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Background: Cisplatin mediates its antineoplastic activity by formation of distinct DNA intrastrand cross links. The clinical efficacy and desirable dose escalations of cisplatin are restricted by the accumulation of DNA lesions in dorsal root ganglion (DRG) cells leading to sensory polyneuropathy (PNP). We investigated in a mouse model by which mechanism recombinant erythropoietin (rhEPO) protects the peripheral nervous system from structural and functional damage caused by cisplatin treatment with special emphasis on DNA damage burden.Results: A cumulative dose of 16 mg cisplatin/kg resulted in clear electrophysiological signs of neuropathy, which were significantly attenuated by concomitant erythropoietin (cisplatin 32,48 m/s +/- 1,68 m/s; cisplatin + rhEPO 49,66 m/s +/- 1,26 m/s; control 55,01 m/s +/- 1,88 m/s; p < 0,001). The co-application of rhEPO, however, did not alter the level of unrepaired cisplatin-DNA lesions accumulating in DRG target cells. Micro-morphological analyses of the sciatic nerve from cisplatin-exposed mice showed damaged myelin sheaths and mitochondria. Co-administered rhEPO inhibited myelin sheaths from structural injuries and resulted in an increased number of intact mitochondria.Conclusion: The protective effect of recombinant erythropoietin is not mediated by reducing the burden of DNA platination in the target cells, but it is likely to be due to a higher resistance of the target cells to the adverse effect of DNA damage. The increased frequency of intact mitochondria might also contribute to this protective role. [ABSTRACT FROM AUTHOR]

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Katzendobler, Do, Weller, Rejeski, Dorostkar, Albert, Forbrig, Niyazi, Egensperger, Tonn, Baumgarten, Quach and Thon.)

Background: An integrated diagnosis consisting of histology and molecular markers is the basis of the current WHO classification system of gliomas. In patients with suspected newly diagnosed or recurrent glioma, stereotactic biopsy is an alternative in cases in which microsurgical resection is deemed to not be safely feasible or indicated. In this retrospective study, we aimed to analyze both the diagnostic yield and the safety of a standardized biopsy technique., Material and Methods: The institutional database was screened for frame-based biopsy procedures (January 2016 until March 2021). Only patients with a suspected diagnosis of glioma based on imaging were included. All tumors were classified according to the current WHO grading system. The clinical parameters, procedural complications, histology, and molecular signature of the tissues obtained were assessed., Results: Between January 2016 and March 2021, 1,214 patients underwent a stereotactic biopsy: 617 (50.8%) for a newly diagnosed lesion and 597 (49.2%) for a suspected recurrence. The median age was 56.9 years (range 5 months-94.4 years). Magnetic resonance imaging (MRI)-guidance was used in 99.3% of cases and additional positron emission tomography (PET)-guidance in 34.3% of cases. In total, stereotactic serial biopsy provided an integrated diagnosis in 96.3% of all procedures. The most frequent diagnoses were isocitrate dehydrogenase (IDH) wildtype glioblastoma ( n = 596; 49.2%), oligodendroglioma grade 2 ( n = 109; 9%), astrocytoma grade 3 ( n = 108; 8.9%), oligodendroglioma grade 3 ( n = 76; 6.3%), and astrocytoma grade 2 ( n = 66; 5.4%). A detailed determination was successful for IDH 1/2 mutation in 99.4% of cases, for 1p/19q codeletion in 97.4% of cases, for TERT mutation in 98.9% of cases, and for MGMT promoter methylation in 99.1% of cases. Next-generation sequencing was evaluable in 64/67 (95.5%) of cases and DNA methylome analysis in 41/44 (93.2%) of cases. Thirteen (1.1%) cases showed glial tumors that could not be further specified. Seventy-three tumors were different non-glioma entities, e.g., of infectious or inflammatory nature. Seventy-five out of 597 suspected recurrences turned out to be post-therapeutic changes only. The rate of post-procedural complications with clinical symptoms of the Common Terminology Criteria for Adverse Events (CTCAE) grade 3 or higher was 1.2% in overall patients and 2.6% in the subgroup of brainstem biopsies. There was no fatal outcome in the entire series., Conclusion: Image-guided stereotactic serial biopsy enables obtaining reliable histopathological and molecular diagnoses with a very low complication rate even in tumors with critical localization. Thus, in patients not undergoing microsurgical resection, this is a valuable tool for precision medicine of patients with glioma., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Katzendobler, Do, Weller, Dorostkar, Albert, Forbrig, Niyazi, Egensperger, Thon, Tonn and Quach.)

Background: Prognostic markers for meningioma recurrence are needed to guide patient management. Apart from rare hereditary syndromes, the impact of a previous unrelated tumor disease on meningioma recurrence has not been described before., Methods: We retrospectively searched our database for patients with meningioma WHO grade I and complete resection provided between 2002 and 2016. Demographical, clinical, pathological, and outcome data were recorded. The following covariates were included in the statistical model: age, sex, clinical history of unrelated tumor disease, and localization (skull base vs. convexity). Particular interest was paid to the patients' past medical history. The study endpoint was date of tumor recurrence on imaging. Prognostic factors were obtained from multivariate proportional hazards models., Results: Out of 976 meningioma patients diagnosed with a meningioma WHO grade I, 416 patients fulfilled our inclusion criteria. We encountered 305 women and 111 men with a median age of 57 years (range: 21-89 years). Forty-six patients suffered from a tumor other than meningioma, and no TERT mutation was detected in these patients. There were no differences between patients with and without a positive oncological history in terms of age, tumor localization, or mitotic cell count. Clinical history of prior tumors other than meningioma showed the strongest association with meningioma recurrence (p = 0.004, HR = 3.113, CI = 1.431-6.771) both on uni- and multivariate analysis., Conclusion: Past medical history of tumors other than meningioma might be associated with an increased risk of meningioma recurrence. A detailed pre-surgical history might help to identify patients at risk for early recurrence., (© 2021. The Author(s).)

Primary spinal cord astrocytomas are rare, hence few data exist about the prognostic significance of molecular markers. Here we analyze a panel of molecular alterations in association with the clinical course. Histology and genome sequencing was performed in 26 spinal astrocytomas operated upon between 2000 and 2020. Next-generation DNA/RNA sequencing (NGS) and methylome analysis were performed to determine molecular alterations. Histology and NGS allowed the distinction of 5 tumor subgroups: glioblastoma IDH wildtype (GBM); diffuse midline glioma H3 K27M mutated (DMG-H3); high-grade astrocytoma with piloid features (HAP); diffuse astrocytoma IDH mutated (DA), diffuse leptomeningeal glioneural tumors (DGLN) and pilocytic astrocytoma (PA). Within all tumor entities GBM (median OS: 5.5 months), DMG-H3 (median OS: 13 months) and HAP (median OS: 8 months) showed a fatal prognosis. DMG-H3 tend to emerge in adolescence whereas GBM and HAP develop in the elderly. HAP are characterized by CDKN2A/B deletion and ATRX mutation. 50% of PA tumors carried a mutation in the PIK3CA gene which is seemingly associated with better outcome (median OS: PIK3CA mutated 107.5 vs 45.5 months in wildtype PA). This exploratory molecular profiling of spinal cord astrocytomas allows to identify distinct subgroups by combining molecular markers and histomorphology. DMG-H3 tend to develop in adolescence with a similar dismal prognosis like GBM and HAP in the elderly. We here describe spinal HAP with a distinct molecular profile for the first time.

Interstitial photodynamic therapy (iPDT) using 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) as a cytotoxic photosensitizer could be a feasible treatment option for malignant gliomas. In a monocentric cohort of consecutive patients treated between 2006 and 2018, a risk profile analysis of salvage iPDT for local malignant glioma recurrences and associated outcome measures are presented here. It was considered indicated in patients with circumscribed biopsy-proven malignant glioma recurrences after standard therapy, if not deemed eligible for safe complete resection. A 3D treatment-planning software was used to determine the number and suitable positions of the cylindrical diffusing fibers placed stereotactically to ensure optimal interstitial irradiation of the target volume. Outcome measurements included the risk profile of the procedure, estimated time-to-treatment-failure (TTF), post-recurrence survival (PRS) and prognostic factors. Forty-seven patients were treated, of which 44 (median age, 49.4 years, range, 33.4-87.0 years, 27 males) could be retrospectively evaluated. Recurrent gliomas included 37 glioblastomas (WHO grade IV) and 7 anaplastic astrocytomas (WHO grade III). Thirty (68.2%) tumors were O-6-methylguanine-DNA methyltransferase (MGMT)-methylated, 29 (65.9%)-isocitrate dehydrogenase (IDH)-wildtype. Twenty-six (59.1%) patients were treated for their first, 9 (20.5%)-for their second, 9 (20.5%)-for the third or further recurrence. The median iPDT target volume was 3.34 cm 3 (range, 0.50-22.8 cm 3 ). Severe neurologic deterioration lasted for more than six weeks in one patient only. The median TTF was 7.1 (95% confidence interval (CI), 4.4-9.8) months and the median PRS was 13.0 (95% CI, 9.2-16.8) months. The 2- and 5-year PRS rates were 25.0% and 4.5%, respectively. The treatment response was heterogeneous and not significantly associated with patient characteristics, treatment-related factors or molecular markers. The promising outcome and acceptable risk profile deserve further prospective evaluation particularly to identify mechanisms and prognostic factors of favorable treatment response.

Background: Intraspinal epidermoid/dermoid cysts are very rare, benign tumors arising from pathological displacement of epidermal cells into the spinal canal. Literature data about the long-term outcome after microsurgical resection with multimodal intraoperative neurophysiological monitoring (IONM) are lacking. We analyzed one of the largest case series with special regard to intraoperative characteristics and long-term outcome after IONM-aided surgery., Method: All 12 patients (m:f = 1.4:1) who underwent microsurgical tumor resection with multimodal IONM for intraspinal epidermoid/dermoid tumors between 1998 and 2019 in our university hospital were included. We retrospectively investigated the patients' characteristics, imaging/surgical parameters, and postoperative long-term outcomes., Results: Symptomatic tumor manifestation was seen during adulthood in 4 patients (median age 33.0 years) and during childhood in 8 patients (median age 4.3 years). Spinal dysraphism was the most often comorbidity (75%). The most frequent symptoms at diagnosis were spastic pareses (75%), ataxia (58%), and vegetative disorders (42%). Tumors were most often lumbosacral (L1-L5 42%, L5-S3 50%) and intradural-extramedullary (92%). For microsurgical resection, IONM with EMG, SSEPs, and TcMEPs of the limbs and pudendal nerve/anal sphincter was always applied and feasible; intraoperative corrective actions were initiated in three cases due to transient IONM deterioration. None of the patients showed a postoperative deterioration of the neurological status with a gross total resection rate of 92%. Pain situation, McCormick grade, and mJOA Score were improved at long-term follow-up (median 4.8 years)., Conclusions: IONM-aided resection of intraspinal epidermoid/dermoid tumors is feasible both in adult and pediatric cases and enables a satisfying clinical and surgical outcome.

Background: We aimed to elucidate the place of dynamic O-(2-[18F]-fluoroethyl)-L-tyrosine (18F-FET) PET in prognostic models of gadolinium (Gd)-negative gliomas., Methods: In 98 patients with Gd-negative gliomas undergoing 18F-FET PET guided biopsy, time activity curves (TACs) of each tumor were qualitatively categorized as either increasing or decreasing. Additionally, post-hoc quantitative analyses were done using minimal time-to-peak (TTPmin) measurements. Prognostic factors were obtained from multivariate hazards models. The fit of the biospecimen- and imaging-derived models was compared., Results: A homogeneous increasing, mixed, and homogeneous decreasing TAC pattern was seen in 51, 19, and 28 tumors, respectively. Mixed TAC tumors exhibited both increasing and decreasing TACs. Corresponding adjusted 5-year survival was 85%, 47%, and 19%, respectively (P < 0.001). Qualitative and quantitative TAC measurements were highly intercorrelated (P < 0.0001). TTPmin was longest (shortest) in the homogeneous increasing (decreasing) TAC group and in between in the mixed TAC group. TTPmin was longer in isocitrate dehydrogenase (IDH)-mutant tumors (P < 0.001). Outcome was similarly precisely predicted by biospecimen- and imaging-derived models. In the biospecimen model, World Health Organization (WHO) grade (P < 0.0001) and IDH status (P < 0.001) were predictors for survival. Outcome of homogeneous increasing (homogeneous decreasing) TAC tumors was nearly identical, with both TTPmin > 25 min (TTPmin ≤ 12.5 min) tumors and IDH-mutant grade II (IDH-wildtype) gliomas. Outcome of mixed TAC tumors matched that of both intermediate TTPmin (>12.5 min and ≤25 min) and IDH-mutant, grade III gliomas. Each of the 3 prognostic clusters differed significantly from the other ones of the respective models (P < 0.001)., Conclusion: TAC measurements constitute a powerful biomarker independent from tumor grade and IDH status., (© The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

To analyze efficacy, functional outcome, and treatment toxicity of low-dose rate I-125 brachytherapy (SBT) alone or in combination with best safe resection (in case of larger tumor volumes) as first-line treatment for pediatric low-grade gliomas (PLGGs) not suitable for complete resection. Consecutively treated (2000-2014) complex located circumscribed WHO grade I/II PLGGs were included. For small tumors (≤4 cm in diameter) SBT alone was performed; for larger tumors best safe resection and subsequent SBT was chosen. Temporary Iodine-125 seeds were used (median reference dose: 54 Gy). Treatment response was estimated with the modified MacDonald criteria. Analysis of functional outcome included ophthalmological, endocrinological and neurological evaluation. Survival was analyzed with the Kaplan-Meier method. Prognostic factors were obtained from proportional hazards models. Toxicity was categorized according to the Common Terminology Criteria for Adverse Events. Fifty-eight patients were included treated either with SBT alone (n = 39) or with SBT plus microsurgery (n = 19). Five-year progression-free survival was 87%. Two patients had died due to tumor progression. Among survivors, improvement/stabilization/deterioration of functional deficits was seen in 20/14/5 patients, respectively. Complete/partial response had beneficial impact on functional scores (P = 0.02). The 5-year estimated risk to receive adjuvant radiotherapy/chemotherapy was 5.2%. The overall early (delayed) toxicity rate was 8.6% (10.3%), respectively. No permanent morbidity occurred. In complex located PLGGs, early SBT alone or combined with best safe resection preserves/improves functional scores and results in tumor control rates usually achieved with complete resection. Long-term analysis is necessary for confirmation of these results., (© 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background: In gliomas molecular biomarkers are increasingly gaining diagnostic, prognostic and predictive significance. Determination of biomarker status after biopsy is important as not all patients are eligible for open tumor resection. We developed and validated prospectively (6/10-12/11) a protocol allowing for both reliable determination of multiple biomarkers and representative histological diagnoses from small-sized biopsies., Methods: All molecular stereotactic biopsies were performed according to a detailed workflow. The selection of specimens best suited for molecular analyses was intra-operatively guided by the attending neuropathologist. Postoperative screening was done by methylation specific PCR using two distinct cryopreserved specimens to test for reproducibility of the findings and to rule out contamination. The DNA of a single best-suited specimen (1 mm(3)) was subjected to detailed molecular analysis (MGMT promoter methylation, IDH1/2 mutational status, LOH 1p and/or 19q)., Results: 159 consecutively enrolled untreated gliomas were analyzed (94 glioblastomas, 2 gliosarcomas, 24 anaplastic astrocytomas, 10 oligo-tumors grade II/III, 20 grade II astrocytomas and 9 pilocytic astrocytomas). Transient morbidity was 2 %. Overall, the drop-out rate due to tissue contamination was 0.4 %. Median time from biopsy to histological and molecular genetic analyses was 3 and 5 days, respectively. Distributions of the respective biomarker status for tumor subgroups were consistent with the literature. The final histological diagnosis was changed/modified in 5/159 patients according to molecular findings. Treatment after molecular biopsy was highly personalized., Conclusions: Molecular stereotactic biopsy is feasible and safe, can be implemented in daily clinical practice, improves diagnostic precision and enables personalized treatment.

Central hallmark of Alzheimer's disease are senile plaques mainly composed of β-amyloid, which is a cleavage product of the amyloid precursor protein (APP). The physiological function of APP and its family members APLP1 and APLP2 is poorly understood. In order to fill this gap, we established a cell-culture based model with simultaneous knockdown of all members of the family. A comprehensive proteome study of the APP/APLP1/APLP2 knockdown cell lysates versus controls revealed significant protein abundance changes of more than 30 proteins. Targeted validation of selected candidates by immunoblotting supported the significant down-regulation of the methionine adenosyltransferase II, alpha (MAT2A) as well as of peroxiredoxin 4 in the knockdown cells. Moreover, MAT2A was significantly down-regulated at the mRNA level as well. MAT2A catalyzes the production of S-adenosylmethionine from methionine and ATP, which plays a pivotal role in the methylation of neurotransmitters, DNA, proteins, and lipids. MAT2A-dependent significant up-regulation of S-adenosylmethionine was also detectable in the knockdown cells compared with controls. Our results point to a role of the APP family proteins in cellular methylation mechanisms and fit to findings of disturbed S-adenosylmethionine levels in tissue and CSF of Alzheimer disease patients versus controls. Importantly, methylation plays a central role for neurotransmitter generation like acetylcholine pointing to a crucial relevance of our findings for Alzheimer's disease. In addition, we identified differential gene expression of BACE1 and PSEN1 in the knockdown cells, which is possibly a consequence of MAT2A deregulation and may indicate a self regulatory mechanism.

Protective proteases are key elements of protein quality control pathways that are up-regulated, for example, under various protein folding stresses. These proteases are employed to prevent the accumulation and aggregation of misfolded proteins that can impose severe damage to cells. The high temperature requirement A (HtrA) family of serine proteases has evolved to perform important aspects of ATP-independent protein quality control. So far, however, no HtrA protease is known that degrades protein aggregates. We show here that human HTRA1 degrades aggregated and fibrillar tau, a protein that is critically involved in various neurological disorders. Neuronal cells and patient brains accumulate less tau, neurofibrillary tangles, and neuritic plaques, respectively, when HTRA1 is expressed at elevated levels. Furthermore, HTRA1 mRNA and HTRA1 activity are up-regulated in response to elevated tau concentrations. These data suggest that HTRA1 is performing regulated proteolysis during protein quality control, the implications of which are discussed.

Molecular imaging studies have recently found inter- and intratumoral heterogeneity in World Health Organization (WHO) grade II gliomas. A correlative analysis with tumor histology, however, is still lacking. For elucidation we conducted the current prospective study. Fifty-five adult patients with an MRI-based suspicion of a WHO grade II glioma were included. [F-18]Fluoroethyltyrosine ((18)FET) uptake kinetic studies were combined with frame-based stereotactic localization techniques and used as a guide for stepwise (1-mm steps) histopathological evaluation throughout the tumor space. In tumors with heterogeneous PET findings, the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status and expression of mutated protein isocitrate dehydrogenase variant R132H (IDH1) were determined inside and outside of hot spot volumes. Metabolic imaging revealed 3 subgroups: the homogeneous WHO grade II glioma group (30 patients), the homogeneous malignant glioma group (10 patients), and the heterogeneous group exhibiting both low- and high-grade characteristics at different sites (15 patients). Stepwise evaluation of 373 biopsy samples indicated a strong correlation with analyses of uptake kinetics (p < 0.0001). A homogeneous pattern of uptake kinetics was linked to homogeneous histopathological findings, whereas a heterogeneous pattern was associated with histopathological heterogeneity; hot spots exhibiting malignant glioma characteristics covered 4-44% of the entire tumor volumes. Both MGMT and IDH1 status were identical at different tumor sites and not influenced by heterogeneity. Maps of (18)FET uptake kinetics strongly correlated with histopathology in suspected grade II gliomas. Anaplastic foci can be accurately identified, and this finding has implications for prognostic evaluation and treatment planning.

Background: We analyzed prospectively whether MGMT (O(6)-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylation is associated with upregulation of DNMT expression., Methodology/principal Findings: ADULT PATIENTS WITH A HISTOLOGICALLY PROVEN MALIGNANT ASTROCYTOMA (GLIOBLASTOMA: N = 53, anaplastic astrocytoma: N = 10) were included. MGMT promoter methylation was determined by methylation-specific PCR (MSP) and sequencing analysis. Expression of MGMT and DNMTs mRNA were analysed by real-time qPCR. Prognostic factors were obtained from proportional hazards models. Correlation between MGMT mRNA expression and MGMT methylation status was validated using data from the Cancer Genome Atlas (TCGA) database (N = 229 glioblastomas). Low MGMT mRNA expression was strongly predictive for prolonged time to progression, treatment response, and length of survival in univariate and multivariate models (p<0.0001); the degree of MGMT mRNA expression was highly correlated with the MGMT promoter methylation status (p<0.0001); however, discordant findings were seen in 12 glioblastoma patients: Patients with methylated tumors with high MGMT mRNA expression (N = 6) did significantly worse than those with low transcriptional activity (p<0.01). Conversely, unmethylated tumors with low MGMT mRNA expression (N = 6) did better than their counterparts. A nearly identical frequency of concordant and discordant findings was obtained by analyzing the TCGA database (p<0.0001). Expression of DNMT1 and DNMT3b was strongly upregulated in tumor tissue, but not correlated with MGMT promoter methylation and MGMT mRNA expression., Conclusions/significance: MGMT mRNA expression plays a direct role for mediating tumor sensitivity to alkylating agents. Discordant findings indicate methylation-independent pathways of MGMT expression regulation. DNMT1 and DNMT3b are likely to be involved in CGI methylation. However, their exact role yet has to be defined.

Purpose: Genotypes of the C825T polymorphism of the GNB3 gene encoding the G protein beta3 subunit were recently associated with the prognosis of different malignomas. We investigated potential associations of GNB3 genotypes with survival of patients with glioblastoma multiforme (GBM)., Methods: One hundred and sixty-one patients suffering from GBM were retrospectively investigated. Inclusion criteria were availability of DNA and a follow-up of at least 24 months. The results were evaluated with respect to the basic clinical data, type of surgical intervention, MGMT promoter methylation, adjuvant therapy, and survival., Results: After 2 years of first diagnosis, 128 (79.5%) of the 161 patients had died, 33 (20.5%) were alive. Kaplan-Meier curves revealed a significant higher rate of survival for homo- and heterozygous T-allele carriers (P = 0.019) with 38.5 and 25.3%, respectively, but only 11.6% for homozygous C-allele carriers. Multivariable Cox regression identified the heterozygous (hazard ratio 3.3, 95% CI 1.3-8.0, P = 0.010), as well as homozygous GNB3 825 C-allele (hazard ratio 3.7, 95% CI 1.5-9.1, P = 0.004) as an independent negative prognostic factor for 2-year survival according to the GNB3 825 TT genotype reference group., Conclusions: Our data suggest an association of the GNB3 825TT genotype and better survival in patients with GBM.

Objective: Cisplatin exerts its cytotoxic effect through distinct DNA lesions, leading to peripheral neuropathy. The risk of sensory neuropathy is a common problem during cancer treatment with cisplatin, leading to somatic hyperalgesia. Yet, data focussing on cisplatin-induced impairment of the autonomic nervous system are limited. The present study was aimed to investigate the effect of recombinant human erythropoietin (rhEPO) on cisplatin-induced visceral hyperalgesia., Methods: C57BL/6 mice were treated either with cisplatin (2 mg/kg, once per week) or with cisplatin (2 mg/kg, once per week) plus rhEPO (40 microg/kg, 3 times per week) for 8 weeks. Controls were treated with saline. To quantify the visceromotor response (VMR) at week 9, standardized electrodes were implanted into the external oblique musculature for electromyographic recordings. After that, animals were decapitated and dorsal root ganglia (DRG) was removed for transmission electron microscopy studies., Results: Cisplatin-treated mice showed a significant increase of VMR compared to the controls [(7080 +/- 969) vs (2864 +/- 279); P< 0.001], while rhEPO dramatically counteracted this effect [(2962 +/- 336) vs (7080 +/- 969); P< 0.001)]. Transmission electron microscopy revealed cisplatin-induced structural lesions of nuclear membrane in DRG cells, which could be ameliorated by rhEPO., Conclusion: Erythropoietin can significantly ameliorate the cisplatin-induced visceral hyperplasia and DRG nuclear membrane structure damage in mice, indicating a neuroprotective role of erythropoietin.

Previous studies have shown that amyloid beta protein (Abeta ), the essential molecule for the formation of toxic oligomers and, subsequently, Alzheimer plaques, has been associated in vivo with the immune modulator, macrophage migration inhibitory factor (MIF) (17). To further investigate this association in vivo we used the APP transgenic mouse model. Serial brain sections of transgenic APP mice were stained for Abeta plaques and MIF and we observed MIF immunolabeling in microglial cells in association with Abeta plaques in the transgenic mouse brain sections. In addition, functional studies in murine and human neuronal cell lines revealed that Abeta-induced toxicity could be reversed significantly by a small molecule inhibitor of MIF (ISO-1). Finally, to elucidate the role of MIF in Alzheimer's Disease (AD) we measured MIF levels in the brain cytosol and cerebrospinal fluid (CSF) of AD patients and age-matched controls. Our results demonstrate a marked increase of MIF levels within the CSF of AD patients compared with controls. Combined, our results indicate a strong role for MIF in the pathogenesis of AD and furthermore suggest that inhibition of MIF may provide a valuable avenue of investigation for the prevention of disease onset, progression and/or severity.

Nucleic acid extraction and purification from whole blood is a routine application in many laboratories. Automation of this procedure promises standardized sample treatment, a low error rate, and avoidance of contamination. The performance of the BioRobot M48 (Qiagen) and the manual QIAmp DNA Blood Mini Kit (Qiagen) was compared for the extraction of DNA from whole blood. The concentration and purity of the extracted DNAs were determined by spectrophotometry. Analytical sensitivity was assessed by common PCR and genotyping techniques. The quantity and quality of the generated DNAs were slightly higher using the manual extraction method. The results of downstream applications were comparable to each other. Amplification of high-molecular-weight PCR fragments, genotyping by restriction digest, and pyrosequencing were successful for all samples. No cross-contamination could be detected. While automated DNA extraction requires significantly less hands-on time, it is slightly more expensive than the manual extraction method., (Copyright (c) 2007 Wiley-Liss, Inc.)

Amyloidogenic processing of the amyloid precursor protein (APP) results in the generation of beta-amyloid, the main constituent of Alzheimer plaques, and the APP intracellular domain (AICD). Recently, it has been demonstrated that AICD has transactivation potential; however, the targets of AICD-dependent gene regulation and hence the physiological role of AICD remain largely unknown. We analyzed transcriptome changes during AICD-dependent gene regulation by using a human neural cell culture system inducible for expression of AICD, its coactivator FE65, or the combination of both. Induction of AICD was associated with increased expression of genes with known function in the organization and dynamics of the actin cytoskeleton, including alpha2-Actin and Transgelin (SM22). AICD target genes were also found to be differentially regulated in the frontal cortex of Alzheimer's disease patients compared with controls as well as in AICD/FE65 transiently transfected murine cortical neurons. Confocal image analysis of neural cells and cortical neurons expressing both AICD and FE65 confirmed pronounced changes in the organization of the actin cytoskeleton, including the destabilization of actin fibers and clumping of actin at the sites of cellular outgrowth. Our data point to a role of AICD in developmental and injury-related cytoskeletal dynamics in the nervous system.

Microglial cells are considered to play an important role in the pathogenesis of Alzheimer disease. Apart from producing the Alzheimer amyloid precursor (APP) as an acute phase protein, microglial cells seem to be involved in the deposition of its amyloidogenic cleavage product, the amyloid-beta peptide (Abeta). Abeta is bound by apolipoprotein E (APOE) in an isoform-specific manner, and it has been demonstrated that inheritance of the AD susceptibility allele, APOE epsilon4, is associated with increased deposition of Abeta in the cerebral cortex. However, the relationship between APOE epsilon4 gene dose and microglial activation is unknown. Using microglial expression of major histocompatibility complex class II molecules as a marker, we have performed a quantitative genotype-phenotype analysis on microglial activation in frontal and temporal cortices of 20 APOE genotyped AD brains. The number of activated microglia and the tissue area occupied by these cells increased significantly with APOE epsilon4 gene dose. When a model of multiple linear regression was used to compare the relative influence of APOE genotype, sex, disease duration, age at death, diffuse and neuritic plaques as well as neurofibrillary tangles on microglial activation, only APOE genotype was found to have a significant effect. Thus, the APOE gene product represents an important determinant of microglial activity in AD. Since microglial activation by APP has been shown to be modulated by apoE in vitro, a direct role of microglia in AD pathogenesis is conceivable.