Medulloblastoma (MB) is a malignant primary brain tumor with poor prognosis. MB-derived CD133/Nestin double-positive cells (MB-DPs) exhibit cancer stem-like cell (CSC)-like properties that may contribute to chemoradioresistance, tumorigenesis and recurrence. In various tumors, signal transducer and activator of transcription 3 (STAT3) upregulation including MB which can regulate the expression of Nestin. Celecoxib, a selective COX-2 inhibitor, has been shown to potentially reduce STAT3 phosphorylation. The aim of the present study was to investigate the role of celecoxib in enhancing the effects of ionizing radiotherapy (IR) on MB-DP. MB-DPs and MB-derived CD133/Nestin double-negative cells (MB-DNs) were isolated from medulloblastoma cell line Daoy. Then, both of them were treated with celecoxib in different concentrations, and cell viability was assessed. The assays of cell survival, sphere formation, radiosensitivity, colony formation, apoptotic activity and mouse xenografting experiments in MB-DPs and MB-DNs treated with celecoxib alone, radiation alone, or celecoxib combined with radiation were further evaluated. We isolated MB-DPs from MB cell line Daoy, which exhibited typical CSC-like characteristics. Microarray analysis and Western blotting both indicated the upregulation of Janus kinase (JAK)-STAT cascade and STAT3 phosphorylation. Incubation with celecoxib dose-dependently suppressed the CSC-like properties and enhanced the IR effect on the induction of apoptosis, as detected by TUNEL assay and staining for Caspase 3 and Annexin V. Finally, celecoxib also enhanced the IR effect to suppress tumorigenesis and synergistically improve the recipient survival in orthotopic MB-derived CD133/Nestin double-positive cells (MB-DP cells) bearing mice.
Purpose: Tumor hypoxia is one of the crucial microenvironments to promote therapy resistance (TR) in glioblastoma multiforme (GBM). Livin, a member of the family of inhibitor of apoptosis proteins, contributes antiapoptosis. However, the role of tumor hypoxia in Livin regulation and its impact on TR are unclear.Experimental Design: Livin expression and apoptosis for tumor hypoxic cells derived from human glioblastoma xenografts or in vitro hypoxic stress-treated glioblastoma cells were determined by Western blotting, immunofluorescence imaging, and annexin V staining assay. The mechanism of hypoxia-induced Livin induction was investigated by chromatin immunoprecipitation assay and reporter assay. Genetic and pharmacologic manipulation of Livin was utilized to investigate the role of Livin on tumor hypoxia-induced TR in vitro or in vivo.Results: The upregulation of Livin expression and downregulation of caspase activity were observed under cycling and chronic hypoxia in glioblastoma cells and xenografts, concomitant with increased TR to ionizing radiation and temozolomide. However, knockdown of Livin inhibited these effects. Moreover, hypoxia activated Livin transcription through the binding of hypoxiainducible factor-1a to the Livin promoter. The targeted inhibition of Livin by the cell-permeable peptide (TAT-Lp15) in intracerebral glioblastoma-bearing mice demonstrated a synergistic suppression of tumor growth and increased the survival rate in standardof-care treatment with radiation plus temozolomide.Conclusions: These findings indicate a novel pathway that links upregulation of Livin to tumor hypoxia-induced TR in GBM and suggest that targeting Livin using cell-permeable peptide may be an effective therapeutic strategy for tumor microenvironmentinduced TR.
A number of approaches are available for stereotactic brainstem biopsy. Surgical approach should be tailored, according to the location neurological function, with special concern for the patients' safety. In selected condition, frameless stereotaxy biopsy also provides competed diagnostic yield.
We consider this hybrid surgery to be a feasible and good alternative surgical procedure for the treatment of CTO of the internal carotid artery.
Background: Due to the potential consequences of post-traumatic epilepsy (PTE) exacerbating secondary injury following traumatic brain injury (TBI), the use of antiepileptic drugs (AEDs) is an accepted option for seizure prophylaxis. However, there is only a paucity of data that can be found regarding outcomes surrounding the use of AEDs. The purpose of this retrospective study is to evaluate whether the prophylactic administration of AEDs significantly decreased the incidence of PTE, when considering the severity of TBI. Methods: All trauma patients who had been newly diagnosed with TBI from January 1, 2010 to December 31, 2017 were retrospectively analyzed. Statistical comparisons were made using the chi-square test, Mann-Whitney U test, and Cox regression modeling. After excluding any exposed subjects with no appropriate match, patients who had received AED prophylaxis were matched by propensity score with those who did not receive AEDs. All of the TBI populations were followed up until June 30, 2018. Results: We identified 1316 patients who met the inclusion and exclusion criteria in our matched cohort through their propensity scores, where 138 patients had been receiving prophylactic AEDs and 138 patients had not. Baseline characteristics were similar in gender, age, Glasgow Coma Scale (GCS) scores, and risk factors of PTE including skull fracture, chronic alcoholism, subdural hematoma, epidural hematoma, and intracerebral hematoma. After adjusting for those risk factors, the relative incidence of seizure was not statistically significant in either of the groups ( p = 0.566). Conclusion: In our cohort analysis, AED prophylaxis was ineffective in preventing seizures, as the rate of seizures was similar whether patients had been receiving the drugs or not. We therefore concluded that the benefits of routine prophylactic anticonvulsant therapy in patients with TBI need to be re-evaluated.
Neurological deterioration of intracerebral hemorrhage (ICH) mostly occurs within the first 24 hours. Together with the microglia/macrophages (MMΦ), astrocytes are important cell population responsible for many brain injuries but rarely being highlighted in acute stage of ICH. In present study, we induced rats ICH either by collagenase or autologous blood injection. Experimental groups were classified as vehicle or Ethyl-1-(4-(2,3,3-trichloroacrylamide)phenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate (Pyr3) treatment group (n = 9, each group). MRI assessments after ICH were used to evaluate the hematoma progression and blood–brain barrier (BBB) integrity. The glia cells accumulations were examined by GFAP and Iba1 immunohistochemistry, respectively. Abundant astrocytes but few MMΦ were observed in hyperacute and acute ICH. Upon suppression of astrocyte activity, ICH rats exhibited decreased size of hematoma expansion, less BBB destruction, reduced astrocyte accumulation in perihematomal regions, postponed course of hemoresolution and gain better outcomes. These finding provide evidence that activated astrocytes are crucial cell populations in hyperacute and acute ICH, and their modulation may offer opportunities for novel therapy and patient management.
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