GliomaBrain NeoplasmsGlioblastomaAstrocytomaOptic Nerve GliomaBrain Stem NeoplasmsCell Line, TumorDacarbazineTumor Cells, CulturedAntineoplastic Agents, AlkylatingSupratentorial NeoplasmsNeoplasm GradingMice, NudeNeoplasm TransplantationGliosarcomaNeoplasm InvasivenessGene Expression Regulation, NeoplasticIsocitrate DehydrogenaseNimustineCell ProliferationCentral Nervous System NeoplasmsMeningiomaApoptosis