Constitutive activation of the EGFR-STAT1 axis increases proliferation of meningioma tumor cells.

Background: Meningiomas are the most frequent primary brain tumors of the central nervous system. The standard of treatment is surgery and radiotherapy, but effective pharmacological options are not available yet. The well-characterized genetic background stratifies these tumors in several subgroups, thus increasing diversification. We identified epidermal growth factor receptor-signal transducer and activator of transcription 1 (EGFR-STAT1) overexpression and activation as a common identifier of these tumors. Methods: We analyzed STAT1 overexpression and phosphorylation in 131 meningiomas of different grades and locations by utilizing several techniques, including Western blots, qPCR, and immunocytochemistry. We also silenced and overexpressed wild-type and mutant forms of the gene to assess its biological function and its network. Results were further validated by drug testing. Results: STAT1 was found widely overexpressed in meningioma but not in the corresponding healthy controls. The protein showed constitutive phosphorylation not dependent on the JAK-STAT pathway. STAT1 knockdown resulted in a significant reduction of cellular proliferation and deactivation of AKT and ERK1/2. STAT1 is known to be activated by EGFR, so we investigated the tyrosine kinase and found that EGFR was also constitutively phosphorylated in meningioma and was responsible for the aberrant phosphorylation of STAT1. The pharmaceutical inhibition of EGFR caused a significant reduction in cellular proliferation and of overall levels of cyclin D1, pAKT, and pERK1/2. Conclusions: STAT1-EGFR-dependent constitutive phosphorylation is responsible for a positive feedback loop that causes its own overexpression and consequently an increased proliferation of the tumor cells. These findings provide the rationale for further studies aiming to identify effective therapeutic options in meningioma

PO-511 High miR-9 levels represent a novel prognostic biomarker to predict development of malignant meningioma

Introduction Meningioma is the most common primary tumour affecting the central nervous system; it is classified as benign (WHO I,~80%), atypical (WHO II,~15%–20%) and anaplastic/malignant (WHO III,~1%–3%). The 3 year recurrence rate in WHO I meningioma is estimated in about 50% and it is much greater in WHO II and III tumours. MicroRNAs (miRNAs) represent a large class of small RNAs driving regulation of gene expression at post-transcriptional level and playing a role in cell proliferation, differentiation, apoptosis and carcinogenesis. Several studies showed that miRNAs are involved in tumour progression and therefore proposed as diagnostic tools. Here, we evaluated miRNAs signature in meningioma to identify novel biomarkers of tumour progression. Material and methods Meningioma (MN) specimens were collected from consented patients, according to the ethics. The 96-miRNA profiling was performed using the QuantimirTM Cancer MicroRNA qPCR Array (System Biosciences, UK) following the instructions of the supplier. Validation studies were achieved using TaqMan MicroRNA reagents (Applied Biosystems). Bioinformatic analysis was done using the NormFinder software and in silico studies were performed using the following datasets for putative miRNA targets: TargetScanHuman7.1, DIANATOOLS microT-CDS, mirDIP and the UTRdb tool. Probability (p) values were calculated using the Student’s t-Test, led by the GraphPad Prism 5.01 (p\u3c0.05±SEM). Results and discussions We established a new miRNA dataset by identifying six miRNA signatures (p\u3c0.01) differentially regulated in benign versus malignant meningioma cells (miR-9, 10b, 125b, 143,–145 and 199). Validation studies by qPCR confirmed that the miR-9 was upregulated in malignant KT21-MG1 cells (10.71 folds; Log2 scale, p=0.0006) and WHO III tissues (3.75 folds versus WHO I=0, Log2 scale, p=0.044). Finally, highly stringent in silico studies suggested that the miR-9 targets and downregulates the ubiquitin-protein ligase E3C (UBE3C), as confirmed by proteomic analysis in malignant KT21-MG1 and IOMM-Lee cells. Conclusion In this study, we identified the miR-9 as significantly upregulated in WHO III tumour-derived meningioma cells and tissues when compared to lower grades. Since miR-9 targets the ubiquitin-protein ligase E3C, involved in the ubiquitin-proteasome pathway and therefore regulating protein homeostasis, this protein, together with miR-9, could represent potential novel diagnostic and/or prognostic biomarkers in meningioma

Ultrafast mid-infrared spectroscopy by chirped pulse upconversion in 1800-1000cm(-1) region

Broadband femtosecond mid-infrared pulses can be converted into the visible spectral region by chirped pulse upconversion. We report here the upconversion of pump probe transient signals in the frequency region below 1800c

High miR-9 levels represent a novel prognostic biomarker to predict development of malignant meningioma

Meningioma is the most common primary tumour affecting the central nervous system; it is classified as benign (WHO I, ~80%), atypical (WHO II, ~15-20%) and anaplastic/malignant (WHO III, ~1-3%). The 3-year recurrence rate in WHO I meningioma is estimated in about 50% and it is much greater in WHO II and III tumours. MicroRNAs (miRNAs) represent a large class of small RNAs driving regulation of gene expression at post-transcriptional level and playing a role in cell proliferation, differentiation, apoptosis and carcinogenesis. Several studies showed that miRNAs are involved in tumour progression and therefore proposed as diagnostic tools. Here, we evaluated miRNAs signature in meningioma to identify novel biomarkers of tumour progression

Relationship between type II diabetes mellitus and Helicobacter pylori infection in Erbil city

Background and objective: Type 2 diabetes mellitus is a metabolic disorder characterized by the increase in blood glucose due to insulin resistance or deficiency of insulin. The subjects are more likely to be prone to infection. So, it could be correlated with Helicobacter pylori infection, which means that gastrointestinal inflammation might be affected by uncontrolled glycemic level. This study aimed to examine the correlation of type II diabetes and infection of gastrointestinal in order to illustrate such complication of diabetes mellitus apart from others. Methods: A total of 64 persons from Erbil city participated in this cross-sectional study. They were divided into two groups, each group involving 32 persons. The cases group included those suffering from type II diabetes and were selected by simple random sampling method. The other group included those not possessing any types of disease including diabetes mellitus. Examination of Helicobacter pylori, glycated hemoglobin (HbA1c), besides measuring blood pressure and body mass index were performed for all individual subjects in both groups. Chi-Square and unpaired t-test were used for data analysis. Results: There was a 59% positively Helicobacter pylori in diabetes group whereas there was a 31% positively Helicobacter pylori in non-diabetes mellitus. The difference between the rates of Helicobacter pylori in both groups was statistically significant (P <0.05). Conclusion: The prevalence of Helicobacter pylori infection in diabetics was significantly higher than the non-diabetics

The Potential of MLN3651 in Combination with Selumetinib as a Treatment for Merlin-Deficient Meningioma

Meningioma is the most common primary intracranial tumour, and surgical resection is the main therapeutic option. Merlin is a tumour suppressor protein that is frequently mutated in meningioma. The activity of the E3 ubiquitin ligase complex, CRL4-DCAF1, and the Raf/MEK/ERK scaffold protein Kinase suppressor of Ras 1 (KSR1) are upregulated in Merlin-deficient tumours, which drives tumour growth. Identifying small molecules that inhibit these key pathways may provide an effective treatment option for patients with meningioma. We used meningioma tissue and primary cells derived from meningioma tumours to investigate the expression of DDB1 and Cullin 4-associated factor 1 (DCAF1) and KSR1, and confirmed these proteins were overexpressed. We then used primary cells to assess the therapeutic potential of MLN3651, a neddylation inhibitor which impacts the activity of the CRL family of E3 ubiquitin ligases and the MAPK/ERK kinase (MEK1/2) inhibitor selumetinib. MLN3651 treatment reduced proliferation and activated apoptosis, whilst increasing Raf/MEK/ERK pathway activation. The combination of MLN3651 and the MEK1/2 inhibitor selumetinib prevented the increase in Raf/MEK/ERK activity, and had an additive effect compared with either treatment alone. Therefore, the combined targeting of CRL4-DCAF1 and Raf/MEK/ERK activity represents an attractive novel strategy in the treatment of Merlin-deficient meningioma.</jats:p

PROTEOME AND PHOSPHOPROTEOME ANALYSIS IDENTIFIES STAT1 AS A NOVEL TARGET IN DIFFERENT GRADE MENINGIOMAS

Meningioma is the most commonly diagnosed primary brain tumor and is associated with significant morbidity. Children treated with therapeutic radiation to the head are at almost ten-fold risk of radiation-associated meningioma (RAM). RAM tumors are associated with aggressive histological features and reduced survival but treatment options remain limited. To discover genes associated with RAM we performed whole-exome sequencing on matched constitutional and tumor materials from 20 patients treated in childhood with ionizing radiation to the head and subsequently diagnosed with cranial meningioma. The mean number of protein-altering somatic mutations was 139.2 (median=94, range=49-541) and did not vary significantly by sex, grade, age at initial or meningioma diagnosis, time since radiation, dose, meningioma location or initial diagnosis (Acute Lymphoblastic Leukemia (ALL) versus other). The average proportion of the genome with copy number variation (CNV) was 6.4 (range 1.2-15.4). Males had twice the CNV rate of females (8.4 vs 4.8, respectively, p=0.05). Although no other variable was significantly associated with difference in CNV rate, of the 5 patients with a CNV value of 10% or more, 4 (80%) had a prior diagnosis of ALL. Eleven genes with significantly more somatic mutations than expected by chance were identified (NF2, VKORC1, GAB1, METTL25, AK3, IL15RA, MIPOL1, MetAP2, AWAT1, ERO1L, ATP6V0D2). The most common were NF2 (n=4 samples) and AK3 (n=4 samples). Two samples had mutations in MetAP2, a gene that encodes the protein methionine aminopeptidase (MetAP2). MetAP2 inhibitors are currently in use for the treatment of a number of cancers suggesting a possible new treatment for some patients with RAM. Our findings suggest a high rate of mutations in RAM; with the exception of NF2 these changes are dissimilar from those reported in non-radiation associated meningioma