507 research outputs found
ABT-888 enhances cytotoxic effects of temozolomide independent of MGMT status in serum free cultured glioma cells
Background: The current standard of care for Glioblastoma Multiforme (GBM) consists of fractionated focal irradiation with concomitant temozolomide (TMZ) chemotherapy. A promising strategy to increase the efficacy of TMZ is through interference with the DNA damage repair machinery, by poly(ADP-ribose) polymerase protein inhibition(PARPi). The o
A Systematic Comparison Identifies an ATP-Based Viability Assay as Most Suitable Read-Out for Drug Screening in Glioma Stem-Like Cells
Serum-free culture methods for patient-derived primary glioma cultures, selecting for glioma stem-like cells (GSCs), are becoming the gold standard in neurooncology research. These GSCs can be implemented in drug screens to detect patient-specific responses, potentially bridging the translational gap to personalized medicine. Since numerous compounds are available, a rapid and reliable readout for drug efficacies is required. This can be done using approaches that measure viability, confluency, cytotoxicity, or apoptosis. To determine which assay is best suitable for drug screening, 10 different assays were systematically tested on established glioma cell lines and validated on a panel of GSCs. General applicability was assessed using distinct treatment modalities, being temozolomide, radiation, rapamycin, and the oncolytic adenovirus Delta24-RGD. The apoptosis and cytotoxicity assays did not unequivocally detect responses and were excluded from further testing. The NADH- and ATP-based viability assays revealed comparable readout for all treatments; however, the latter had smaller standard deviations and direct readout. Importantly, drugs that interfere with cell metabolism require alternative techniques such as confluency monitoring to accurately measure treatment effects. Taken together, our data suggest that the combination of ATP luminescence assays with confluency monitoring provides the most specific and reproducible readout for drug screening on primary GSCs
Contemporary frameless intracranial biopsy techniques: Might variation in safety and efficacy be expected?
Background: Frameless stereotactic neuronavigation has proven to be a feasible technology to acquire brain biopsies with good accuracy and little morbidity and mortality. New systems are constantly i
Late neurocognitive sequelae in patients with WHO grade I meningioma
BACKGROUND: Information on the neurocognitive outcome following treatment of benign meningiomas is virtually lacking. This is remarkable considering these patientsś survival is the most favorable of all intracranial tumors. The aim of the present study is therefore to document the extent and nature of neurocognitive deficits in WHO grade I meningioma patients after treatment. METHODS: Eighty-nine WHO grade I meningioma patients who underwent surgery with or without adjuvant radiotherapy were individually matched to 89 healthy controls for age, sex, and educational level. Neurocognitive functioning of patients was assessed at least one year following treatment and compared to that of healthy controls using Student's t-tests. Additionally, associations between tumor characteristics (size, lateralization and localization), treatment characteristics (radiotherapy), and epilepsy burden (based on seizure frequency and antiepileptic drug use) and neurocognitive functioning were investigated. RESULTS: Compared to healthy controls meningioma patients showed significant impairments in executive functioning (p < 0.001), verbal memory (p < 0.001), information processing capacity (p = 0.001), psychomotor speed (p = 0.001), and working memory (p = 0.006). Patients with skull base meningiomas performed significantly lower on three out of six neurocognitive domains when compared to convexity meningiomas. Left-sided as opposed to right sided meningiomas were related to verbal memory deficits. A higher epilepsy burden was significantly associated with lower executive functioning, which primarily could be attributed to antiepileptic drug use. No significant associations were established between neurocognitive status and radiotherapy or tumor volume. CONCLUSIONS: Meningioma patients are characterized by long-term deficits in neurocognitive functioning that can partly be attributed to the use of antiepileptic drugs and tumor location, but not to the use of radiotherap
The Sequence of Delta24-RGD and TMZ Administration in Malignant Glioma Affects the Role of CD8+T Cell Anti-tumor Activity
The conditionally replicating oncolytic adenovirus Delta24-RGD (Ad) is currently under investigation in clinical trials for glioblastoma, including in combination with temozolomide (TMZ), the standard chemotherapy for this tumor. Previously, we showed that the efficacy of Delta24-RGD in a murine model is primarily dependent on the virus-induced anti-tumor immune response. As observed with most chemotherapies, TMZ has pronounced immune-modulating effects. Here, we studied the combined effects of these treatments in a murine glioma model. In vitro, we observed a synergistic activity between Delta24-RGD and TMZ. In vivo, C57BL/6 mice bearing intracranial GL261 tumors were treated with TMZ for 5 days either prior to intratumoral Delta24-RGD injection (TMZ/Ad) or post virus injection (Ad/TMZ). Notably, the Ad/TMZ regimen led to similar tumoral CD8+ T cell influx as the virus-only treatment, but increased the ability of CD8+ T cells to specifically recognize the tumor cells. This was accompanied by improved survival. The TMZ/Ad regimen also improved survival significantly compared to controls, but not compared to virus alone. In this group, the influx of dendritic cells is impaired, followed by a significantly lower number of tumor-infiltrating CD8+ T cells and no recognition of tumor cells. Depletion of either CD4+ T cells or CD8+ T cells impaired the efficacy of Delta24-RGD, underscoring the role of these cells in therapeutic activity of the virus. Overall, we show that the addition of TMZ to Delta24-RGD treatment leads to a significant increase in survival and that the order of sequence of these treatments affects the CD8+T cell anti-tumor activity
The in vivo therapeutic efficacy of the oncolytic adenovirus Delta24-RGD is mediated by tumor-specific immunity
The oncolytic adenovirus Delta24-RGD represents a new promising therapeutic agent for patients with a malignant glioma and is currently under investigation in clinical phase I/II trials. Earlier preclinical studies showed that Delta24-RGD is able to effectively lyse tumor cells, yielding promising results in various immune-deficient glioma models. However, the role of the immune response in oncolytic adenovirus therapy for glioma has never been explored. To this end, we assessed Delta24-RGD treatment in an immune-competent orthotopic mouse model for glioma and evaluated immune responses against tumor and virus. Delta24-RGD treatment led to long-term survival in 50% of mice and this effect was completely lost upon administration of the immunosuppressive agent dexamethasone. Delta24-RGD enhanced intra-tumoral infiltration of F4/80+ macrophages, CD4+ and CD8+ T-cells, and increased the local production of pro-inflammatory cytokines and chemokines. In treated mice, T cell responses were directed to the virus as well a
The HDAC inhibitors scriptaid and LBH589 combined with the oncolytic virus Delta24-RGD exert enhanced anti-tumor efficacy in patient-derived glioblastoma cells
Background: A phase I/II trial for glioblastoma with the oncolytic adenovirus Delta24-RGD was recently completed. Delta24-RGD conditionally replicates in cells with a disrupted retinoblastomapathway and enters cells via αvβ3/5 integrins. Glioblastomas are differentially sensitive to Delta24-RGD. HDAC inhibitors (HDACi) affect integrins and share common cell death pathways with Delta24-RGD. We studied the combination treatment effects of HDACi and Delta24-RGD in patient-derived glioblastoma stem-like cells (GSC), and we determined the most effective HDACi. Methods: SAHA, Valproic Acid, Scriptaid, MS275 and LBH589 were combined with Delta24-RGD in fourteen distinct GSCs. Synergy was determined by Chou Talalay method. Viral infection and replication were assessed using luciferase and GFP encoding vectors and hexon-titration assays. Coxsackie adenovirus receptor and αvβ3 integrin levels were determined by flow cytometry. Oncolysis and mechanisms of cell death were studied by viability, caspase-3/7, LDH and LC3B/p62, phospho-p70S6K. Toxicity was studied on normal human astrocytes. MGMT promotor methylation status, TCGA classification, Rb-pathway and integrin gene expression levels were assessed as markers of responsiveness. Results: Scriptaid and LBH589 acted synergistically with Delta24-RGD in approximately 50% of the GSCs. Both dr
Does early resection of presumed low-grade glioma improve survival? A clinical perspective
Early resection is standard of care for presumed low-grade gliomas. This is based on studies including only tumors that were post-surgically confirmed as low-grade glioma. Unfortunately this does not represent the clinicians’ situation wherein he/she has to deal with a lesion on MRI that is suspect for low-grade glioma (i.e. without prior knowledge on the histological diagnosis). We therefore aimed to determine the optimal initial strategy for patients with a lesion suspect for low-grade glioma, but not histologically proven yet. We retrospectively identified 150 patients with a resectable presumed low-grade-glioma and who were otherwise in good clinical condition. In this cohort we compared overall survival between three types of initital treatment strategy: a wait-and-scan approach (n = 38), early resection (n = 83), or biopsy for histopathological verification (n = 29). In multivariate analysis, no difference was observed in overall survival for early resection compared to wait-and-scan: hazard ratio of 0.92 (95% CI 0.43–2.01; p = 0.85). However, biopsy strategy showed a shorter overall survival compared to wait-and-scan: hazard ratio
Prevalence of vertebral fractures in a disease activity steered cohort of patients with early active rheumatoid arthritis
<p>Abstract</p> <p>Objective</p> <p>To determine the prevalence of vertebral fractures (VFs) after 5 years of disease activity score (DAS)-steered treatment in patients with early rheumatoid arthritis (RA) and to investigate the association of VFs with disease activity, functional ability and bone mineral density (BMD) over time.</p> <p>Methods</p> <p>Five-year radiographs of the spine of 275 patients in the BeSt study, a randomized trial comparing four treatment strategies, were used. Treatment was DAS-steered (DAS ≤ 2.4). A height reduction >20% in one vertebra was defined a vertebral fracture. With linear mixed models, DAS and Health Assessment Questionnaire (HAQ) scores over 5 years were compared for patients with and without VFs. With generalized estimating equations the association between BMD and VFs was determined.</p> <p>Results</p> <p>VFs were observed in 41/275 patients (15%). No difference in prevalence was found when stratified for gender, prednisone use and menopausal status. Disease activity over time was higher in patients with VFs, mean difference 0.20 (95% CI: 0.05-0.36), and also HAQ scores were higher, independent of disease activity, with a mean difference of 0.12 (95% CI: 0.02-0.2). Age was associated with VFs (OR 1.06, 95% CI: 1.02-1.09), mean BMD in spine and hip over time were not (OR 95% CI, 0.99: 0.78-1.25 and 0.94: 0.65-1.36, respectively).</p> <p>Conclusion</p> <p>After 5 years of DAS-steered treatment, 15% of these RA patients had VFs. Higher age was associated with the presence of VFs, mean BMD in hip and spine were not. Patients with VFs have greater functional disability over time and a higher disease activity, suggesting that VFs may be prevented by optimal disease activity suppression.</p
Internet-based guided self-help for glioma patients with depressive symptoms: a randomized controlled trial
Depressive symptoms are common in glioma patients, and can negatively affect health-related quality of life (HRQOL). We performed a nation-wide randomized controlled trial to evaluate the effects of an online guided self-help intervention for depressive symptoms in adult glioma patients. Glioma patients with depressive symptoms were randomized to a 5-week online course based on problem-solving therapy, or a waiting list control group. After having received the intervention, the glioma patient groups combined were compared with patients with cancer outside the central nervous system (non-CNS cancer controls), who also received the intervention. Sample size calculations yielded 63 participants to be recruited per arm. The primary outcome [depressive symptoms (CES-D)] and secondary outcomes [fatigue (Checklist Individual Strength (CIS)) and HRQOL (Short Form-36)], were assessed online at baseline, post-intervention, and 3 and 12 months follow-up. In total, 89 glioma patients (intervention N = 45; waiting list N = 44) and 26 non-CNS cancer controls were included, of whom 35 and 54% completed the intervention, respectively. Recruitment could not be extended beyond 3.5 years due to funding. On depression, no statistically significant differences between the groups were found. Fatigue decreased post-treatment in the glioma intervention group compared with the waiting list group (p = 0.054, d = 0.306). At 12 months, the physical component summary (HRQOL) remained stable in glioma patients, while scores improved in non-CNS cancer controls (p = 0.035, d = 0.883). In this underpowered study, no evidence for the effectiveness of online guided self-help for depression or HRQOL in glioma patients was found, but it may improve fatigue
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