Antiepileptic therapy in patients with central nervous system malignancies

Antiproliferative activity of CD44 siRNA-PEI-PEG nanoparticles in glioblastoma: involvement of AKT signaling

Background and purpose

Glioblastoma multiforme (GBM) is the most invasive type of cancer which starts inside the brain. GBM cells were found to have similar properties to glioblastoma cancer stem cells. CD44 can be used as a marker of the cancer stem cells in a subset of glioblastoma tumor cells. Recent studies showed that CD44 is involved in developing cancer cells via the protein kinase B (PKB or AKT) signaling pathway. Therefore, this study aimed to investigate the CD44 mRNA silencing effects on the glioblastoma cell cycle via AKT signaling pathway.

Experimental approach

To determine CD44 expression in the samples of the patients with GBM, we used the analysis of data extracted from TCGA database. qRT-PCR and western blotting were used to evaluate the expression level of genes and proteins. Different cell cycles were evaluated by DAPI staining and flow cytometry.

Findings/Results

Bioinformatics results showed that CD44 expression level in GBM tumor samples is higher than in normal samples. Effects of poly (ethylene imine)-polyethylene glycol (PEI-PEG)-loaded CD44 siRNA in cell cycle showed that CD44 silencing could inhibit cell cycle in G0-G1 phase by more than 20% compared to the negative control (P < 0.05). Furthermore, PEI-PEG-loaded CD44 siRNA reduces the expression of cyclin D1 and CKD-4. According to our findings, this structure also prevented AKT phosphorylation at Thr-308 and Ser-473.

Conclusion and implications

Our results suggest that PEI-PEG-loaded CD44 siRNA may attenuate the cell cycle by suppressing AKT signaling pathway.

Pediatric brain tumors and epilepsy

Seizures are a common complication of pediatric brain tumors and their treatment. This article reviews the epidemiology, evaluation, and treatment of seizures in children with brain tumors. Seizures in known brain tumor patients may signify tumor progression or recurrence, or treatment-related brain damage, as well as other causes, including low drug levels and metabolic disturbances. Careful selection of antiepileptic medications is needed in this population. There are advantages to nonenzyme-inducing antiepileptic drugs including valproic acid, which has potential antitumoral properties as a histone deacetylase inhibitor. Tumor surgery cures many cases of pediatric tumor-associated seizures, and some children are controlled with anti-epileptic medication, however additional epilepsy surgery may be needed for refractory cases.