In vivo MRI visualization of U87 glioblastoma development dynamics in the model of orthotopic xenotransplantation to the SCID mouse

Abstract

Glioblastoma is an extremely aggressive type of brain tumor. The average life span of patients with this diagnosis is 9–12 months. The development of adequate experimental models is required for the search of efficient approaches for the therapy and diagnostics of this disease. In this study, we used a number of magnetic resonance imaging (MRI) methods for describing the growth dynamics and cell morphology of U87 glioblastoma orthotopically xenotransplanted into mice of the immunodeficient SCID line. A comparison of the visualization efficiency of the developing tumor by means of T1- and T2-weighted images (obtained using an ultra-high field Bruker BioSpec (11.7 T) tomograph) demonstrated that T1-weighted images do not provide the required contrast of a pathological tissue relative to a healthy one (as opposed to T2-weighted images) due to the strong longitudinal magnetization of the tomograph’s magnetic field. of T1-weighted images, together with the intravenous introduction of paramagnetic nanoparticles (manganese oxide, MnO) significantly increased the tumor/normal tissue contrast in the MRI images. The study of the dynamics of the tumor cell growth by means of T2-weighted images demonstrated that the tumor development starts no earlier than 3 weeks after the intracranial introduction of the U87 cell culture (and the tumor cells grow exponentially). Thus, the methods of T1- and T2-weighted and MnO-enforced MRI were developed and characterized on the model of orthotopic xenotransplantation of U87 human glioblastoma cells into immunodeficient SCID animals, which can be used as the in vivo experimental model for checking new antitumor drugs and schemes of the treatment of the human brain’s oncological diseases.