Effects of Two Types of Human Cells on Outgrowth of Human Glioma in Rats.

AIM: Glioblastoma multiforme (GBM) is one of the malignant brain tumors that occur most frequently. Despite advances in therapy techniques, the cure of GBM is a major concern. Accordingly, there is a lot of interest in devising novel approaches, such as stem cell therapy, to treat patients with GBM. The aim of this study was to investigate the effects of human bone marrow stem (BMS) cells as well as human olfactory ensheathing cells (OECs) on the outgrowth of U87 glioma in rats. MATERIAL AND METHODS: OECs and BMS cells were obtained from volunteers. After verification of the stem cell type by flow cytometry and immunocytochemistry (ICC), cells were labeled and injected into human glioma-bearing rats. Magnetic resonance imaging (MRI), Hematoxylin and Eosin (H&E), and Immunohistochemistry (IHC) were utilized to assess the properties of the groups. RESULTS: We found extensive migration and homing of the OECs and BMS cells towards the tumor area. H&E and IHC staining indicated that the grafted OECs survived and prevented the development of glioma. BMS cells supported proliferation and new vessel formation, and metastasis in glioma tissue. CONCLUSION: OECs and BMS cells can pass the blood brain barrier and reach the glioma mass. Therefore, this approach can be a potentially powerful method for the delivery of therapeutic agents to malignant brain tumors. In addition, these cells may be genetically modified in order to specifically express tumor-suppressive factors.

Induction of Human Glioma Tumor in Sprague-Dawley Rats with Intact Immune System.

AIM: Glioblastoma (GBM) is an aggressive brain tumor in humans. The median survival rate of patients is one year after the diagnosis. So, development of an animal model is necessary for the advances in the research treatment of GBM. The aim of this study was to investigate the capability of human glioma cells in inducing glioma tumors in rats with intact immune system. MATERIAL AND METHODS: U87 cells were implanted in the frontal lobe of rats without suppressing the immune system. We used magnetic resonance imaging (MRI), Hematoxylin-Eosin (H&E) and Immunohistochemical (IHC) staining to assess characteristics of tumor. RESULTS: At the 10th and 14th days of tumor inoculation, MRI images contained the tumor areas in the brain. All tumor-bearing rats developed tumors. The rats retained the morphology and histological characteristics of human glioma. Animals mimic GBM characteristics, such as mitotic activity, invasion, neovascularization, necrosis and pseudopalisading cells. IHC staining revealed tumor growth and progression in the tumor-bearing rats. CONCLUSION: This model is a standard system for studying the tumor phenotype, genotype, and for evaluating the efficacy of anti-cancer agents. It is a reliable, simple, inexpensive, and easily reproducible model, which may be a way for pre-clinical studies.