21 research outputs found

    Expression und Funktion des Transkriptionsfaktors KLF-8 in Gliomen

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    Krüppel-like factor 8 (KLF8) is expressed in gliomas of different WHO grades and is essential for tumor cell proliferation.

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    Krüppel-like factor 8 (KLF8) has only recently been identified to be involved in tumor cell proliferation and invasion of several different tumor entities like renal cell carcinoma, hepatocellular carcinoma and breast cancer. In the present study, we show for the first time the expression of KLF8 in gliomas of different WHO grades and its functional impact on glioma cell proliferation. In order to get information about KLF8-mRNA regulation qPCR was performed and did not reveal any significant difference in samples (n = 10 each) of non-neoplastic brain (NNB), low-grade gliomas (LGG, WHO°II) and glioblastomas (GBM, WHO°IV). Immunohistochemistry of tissue samples (n = 7 LGG, 11 AA and 12 GBM) did not show any significant difference in the fraction of KLF8-immunopositive cells of all analyzed cells in LGG (87%), AA (80%) or GBM (89%). Tissue samples from cerebral breast cancer metastasis, meningiomas but also non-neoplastic brain demonstrated comparable relative cell counts as well. Moreover, there was no correlation between KLF8 expression and the expression pattern of the assumed proliferation marker Ki67, which showed high variability between different tumor grade (9% (LGG), 6% (AA) and 15% (GBM) of Ki67-immunopositive cells). Densitometric analysis of Western blotting revealed that the relative amount of KLF8-protein did also not differ between the highly aggressive and proliferative GBM (1.05) compared to LGG (0.93; p<0.05, studens t-test). As demonstrated for some other non-glial cancer entities, KLF8-knockdown by shRNA in U87-MG cells confirmed its functional relevance, leading to an almost complete loss of tumor cell proliferation. Selective blocking of KLF8 might represent a novel anti-proliferative treatment strategy for malignant gliomas. Yet, its simultaneous expression in non-proliferating tissues could hamper this approach

    Expression of Integrin αvβ3 in Gliomas Correlates with Tumor Grade and Is not Restricted to Tumor Vasculature

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    In malignant gliomas, the integrin adhesion receptors seem to play a key role for invasive growth and angiogenesis. However, there is still a controversy about the expression and the distribution of αvβ3 integrin caused by malignancy. The aim of our study was to assess the extent and pattern of αvβ3 integrin expression within primary glioblastomas (GBMs) compared with low-grade gliomas (LGGs). Tumor samples were immunostained for the detection of αvβ3 integrin and quantified by an imaging software. The expression of αvβ3 was found to be significantly higher in GBMs than in LGGs, whereby focal strong reactivity was restricted to GBMs only. Subsequent analysis revealed that not only endothelial cells but also, to a large extent, glial tumor cells contribute to the overall amount of αvβ3 integrin in the tumors. To further analyze the integrin subunits, Western blots from histologic sections were performed, which demonstrated a significant difference in the expression of the β3 integrin subunit between GBMs and LGGs. The presented data lead to new insights in the pattern of αvβ3 integrin in gliomas and are of relevance for the inhibition of αvβ3 integrin with specific RGD peptides and interfering drugs to reduce angiogenesis and tumor growth

    Surgeon experience in glioblastoma surgery of the elderly : a multicenter, retrospective cohort study

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    Purpose To assess the impact of individual surgeon experience on overall survival (OS), extent of resection (EOR) and surgery-related morbidity in elderly patients with glioblastoma (GBM), we performed a retrospective case-by-case analysis. Methods GBM patients aged≥65 years who underwent tumor resection at two academic centers were analyzed. The experience of each neurosurgeon was quantifed in three ways: (1) total number of previously performed glioma surgeries (lifetime experience); (2) number of surgeries performed in the previous fve years (medium-term experience) and (3) in the last two years (short-term experience). Surgeon experience data was correlated with survival (OS) and surrogate parameters for surgical quality (EOR, morbidity). Results 198 GBM patients (median age 73.0 years, median preoperative KPS 80, IDH-wildtype status 96.5%) were included. Median OS was 10.0 months (95% CI 8.0–12.0); median EOR was 89.4%. Surgery-related morbidity afected 19.7% patients. No correlations of lifetime surgeon experience with OS (P=.693), EOR (P=.693), and surgery-related morbidity (P=.435) were identifed. Adjuvant therapy was associated with improved OS (PConclusion Less experienced neurosurgeons achieve similar surgical results and outcome in elderly GBM patients within the setting of academic teaching hospitals. Adjuvant treatment and avoidance of surgery-related morbidity are crucial forgenerating a treatment beneft for this cohort.Peer reviewe

    Assessment of the role of DNA damage and repair in the survival of primary cultures of rat cutaneous keratinocytes exposed to bis(2-chloroethyl)sulfide

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    Toxicity manifests itself as vesication in human skin exposed topically to bis(2-chloroethyl)sulfide (BCES). The destruction of the proliferating population of epidermal cells is a major component of the pathogenic process. Available data strongly suggest that damage to cellular DNA is a critical factor in the loss of these cells. However, the influence of DNA repair on this toxic response has not been adequately studied. Therefore, a study was undertaken to ascertain the influence of DNA repair on the survival of primary monolayer cultures of rat cutaneous keratinocytes exposed to BCES. The sensitive nucleoid sedimentation assay was employed for the determination of DNA damage in cultures exposed to very low levels of BCES. Initial experiments demonstrated that within 1 hr of exposure to as little as 0.1 [mu] BCES the structural integrity of cellular DNA was compromised, presumably resulting from the appearance of single-strand breaks in the nucleic acid. This same effect was demonstrated in basal cells derived from a stratified, cornified culture grown at the air-liquid interface and exposed topically to the vesicant. Further studies with the monolayer culture demonstrated that the gross structural integrity of the DNA in cells exposed to as much as 5 [mu] BCES was completely restored within the first 22 hr following the exposure. However, this repair process appeared to be inefficient since a depression of thymidine incorporation into DNA and a significant loss of DNA were exhibited in exposed cultures as long as 72 hr after the initial exposure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29057/1/0000090.pd

    Suspected recurrence of brain metastases after focused high dose radiotherapy: can [F-18]FET-PET overcome diagnostic uncertainties?

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    Background: After focused high dose radiotherapy of brain metastases, differentiation between tumor recurrence and radiation-induced lesions by conventional MRI is challenging. This study investigates the usefulness of dynamic O-(2-F-18-Fluoroethyl)-L-Tyrosine positron emission tomography (F-18-FET PET) in patients with MRI-based suspicion of tumor recurrence after focused high dose radiotherapy of brain metastases. Methods: Twenty-two patients with 34 brain metastases (median age 61.9 years) were included. Due to follow-up scan evaluations after repeated treatment in a subset of patients, a total of 50 lesions with MRI-based suspicion of tumor recurrence after focused high dose radiotherapy could be evaluated. F-18-FET PET analysis included the assessment of maximum and mean tumor-to-background ratio (TBRmax and TBRmean) and analysis of time-activity-curves (TAC;increasing vs. decreasing) including minimal time-to-peak (TTPmin). PET parameters were correlated with histological findings and radiological-clinical follow-up evaluation. Results: Tumor recurrence was found in 21/50 cases (15/21 verified by histology, 6/21 by radiological-clinical follow-up) and radiation-induced changes in 29/50 cases (5/29 verified by histology, 24/29 by radiological-clinical follow-up). Median clinical-radiological follow-up was 28.3 months (range 4.2-99.1 months). F-18-FET uptake was higher in tumor recurrence compared to radiation-induced changes (TBRmax 2.9 vs. 2.0, p < 0.001;TBRmean 2.2 vs. 1.7, p < 0.001). Receiver-operating-characteristic (ROC) curve analysis revealed optimal cut-off values of 2.15 for TBRmax and 1.95 for TBRmean (sensitivity 86 %, specificity 79 %). Increasing TACs and long TTPmin were associated with radiation-induced changes, decreasing TACs with tumor recurrence (p = 0.01). By combination of TBR and TACs, sensitivity and specificity could be increased to 93 and 84 %. Conclusions: In patients with MRI-suspected tumor recurrence after focused high dose radiotherapy, F-18-FET PET has a high sensitivity and specificity for the differentiation of vital tumor tissue and radiation-induced lesions

    Spinal arachnoid web-a distinct entity of focal arachnopathy with favorable long-term outcome after surgical resection. Analysis of a multicenter patient population

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    BACKGROUND CONTEXT Spinal arachnoid web (SAW) is a rare condition characterized by focal thickening of the arachnoid membrane causing displacement and compression of the spinal cord with progressive symptoms and neurological deficits. Recent reports and clinical experience suggest that SAW is a distinct entity with specific radiological findings and treatment strategies distinguishable from other arachnopathies and potential differential diagnoses. PURPOSE To better define the diagnostic and clinical features, treatment options and outcomes of surgically treated SAW. STUDY DESIGN Multicentric retrospective cohort study. PATIENT SAMPLE Twelve cases of SAW surgically treated at three different centers. OUTCOME MEASURES Self-reported and neurological outcome measurements (pain, sensory-motor deficits, vegetative dysfunctions) were assessed at follow-up timepoints. METHODS Retrospective review of prospectively collected data on all patients surgically treated for SAW from three participating neurosurgical centers between 2014 and 2020. Clinicopathological data, including neurological presentation, radiological and histological findings and outcome data were analyzed. RESULTS Twelve radiologically and surgically confirmed cases of SAW were analyzed. Mean patient age was 54.7 [±12.7], 67% were male. All SAWs were located in the posterior thoracic dural sac. On magnetic resonance imaging (MRI), the "scalpel sign" - a characteristic focal dorsal indentation of the spinal cord resembling a scalpel blade - was identified in all patients. A focal intramedullary syrinx was present in 83%. Preoperative clinical symptoms included signs of myelopathy, pain, weakness and sensory loss, most commonly affecting the trunk/upper back or lower extremities. Laminectomy or laminoplasty with intradural excision of the SAW was the surgical treatment of choice in all cases. Intraoperative ultrasound was valuable to visualize the cerebrospinal fluid (CSF) flow obstruction, confirm the SAW location before dura incision and to control adequacy of resection. After surgery, sensory loss and weakness in particular showed significant improvement. CONCLUSIONS The present study comprises the largest series of surgically treated SAW, underscoring the unique clinical, radiographic, histopathological, and surgical findings. We want to emphasize SAW being a distinct entity of spinal arachnopathy with a favorable long-term outcome if diagnosed correctly and treated surgically. Intraoperative ultrasound aids visualizing the SAW before dural incision, as well as verifying restored CSF flow after resection

    Long-term outcome of stereotactic brachytherapy with temporary Iodine-125 seeds in patients with WHO grade II gliomas

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    Background!#!This long-term retrospective analysis aimed to investigate the outcome and toxicity profile of stereotactic brachytherapy (SBT) in selected low-grade gliomas WHO grade II (LGGII) in a large patient series.!##!Methods!#!This analysis comprised 106 consecutive patients who received SBT with temporary Iodine-125 seeds for histologically verified LGGII at the University of Munich between March 1997 and July 2011. Investigation included clinical characteristics, technical aspects of SBT, the application of other treatments, outcome analyses including malignization rates, and prognostic factors with special focus on molecular biomarkers.!##!Results!#!For the entire study population, the 5- and 10-years overall survival (OS) rates were 79% and 62%, respectively, with a median follow-up of 115.9 months. No prognostic factors could be identified. Interstitial radiotherapy was applied in 51 cases as first-line treatment with a median number of two seeds (range 1-5), and a median total implanted activity of 21.8 mCi (range 4.2-43.4). The reference dose average was 54.0 Gy. Five- and ten-years OS and progression-free survival rates after SBT were 72% and 43%, and 40% and 23%, respectively, with a median follow-up of 86.7 months. The procedure-related mortality rate was zero, although an overall complication rate of 16% was registered. Patients with complications had a significantly larger tumor volume (p = 0.029).!##!Conclusion!#!SBT is a minimally invasive treatment modality with a favorable outcome and toxicity profile. It is both an alternative primary treatment method as well as an adjunct to open tumor resection in selected low-grade gliomas

    Risks and Benefits of Glioblastoma Resection in Older Adults : A Retrospective Austrian Multicenter Study

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    OBJECTIVE: To assess the prognostic profile, clinical outcome, treatment-associated morbidity, and treatment burden of elderly patients with glioblastoma (GBM) undergoing microsurgical tumor resection as part of contemporary treatment algorithms. METHODS: We retrospectively identified patients with GBM >= 65 years of age who were treated by resection at 2 neuro-oncology centers. Survival was assessed by Kaplan-Meier analyses; log-rank tests identified prognostic factors. RESULTS: The study population included 160 patients (mean age, 73.1 +/- 5.1 years), and the median contrastenhancing tumor volume was 31.0 cm(3). Biomarker analyses revealed 0(6)-methylguanine-DNA methyltransferase-promoter methylation in 62.7% and wild-type isocitrate dehydrogenase in 97.5% of tumors. The median extent of resection (EOR) was 92.3%, surgical complications were noted in 10.0% of patients, and the median postoperative hospitalization period was 8 days. Most patients (60.0%) received adjuvant radio-/chemotherapy. The overall treatment-associated morbidity was 30.6%. The median progression-free and overall survival were 5A months (95% confidence interval [Cl], 4.6-6.4 months) and 10.0 months (95% CI, 7.9-11.7 months). The strongest predictors for favorable outcome were patient age = 80% (P = 0.0179), postoperative modified Rankin Scale score CONCLUSIONS: Clinical outcome for elderly patients with GBM remains limited. Nonetheless, the observed treatment-associated morbidity and treatment burden were moderate in the patients, and patient age and performance status remained the strongest predictors for survival. The risks and benefits of tumor resection in the age of biomarker-adjusted treatment concepts require further prospective evaluation.Peer reviewe

    KLF8 and Ki67 expression in non-CNS tumors.

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    <p>KLF8 (A, C, E) and Ki67 (B, D, F) protein expression was analyzed in some additional tissue samples of breast cancer metastasis (A, B), meningioma (C, D) and non-neoplastic brain (E, F). All tissue samples analyzed confirmed ubiquitous expression of this transcription molecule, irrespective of the assumed proliferation rate.</p
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