Robert T. Jensen, M.D.

Research Goal

The ultimate goal of our research is to understand the role of digestive hormones in health and disease and to allow better treatment of patients with Zollinger-Ellison syndrome.

Current Research

The Gastrointestinal Cell Biology Section is involved in research studying the cellular basis of action of gastrointestinal (GI) hormones (primarily bombesin-related peptides, gastrin-releasing peptide, neuromedin B, CCK-related peptides, and VIP secretin-related peptides) and clinical and laboratory studies on human gastric acid hypersecretory states such as Zollinger-Ellison syndrome.

The studies on GI hormones involve intracellular signaling cascades, especially tyrosine phosphorylation (primarily CCK, bombesin), molecular pharmacology of their receptors (especially bombesin-related peptides), and structure-function studies of various receptor ligands to develop selective agonists and antagonists. In addition, we are conducting studies on characterizing the bombesin-related receptor, BRS-3, as well as developing ligands to deliver receptor-specific chemotherapy to tumors ectopically expressing these receptors.

Studies of patients with Zollinger-Ellison syndrome involve clinical studies of the diagnosis, localization, and treatment of the gastrinoma and of multiple endocrine neoplasia type 1, which occurs in a portion of the patients. Laboratory studies involve the characterization of the molecular pathogenesis of gastrinomas and identification of useful prognostic factors.

Applying our Research

These studies will lead to insights that will help in the treatment of patients with GI disorders or with Zollinger-Ellison syndrome.

Research in Plain Language

Our research group is called the Gastrointestinal Cell Biology Section. We study hormones secreted by the stomach and intestine. These hormones help regulate digestion. We study how these hormones work at a cellular level. We also perform clinical and laboratory studies. In these studies, we focus on conditions in which the stomach releases too much gastric acid, a digestive fluid. One of these conditions is called Zollinger-Ellison syndrome.

Our research examines how cells receive and respond to digestive hormones. We study how their receptors trigger a cascade of reactions within the cell. We also investigate chemicals that bind to these receptors. We look at how their structure relates to their function. This research will help us develop agents that stimulate or block the receptors. Using that information, we are developing agents that bind only to specific receptors to treat tumors.

Our clinical studies involve patients with Zollinger-Ellison syndrome. In these studies, we focus on diagnosis, localization, and treatment of tumors. Our laboratory describes these tumors at the molecular level. The goal is to identify tumor characteristics that provide good information about patient outcomes.