Abstract 926: IIKKa deletion amplifies renal transitional epithelial stem cells and initiates lethal invasive papillary urothelial cell carcinoma development

Abstract Urothelial cell carcinoma is the most common cancer of the renal pelvis or ureter in humans. Due to a lack of animal models, its pathogenic causes remain elusive. Here, we generated IkkαΔKsp mice lacking Ikkα specifically in epithelial cells of the developing kidney and genitourinary tract as well as renal tubules. The mutant mice developed invasive papillary urothelial cell carcinomas initiated from the pelvis, leading to hydronephrosis, and the animals eventually died. Depleting neutrophils or antibiotic treatment slowed down the development of phenotypes but did not rescue them, suggesting that epithelial-cell-autonomous aberrant alterations induced by Ikkα loss are critical for the initiation of urothelial cancer. Moreover, We found that the urothelial cell carcinomas in the mutant mice highly expressed cancer stem-cell markers such as Sox2, K15, p63, Nanog, and CD44, as well as FGFR3 and osteopontin (OPN). Thus, we hypothesize that Ikkα ablation-mediated OPN and FGFR3 overexpression regulates and amplifies CD44+ renal cancer-stem cells for tumor initiation. These alterations are shared with human papillary urothelial cell carcinomas. Citation Format: Xin Li, Feng Zhu, Chengfei Jiang, Yongmei Zhao, Bao Tran, Donna Butcher, Xiaolin Wu, Tross Debra, Yinling Hu. IIKKa deletion amplifies renal transitional epithelial stem cells and initiates lethal invasive papillary urothelial cell carcinoma development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 926.