Proteomic Profiling of Adhesive Structures in Breast Cancer
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: When normal breast cells in the breast undergo a change called transformation, they acquire a different appearance and become more mobile. Despite these characteristic changes, the factors controlling this process are still poorly understood. We know that the loss of adhesion both between cells and to the cell matrix plays a critical role. Cell adhesion is modulated by several multi-protein complexes that transmit signals from the outside of the cell to its interior. In breast cancer, one of these complexes is associated with normal cell behavior and forms a stable structure while the other is associated with a pre-cancerous state and forms a transient structure. Many of the proteins that exist in these complexes are known and common to both, but new factors are constantly recruited to these sites to accommodate changes in the environment. Our goal is to better define the components of these structures using cutting-edge approaches. We believe that a more comprehensive list of components will not only open up new avenues for therapeutic advances in breast cancer but also provide basic biological ideas for other cancer types.
 
 
 
 
 
 
 
 I hypothesize that the factors that drive the formation of stable adhesive structures are distinct from the factors that promote transient adhesion sites. I am asking the simple question: what determines the formation of one structure over another? Furthermore, I suggest that defining the composition of proteins found in each type of adhesive structure will provide a fundamental basis for their assembly, and will provide a menu of potential drug targets.
 
 
 
 
 
 
 
 I am using well-defined breast cancer cells and placing them on substrates that mimic the signals from the normal physiological environment. By stimulating the cells with a specific growth factor, I can force them to change the type of adhesion structure--we then have a 2-state system for analysis. Following this change, I am using a combination of detergents and mechanical disruption to remove the majority of the cell and leave a footprint of the adhesion structure which I can pool. Once collected, the samples are labeled with a reagent called ICAT that can be used for downstream analysis by mass spectrometry. The ICAT reagents will provide me with information about the expression levels of proteins in the form of a ratio. Ratios that differ significantly represent potential protein targets for further biochemical examination. Those targets that are increased in the transient adhesive structures would be considered pro-tumorigenic and so, we will use strategies to reduce the expression of these targets, thus converting the adhesive sites to a more stable structure associated with normal appearance.
 
 
 
 
 
 
 
 Our goal is to identify unique molecules causally involved in cell transformation. The proposed study has two innovative elements: (1) We are using state-of-the-art proteomic tools and software to label and analyze the samples, and (2) The new isolation procedures refined in this lab to investigate the biological process will provide more significant samples not previously obtained.