Glioblastoma multiforme (GBM) is the most aggressive form of brain cancer. GBM tumors grow within a fairly immunosuppressive tumor microenvironment and a relatively immune-privileged central nervous system. For patients diagnosed with GBM, prognosis remains poor with conventional therapies that include radiotherapy, chemotherapy, and surgery.
Immunotherapy drugs provide an alternate approach to treatment, aiming to bolster the immune system to eradicate disease. In the past, use of antibody therapies has been limited in GBM due to the obstruction caused by the blood brain barrier to therapy delivery. However investigation of immuno-oncology drugs may overcome this limitation as one may only need the immune cells to cross the blood brain barrier. Preclinical testing of this class of drugs requires the use of a unique set of preclinical models utilizing immunocompetent mice and orthotopic placement of the tumor cells within the brain. We have been utilizing orthotopic GBM models for more than 12 years.
GL261 is one of the most frequently used syngeneic murine glioma models available. We capitalize on our state-of-the-art imaging capabilities to further interrogate the pharmacology of this model by utilizing a GL261 cell line that expresses luciferase (GL261-luc2, Caliper Life Sciences). This allows for longitudinal, in vivo visualization of the tumor’s growth and response to treatment within the brain via bioluminescence imaging (BLI).
At Labcorp, we have acquired Xstrahl’s Small Animal Radiation Research Platform (SARRP) allowing for focal beam irradiation of the brain, sparing the rest of the mouse, including secondary lymphoid organs critical for mounting an immune response.