Abstract 3675: Loss of Pkhd1 promotes intestinal tumorigenesis in Apc mice

Objectives: PKHD1 (Polycystic Kidney and Hepatic Disease 1), a causal gene for ARPKD (Autosomal Recessive Polycystic Kidney Disease), has been proposed to play a role in the colorectal carcinogenesis. This study is to explore the role of PKHD1 in colorectal carcinogenesis. Methods: Mouse model with Pkhd1 mutation (Pkhd1-/-) was used to mate with ApcMin/+ mouse in the same genetic background. The resulting ApcMin/+ mice with and without Pkhd1-/- alleles were randomly sorted into two experimental groups (i.e. Pkhd1-/-;ApcMin/+ n = 36; ApcMin/+ n = 23). Tumorigenic susceptibility of Pkhd1-/-;ApcMin/+ and ApcMin/+ mice was compared. The number, size, pathology of intestinal tumors in the mice were analyzed at the age of 1-, 3-, and 6-month. The survival rates were investigated in the two groups of mice. Results: There was no statistical difference in tumor number and size between 1-month-old ApcMin/+ and Pkhd1-/-;ApcMin/+ mice. However, the number and size of the intestinal tumors in 3- and 6-month-old Pkhd1-/-;ApcMin/+ mice were significantly increased compared with those of ApcMin/+ mice alone (P = 0.017,P = 0.022). In addition, the pathology of tumors was also analyzed between the two groups. There was no pathological difference between 1-month-old ApcMin/+ and Pkhd1-/-;ApcMin/+ mice. However, at 3-month-old, Pkhd1-/-;ApcMin/+ mice exhibited severer atypical hyperplasia in the intestinal tumor than those of ApcMin/+ mice; while at 6-month-old, focal necrosis were often seen in intestinal tumors of Pkhd1-/-;ApcMin/+ mice, but none from ApcMin/+ mice. Strikingly, tumor infiltration into the muscular mucosa was also seen in a 6-month-old Pkhd1-/-;ApcMin/+ mice. There was no statistically survival difference between ApcMin/+ and Pkhd1-/-;ApcMin/+ mice. Conclution: Loss of Pkhd1 promotes the intestinal tumorigenesis and induces tumor malignant transformation in ApcMin/+ mice. Citation Format: Bo Hu, Wei Li, Qingchao Qiu, Zhengxi He, Xiusheng He, Guanqing Wu. Loss of Pkhd1 promotes intestinal tumorigenesis in Apc mice. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3675.