News from CRG
Sometimes, the silencing of a gene is as important as its activation. Nonetheless, up to now, most studies on hormone-mediated gene regulation have focused on researching the factors that influence the activation of certain genes. Little attention has been paid to gene silencing. But researchers at the Centre for Genomic Regulation (CRG) have discovered that there is a mechanism of active repression in hormone-dependent breast cancer cells that acts on genes related with cell proliferation and death.
“Up to now, the emphasis has focused more on the fact that steroid hormones can augment the activity of certain genes, and little was known about the mechanisms by which these hormones can also repress or silence genes,” says Guillermo Vicent, main author of the study and researcher in the Chromatin and Gene Expression Group led by Dr. Miguel Beato.
In a study published in The EMBO Journal, Vicent and his team show that in the cell lines derived from breast cancer, some 1,000 genes are activated by the steroid hormone progesterone, but another 650 are repressed by it. “For the first time, we have described an active repression mechanism involving the progesterone receptor and a repressor complex made up of different proteins, among them the ATPase BRG1, the demethylase KDM1, the histone deacetylases HDAC1/2 and the protein HP1g,” adds the researcher.