Our Science – Byun Website
Jung Shin Byun, Ph.D.
We are interested in defining the mechanism and roles of the metabolic regulators in the control of transcription during phenotypic reprogramming in breast cancer. We want to investigate the profile of genome-wide changes in the metabolic regulators associated with epigenetic control and histone modification during the phenotypic transitions in mammary epithelial cells.
It has been known that C-terminal binding protein (CTBP) is a dimeric nuclear protein involved in important functions in transcriptional regulation of mammalian cells. In the presence of NADH, CTBP recruits a variety of epigenetic regulators including histone deacetylase (HDAC), lysine specific demethylase (LSD), and histone methyltransferease (G9a) to the gene proximal promoter by interacting with DNA sequence-specific binding proteins. This provides a potential link between metabolism and control of the epigenetic landscape of the nuclei.
We have recently shown that CTBP recruits many negative regulators, including HDAC, in the presence of NADH to the BRCA1 promoter to turn off gene expression; however, under conditions of caloric restriction or caloric consumption, as with estrogen induction, the negative regulators are dismissed from the promoter with CTBP to allow an exchange for positive regulators containing p300/CBP complexes. This antagonism between CTBP and p300 is played out in many genes. Our recent genome-wide survey in MCF-7 reveals that CTBP regulates many different gene pathways that drive major hallmarks of cancer including genome instability, epithelial to mesenchymal transition, and tumor initiation cells/stem cell pathways.
We will continue to investigate the new roles of CTBP and metabolic imbalance in breast cancer invasion and metastasis using murine models for invasion and metastasis and we will characterize the impact
of CTBP in developmental windows associated with increased breast cancer risk using patient samples.
This page was last updated on 5/28/2014.