PROJECT SUMMARY / ABSTRACT This application proposes a five-year research career development program focused on determining how glycosylation epitopes expressed during metaplasia and cancer contribute to these clinically significant cellular transformations. The applicant, Jeffrey W. Brown, M.D., Ph.D., is an Instructor of Medicine in the Division of Gastroenterology at Washington University School of Medicine. Since completing gastroenterology fellowship, Dr. Brown had worked in the laboratory of Jason Mills, where he has discovered a novel cellular process that he calls cathartocytosis [Greek: cellular cleansing] which is used by cells to efficiently dedifferentiate in the processes of metaplasia and cancer. He has subsequently determined that cathartocytosis is annotated by the glycan 3’-Sulfo-LeA/C and mice null for galectins that preferentially bind this epitope either fail to perform cathartocytosis or fail to package sulfomucins into mature granules. As glycobiology is a new field for Dr. Brown, Stuart Kornfeld will serve as his primary mentor with continued support from Jason Mills (Co-Mentor). Together, the candidate will be uniquely positioned to acquire the knowledge and skill set necessary to develop an independent research program investigating how specific glycosylation epitopes modulate tissue transformation and differentiation states in metaplasia and cancer. The expression and secretion of sulfomucins is uniformly present in Barrett’s esophagus and esophageal cancer, is the defining feature of type III [high-risk] gastric intestinal metaplasia, and is currently the best biomarker for detecting high-grade dysplasia and cancer in pancreatic cystic lesions. Using a comprehensive approach involving cell lines, organoid culture, and murine models, the experiments proposed herein will determine the proteome carrying 3’-Sulfo-LeA/C, the cellular signaling and transcriptional profile regulating its synthesis and secretion, as well as the molecular mechanism by which specific galectins modulate cellular differentiation. Ultimately, with the mentorship provided by Stuart Kornfeld, Jason Mills, and the research advisory committee, the knowledge and technical skills derived from the proposed experiments, and completion of the outlined career development plan, Dr. Brown will be well-prepared to establish an independent research program and is expected to be highly-competitive for R01 funding.

PROJECT NARRATIVE Neoglycosylation epitopes have been widely used to aid in the diagnosis as well as the management of metaplasia and cancers; however, the function of these epitopes is unknown. Here, we begin to study how these epitopes orchestrate the metaplastic and oncogenic transformations in foregut metaplasias and cancer using in vitro cell and organoid culture as well as murine models. Specifically, we focus on the transition from sialylation to sulfated epitopes, which has been associated with increased likelihood of progressing to gastric cancer by numerous groups over the past several decades.