Doctor of Philosophy, The Ohio State University, 2004, Public Health
Cancer incidence estimates for 2003 indicate that 18% of all cancers diagnosed originate in the aerodigestive tract, including the larynx, lung and bronchus, oral cavity, pharynx and esophagus. Specifically esophageal squamous cell carcinoma represents over 90% of all esophageal cancer cases. It is the 8th leading cause of cancer and the 5th leading cause of cancer death. Our laboratory has evaluated the chemopreventive potential of certain foods and a variety of single agents, including food-derived and synthetic compounds, in animal models of lung, colon and esophageal cancer. The goal of these studies was to determine the efficacy of food based and single agents for future use in human chemoprevention trials in individuals at high risk for esophageal cancer. Certain foods, particularly fruits and vegetables, contain a number of complex mixtures that possess preventative properties which may be active at multiple stages of carcinogenesis and / or have additive or synergistic effects. Following a food-based approach for cancer chemoprevention, we initially conducted a study to determine if a freeze-dried preparation of blueberries would inhibit N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis. A single-agent strategy for cancer chemoprevention typically involves the use of an agent which targets a specific process in carcinogenesis. Earlier studies have demonstrated that elevated polyamines may play an important role in the development of tumors in the human esophagus. Based on our findings, our second study evaluated the effect of difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, on post-initiation events in NMBA-induced rat esophageal tumorigenesis. Since black raspberries are effective at inhibiting tumors in both during the initiation and promotion / progression stages of carcinogenesis, our third study evaluated whether black raspberries might also exhibit therapeutic effects against esophageal cancer. The (open full item for complete abstract)
Committee: Gary Stoner (Advisor)
Subjects: Health Sciences, Public Health