They applied an analysis known as ChIP sequencing to study the protein's interactions with genes that comprise the entire mouse genome, and found it occupied the regulatory region of genes governing chromosomal stability with high incidence.
They went on to show cyclin D1 promoted aneuploidy and chromosomal rearrangements typically found in cancers.
Faulty chromosomeseither too many or too few, or even ones that are the wrong shape or sizehave been shown to be the crux of many cancers. However, a major question of cancer genetics is the mechanisms of CIN. What causes the breakdown in chromosomal stability?
As cyclin D1 expression is increased in the early phases of tumorigenesis, cyclin D1 may be an important inducer of CIN in tumors.
To analyze the association between CIN and cyclin D1 expression in the context of breast cancer, the team aligned an expression of a 70-gene set with the highest CIN score against over 2,000 breast cancer samples. They stratified the samples based on previously described subtypes and aligned them with cyclin D1 expression profiled across the dataset.
A significant correlation among CIN, cyclin D1 and the luminal B subtype was identified, and it was apparent that the relationship between these levels was subtype specific.
"Interestingly, previous studies have presented contradictory results," Dr. Pestell says. "Many studies have suggested a positive correlation between cyclin D1 expression and outcomes, while others have shown reduced survival. Here, we've dug deep, using a genome-wide analysis, and found that overexpression of the protein appears to be directly associated with the genes involved in CIN and this correlates with the luminal B subtype."
Drugs targeting chromosomal instability for cancer therapy have been explored, but a sub-stratifica
|Contact: Steve Graff|
Thomas Jefferson University