Stem Cell Markers in Neoplasms and their Relationship with Progression-free and Overall Survival in Patients with Recurrence.

BACKGROUND: Gliomas account for 30% of primary brain tumors in adults, and despite the scientific progress in the field, recurrence is prevalent. Glioma Stem Cells (GSCs) can generate tumor cells in vivo and in vitro and they are associated with treatment resistance, tumor progression, and recurrence. Furthermore, the expression of SOX transcription factors (SOX1, SOX2, SOX9) in these cells is responsible for maintaining an oncogenic genotype and is associated with an aggressive tumor phenotype. The relationship between SOX transcription factors and their prognostic role in recurrent gliomas has not been described in detail. Therefore, we set out to describe the relationship between SOX expression and Progression-free Survival (PFS) and Overall Survival (OS) in patients with recurrent gliomas. METHODS: In this observational study, we have retrospectively analyzed 69 patients, of which 20 met the inclusion criteria. The clinical, radiological, and histopathological findings have been described, and survival analysis has been performed according to SOX expression for PFS and OS. RESULTS: We found SOX1, SOX2, and SOX9 to show a non-statistically significant trend with increasing histopathological grade, co-expressed with Ki67, a cell proliferation factor. CONCLUSION: There has been found an inversely proportional correlation between the degree of immunopositivity of SOX1 and OS. A higher SOX1 immunopositivity could predict a worse clinical prognosis. There has also been found an interaction between a pluripotent genotype (GSC) and cell proliferation.

Antiepileptogenic Effect of Retinoic Acid.

Retinoic acid, a metabolite of vitamin A, acts through either genomic or nongenomic actions. The genomic action of retinoids exerts effects on gene transcription through interaction with retinoid receptors such as retinoic acid receptors (RARα, ß, and γ) and retinoid X receptors (RXRα, ß, and γ) that are primarily concentrated in the amygdala, pre-frontal cortex, and hippocampal areas in the brain. In response to retinoid binding, RAR/RXR heterodimers undergo major conformational changes and orchestrate the transcription of specific gene networks. Previous experimental studies have reported that retinoic acid exerts an antiepileptogenic effect through diverse mechanisms, including the modulation of gap junctions, neurotransmitters, long-term potentiation, calcium channels and some genes. To our knowledge, there are no previous or current clinical trials evaluating the use of retinoic acid for seizure control.

Increase Signaling of Wnt/ß-Catenin Pathway and Presence of Apoptosis in Cerebellum of Kindled Rats.

BACKGROUND: Epilepsy is one of the most common neurological disorders in humans, and the role of the cerebellum in its physiopathology remains the subject of study. The Purkinje cells (PC), whose axons target the dentate and interpositus nuclei, form the main cerebellar output to forebrain structures involved in epilepsy. Cerebellar atrophy related to loss of PC has been reported in chronic epilepsy although its mechanism remains unclear. Taking into account that an overexpression of ß-Catenin has been related with cell death, here we present the signaling of ß-Catenin and the type of PC death in cerebellum of rats with seizures induced by the amygdaloid kindling model. METHOD: Using an immunohistochemistry and western blot assay for ß-Catenin, c-Myc, cyclin D3, TUNEL and caspase-3, in rats chronically implanted with electrodes, receiving 0, 3, 15, and 45 electrical stimuli. RESULTS: We found that such rats suffering a major number of stimuli showed the highest amount of marks assessed. CONCLUSION: We concluded that there is a higher activity of the Wnt/ß-Catenin pathway associated with increased number of stimuli may be related with the presence of apoptosis in the cerebellum treated with amygdala kindling. In this way, we suggest this pathway as one of the mechanisms by which cerebellar neurons death in generalized seizures.

Decreased Expression of Sox-1 in Cerebellum of Rat with Generalized Seizures Induced by Kindling Model.

The single feature of all malformations in cortical development is the clinical association with epilepsy. It has been proven that Sox-1 expression is essential during neurodevelopment and it is reported that Sox-1 knockout mice present spontaneous generalized seizures. Particularly in cerebellum, Sox-1 plays a key role in the Bergmann´s glia (BG) function, which allows the correct function of the Purkinje cells (PC). The targets of PC are the dentate and interpositus nuclei, which form the main cerebellar efferents involved in the physiopathology of epilepsy. Here we present the Sox-1 expression in cerebellum of rats during electric amygdala-kindling. We obtained seizures and once they had 3, 15 and 45 electric stimuli, the animals were sacrificed; the cerebellum was processed for inmunohistochemistry and Western blot analysis was performed to determine Sox-1 expression. Liquid chromatography was performed to examine gammaaminobutyric acid (GABA) and glutamate concentration. According to the literature, a progressive increase was observed in the electrographic and behavioral parameters. We found that Sox-1 expression in 15 and 45-stimuli groups had a statistically significant decrease as compared with controls, while the 3-stimuli group was similar to the control group. The concentration of glutamate was increased in rats with 45 stimuli. We can conclude that Sox-1 expression decreases as the number of seizures increases, and this is probably due to an altered glutamate regulation by a dysfunctional BG. In this way, we can suggest this mechanism as a one possible explanation of how the cerebellum participates in the pathophysiology of epilepsy.