Her2 is a receptor tyrosine kinase and cellular proto-oncogene that plays a major role in breast and other human cancers. Her2 is a member of the ErbB - epidermal growth factor receptor (EGFR) family. Under physiologic conditions, Her2 functions by heterodimerizing with EGFR, Her3 or Her4 and then activating its tyrosine kinase. We developed a reconstituted in vitro system to study the heterodimerization and enzyme activation of Her2. We will study the structure of Her2 heterodimers using two mass spectrometry (MS) approaches, termed chemical footprinting MS, and we will combine this with molecular dynamics simulations to obtain atom level interpretations of the MS results. Conclusions from MS and molecular dynamics will be functionally tested using Fluorescence Resonance Energy Transfer (FRET) experiments and mutagenesis experiments in cell lines. This proposal will produce a sustained, powerful influence by producing a number of scientific "firsts", chief among them is the first structural study of a Her2-Her3 heterodimer. Her2-Her3 heterodimers form a very potent signaling pair and it is has been shown that knocking down Her3 in Her2- positive breast cancer cell lines reverses oncogenic transformation. Achieving the aims of this project will advance scientific knowledge by providing new structural and functional information on Her2-Her3 and EGFR-Her2 heterodimers. Achieving the aims of this project will also advance clinical practice by identifying which Her2 and Her3 cancer associated mutations likely drive cancer cell growth and are sensitive to Her2 targeted drugs. This information will identify new patients who are likely to benefit from Her2 targeted drugs and will provide the key scientific findings to support a future breast cancer clinical trial.

Public Health Relevance

Her2 is an oncogene that plays a major role in breast, lung, stomach and other human cancers. Obtaining a detailed understanding of the activation process of Her2 will provide new scientific information on an important cancer protein and help guide the use of anti-cancer drugs that target this protein.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA161001-01A1
Application #
8439379
Study Section
Macromolecular Structure and Function E Study Section (MSFE)
Program Officer
Salnikow, Konstantin
Project Start
2013-03-01
Project End
2018-02-28
Budget Start
2013-03-01
Budget End
2014-02-28
Support Year
1
Fiscal Year
2013
Total Cost
$315,400
Indirect Cost
$107,900
Name
Washington University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Bose, Ron (2013) A neu view of invasive lobular breast cancer. Clin Cancer Res 19:3331-3
Collier, Timothy S; Diraviyam, Karthikeyan; Monsey, John et al. (2013) Carboxyl group footprinting mass spectrometry and molecular dynamics identify key interactions in the HER2-HER3 receptor tyrosine kinase interface. J Biol Chem 288:25254-64