Die Rolle der Wechselwirkung von p53 und NFkB für den sekundären Hirnschaden nach Schädel-Hirn Trauma

In der Pathophysiologie des Schädel-Hirn Traumas unterscheidet man Primär- und Sekundärschaden. Der Primärschaden kommt durch die initiale Gewalteinwirkung zustande und kann therapeutisch nicht beeinflusst werden. Der Sekundärschaden setzt nach einer gewissen Zeit (Stunden bis Tage) ein, und führt zur Progression von Verletzung und neurologischer Dysfunktion. Apoptotischer Zelluntergang von Neuronen kann im Kortex von Patienten nach Schädel-Hirn Trauma nachgewiesen werden und stellt möglicherweise eine Ursache für die sekundäre klinische Verschlechterung dar. In der Regulation der neuronalen Apoptose besitzt p53 und NFкB eine Schlüsselfunktion. P53 kann als übergeordnetes Steuermolekül den Zelluntergang initiieren, NFкB kann durch Transkriptionssteigerung von anti-apoptotisch wirksamen Proteinen möglicherweise den neuronalen Untergang verhindern. Die vorliegenden Arbeit untersucht die Rolle der Wechselwirkung von p53 und NFкB für den sekundären Hirnschaden nach Trauma. Nach experimentellem Schädel-Hirn Trauma der Maus nach dem Modell des Controlled Cortical Impact nimmt dass das Kontusionsvolumen nach initialer Verletzung des Mauskortex durch einen pneumatisch getriebenen Kolben, innerhalb von 24 Stunden sekundär um bis zu 60% zu. Dies geht einher mit einer gesteigerten kortikalen p53-Expression: Western Blot-Analysen von Hirnlysaten zeigen, dass es im Bereich der Kontusion und des eng benachbarten unverletzten Kortex bereits 15 Minuten nach Trauma zum signifikanten Anstieg der p53-Expression kommt. Dieser Anstieg ist über 24 Stunden nachweisbar. Immunhistochemische Analysen von Hirngewebe nach Trauma zeigen weiterhin, dass p53 selektiv im Bereich der Kontusion sowie im perikontusionellen Hirngewebe akkumuliert. Die Hemmung von p53 durch Pifithrin kann den sekundären Hirnschaden signifikant um bis zu 60% reduzieren. Bemerkenswert ist hierbei die Tatsache, dass eine einzelne Applikation bis zu sechs Stunden nach Trauma neuroprotektive Wirksamkeit besitzt. Die vorliegende Arbeit zeigt weiterhin, dass es nach Trauma zum signifikanten Abfall der NFкB- Transkriptionsaktivität kommt. Inhibitorische, p53-abhängige Effekte auf die Transkriptionsaktivität von NFкB sind bekannt. Hierbei spielt die kompetitive Bindung beider Transkriptionsfaktoren an den aktivierenden Kofaktor p300 eine Rolle. Die Untersuchung der NFкB-Transkriptionsaktivität unter p53-Inhibition mit Pifithrin zeigt, dass es zum signifikanten Anstieg der, ohne Therapie, supprimierten NFкB-Transkriptionsaktivität nach Trauma kommt. P53-abhängige Effekte auf den Sekundärschaden nach Trauma involvieren somit neben der p53-abhängigen Expressionssteigerung pro-apoptotischer Zielgene die Inhibition NFкB-vermittelter, endogener, neuroprotektiver Mechanismen.Die Inhibition von p53 durch Pifithrin stellt einen viel versprechenden Ansatzpunkt in der Therapie nach Schädel-Hirn Trauma dar, die bei guter Verträglichkeit, einem klinisch relevanten therapeutische Fenster und vielfach belegter zerebroprotektiver Wirksamkeit viel Potential besitz

Synthetic Cell-Based Immunotherapies for Neurologic Diseases

The therapeutic success and widespread approval of genetically engineered T cells for a variety of hematologic malignancies spurred the development of synthetic cell-based immunotherapies for CNS lymphoma, primary brain tumors, and a growing spectrum of nononcologic disease conditions of the nervous system. Chimeric antigen receptor effector T cells bear the potential to deplete target cells with higher efficacy, better tissue penetration, and greater depth than antibody-based cell depletion therapies. In multiple sclerosis and other autoimmune disorders, engineered T-cell therapies are being designed and currently tested in clinical trials for their safety and efficacy to eliminate pathogenic B-lineage cells. Chimeric autoantibody receptor T cells expressing a disease-relevant autoantigen as cell surface domains are designed to selectively deplete autoreactive B cells. Alternative to cell depletion, synthetic antigen-specific regulatory T cells can be engineered to locally restrain inflammation, support immune tolerance, or efficiently deliver neuroprotective factors in brain diseases in which current therapeutic options are very limited. In this article, we illustrate prospects and bottlenecks for the clinical development and implementation of engineered cellular immunotherapies in neurologic diseases

The Role of BAFF-R Signaling in the Growth of Primary Central Nervous System Lymphoma

Primary CNS lymphoma (PCNSL) is an aggressive brain tumor. Despite improvements in therapeutic algorithms, long-term survival remains rare, illustrating an urgent need for novel therapeutic targets. BAFF-R is a pro-survival receptor expressed on most malignant B cells, including PCNSL. To date, its role in PCNSL growth remains elusive. Here, we have created a BAFF-R knockout lymphoma cell line (BAFF-R-KO) using CRISPR-Cas9. In serum-starved conditions, BAFF-R-KO cells exhibit decreased viability in vitro compared to BAFF-R+ cells. Combining an orthotopic mouse model of PCNSL with chronic cranial windows and intravital microscopy, we have demonstrated a significant delay in tumor growth in mice inoculated with BAFF-R-KO cells compared to BAFF-R+ PCNSL. Additionally, median survival of BAFF-R-KO mice was significantly prolonged. Altogether, our results indicate the high potential of BAFF-R as a novel treatment target for PCNSL

CXCL13 and CXCL9 CSF Levels in Central Nervous System Lymphoma-Diagnostic, Therapeutic, and Prognostic Relevance

Background: Diagnostic delay and neurologic deterioration are still a problem for the treatment of rapidly progressing CNS lymphoma (CNSL); there is an unmet need for a diagnostic test with a high diagnostic yield and limited risk, minimizing the time to the initiation of effective treatment. Methods: In this prospective monocentric study, we analyzed the utility of CXCL13 and CXCL9 as diagnostic, therapeutic and prognostic biomarkers for CNSL. Cerebrospinal fluid (CSF) from 155 consecutive patients admitted with brain lesions of various origins was collected. Levels of CXCL13 and CXCL9 were analyzed by ELISA. Additionally, CSF was analyzed during CNSL disease course (relapse, remission, progress) in 17 patients. Results: CXCL13 and CXCL9 CSF levels were significantly increased in patients with CNSL compared to control patients with lesions of other origin. Using logistic regression and a minimal-p-value approach, a cut-off value of 80 pg/ml for CXCL13 shows high sensitivity (90.7%) and specificity (90.1%) for the diagnosis of active CNSL. CXCL9 at a cut-off value of 84 pg/ml is less sensitive (61.5%) and specific (87.1%). Both cytokines correlate with the clinical course and response to therapy. Conclusions: Our results confirm the excellent diagnostic potential of CXCL13 and introduce CXCL9 as a novel albeit less powerful marker for PCNSL

Extent, pattern, and prognostic value of MGMT promotor methylation: does it differ between glioblastoma and IDH-wildtype/TERT-mutated astrocytoma?

INTRODUCTION The cIMPACT-NOW update 6 first introduced glioblastoma diagnosis based on the combination of IDH-wildtype (IDHwt) status and TERT promotor mutation (pTERTmut). In glioblastoma as defined by histopathology according to the WHO 2016 classification, MGMT promotor status is associated with outcome. Whether this is also true in glioblastoma defined by molecular markers is yet unclear. METHODS We searched the institutional database for patients with: (1) glioblastoma defined by histopathology; and (2) IDHwt astrocytoma with pTERTmut. MGMT promotor methylation was analysed using methylation-specific PCR and Sanger sequencing of CpG sites within the MGMT promotor region. RESULTS We identified 224 patients with glioblastoma diagnosed based on histopathology, and 54 patients with IDHwt astrocytoma with pTERTmut (19 astrocytomas WHO grade II and 38 astrocytomas WHO grade III). There was no difference in the number of MGMT methylated tumors between the two cohorts as determined per PCR, and also neither the number nor the pattern of methylated CpG sites differed as determined per Sanger sequencing. Progression-free (PFS) and overall survival (OS) was similar between the two cohorts when treated with radio- or chemotherapy. In both cohorts, higher numbers of methylated CpG sites were associated with favourable outcome. CONCLUSIONS Extent and pattern of methylated CpG sites are similar in glioblastoma and IDHwt astrocytoma with pTERTmut. In both tumor entities, higher numbers of methylated CpG sites appear associated with more favourable outcome. Evaluation in larger prospective cohorts is warranted

Penumbra Pattern Assessment in Acute Stroke Patients: Comparison of Quantitative and Non-Quantitative Methods in Whole Brain CT Perfusion

Background and Purpose: While penumbra assessment has become an important part of the clinical decision making for acute stroke patients, there is a lack of studies measuring the reliability and reproducibility of defined assessment techniques in the clinical setting. Our aim was to determine reliability and reproducibility of different types of three-dimensional penumbra assessment methods in stroke patients who underwent whole brain CT perfusion imaging (WB-CTP). Materials and Methods: We included 29 patients with a confirmed MCA infarction who underwent initial WB-CTP with a scan coverage of 100 mm in the z-axis. Two blinded and experienced readers assessed the flow-volume-mismatch twice and in two quantitative ways: Performing a volumetric mismatch analysis using OsiriX imaging software (MMVOL) and visual estimation of mismatch (MMEST). Complementarily, the semiquantitative Alberta Stroke Programme Early CT Score for CT perfusion was used to define mismatch (MMASPECTS). A favorable penumbral pattern was defined by a mismatch of >= 30% in combination with a cerebral blood flow deficit of = 1, respectively. Inter-and intrareader agreement was determined by Kappa-values and ICCs. Results: Overall, MMVOL showed considerably higher inter-/intrareader agreement (ICCs: 0.751/0.843) compared to MMEST (0.292/0.749). In the subgroup of large (>= 50 mL) perfusion deficits, inter-and intrareader agreement of MMVOL was excellent (ICCs: 0.961/0.942), while MMEST interreader agreement was poor (0.415) and intrareader agreement was good (0.919). With respect to penumbra classification, MMVOL showed the highest agreement (interreader agreement: 25 agreements/4 non-agreements/kappa: 0.595;intrareader agreement 27/2/0.833), followed by MMEST (22/7/0.471;23/6/0.577), and MMASPECTS (18/11/0.133;21/8/0.340). Conclusion: The evaluated approach of volumetric mismatch assessment is superior to pure visual and ASPECTS penumbra pattern assessment in WB-CTP and helps to precisely judge the extent of 3-dimensional mismatch in acute stroke patients

Extent and prognostic value of MGMT promotor methylation in glioma WHO grade II

MGMT promotor methylation is associated with favourable outcome in high-grade glioma. In glioma WHO grade II, it is unclear whether the extent of MGMT promotor methylation and its prognostic role is independent from other molecular markers. We performed a retrospective analysis of 155 patients with glioma WHO grade II. First, all 155 patients were assigned to three molecular groups according to the 2016 WHO classification system: (1) oligodendroglioma, IDH-mutant and 1p19q co-deleted (n=81);(2) astrocytoma, IDH-mutant and 1p19q non-codeleted (n=54);(3) astrocytoma, IDH-wildtype (n=20). MGMT promotor methylation was quantified using Sanger sequencing of the CpG sites 74-98 within the MGMT promotor region. Highest numbers of methylated CpG sites were found for oligodendroglioma, IDH-mutant and 1p19q co-deleted. When 1p19q co-deletion was absent, numbers of methylated CpG sites were higher in the presence of IDH-mutation. Accordingly, lowest numbers were seen in the IDH-wildtype subpopulation. In the entire cohort, larger numbers of methylated CpG sites were associated with favourable outcome. When analysed separately for the three WHO subgroups, a similar association was only retained in astrocytoma, IDH-wildtype. Collectively, extent of MGMT promotor methylation was strongly associated with other molecular markers and added prognostic information in astrocytoma, IDH-wildtype. Evaluation in prospective cohorts is warranted

Subventricular zone involvement is associated with worse outcome in glioma WHO grade 2 depending on molecular markers

Neural stem cells within the subventricular zone were identified as cells of origin driving growth of high-grade gliomas, and anatomical involvement of the subventricular zone has been associated with an inferior clinical outcome. Whether the association between poor outcome and subventricular zone involvement also applies to glioma of lower grades is unclear. We therefore analysed a retrospective cohort of 182 patients with glioma grade 2 (according to the WHO 2016 classification) including 78 individuals (43%) with subventricular zone involvement. Patients with and without subventricular zone involvement did not differ in regard to demographics, histopathology, and molecular markers. Notably, subventricular zone involvement was a negative prognostic marker for malignant progression and overall survival on uni- and multivariate analysis. When patients were stratified according to the cIMPACT-NOW update 6, subventricular zone involvement was negatively associated with outcome in IDH-wildtype astrocytomas and 1p19q-codeleted oligodendrogliomas but not in IDH-mutant astrocytomas. Collectively, subventricular zone involvement may represent a risk factor for worse outcome in glioma WHO grade 2 depending on the molecular tumor signature. The present data confirm the relevance of molecular glioma classifications as proposed by the cIMPACT-NOW update 6. These findings warrant evaluation in prospective cohorts

The value of stereotactic biopsy of primary and recurrent brain metastases in the era of precision medicine

BackgroundBrain metastases (BM) represent the most frequent intracranial tumors with increasing incidence. Many primary tumors are currently treated in protocols that incorporate targeted therapies either upfront or for progressive metastatic disease. Hence, molecular markers are gaining increasing importance in the diagnostic framework of BM. In cases with diagnostic uncertainty, both in newly diagnosed or recurrent BM, stereotactic biopsy serves as an alternative to microsurgical resection particularly whenever resection is not deemed to be safe or feasible. This retrospective study aimed to analyze both diagnostic yield and safety of an image-guided frame based stereotactic biopsy technique (STX).Material and methodsOur institutional neurosurgical data base was searched for any surgical procedure for suspected brain metastases between January 2016 and March 2021. Of these, only patients with STX were included. Clinical parameters, procedural complications, and tissue histology and concomitant molecular signature were assessed.ResultsOverall, 467 patients were identified including 234 (50%) with STX. Median age at biopsy was 64 years (range 29 – 87 years). MRI was used for frame-based trajectory planning in every case with additional PET-guidance in 38 cases (16%). In total, serial tumor probes provided a definite diagnosis in 230 procedures (98%). In 4 cases (1.7%), the pathological tissue did not allow a definitive neuropathological diagnosis. 24 cases had to be excluded due to non-metastatic histology, leaving 206 cases for further analyses. 114 patients (49%) exhibited newly diagnosed BM, while 46 patients (20%) displayed progressive BM. Pseudoprogression was seen in 46 patients, a median of 12 months after prior therapy. Pseudoprogression was always confirmed by clinical course. Metastatic tissue was found most frequently from lung cancer (40%), followed by breast cancer (9%), and malignant melanoma (7%). Other entities included gastrointestinal cancer, squamous cell cancer, renal cell carcinoma, and thyroid cancer, respectively. In 9 cases (4%), the tumor origin could not be identified (cancer of unknown primary). Molecular genetic analyses were successful in 137 out of 144 analyzed cases (95%). Additional next-generation sequencing revealed conclusive results in 12/18 (67%) cases. Relevant peri-procedural complications were observed in 5 cases (2.4%), which were all transient. No permanent morbidity or mortality was noted.ConclusionIn patients with BM, frame-based stereotactic biopsy constitutes a safe procedure with a high diagnostic yield. Importantly, this extended to discerning pseudoprogression from tumor relapse after prior therapy. Thus, comprehensive molecular characterization based on minimal-invasive stereotactic biopsies lays the foundation for precision medicine approaches in the treatment of primary and recurrent BM

The value of stereotactic biopsy of primary and recurrent brain metastases in the era of precision medicine

Background: Brain metastases (BM) represent the most frequent intracranial tumors with increasing incidence. Many primary tumors are currently treated in protocols that incorporate targeted therapies either upfront or for progressive metastatic disease. Hence, molecular markers are gaining increasing importance in the diagnostic framework of BM. In cases with diagnostic uncertainty, both in newly diagnosed or recurrent BM, stereotactic biopsy serves as an alternative to microsurgical resection particularly whenever resection is not deemed to be safe or feasible. This retrospective study aimed to analyze both diagnostic yield and safety of an image-guided frame based stereotactic biopsy technique (STX). Material and methods: Our institutional neurosurgical data base was searched for any surgical procedure for suspected brain metastases between January 2016 and March 2021. Of these, only patients with STX were included. Clinical parameters, procedural complications, and tissue histology and concomitant molecular signature were assessed. Results: Overall, 467 patients were identified including 234 (50%) with STX. Median age at biopsy was 64 years (range 29 – 87 years). MRI was used for frame-based trajectory planning in every case with additional PET-guidance in 38 cases (16%). In total, serial tumor probes provided a definite diagnosis in 230 procedures (98%). In 4 cases (1.7%), the pathological tissue did not allow a definitive neuropathological diagnosis. 24 cases had to be excluded due to non-metastatic histology, leaving 206 cases for further analyses. 114 patients (49%) exhibited newly diagnosed BM, while 46 patients (20%) displayed progressive BM. Pseudoprogression was seen in 46 patients, a median of 12 months after prior therapy. Pseudoprogression was always confirmed by clinical course. Metastatic tissue was found most frequently from lung cancer (40%), followed by breast cancer (9%), and malignant melanoma (7%). Other entities included gastrointestinal cancer, squamous cell cancer, renal cell carcinoma, and thyroid cancer, respectively. In 9 cases (4%), the tumor origin could not be identified (cancer of unknown primary). Molecular genetic analyses were successful in 137 out of 144 analyzed cases (95%). Additional next-generation sequencing revealed conclusive results in 12/18 (67%) cases. Relevant peri-procedural complications were observed in 5 cases (2.4%), which were all transient. No permanent morbidity or mortality was noted. Conclusion: In patients with BM, frame-based stereotactic biopsy constitutes a safe procedure with a high diagnostic yield. Importantly, this extended to discerning pseudoprogression from tumor relapse after prior therapy. Thus, comprehensive molecular characterization based on minimal-invasive stereotactic biopsies lays the foundation for precision medicine approaches in the treatment of primary and recurrent BM