抄録
DNA polymerase B (pol-B) is an important contributor to genomic stability through its function in the DNA base excision repair pathway. Mutations in the pol-B gene have been associated with high levels of pol-B expression in human colorectal 1) and gastric cancer 2). We carried out histopathological examinations of 15 male and 21 female 2-year old transgenic mice engineered to over-express pol-B and maintained on a C57BL background. There was a high incidence of Brunner’s gland and mucosal hyperplasia in the duodenum seen in 27% of the males and 47.6% of the females. These proliferative lesions were mainly located in the area of Vater's papilla or at the junction of stomach and duodenum. Herniation / diverticulation of proliferating epithelial cells into muscular and serous layers of the affected intestines was also noted. Adenomas were diagnosed in 4.8% of the females. The incidence of proliferative duodenal lesions in these pol-B transgenic mice is considerably higher than previously reported incidences in aged C57BL mice 3,4). These findings may provide new insights relative to the relationship between pol-B expression and duodenal carcinogenesis.
(References)
1. Wang, L., et al. Cancer Res., 52, 4824-4827, 1992.
2. Tan, X.H., et al. Cancer Lett., 220, 101-114, 2005.
3. Rowlatt, C., et al. J. Nat.Cancer Inst., 43, 1353-1364, 1969.
4. Ward, J.M., et al. Cancer Res., 35, 1938-1943, 1975.
