A rat glioblastoma model with diffuse leptomeningeal gliomatosis induced by intracarotid injection of C6 glioma cells.

OBJECTIVE: A reproducible brain tumor model using experimental animals is required to study biological behavior and develop more potent antineoplastic drugs and effective therapeutic modalities. In this work, we attempted to establish diffuse leptomeningeal gliomatosis in the rat by intracarotid injection of C6 glioma cells. METHODS: Intracarotid injection of 1 x 10(7) C6 glioma cells in Wistar rats was performed to establish a primary diffuse leptomeningeal gliomatosis model. Ki-67 and matrix metalloproteinases (MMPs) immunohistochemistry staining were used to study the biological behavior of the developed tumor. Methodology, physical findings and histopathological features were also discussed. RESULTS: Leptomeningeal gliomas grew in all Wistar rats after the administration of 1 x 10(7) C6 glioma cells. Intracranial hypertension, weight loss and cachexia developed, and the median survival time was 18.0 +/- 2.9 days. The glioma mass distributed throughout the ventricles, the leptomeningeal regions in the brain and the brainstem, with typical pathological features of glioblastoma. The immunohistochemistry stainings showed high Ki-67 labeling index (42.1 +/- 10.3%), and concomitant overexpression of MMP-2 and MMP-9 suggested proliferation, invasion and angiogenesis potential. DISCUSSION: The advantage of the intracarotid injection route is the absence of an operative scar in the cranium. This established animal model is a novel model of primary diffuse leptomeningeal gliomatosis. This model probably can be used for pre-clinical testing in the progression of glioblastoma.

A gene delivery system with a human artificial chromosome vector based on migration of mesenchymal stem cells towards human glioblastoma HTB14 cells.

Mesenchymal stem cells (MSCs) have been expected to become useful gene delivery vehicles against human malignant gliomas when coupled with an appropriate vector system, because they migrate towards the lesion. Human artificial chromosomes (HACs) are non-integrating vectors with several advantages for gene therapy, namely, no limitations on the size and number of genes that can be inserted. We investigated the migration of human immortalized MSCs bearing a HAC vector containing the herpes simplex virus thymidine kinase gene (HAC-tk-hiMSCs) towards malignant gliomas in vivo. Red fluorescence protein-labeled human glioblastoma HTB14 cells were implanted into a subcortical region in nude mice. Four days later, green fluorescence protein-labeled HAC-tk-hiMSCs were injected into a contralateral subcortical region (the HTB14/HAC-tk-hiMSC injection model). Tropism to the glioma mass and the route of migration were visualized by fluorescence microscopy and immunohistochemical staining. HAC-tk-hiMSCs began to migrate toward the HTB14 glioma area via the corpus callosum on day 4, and gathered around the HTB14 glioma mass on day 7. To test whether the delivered gene could effectively treat glioblastoma in vivo, HTB14/HAC-tk-hiMSC injected mice were treated with ganciclovir (GCV) or PBS. The HTB14 glioma mass was significantly reduced by GCV treatment in mice injected with HAC-tk-hiMSCs. It was confirmed that gene delivery by our HAC-hiMSC system was effective after migration of MSCs to the glioma mass in vivo. Therefore, MSCs containing HACs carrying an anticancer gene or genes may provide a new tool for the treatment of malignant gliomas and possibly of other tumor types.