Analysis of Tissue Chimerism in Nude Mouse Brain and Abdominal Xenograft Models of Human Glioblastoma Multiforme: What Does It Tell Us About the Models and About Glioblastoma Biology and Therapy?

Abstract

S U M M A R YIn situ hybridization coupled to immunohistochemistry for antigens of interest allows unequivocal identification of tumor cells from reactive stroma cells and normal adjacent structures in human glioblastoma multiforme grafts transplanted into nude mice. With this methodology, we have explored the development of glioblastoma multiforme solid grafts transplanted into nude mouse brains or flanks. The brain transplants closely resembled the human situation, particularly in relation to differentiation and growth patterns. The morphological features of peritumoral reactive gliosis were similar to those observed in humans. A mouse glial stroma within the main tumor masses was also demonstrated. Kinetic studies showed that the compartment of isolated tumor cells that infiltrated host brains and the reactive gliosis constituted two cycling cell populations. Despite VEGF protein expression by tumor cells and some reactive astrocytes, the abnormally permeable microvascular beds were not hyperplastic. The observation of a non-infiltrative pattern of growth when grafts were established in host flanks demonstrated that the organ-specific environment plays a determining role in the growth and invasive properties of glioblastoma. The phylogenetic distance between man and mouse and the recipient immunoincompetence should not impose serious limitations on the use of this model for studying malignant glioma biology and therapy in vivo.

DDB2: A Novel Regulator of NF-κB and Breast Tumor Invasion

“…For histologic analysis, several slices from each lung per mouse were cut and fixed in 4% bufferedformaldehyde for 16 hours and embedded in paraffin. Several sections (5 mm thick) were processed for in situ hybridization to detect specifically the genotype of human infiltrating breast tumor cells with the fragmented human genomic DNA, which was first digoxigenin-labeled by a random primer-labeling method, as described previously (12). Digoxigenin was detected using specific alkaline phosphatase-labeled antidigoxigenin polyclonal antibodies from sheep (Roche) with a substrate solution containing 5-bromo-chloro-indolyl phosphate and nitroblue tetrazolium.…”

Rapid and Robust Transgenic High-Grade Glioma Mouse Models for Therapy Intervention Studies

“…Recently, more sophisticated models that might be useful for preclinical testing of anticancer agents are being developed by direct grafting of patientderived surgical specimens without cell culturing (7,8) and by engraftment of GBM-derived stem cell cultures (9,10). Also, genetically engineered mouse (GEM) models of glioma have been generated (11), which have been helpful in unequivocally identifying the driver mutations in these tumors.…”

A murine model of xenotransplantation of human glioblastoma with imunosupression by orogastric cyclosporin

“…We have verified the presence of histopathological characteristic aspects of human glioblastoma multiforme -hipercellularity, nuclear atypia, mitosis, abundant vascularization and necrosis, also with areas of pseudopalisading necrosis -that had been more intense at the fourth week. According to other studies 18,35 , endothelial proliferation is not usually observed in these type of models.…”

“…The GBM cells migration capacity is not determined only by genetic characteristics of the tumor cell but also depends of the interactions of its cells with the tissues microenvironment, which seems to be organ specific 35 . Therefore, these models are not adequate for the study of cellular migration, but they are useful in the study of proliferation 17,36 .…”