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19 result(s) for "Flueh, Charlotte"
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Detection of gene mutations and gene–gene fusions in circulating cell‐free DNA of glioblastoma patients: an avenue for clinically relevant diagnostic analysis
Glioblastoma (GBM) is the most common type of glioma and is uniformly fatal. Currently, tumour heterogeneity and mutation acquisition are major impedances for tailoring personalized therapy. We collected blood and tumour tissue samples from 25 GBM patients and 25 blood samples from healthy controls. Cell‐free DNA (cfDNA) was extracted from the plasma of GBM patients and from healthy controls. Tumour DNA was extracted from fresh tumour samples. Extracted DNA was sequenced using a whole‐genome sequencing procedure. We also collected 180 tumour DNA datasets from GBM patients publicly available at the TCGA/PANCANCER project. These data were analysed for mutations and gene–gene fusions that could be potential druggable targets. We found that plasma cfDNA concentrations in GBM patients were significantly elevated (22.6 ± 5 ng·mL−1), as compared to healthy controls (1.4 ± 0.4 ng·mL−1) of the same average age. We identified unique mutations in the cfDNA and tumour DNA of each GBM patient, including some of the most frequently mutated genes in GBM according to the COSMIC database (TP53, 18.75%; EGFR, 37.5%; NF1, 12.5%; LRP1B, 25%; IRS4, 25%). Using our gene–gene fusion database, ChiTaRS 5.0, we identified gene–gene fusions in cfDNA and tumour DNA, such as KDR–PDGFRA and NCDN–PDGFRA, which correspond to previously reported alterations of PDGFRA in GBM (44% of all samples). Interestingly, the PDGFRA protein fusions can be targeted by tyrosine kinase inhibitors such as imatinib, sunitinib, and sorafenib. Moreover, we identified BCR–ABL1 (in 8% of patients), COL1A1–PDGFB (8%), NIN–PDGFRB (8%), and FGFR1–BCR (4%) in cfDNA of patients, which can be targeted by analogues of imatinib. ROS1 fusions (CEP85L–ROS1 and GOPC–ROS1), identified in 8% of patient cfDNA, might be targeted by crizotinib, entrectinib, or larotrectinib. Thus, our study suggests that integrated analysis of cfDNA plasma concentration, gene mutations, and gene–gene fusions can serve as a diagnostic modality for distinguishing GBM patients who may benefit from targeted therapy. These results open new avenues for precision medicine in GBM, using noninvasive liquid biopsy diagnostics to assess personalized patient profiles. Moreover, repeated detection of druggable targets over the course of the disease may provide real‐time information on the evolving molecular landscape of the tumour. Personalized therapy of patients with glioblastoma (GBM) is challenging owing to tumour heterogeneity. Here, we extracted and sequenced cell‐free DNA (cfDNA) from the plasma of 25 GBM patients and tumour DNA from fresh tumour samples. We found that cfDNA concentrations in the plasma of GBM patients were significantly elevated, as compared to healthy controls. Moreover, we identified unique mutations and gene–gene fusions in the cfDNA and tumour DNA of GBM patients, some of which could be therapeutically targeted by tyrosine kinase inhibitors.
Primidone blocks RIPK1-driven cell death and inflammation
The receptor-interacting serine/threonine protein kinase 1 (RIPK1) is a key mediator of regulated cell death and inflammation. Recent studies suggest that RIPK1 inhibition would fundamentally improve the therapy of RIPK1-dependent organ damage in stroke, myocardial infarction, kidney failure, and systemic inflammatory response syndrome. Additionally, it could ameliorate or prevent multi-organ failure induced by cytokine release in the context of hyperinflammation, as seen in COVID-19 patients. Therefore, we searched for a RIPK1 inhibitor and present the aromatic antiepileptic and FDA-approved drug primidone (Liskantin®) as a potent inhibitor of RIPK1 activation in vitro and in a murine model of TNFα-induced shock, which mimics the hyperinflammatory state of cytokine release syndrome. Furthermore, we detected for the first time RIPK1 activation in the respiratory tract epithelium of hospitalized patients who tested positive for SARS-CoV-2 infection. Our data provide a strong rationale for evaluating the drug primidone in conditions of hyperinflammation in humans.
NKG2D ligands in glioma stem-like cells: expression in situ and in vitro
Glioblastoma multiforme (GBM) is a highly malignant brain tumor. Tumor stem cells have a major influence on tumor malignancy, and immunological escape mechanisms, involving the Natural Killer Group 2, member D (NKG2D) receptor-ligand-system, are key elements in tumor immuno-surveillance. We analyzed the expression profile and localization of NKG2D ligands (NKG2DL) and embryonic and neural stem cell markers in solid human GBM and stem-like cells isolated from glioma cell lines by qRT-PCR and immunohistochemistry, including quantitative analysis. We also evaluated the effect of Temozolomide (TMZ), the standard chemotherapeutic agent used in GBM therapy, on NKG2DL expression. NKG2DL-positive cells were mostly found scattered and isolated, were detectable in glial fibrillary acidic protein (GFAP)-positive tumor regions and partly in the penumbra of tumor vessels. NKG2DL were found in a distinct tumor stem-like cell subpopulation and were broadly costained with each other. Quantitative analysis revealed, that dependent on the individual NKG2DL investigated, cell portions costained with different stem cell markers varied between small (Musashi-1) and high (KLf-4) amounts. However, a costaining of NKG2DL with CD3γ, typically found in T cells, was also observable, whereas CD11b as a marker for tumor micoglia cells was only rarely costained with NKG2DL. Stem-like cells derived from the glioma cell lines T98G and U251MG showed a distinct expression pattern of NKG2DL and stem cell markers, which seemed to be balanced in a cell line-specific way. With differentiation, T98G displayed less NKG2DL, whereas in U251MG, only expression of most stem cell markers decreased. In addition, stimulation with TMZ led to a significant upregulation of NKG2DL in stem-like cells of both lines. As stem-like glioma cells tend to show a higher expression of NKG2DL than more differentiated tumor cells and TMZ treatment supports upregulation of NKG2DL, the NKG2D system might play an important role in tumor stem cell survival and in GBM therapy.
Multimodal validation of focal enhancement in intracranial aneurysms as a surrogate marker for aneurysm instability
Purpose Circumferential enhancement on MR vessel wall imaging has been proposed as a biomarker of a higher risk of rupture in intracranial aneurysms. Focal enhancement is frequently encountered in unruptured aneurysms, but its implication for risk stratification and patient management remains unclear. This study investigates the association of focal wall enhancement with hemodynamic and morphological risk factors and histologic markers of wall inflammation and degeneration. Methods Patients with an unruptured middle cerebral artery aneurysm who underwent 3D rotational angiography and 3T MR vessel wall imaging showing focal wall enhancement were included. Hemodynamic parameters were calculated based on flow simulations and compared between enhanced regions and the entire aneurysm surface. Morphological parameters were semiautomatically extracted and quantitatively associated with wall enhancement. Histological analysis included detection of vasa vasorum, CD34, and myeloperoxidase staining in a subset of patients. Results Twenty-two aneurysms were analyzed. Enhanced regions were significantly associated with lower AWSS, lower maxOSI, and increased LSA. In multivariate analysis, higher ellipticity index was an independent predictor of wall enhancement. Histologic signs of inflammation and degeneration and higher PHASES score were significantly associated with focal enhancement. Conclusion Focal wall enhancement is colocalized with hemodynamic factors that have been related to a higher rupture risk. It is correlated with morphological factors linked to rupture risk, higher PHASES score, and histologic markers of wall destabilization. The results support the hypothesis that focal enhancement could serve as a surrogate marker for aneurysm instability.
Clinical and radiological differences between patients with probable cerebral amyloid angiopathy and mixed cerebral microbleeds
Background The key imaging features of cerebral amyloid angiopathy (CAA) are lobar, cortical, or cortico-subcortical microbleeds, macrohaemorrhages and cortical superficial siderosis (cSS). In contrast, hypertensive angiopathy is characterized by (micro) haemorrhages in the basal ganglia, thalami, periventricular white matter or the brain stem. Another distinct form of haemorrhagic microangiopathy is mixed cerebral microbleeds (mixed CMB) with features of both CAA and hypertensive angiopathy. The distinction between the two entities (CAA and mixed CMB) is clinically relevant because the risk of haemorrhage and stroke should be well balanced if oral anticoagulation is indicated in CAA patients. We aimed to comprehensively compare these two entities. Methods Patients with probable CAA according to the modified Boston criteria and mixed CMB without macrohaemorrhage were retrospectively identified from our database. Comprehensive comparison regarding clinical and radiological parameters was performed between the two cohorts. Results Patients with CAA were older (78 ± 8 vs. 74 ± 9 years, p  = 0.036) and had a higher prevalence of cSS (19% vs. 4%, p  = 0.027) but a lower prevalence of lacunes (73% vs. 50%, p  = 0.018) and deep lacunes (23% vs. 51%, p  = 0.0003) compared to patients with mixed CMB. Logistic regression revealed an association between the presence of deep lacunes and mixed CMB. The other collected parameters did not reveal a significant difference between the two groups. Conclusions CAA and mixed CMB demonstrate radiological differences in the absence of macrohaemorrhages. However, more clinically available biomarkers are needed to elucidate the contribution of CAA and hypertensive angiopathy in mixed CMB patients.
Tumor associated microglia/macrophages utilize GPNMB to promote tumor growth and alter immune cell infiltration in glioma
Tumor-associated microglia and blood-derived macrophages (TAMs) play a central role in modulating the immune suppressive microenvironment in glioma. Here, we show that GPNMB is predominantly expressed by TAMs in human glioblastoma multiforme and the murine RCAS-PDGFb high grade glioma model. Loss of GPNMB in the in vivo tumor microenvironment results in significantly smaller tumor volumes and generates a pro-inflammatory innate and adaptive immune cell microenvironment. The impact of host-derived GPNMB on tumor growth was confirmed in two distinct murine glioma cell lines in organotypic brain slices from GPNMB-KO and control mice. Using published data bases of human glioma, the elevated levels in TAMs could be confirmed and the GPNMB expression correlated with a poorer survival.
Dormancy and NKG2D system in brain metastases: Analysis of immunogenicity
Patients with breast cancer (BC) and lung cancer (LC) are prone to developing brain metastases, which are associated with devastating prognoses. Dormant tumor cells, a population of non-apoptotic quiescent cells and immunological escape mechanisms, including the Natural Killer Group 2 member D (NKG2D) receptor-ligand system, represent potential mechanisms of tumor recurrence. To date, the immunological characteristics of dormant tumor cells concerning the NKG2D system in cerebral malignancies are mostly unknown. In the present study, an extensive characterization of dormant and NKG2D ligand (NKG2DL)+ cells in cerebral metastases was performed. The expression profiles and localization patterns of various NKG2DL and several dormancy markers were analyzed in solid human brain metastases from patients with BC and LC using immunostaining and reverse transcription-quantitative polymerase chain reaction analyses. Statistical analysis was performed using Student's t-test and Bravais-Pearson correlation analysis. Not only 'peripheral', but also 'central' dormancy markers, which had been previously described in primary brain tumors, were identified in all cerebral metastases at detectable levels at protein and mRNA levels. Notably, the majority of NKG2DL+ cells were also positive for 'central' dormancy markers, but not 'peripheral' dormancy markers in both patient groups. This cell population may represent a promising future therapeutic target.
Nutritional Gender-Specific Differences in Head and Neck Cancer Patients Treated with (Chemo)Radiotherapy: Results from a Prospective Trial
Background/Objectives: This analysis aims to evaluate gender-specific differences in nutritional status, body weight changes, and their impact on overall survival (OS) in head and neck cancer (HNC) patients undergoing (chemo)radiotherapy (CRT). Methods: Between 2018 and 2020, 61 HNC (17 female and 44 male) patients were prospectively recruited to receive curative (chemo)radiotherapy. Nutritional assessments included dietary questionnaire screenings and records, anthropometric methods (body mass index, BMI, body composition via bioelectrical impedance analysis (BIA)), and the determination of biomarkers like albumin and CRP. Assessments were conducted before, during, and after (chemo)radiotherapy. Results: Gender differences were observed at baseline in Karnofsky performance status (p = 0.01), daily calorie intake (p = 0.04), phase angle (PA) (p = 0.003), and fat-free mass index (FFMI) (p < 0.001). During CRT, males showed a larger increase in calorie deficit (p < 0.001) and greater reductions in BMI, FFMI, and PA compared to females. Malnutrition risk (MUST score) increased significantly in males (p = 0.008) but not in females. Albumin and total protein declined in both genders, with a more pronounced drop in albumin for females. Survival analysis revealed that, for males, several factors, including baseline calorie deficit, BMI, PA, and FFMI, were linked to survival. For females, only albumin at therapy end was significantly associated with survival (p < 0.001). In multivariable analysis, baseline PA remained a significant predictor of survival for males (p = 0.026). Conclusions: Our findings suggest distinct gender differences in the nutritional and biochemical responses of HNC patients undergoing CRT, indicating the importance of tailored, gender-specific nutritional support during treatment.
Cerebrospinal Fluid Biomarkers in Cerebral Amyloid Angiopathy: New Data and Quantitative Meta-Analysis
Background: To evaluate the diagnostic accuracy of CSF biomarkers in patients with probable cerebral amyloid angiopathy (CAA) according to the Modified Boston criteria in a retrospective multicentric cohort. Methods: Aß40, Aß42, t-tau, and p-tau181 were measured in 31 patients with probable CAA, 28 patients with Alzheimer’s disease (AD), and 30 controls. Receiver-operating characteristics (ROC) analyses were performed for the measured parameters as well as the Aß42/40 ratio to estimate diagnostic parameters. A meta-analysis of all amenable published studies was conducted. Results: In our data Aß42/40 (AUC 0.88) discriminated best between CAA and controls while Aß40 did not perform well (AUC 0.63). Differentiating between CAA and AD, p-tau181 (AUC 0.75) discriminated best in this study while Aß40 (AUC 0.58) and Aß42 (AUC 0.54) provided no discrimination. In the meta-analysis, Aß42/40 (AUC 0.90) showed the best discrimination between CAA and controls followed by t-tau (AUC 0.79), Aß40 (AUC 0.76), and p-tau181 (AUC 0.71). p-tau181 (AUC 0.76), Aß40 (AUC 0.73), and t-tau (AUC 0.71) differentiated comparably between AD and CAA while Aß42 (AUC 0.54) did not. In agreement with studies examining AD biomarkers, Aß42/40 discriminated excellently between AD and controls (AUC 0.92-0.96) in this study as well as the meta-analysis. Conclusions: The analyzed parameters differentiate between controls and CAA with clinically useful accuracy (AUC > ~ 0.85) but not between CAA and AD. Since there is a neuropathological, clinical and diagnostic continuum between CAA and AD, other diagnostic markers, e.g. novel CSF biomarkers or other parameters might be more successful.
Visualization of Aneurysm Healing
Purpose Wall enhancement of intracranial aneurysms in vessel wall magnetic resonance imaging (MRI) has been linked to aneurysm progression. The clinical significance of aneurysm enhancement after embolization has not yet been investigated. The goal of this study was to identify factors associated with aneurysm wall enhancement and reperfusion after embolization. Methods Patients who underwent treatment of intracranial aneurysms with coils or the Woven Endobridge (WEB) and follow-up MR vessel wall imaging were included. Enhancement of the treated aneurysms was separately recorded for the following locations: a) wall at the neck, b) wall at the dome, and c) in the aneurysmal cavity. Reperfusion was determined on follow-up digital subtraction angiography (DSA) and MR time of flight (TOF) angiography. Results In this study 48 patients with 53 aneurysms were included. Wall enhancement at the neck and the dome of the aneurysm was significantly associated with time between embolization and follow-up MRI under 6 months. Enhancement inside the aneurysmal cavity was significantly associated with a follow-up time longer than 6 months, and with stable aneurysms without reperfusion. Conclusion Wall enhancement is a regular feature in intracranial aneurysms after embolization and decreases over time. Enhancement inside the aneurysmal cavity is associated with a stable state and could possibly serve as an imaging marker of completed aneurysm healing.