Rodent Brain Tumor Models for Neuro-Oncology Research

Neuro-Oncology research has dictated the need for animal models and since early 1970s rodent glioma models have been the choice model for investigators. These initial models were developed by exposing adult rodents to carcinogens to induce brain tumors. A panel of rodent tumor derived cells which form tumors upon reimplantation were then used to study tumor biology and response to therapeutics. The advent of immune compromised mouse models led to the expansion of these efforts to include human patient derived tumor cells. While these tumors captured the molecular background of GBM, they were poor models to understand immune micro-environment of brain tumors. Molecular biology advances further led to the development of murine models that generated spontaneous tumors. These models exquisitely recapitulate GBM molecular alterations in an immune competent environment. However the murine origin of these models often limits their utility for investigations of biological therapeutics that are inherently species specific. The advent of humanized mouse models heralds a new phase providing mice repopulated with human immune cells that bear human tumors. While these models are rarely isogenic, they are now considered the gold standard for research. However these models are cumbersome to use, and extremely expensive. Here we summarize the utility and challenges of the different rodent models frequently used in Neuro-Oncology research.