perampanel and Glioblastoma

Epileptic seizures are frequent in patients with glioblastoma, and anticonvulsive treatment is often necessary. While clinical guidelines recommend all approved anticonvulsants, so far it is still unclear which of the available drugs is the best therapeutic option for treating glioma-associated seizures, also in view of possible anti-tumorigenic effects. In our study, we employed four patient-derived low-passage cell lines of glioblastoma and three cell lines of brain metastases, and challenged these cultures with four anticonvulsants with different mechanisms of action: levetiracetam, valproic acid, carbamazepine and perampanel. Cell proliferation was determined by bromodeoxyuridine incorporation. To further analyze the effects of perampanel, apoptosis induction was measured by caspase 3/7 activation. Glutamate release was quantified and glucose uptake was determined using 18F-fluorodeoxyglucose. Real-time polymerase chain reaction was employed to assess the expression of genes associated with glutamate release and uptake in brain tumor cells. Of the four anticonvulsants, only perampanel showed systematic inhibitory effects on cell proliferation, whereas all other anticonvulsants failed to inhibit glioma and metastasis cell growth in vitro. Metastasis cells were much more resistant to perampanel than glioblastoma cell lines. Glucose uptake was attenuated in all glioblastoma cells after perampanel exposure, whereas cell death via apoptosis was not induced. Extracellular glutamate levels were found to be significantly higher in glioblastoma cell lines as compared to metastasis cell lines, but could be reduced by perampanel exposure. Incubation with perampanel up-regulated glutamine synthetase expression in glioblastoma cells, whereas treatment with valproic acid and levetiracetam downregulated excitatory amino acid transporter-2 expression. Overall, our data suggest that perampanel acts as an anticonvulsive drug and additionally mediated anti-tumorigenic effects.

Topics: Anticonvulsants; Antineoplastic Agents; Apoptosis; Brain; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Epilepsy; Glioblastoma; Glutamic Acid; Humans; Nitriles; Pyridones; Receptors, AMPA; Seizures; Up-Regulation; Valproic Acid

Malignant gliomas like glioblastoma multiforme (GBM) release glutamate which causes excitotoxic death to surrounding neurons, thereby vacating room for tumor expansion. We report the case of a patient with GBM treated with the AMPA receptor blocker Perampanel (PER) in combination therapy for partial seizures. Histological work-up of a biopsy showed the tissue of a GBM without mutation of the isocitrate dehydrogenase 1 (IDH1) and without promotor methylation of the O6-methylguanine-DNA methyltransferase (MGMT). In a group of patients with IDH 1 wild type and non-methylated MGMT a median survival of 199 days after surgery (i. e. 6.5 months) was described. Our patient lived about one year longer. PER rendered our patient seizure-free for at least the last seven months of his life. It was well tolerated and did not increase the toxicity of temozolomide. When choosing an antiepileptic drug (AED) for the treatment of seizures in patients with malignant brain tumors, the efficacy, the tolerability and perhaps possible effects on tumor progression of the AED should be taken into account.

Topics: Alkylating Agents; Brain Neoplasms; Dacarbazine; Epilepsies, Partial; Excitatory Amino Acid Antagonists; Glioblastoma; Humans; Isocitrate Dehydrogenase; Magnetic Resonance Imaging; Male; Methylation; Middle Aged; Mutation; Nitriles; O(6)-Methylguanine-DNA Methyltransferase; Promoter Regions, Genetic; Pyridones; Survival Analysis; Temozolomide