Early Targets in Progression of Barrett's Esophagus to Esophageal Adenocarcinoma

Original Project Abstract Recently, the incidence of esophageal (EAC) and gastro-esophageal junction (GEJAC) adenocarcinoma has increased dramatically, and have a poor 5-year survival rate of less than 15%. When detected early, these patients can have a good clinical outcome following surgery. These observations underscore the importance of early cancer detection. Patients with Barrett’s esophagus (BE) are known to be at increased risk. Our overarching goal is to advance new methods of imaging to visualize the effects of spatial distribution of genetic alterations in BE by using novel imaging methods to evaluate tumor heterogeneity on the progression toward EAC. We propose a multi-institutional, trans- disciplinary, translational Research Center in the Barrett’s Esophagus Translational Research Network (BETRNet). Our mission is to build on our expertise in genomic characterization, peptide biochemistry, and clinical translation to achieve our ultimate goal to perform early cancer detection at an early stage where therapeutic intervention can be most effective. We will identify a complementary panel of genes that are overexpressed on the cell surface and will be used to develop and validate new peptide imaging agents. The targets chosen will address 3 important clinical needs: 1) Real-time endoscopic identification of pre-malignant lesions and early stage cancer to guide endoscopic resection; 2) Risk stratification of BE patients for timing of endoscopic surveillance; and 3) Detection of gastro-esophageal junction adenocarcinomas in patients without endoscopic appearance of BE. We will use state-of-the-art genomic tools to to identify early overexpressed gene targets that arise in progression of BE to EAC by providing comprehensive analyses of gene expression alterations, DNA copy number variation, and genetic mutations. We will select candidate genes that are expressed on the cell surface where they can be endoscopically imaged in vivo. We will rigorously validate the panel of candidate targets with quantitative RT-PCR and immunohistochemistry on tissue microarrays using an independent cohort of human esophagus specimens. We will use these targets to first identify and validate monomer peptides that are highly specific. We will then arrange monomer peptides in a dimer configuration to produce multivalent ligand target interactions to improve binding performance and allow for early targets to be detected at low levels of expression. We will use a flexible fiber multi-spectral endoscope that can pass through the working channel of a standard medical endoscope to detect multiple targets at the same time. Successful completion of these aims will provide an integrated multi-spectral imaging methodology to longitudinally visualize overexpressed molecular targets that drive progression of Barrett’s esophagus to esophageal adenocarcinoma. This innovative approach can serve as the foundation for validated preventive measures to improve patient management.