Estrogen receptor-mediated long-range chromatin interactions and transcription in breast cancer

Estrogen induces the binding of ER alpha to thousands of locations in the breast cancer genome, preferring intergenic and distal regions rather than near the promoters of estrogen-regulated genes. With recent technological innovations in mapping and characterization of global chromatin organization, evidence now indicates ER alpha mediates long-range chromatin interactions to control gene transcription. The principles that govern how ER alpha communicates with their putative target genes via chromosomal interactions are also beginning to unravel. Herein, we summarize our current knowledge on the functional significance of chromatin looping in estrogen-mediated transcription. ER alpha collaborative factors and other players that contribute to define the genomic interactions in breast cancer cells will also be discussed. Defects in chromatin organization are emerging key players in diseases such as cancer, thus understanding how ER alpha-mediated chromatin looping affects genome organization will clarify the receptor's role in estrogen responsive pathways sensitive to defects in chromatin organization. (C) 2013 Elsevier Ireland Ltd. All rights reserved.