LRES) can be a frequent occurrence throughout the human genome. To comprehensively characterize the influence of estrogen signaling on LRES, we analyzed transcriptome, methylome, and estrogen receptor alpha (ESR1)-binding datasets from normal breast epithelia and breast cancer cells. This "omics" approach uncovered 11 large repressive zones (range, 0.35 approximately 5.98 megabases), including a 14-gene cluster located on 16p11.2. In normal cells, estrogen signaling induced transient formation of multiple DNA loops in the 16p11.2 region by bringing 14 distant loci to focal ESR1-docking sites for coordinate repression. However, the plasticity of this free DNA movement was reduced in breast cancer cells. Together with the acquisition of DNA methylation and repressive chromatin modifications at the 16p11.2 loci, an inflexible DNA scaffold may be a novel determinant used by breast cancer cells to reinforce estrogen-mediated repression.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Chromosomes, Human, Pair 16
/
Breast Neoplasms
/
Gene Silencing
/
Epigenesis, Genetic
/
Estrogens
Limits:
Animals
/
Female
/
Humans
Language:
En
Journal:
Genome Res
Journal subject:
BIOLOGIA MOLECULAR
/
GENETICA
Year:
2010
Document type:
Article
Affiliation country:
United States