Tumor Treating Fields (TTFields) combined with the drug repurposing approach CUSP9v3 induce metabolic reprogramming and synergistic anti-glioblastoma activity in vitro.

BACKGROUND: Glioblastoma represents a brain tumor with a notoriously poor prognosis. First-line therapy may include adjunctive Tumor Treating Fields (TTFields) which are electric fields that are continuously delivered to the brain through non-invasive arrays. On a different note, CUSP9v3 represents a drug repurposing strategy that includes 9 repurposed drugs plus metronomic temozolomide. Here, we examined whether TTFields enhance the antineoplastic activity of CUSP9v3 against this disease. METHODS: We performed preclinical testing of a multimodal approach of TTFields and CUSP9v3 in different glioblastoma models. RESULTS: TTFields had predominantly synergistic inhibitory effects on the cell viability of glioblastoma cells and non-directed movement was significantly impaired when combined with CUSP9v3. TTFields plus CUSP9v3 significantly enhanced apoptosis, which was associated with a decreased mitochondrial outer membrane potential (MOMP), enhanced cleavage of effector caspase 3 and reduced expression of Bcl-2 and Mcl-1. Moreover, oxidative phosphorylation and expression of respiratory chain complexes I, III and IV was markedly reduced. CONCLUSION: TTFields strongly enhance the CUSP9v3-mediated anti-glioblastoma activity. TTFields are currently widely used for the treatment of glioblastoma patients and CUSP9v3 was shown to have a favorable safety profile in a phase Ib/IIa trial (NCT02770378) which facilitates transition of this multimodal approach to the clinical setting.

Current state and future perspective of drug repurposing in malignant glioma.

Malignant gliomas are still extremely difficult to treat because complete surgical resection is biologically not feasible due to the invasive nature of these diseases and the proximity of tumors to functionally sensitive areas. Moreover, adjuvant therapies are facing a strong therapeutic resistance since the central nervous system is a highly protected environment and the tumor cells display a vast intra-tumoral genetic and epigenetic variation. As a consequence, new therapeutics are urgently needed but the process of developing novel compounds that finally reach clinical application is highly time-consuming and expensive. Drug repurposing is an approach to facilitate and accelerate the discovery of new cancer treatments. In malignant glioma, like in other cancers, pre-existing physiological pathways that regulate cell growth, cell death or cell migration are dysregulated causing malignant transformation. A wide variety of drugs are clinically used to treat non-cancerous diseases interfering with these malignancy-associated pathways. Repurposed drugs have key advantages: They already have approval for clinical use by national regulatory authorities. Moreover, they are for the most part inexpensive and their side effect and safety profiles are well characterized. In this work, we provide an overview on current repurposing strategies for the treatment of malignant glioma.

Characterization of tumor remnants in intraoperative MRI-assisted microscopic and endoscopic transsphenoidal resection of less invasive pituitary adenomas.

INTRODUCTION: Intraoperative magnetic resonance imaging (iMRI) improves the intraoperative detection of adenoma remnants in transsphenoidal surgery. iMRI might be redundant in endoscopic pituitary surgery in non-invasive tumors (Knosp 0-2) due to a superior visualization of anatomical structures in the periphery of the sella turcica compared to the microscopic technique. We identified the anatomical location of tumor remnants in iMRI and evaluated risk factors for secondary resection after iMRI and hereby selected patients with pituitary adenomas who may benefit from iMRI-assisted resection. METHODS: We conducted a retrospective monocenter study of patients who underwent iMRI-assisted transsphenoidal surgical resection of pituitary adenomas at our department between 2012 and 2020. A total number of 190 consecutive iMRI-assisted transsphenoidal surgeries of pituitary adenomas graded as Knosp 0-2 were selected for analysis. Exclusion criteria were missing iMRI availability or pathologies other than adenomas. Of these 190 cases, 46.3% (N = 88) were treated with microscopic, 48.4% (N = 92) with endoscopic, and 5.3% (N = 10) with endoscopic-assisted technique. Volumetric measurement of preoperative, intraoperative, and postoperative tumor extension was performed. Demographic data, tumor characteristics, and MRI features were evaluated. Additionally, analysis of adenoma remnants identified by iMRI was performed. RESULTS: An additional resection after iMRI was performed in 16.3% (N = 31). iMRI helped to reach gross total resection (GTR) in 83.9% (26/31) of these cases. False-positive resection was found in 1 patient (0.5%). Multivariable logistic analysis identified tumor volume (OR = 1.2, p = 0.007) recurrence (OR = 11.3, p = 0.002) and microscopic technique (OR = 2.8, p = 0.029) as independent risk factors for additional resection. Simultaneously, the endoscopic technique was significantly associated with GTR as evaluated by iMRI (OR = 2.8, p = 0.011) and postoperative MRI (OR = 5.8, p = 0.027). The detailed analysis of adenoma remnants on iMRI revealed the suprasellar location in a diaphragm fold, penetrating tumor above the diaphragm, or undetected invasion of cavernous sinus as well as in case of microscopic resection tumor location outside the line of sight as the main reasons for incomplete resections. CONCLUSION: Tumor volume, recurrence, and microscopic technique were identified as independent predictors for additional resection in patients with Knosp 0-2 adenomas. iMRI might increase the extent of resection (EOR) safely even after the endoscopic visualization of the sella with very low risk for false-positive findings. Remnants of tumors hidden within the diaphragmic folds, intrathecally, or behind the infiltrated wall of cavernous sinus not recognized on preoperative MRI were the most common findings in iMRI.

Augmented reality-assisted ventriculostomy.

OBJECTIVE: Placement of a ventricular drain is one of the most common neurosurgical procedures. However, a higher rate of successful placements with this freehand procedure is desirable. The authors' objective was to develop a compact navigational augmented reality (AR)-based tool that does not require rigid patient head fixation, to support the surgeon during the operation. METHODS: Segmentation and tracking algorithms were developed. A commercially available Microsoft HoloLens AR headset in conjunction with Vuforia marker-based tracking was used to provide guidance for ventriculostomy in a custom-made 3D-printed head model. Eleven surgeons conducted a series of tests to place a total of 110 external ventricular drains under holographic guidance. The HoloLens was the sole active component; no rigid head fixation was necessary. CT was used to obtain puncture results and quantify success rates as well as precision of the suggested setup. RESULTS: In the proposed setup, the system worked reliably and performed well. The reported application showed an overall ventriculostomy success rate of 68.2%. The offset from the reference trajectory as displayed in the hologram was 5.2 ± 2.6 mm (mean ± standard deviation). A subgroup conducted a second series of punctures in which results and precision improved significantly. For most participants it was their first encounter with AR headset technology and the overall feedback was positive. CONCLUSIONS: To the authors' knowledge, this is the first report on marker-based, AR-guided ventriculostomy. The results from this first application are encouraging. The authors would expect good acceptance of this compact navigation device in a supposed clinical implementation and assume a steep learning curve in the application of this technique. To achieve this translation, further development of the marker system and implementation of the new hardware generation are planned. Further testing to address visuospatial issues is needed prior to application in humans.

Dual metabolic reprogramming by ONC201/TIC10 and 2-Deoxyglucose induces energy depletion and synergistic anti-cancer activity in glioblastoma.

BACKGROUND: Dysregulation of the metabolome is a hallmark of primary brain malignancies. In this work we examined whether metabolic reprogramming through a multi-targeting approach causes enhanced anti-cancer activity in glioblastoma. METHODS: Preclinical testing of a combined treatment with ONC201/TIC10 and 2-Deoxyglucose was performed in established and primary-cultured glioblastoma cells. Extracellular flux analysis was used to determine real-time effects on OXPHOS and glycolysis. Respiratory chain complexes were analysed by western blotting. Biological effects on tumour formation were tested on the chorioallantoic membrane (CAM). RESULTS: ONC201/TIC10 impairs mitochondrial respiration accompanied by an increase of glycolysis. When combined with 2-Deoxyglucose, ONC201/TIC10 induces a state of energy depletion as outlined by a significant decrease in ATP levels and a hypo-phosphorylative state. As a result, synergistic anti-proliferative and anti-migratory effects were observed among a broad panel of different glioblastoma cells. In addition, this combinatorial approach significantly impaired tumour formation on the CAM. CONCLUSION: Treatment with ONC201/TIC10 and 2-Deoxyglucose results in a dual metabolic reprogramming of glioblastoma cells resulting in a synergistic anti-neoplastic activity. Given, that both agents penetrate the blood-brain barrier and have been used in clinical trials with a good safety profile warrants further clinical evaluation of this therapeutic strategy.

Application of a novel FAM-conjugated activity-based probe to determine cathepsin G activity intracellularly.

Cathepsin G (CatG) is responsible for several distinct immune processes of adaptive and innate immunity depending on extra- or intracellular occurrence of CatG. Recently, we established a method to detect CatG activity at the cell surface of natural killer cells by using the activity-based probe MARS116-Bt in flow cytometry. MARS116-Bt consists of biotin, spacer, amino acid sequence, and a phosphonate warhead which binds covalently to the serine amino acid residue within the active center of CatG. Herein, MARS116 was conjugated to 5(6)-carboxyfluorescein (FAM) in order to limit non-specific signal-to-noise ratio generally resulting from binding of fluorescein-labelled avidin (avidin-FAM) to biotinylated, intracellular proteins; since MARS116-Bt is incubated with avidin-FAM in a second labelling step. MARS116-FAM was capable to detect intracellular CatG activity, in contrast to the control compound MARS116*-FAM which lacks the functional phosphonate warhead crucial for binding to the active-site of CatG and contains a carboxyl group instead. Furthermore, intracellular CatG activity was determined in CD4+ T cells, CD8+ T cells as well as in T regulatory cell (Treg) subsets. Thus, MARS116-FAM is a convenient activity-based probe to detect intracellular CatG activity in a flow cytometry approach.

Health-related quality of life and distress in elderly vs. younger patients with high-grade glioma-results of a multicenter study.

OBJECTIVE: Half of all newly diagnosed patients with glioblastoma are > 65 years still with a poor prognosis. Preserving quality of life is of high importance. However, patient reported outcome (PRO) data in this patient group is rare. The aim was to compare health-related quality of life (HRQoL) and distress between elderly and younger patients with high-grade glioma (HGG). METHODS: We used baseline data of a prospective study where HGG patients were enrolled from 4 hospitals. Distress was measured using the distress thermometer (DT), HRQoL using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Core Questionnaire (QLQ-C30) plus brain module (BN20). We compared distress and HRQoL by age (≥ 65 vs. < 65 years), gender, performance score, and time since diagnosis using multivariate linear and logistic regressions. RESULTS: A total of n = 93 (30%) out of n = 309 patients were ≥ 65 years (mean 70 years, range 65-86 years). Mean DT score of elderly patients (5.2, SD 2.6) was comparable with younger patients (4.9, SD 2.6). Elderly patients reported significantly lower global health (GHS, mean elderly vs. younger; 50.8 vs. 60.5, p = 0.003), worse physical (56.8 vs. 73.3, p < 0.001) and lower cognitive functioning (51.1 vs. 63.2, p = 0.002), worse fatigue (52.5 vs. 43.5, p = 0.042), and worse motor dysfunction (34.9 vs. 23.6, p = 0.030). KPS and not age was consistently associated with HRQoL. CONCLUSION: Physical functioning was significantly reduced in the elderly compared with younger HGG patients, and at the same time, emotional functioning and DT scores were comparable. KPS shows a greater association with HRQoL than with calendric age in HGG patients reflecting the particular importance for adequate assessment of HRQoL and general condition in elderly patients.

Ten years' experience with intraoperative MRI-assisted transsphenoidal pituitary surgery.

OBJECTIVE: Many innovations have been introduced into pituitary surgery in the quest to maximize the extent of tumor resection. Because of the deep and narrow surgical corridor as well as the heterogeneity of confronted pathologies, anatomical orientation and identification of the target tissue can become difficult. Intraoperative MRI (iMRI) may have the potential to increase extent of resection (EOR) in transsphenoidal pituitary surgery. Furthermore, it may simplify anatomical orientation and risk assessment in difficult cases. Here, the authors evaluated the additional value of iMRI for the resection of pituitary adenomas performed in the past 10 years in their department. METHODS: They performed a retrospective single-center analysis of patients treated for pituitary adenoma in their department after the introduction of iMRI between 2008 and 2018. Of 495 transsphenoidal approaches, 300 consecutive MRI-assisted surgeries for pituitary adenomas encompassing 294 patients were selected for further analysis. Microscopic, endoscopic, or endoscope-assisted microscopic transsphenoidal approaches were distinguished. EOR as well as additional resection following iMRI was evaluated via detailed volumetric analysis. Patients were stratified according to the Knosp adenoma classification. Furthermore, demographic data, clinical symptoms, endocrine outcome, and complications were evaluated. Univariable and multivariable Cox regression analyses of progression-free survival (PFS) were performed. RESULTS: Pituitary adenomas classified as Knosp grades 0-2 were found in 60.3% of cases (n = 181). The most common tumors were nonfunctioning adenomas (75%). Continued resection following iMRI significantly increased EOR (7.5%, p < 0.001) and the proportion of gross-total resections (GTRs) in transsphenoidal pituitary surgery (54% vs 68.3%, p < 0.001). Additional resection after iMRI was performed in 37% of cases. Only in the subgroup of patients with Knosp grades 0-2 adenomas treated with the microsurgical technique was additional resection significantly more common than in the endoscopic group (p = 0.039). Residual tumor volume, Knosp grade, and age were confirmed as independent predictors of PFS (p < 0.001, p = 0.021, and p = 0.029, respectively) in a multivariable Cox regression analysis. Improvement of visual field deficits was documented in 78.6% of patients whose optic apparatus had been affected preoperatively. Revision surgery was done in 7.3% of cases; in 5.6% of cases, it was performed for cerebrospinal fluid fistula. CONCLUSIONS: In this series, iMRI led to the detection of a resectable tumor remnant in a high proportion of patients, resulting in a greater EOR and higher proportion of GTRs after continued resection in microsurgical and endoscopic transsphenoidal resection of pituitary adenomas. The volume of residual tumor was the most important predictor of PFS. Given the study data, the authors postulated that every bit of removed tumor serves the patient and increases their chances of a favorable outcome.

Fluorescence guided surgery by 5-ALA and intraoperative MRI in high grade glioma: a systematic review.

PURPOSE: Fluorescence guided surgery by 5-aminolevulinic acid (5-ALA) and intraoperative MRI (iMRI) are currently the most important intraoperative imaging techniques in high grade glioma (HGG) surgery. Few comparative studies exist for these techniques. This review aims to systematically compare 5-ALA and iMRI assisted surgery based on the current literature and discuss the potential impact of a combined use of both techniques. METHODS: A systematic literature search based on preferred reporting items for systematic reviews and meta-analysis was performed concerning accuracy of tumor detection; extent of resection; neurological deficits (ND); Quality of life (QoL); usability and combined use of both techniques. Original clinical articles on HGG published until March 31st were screened. RESULTS: 169 publications were screened, 81 were eligible and 22 were finally included in the review using. Overall, there is evidence that both imaging techniques improve gross total resection rate in non-eloquent lesions. Imaging results do not correlate at the border zone of a HGG. 5-ALA and contrast-enhanced iMRI seem to have a supplementary effect in tumor detection. Overall, both imaging techniques alone or combined do not seem to increase rate of permanent ND or decrease QoL in HGG surgery when used with intraoperative monitoring/mapping. CONCLUSION: Based on the currently available literature no superiority of one technique over the other can be found in the most important outcome parameters. Based on the available information a combined use of 5-ALA and iMRI seems very promising to achieve a resection beyond gadolinium-enhancement. However, only low quality of evidence exists for this approach.

Intraoperative MRI in transsphenoidal resection of invasive pituitary macroadenomas.

The use of intraoperative MRI (iMRI) increases extent of resection in transsphenoidal pituitary surgery. Microsurgical and endoscopic techniques have been established as equal and standard surgical methods. The object of the current study was to evaluate the additional value of iMRI for resection of invasive pituitary adenomas. We conducted a retrospective monocenter study of all consecutive patients treated with invasive pituitary adenomas graded as Knosp III-IV at our department after the introduction of iMRI in 2008. Out of 315 transsphenoidal surgeries for pituitary adenomas, 111 met the criteria for analysis. Patients treated with endoscopic or microsurgical technique were included. iMRI was performed at surgeons' discretion, when maximal safe resection was assumed. Detailed volumetric tumor analysis using semiautomatic segmentation software (Brainlab Elements) before surgery, during surgery, and after surgery was performed. Additionally, demographic data, additional resection, endocrinological outcome as well as complications were evaluated. Postoperative tumor volume as measured in the follow-up MRI 3 months after surgery was significantly lower compared with intraoperative tumor volume (p < 0.001). The difference was statistically significant for both surgical techniques (p < 0.001). No significant difference was found between both techniques in intraoperative and postoperative tumor volume (p = 0.395 and p = 0.329 respectively). Additional tumor resection was performed in 56 cases (50.5%). We found no significant difference between microsurgical and endoscopic techniques regarding additional resection after iMRI (p = 0.512). New diagnosed permanent diabetes insipidus was found in 10 patients (10.5%, 10/95). New hypopituitarism was seen in 22.1% (21/95) cases and according to multivariate logistic regression was significantly associated with microsurgical technique (p = 0.035). Visual improvement was achieved in 76.8% (N = 53/69, p < 0.001) of patients with visual impairment before surgery. Revision surgery as the consequence of cerebrospinal fistula was performed in eight cases (7.2%). Meningitis was documented in three patients (2.7%). One patient died as a consequence of intraoperative vascular injury. Intraoperative MRI after maximal safe resection significantly improves the overall extent of resection in invasive pituitary adenomas independent of the surgical technique employed. Simultaneously, iMRI-assisted transsphenoidal surgery results in excellent visual recovery with low-risk profile for surgical complications for both endoscopic as well as microsurgical technique. Endoscopic technique might be related to the lower incidence of new hypopituitarism after surgery.

The evolution of invasive cerebral vasospasm treatment in patients with spontaneous subarachnoid hemorrhage and delayed cerebral ischemia-continuous selective intracarotid nimodipine therapy in awake patients without sedation.

Cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) are major factors that limit good outcome in patients with spontaneous subarachnoid hemorrhage (SAH). Continuous therapy with intra-arterial calcium channel blockers has been introduced as a new step in the invasive treatment cascade of CV and DCI. Sedation is routinely necessary for this procedure. We report about the feasibility to apply this therapy in awake compliant patients without intubation and sedation. Out of 67 patients with invasive endovascular treatment of cerebral vasospasm due to spontaneous SAH, 5 patients underwent continuous superselective intracarotid nimodipine therapy without intubation and sedation. Complications, neurological improvement, and outcome at discharge were summarized. Very good outcome was achieved in all 5 patients. The Barthel scale was 100 and the modified Rankin scale 0-1 in all cases at discharge. We found no severe complications and excellent neurological monitoring was possible in all cases due to patients' alert status. Symptoms of DCI resolved within 24 h in all 5 cases. We could demonstrate the feasibility and safety of selective intracarotid arterial nimodipine treatment in awake, compliant patients with spontaneous SAH and symptomatic CV and DCI. Using this method, an excellent monitoring of neurological function as well as early detection of other complications is possible. It might be an important step in the risk reduction of invasive CV therapy to improve the outcome with CV and DCI after SAH in selected patients.

The patients' view: impact of the extent of resection, intraoperative imaging, and awake surgery on health-related quality of life in high-grade glioma patients-results of a multicenter cross-sectional study.

The objective of the present study is to assess the influence of extent of resection (EoR), use of intraoperative imaging, and awake surgery on health-related quality of life (HRQoL) in high-grade glioma (HGG) patients in a prospective multicenter study. We analyzed 170 surgeries of patients suffering from a HGG. During the first year after resection, HRQoL was evaluated using the European Organization of Research and Treatment of Cancer Core Questionnaire C30 and Brain Neoplasm 20 questionnaires. We assessed the influence of EoR; awake surgery; and use of 5-aminolevulinic acid (5-ALA), intraoperative MRI (iMRI), and their combination on sum scores for function and symptoms as well as several neurological single items. In mixed-model analyses, adjustments for age, Karnofsky performance status (KPS), and eloquent location were performed. In the mixed model, EoR generally did not significantly influence HRQoL (p = 0.10). Yet, patients receiving subtotal resection (STR) vs. patients with biopsy showed significantly better QoL and role and cognitive functions (p = 0.04, p = 0.02, and p < 0.01, respectively). The combination of iMRI and 5-ALA reached the highest EoR (95%) followed by iMRI alone (94%), 5-ALA alone (74%), and no imaging (73%). Thereby, neurological symptoms were lowest and functioning score highest after combined use of iMRI and 5-ALA, without reaching significance (p = 0.59). Despite lower scores in emotional function (59 vs. 46, p = 0.24), no significant impact of awake surgery on HRQoL was found (p = 0.70). In HGG patients, STR compared to biopsy was significantly associated with better HRQoL and fewer neurological symptoms in this series. An escalated use of intraoperative imaging increased EoR with stable or slightly better HRQoL and fewer neurological symptoms. Based on HRQoL, awake surgery was a well-tolerated and safe method in our series.

Cancer stem cells: The potential role of autophagy, proteolysis, and cathepsins in glioblastoma stem cells.

One major obstacle in cancer therapy is chemoresistance leading to tumor recurrence and metastasis. Cancer stem cells, in particular glioblastoma stem cells, are highly resistant to chemotherapy, radiation, and immune recognition. In case of immune recognition, several survival mechanisms including, regulation of autophagy, proteases, and cell surface major histocompatibility complex class I molecules, are found in glioblastoma stem cells. In different pathways, cathepsins play a crucial role in processing functional proteins that are necessary for several processes and proper cell function. Consequently, strategies targeting these pathways in glioblastoma stem cells are promising approaches to interfere with tumor cell survival and will be discussed in this review.

Anti-glioma Activity of Dapsone and Its Enhancement by Synthetic Chemical Modification.

The sulfone dapsone is an old antibiotic used for the treatment of mycobacterial and protozoal infections. We postulated before that dapsone might possess biological activity exceeding its anti-infectious properties and that it could potentially be repurposed for the treatment of glioma. To test this hypothesis, we treated established and primary cultured glioma cells with dapsone or several dapsone analogues which we previously synthesized (D2-D5) and determined effects on proliferation, anchorage-independent growth and migration. While dapsone and its synthetic analogues D2-D5 displayed only modest anti-proliferative activity, important neoplastic features such as anchorage-independent growth, clonogenic survival and directed migration were significantly inhibited by dapsone treatment. Moreover, dapsone analogues D3, D4 and D5 yielded even enhanced anti-glioma activity against different pro-neoplastic features. Overall these data suggest that dapsone provides activity against glioma which can be further enhanced by molecular modifications. These compounds could potentially serve as a therapeutic adjunct to the treatment of gliomas in a repurposing approach.

Evaluating patients for psychosocial distress and supportive care needs based on health-related quality of life in primary brain tumors: a prospective multicenter analysis of patients with gliomas in an outpatient setting.

The association between health-related quality of life (HRQoL), psychosocial distress, and supportive care is in the focus of patient-centered neuro-oncology. We investigated the relationship between the aforementioned in glioma-patients to evaluate the association of these instruments and determine cut-off values for suitable HRQoL scales indicating a potential need for intervention. In an observational multi-center study, outpatients completed the Distress Thermometer (DT), EORTC Quality of Life Questionnaire (EORTC-QLQ-C30/BN20, HRQoL), and Supportive-Care-Needs-Survey-SF34-G (SCNS). Based on nine EORTC-function and selected -symptom scales items of the questionnaires were matched. Convergent validity of related single items and scores across the instruments was estimated. EORTC cut-off values were calculated. Data of 167 patients were analyzed. The strongest correlation of EORTC-QLQ-C30 and DT was found for cognitive function (cogf), global health status (GHS), emotional (emof), role function (rolef), future uncertainty (FU), fatigue, and between EORTC-QLQ-C30 and SCNS for FU, emof, rolef (r = |0.4-0.7|; p < 0.01). EORTC cut-off values of <54.2 (GHS/QoL) and <62.5 (emof) predicted a DT ≥ 6 (AUC 0.79, 0.85, p < 0.01). EORTC cut-off values of <70.8 (emof) and <52.8 (FU) predicted the need for supportive care (AUC 0.78, 0.85; p < 0.01). Worse EORTC-C30 scores correlate with higher DT and SCNS scores. With this exploratory assessment, cut-off values for EORTC-C30 subscores to predict distress and pathological SCNS-scores could be determined, which could influence patients' referral to further treatment. However, further prospective clinical trials are needed to confirm the clinical relevance of these cut-off values.

Cathepsin G-mediated proteolytic degradation of MHC class I molecules to facilitate immune detection of human glioblastoma cells.

To mount an adaptive immune response, MHC I molecules present antigenic peptides to CTLs. Transcriptional reduction of MHC I molecules is a strategy of immune evasion, which impairs the detection of infected or tumorous cells by CTLs. Natural killer (NK) cells, on the other hand, eliminate target cells specifically in the absence of MHC I. Consequently, infected or tumorous cells partly retain their MHC I at the cell surface to avoid NK recognition. However, it remains unclear which protease degrades MHC I molecules and how these cells maintain a limited set of MHC I at the cell surface. Here, we demonstrate that cathepsin G (CatG), a serine protease, found in the endocytic compartment of APCs and, to a lesser extent, CatD and CatS proteolytically degrade MHC I molecules. Inhibition of CatG boosted MHC I expression at the cell surface of primary human immune cells. In contrast, human glioblastoma cells do not harbor active CatG and might have lost the ability to proteolytically degrade MHC I during tumorigenesis to avoid NK-mediated killing. Overexpression of CatG in glioblastoma cells resulted in a rapid and efficient MHC I degradation. In conclusion, CatG is an essential protease for regulating MHC I molecules and thus modulation of CatG activity might present a new avenue for therapeutic intervention.

Olanzapine inhibits proliferation, migration and anchorage-independent growth in human glioblastoma cell lines and enhances temozolomide's antiproliferative effect.

The poor prognosis of patients with glioblastoma fuels the search for more effective therapeutic compounds. We previously hypothesised that the neuroleptic olanzapine may enhance antineoplastic effects of temozolomide the standard chemotherapeutic agent used in this disease. This study tested this hypothesis. The anti-proliferative effect of olanzapine was examined by MTT assays and cell count analysis. Soft-agar assays were performed to examine colony-forming ability. In addition, the inhibitory effect of olanzapine on the migratory capacity of U87MG and A172 cells was analyzed by Transwell(®) assays. Moreover, staining for annexin V/propidium iodide or carboxyfluorescein succinimidyl ester was performed prior to flow cytometric analysis in order to better understand the subjacent cellular mechanism. Our initial hypothesis that olanzapine may enhance temozolomide's anti-tumor activity could be confirmed in U87MG and A172 glioblastoma cell lines. Moreover, treatment with olanzapine alone resulted in a marked anti-proliferative effect on U87MG, A172 and two glioma stem-like cells with IC50 values ranging from 25 to 79.9 µM. In U87MG cells, anchorage-independent growth was dose-dependently inhibited. In A172 cells, migration was also shown to be inhibited in a dose-dependent manner. In addition, olanzapine was shown to exert a cell line-dependent pleomorphism with respect to the induction of apoptosis, necrosis and/or cytostasis. Our data show that the neuroleptic olanzapine enhances the anti-tumor activity of temozolomide against glioblastoma cell lines. Moreover, this is the first study to show that olanzapine provides on its own anti-cancer activity in glioblastoma and thus may have potential for repurposing.

Intraoperative high-resolution ultrasound and contrast-enhanced ultrasound of peripheral nerve tumors and tumorlike lesions.

The diagnostic workup and surgical therapy for peripheral nerve tumors and tumorlike lesions are challenging. Magnetic resonance imaging is the standard diagnostic tool in the preoperative workup. However, even with advanced pulse sequences such as diffusion tensor imaging for MR neurography, the ability to differentiate tumor entities based on histological features remains limited. In particular, rare tumor entities different from schwannomas and neurofibromas are difficult to anticipate before surgical exploration and histological confirmation. High-resolution ultrasound (HRU) has become another important tool in the preoperative evaluation of peripheral nerves. Ongoing software and technical developments with transducers of up to 17-18 MHz enable high spatial resolution with tissue-differentiating properties. Unfortunately, high-frequency ultrasound provides low tissue penetration. The authors developed a setting in which intraoperative HRU was used and in which the direct sterile contact between the ultrasound transducer and the surgically exposed nerve pathology was enabled to increase structural resolution and contrast. In a case-guided fashion, the authors report the sonographic characteristics of rare tumor entities shown by intraoperative HRU and contrast-enhanced ultrasound.

Tumor detection with 5-aminolevulinic acid fluorescence and Gd-DTPA-enhanced intraoperative MRI at the border of contrast-enhancing lesions: a prospective study based on histopathological assessment.

OBJECT: High-grade gliomas (HGGs) and metastasis (MET) are the most common intracranial lesions in neurosurgical routine. Both of them show an invasive growth pattern extending into neural tissue beyond the margins of contrast enhancement on MRI. These "undetected" areas might be the origin of early tumor recurrence. The aim of the present study was to evaluate whether 5-aminolevulinic acid (5-ALA) fluorescence provides an additional benefit in detection of invasive tumor compared with intraoperative MRI (iMRI). METHODS: The authors prospectively enrolled 45 patients harboring contrast-enhancing lesions, in whom gross-total resection was intended. All patients had surgery in which iMRI and 5-ALA-guided resection were used following a specific protocol. First, a typical white light tumor resection was performed. Then, spatial location of residual fluorescence was marked. After that, an iMRI was performed and residual uptake of contrast was marked. Navigated biopsy samples were taken from all marked areas and from additional sites according to the surgeon's judgment. Cross tables and receiver operating characteristic curves were calculated, assessing performance of the imaging methods for tumor detection alone and for combined detection of infiltration zone and solid tumor (pathological tissue). Also, correlations of histopathological findings with imaging results were tested using Spearman rho. RESULTS: Thirty-four patients with HGGs and 11 with METs were enrolled. Three patients harboring a MET showed no 5-ALA enhancement and were excluded; 127 histopathological samples were harvested in the remaining patients. In HGG, sensitivity for tumor detection was significantly higher (p < 0.001) in 5-ALA (0.85) than in iMRI (0.41). Specificity was significantly lower (p < 0.001) in 5-ALA (0.43) than in iMRI (0.70). For detection of pathological tissue, 5-ALA significantly exceeded iMRI in specificity (0.80 vs 0.60) and sensitivity (0.91 vs 0.66) (p < 0.001). Imaging results of iMRI and 5-ALA did not correlate significantly; only 5-ALA showed a significant correlation with final histopathological diagnosis of the specimen and with typical histopathological features of HGGs. In METs, sensitivity and specificity for tumor detection were equal in 5-ALA and iMRI. Both techniques showed high values for sensitivity (0.75) and specificity (0.80). The odds ratio for detection of tumor tissue was 12 for both techniques. Concerning pathological tissue, no statistically significant difference was found either. Imaging results of iMRI and 5-ALA correlated significantly (p < 0.022), as with final histopathological diagnosis in METs. CONCLUSIONS: In METs, due to the rate of nonenhancing lesions, the authors found no additional benefit of 5-ALA compared with iMRI. In HGG, imaging results of 5-ALA and iMRI are significantly different at the border zone; 5-ALA has a higher sensitivity and a lower specificity for tumor detection than Gd-DTPA-enhanced iMRI. For detection of infiltrating tumor at the border of the resection cavity, 5-ALA is superior to Gd-DTPA-enhanced iMRI concerning both sensitivity and specificity. Thus, use of 5-ALA in addition to iMRI might be beneficial to maximize extent of resection. Clinical synergistic effects will be evaluated in a prospective randomized trial.

Cognitive performance following spontaneous subarachnoid haemorrhage versus other forms of intracranial haemorrhage.

OBJECTIVE: The exact cause of cognitive deficits following intracranial haemorrhage is unclear. This prospective study examines the abilities after spontaneous subarachnoid haemorrhage (SAH), intracerebral haemorrhage (ICH) and chronic subdural haematoma (SDH) to elucidate the cognitive outcome. PATIENTS AND METHODS: Ninety-nine patients with SAH (N = 60), ICH (N = 25), and SDH (N = 14) were followed up for an average of 6 and 12 months post-haemorrhage. Cognitive tests were used to examine attention, memory, concentration, and executive function. Following were used for analysis: 1. the percentage of patients falling below the 25th percentile per test, 2. the general development from the first to second test point and 3. the incidence of significant changes between the test points. Significance was established as p ≤ 0.05. RESULTS: All three types of haemorrhage resulted in deficits as concerns abstract language (53%-75%). The processing speed was below the normal levels in more than 70% of the patients tested. The cognitive performance of SAH patients was similar to that of patients with SDH and ICH patients after 6 months. The number of patients with outcomes falling below the 25th percentile (to some extent more than 75% in patients post-SAH) is high in all patient groups and mostly decreases over the course. Nevertheless, patients with SAH reveal improvements in many more areas than with ICH and SDH (p ≤ 0.006). CONCLUSIONS: The cognitive impairments following SAH, ICH and SDH deficits appear to develop in a similar way regardless of the type of haemorrhage. Cognitive improvement is most pronounced in patients with SAH.