Gene silencing in breast cancer is also very important
A study conducted by scientists at the Centre for Genomic Regulation has identified a mechanism by which genes that regulate cell proliferation and apoptosis are suppressed in hormone-dependent breast cancer cells.
Previous researches on hormone-mediated gene regulation mainly look at the activation of genes. However, the silencing of genes is also very important. The senior author Guillermo Vicent noted that previously scientists mainly explore how steroid hormones enhance gene activity, but how the hormones can silence genes remains unclear.
Vicent and colleagues studied gene silencing in breast cancer cells. They found that steroid hormone progesterone activates about 1,000 genes, and represses another 650 genes. The progesterone receptor and a repressor complex are involved in the repression process. The repressor complex consists of several proteins, including BRG1, HDAC1/2, HP1g, and KDM1.
As is known, proteins perform a vast array of functions in the cells, and they are encoded by genes. The expression of genes must be properly controlled. Transcription factors play key roles in regulating gene expression.
The research team found that the FOXA1 protein
can interact with BRG1, which is a component of the repressor complex. By doing so, FOXA1 signals the genes to be repressed to the progesterone receptor.
The study identified which components play a role in gene silencing, and could offer novel drug targets for the treatment of breast cancer.