Affiliations: [a] Department of Medicine, Division of Hematology and Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| [b] Current: Stritch School of Medicine, Loyola University Chicago, Chicago, IL, USA
| [c] Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI, USA
| [d] Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA
| [e] Current: Department of Pathology, John Hopkins University, Baltimore, MD, USA
Corresponding authors. Gary D. Stoner, Department of Medicine, Division of Hematology and Oncology, Medical College of Wisconsin, Milwaukee, WI, USA. E-mail: [email protected] and Li-Shu Wang, Division of Hematology and Oncology, Department of Medicine, Medical College of Wisconsin, RM C4930, 8701 Watertown Plank Rd, Milwaukee, WI, 53226, USA. Tel.: +1 414 955 2827; Fax: +1 414 955 6059; E-mail: [email protected].
Note:  Co-first author.
Note:  Dr. Gary Stoner was a former member of Department of Medicine at Medical College of Wisconsin.
Abstract: BACKGROUND:Esophageal squamous cell carcinoma (ESCC) is one of two subtypes of esophageal cancer, with high incidence and mortality rates in developing countries. OBJECTIVE:The current study investigated the potential chemoprotective effects of strawberries and aspirin against the development of rat esophageal papillomas, the precursors to ESCC. METHODS:Using a prevention model, we administered study diets to rats before, during, and after N-nitrosomethylbenzylamine (NMBA) treatment. The effects of the four diets were evaluated: the control diet, 5% strawberry powder in the control diet, 0.01% aspirin in the drinking water, and the combination of strawberries and aspirin. At week 25, we euthanized all the rats and collected their esophagi to quantify tumor incidence, multiplicity, and burden, as well as for molecular analysis. RESULTS:Both strawberries and aspirin significantly decreased esophageal tumor multiplicity, with the combination causing the most robust suppression. Aspirin alone and the combination decreased the total tumor burden in the esophagus. None of the diets had a significant effect on tumor incidence or the expression of COX-1 and COX-2. Strawberries and aspirin, alone and in combination, significantly suppressed squamous epithelial cell proliferation (PCNA). CONCLUSIONS:Strawberries, aspirin, and their combination exhibit chemoprotective effects against NMBA-induced esophageal tumors in rats.