Culture, manipulation, and orthotopic transplantation of mouse bladder tumor organoids

The development of advanced tumor models has long been encouraged because current cancer models have shown limitations such as lack of three-dimensional (3D) tumor architecture and low relevance to human cancer. Researchers have recently developed a 3D in vitro cancer model referred to as tumor organoids that can mimic the characteristics of a native tumor in a culture dish. Here, experimental procedures are described in detail for the establishment of bladder tumor organoids from a carcinogen-induced murine bladder tumor, including culture, passage, and maintenance of the resulting 3D tumor organoids in vitro. In addition, protocols to manipulate the established bladder tumor organoid lines for genetic engineering using lentivirus-mediated transduction are described, including optimized conditions for the efficient introduction of new genetic elements into tumor organoids. Finally, the procedure for orthotopic transplantation of bladder tumor organoids into the wall of the murine bladder for further analysis is laid out. The methods described in this article can facilitate the establishment of an in vitro model for bladder cancer for the development of better therapeutic options.