Molecular subtype-specific immunocompetent models of high-grade urothelial carcinoma reveal differential neoantigen expression and response to immunotherapy

R Saito, CC Smith, T Utsumi, LM Bixby, J Kardos… - Cancer research, 2018 - AACR
R Saito, CC Smith, T Utsumi, LM Bixby, J Kardos, SE Wobker, KG Stewart, S Chai
Cancer research, 2018AACR
High-grade urothelial cancer contains intrinsic molecular subtypes that exhibit differences in
underlying tumor biology and can be divided into luminal-like and basal-like subtypes. We
describe here the first subtype-specific murine models of bladder cancer and show that
Upk3a-CreERT2; Trp53L/L; PtenL/L; Rosa26LSL-Luc (UPPL, luminal-like) and BBN (basal-
like) tumors are more faithful to human bladder cancer than the widely used MB49 cells.
Following engraftment into immunocompetent C57BL/6 mice, BBN tumors were more …
Abstract
High-grade urothelial cancer contains intrinsic molecular subtypes that exhibit differences in underlying tumor biology and can be divided into luminal-like and basal-like subtypes. We describe here the first subtype-specific murine models of bladder cancer and show that Upk3a-CreERT2; Trp53L/L; PtenL/L; Rosa26LSL-Luc (UPPL, luminal-like) and BBN (basal-like) tumors are more faithful to human bladder cancer than the widely used MB49 cells. Following engraftment into immunocompetent C57BL/6 mice, BBN tumors were more responsive to PD-1 inhibition than UPPL tumors. Responding tumors within the BBN model showed differences in immune microenvironment composition, including increased ratios of CD8+:CD4+ and memory:regulatory T cells. Finally, we predicted and confirmed immunogenicity of tumor neoantigens in each model. These UPPL and BBN models will be a valuable resource for future studies examining bladder cancer biology and immunotherapy.
Significance: This work establishes human-relevant mouse models of bladder cancer. Cancer Res; 78(14); 3954–68. ©2018 AACR.
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