P16.11 Vitamin C levels and the hypoxic pathway in human glioma tissues

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii57-ii58
Author(s):  
E R Burgess ◽  
R L I Crake ◽  
E Phillips ◽  
H R Morrin ◽  
J A Royds ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Tissue Bank ◽  
The Body ◽  
Low Grade ◽  
Normal Brain ◽  
High Grade ◽  
Human Glioma ◽  
Cancer Society ◽  
Ca Ix ◽  
Hif Pathway

Abstract BACKGROUND Gliomas are the most common brain cancer and survival is poor, with 11–15 months for high-grade glioblastoma patients, despite treatment. Gliomas are hypoxic tumours, which increases with tumour grade. Under hypoxia, the transcription factor hypoxia inducible factor-1 (HIF) accumulates and upregulates expression of genes involved in tumour development and progression. HIF-1 levels and activity are controlled by HIF hydroxylases which target HIF-1α for degradation and prevent co-activation. HIF hydroxylases are part of the 2-oxoglutarate (2-OG)-dependent dioxygenase enzyme family, that require 2-OG and oxygen as substrates and ascorbate and iron as co-factors. The role of ascorbate in regulating the hypoxic pathway in cancer is of interest, with previous research showing reduced HIF pathway activity with increasing tumour ascorbate levels. Brain tissue has one of the highest ascorbate levels in the body, and is one of the last to become depleted under deficiency, indicating an important role for ascorbate in this tissue. One previous study has analysed ascorbate levels in 11 human glioblastoma patients, and showed lower ascorbate in tumour tissue compared to normal brain tissue. There have been no studies investigating the relationship between ascorbate levels and the hypoxic pathway in human glioma tissues. MATERIAL AND METHODS Human glioma tissues (n = 39), obtained from the Cancer Society Tissue Bank Christchurch (ethics approval H19/163), were processed for ascorbate and hypoxic pathway proteins (HIF-1α, CA-IX, BNIP3, HKII, GLUT1 and VEGF). Ascorbate levels were quantified by HPLC-ED, and proteins were measured by Western blotting and ELISA. Spearman’s correlations were used to identify relationships between ascorbate and HIF pathway proteins. RESULTS Of the samples, 64% were GBM. Ascorbate was significantly lower in GBM compared to low-grade gliomas (p = 0.04). VEGF was significantly higher in GBM compared to astrocytomas (p = 0.01). Increased tumour ascorbate was associated with lower VEGF and CA-IX proteins. HIF-1α and BNIP3 protein were positively associated, and VEGF was positively associated with HKII and CA-IX. VEGF inversely associated with BNIP3, and CA-IX inversely associated with HKII. The hypoxic pathway score (calculated from protein levels of members of the hypoxic pathway) was reduced in tumours with higher ascorbate but this did not reach significance (p = 0.2). CONCLUSION This is the first study to show that ascorbate levels were reduced in high-grade gliomas compared to low-grade. Some members of the hypoxic pathway were associated with ascorbate levels. The overall hypoxic pathway score did not significantly correlate with ascorbate and increased numbers of samples are required to confirm any associations. Other variables, such as IDH-1 mutation status of the tumours may affect the correlation and will be analysed next.

scholarly journals Determination of SOX9 Gene Expression In Brain Tumours Among East Coast Malaysia Population

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Md Dzali NB ◽  
Wan Taib WR ◽  
Zahary MN ◽  
Abu Bakar NH ◽  
Abd Latif AZ ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Brain Tumour ◽  
Brain Tumours ◽  
East Coast ◽  
Rna Extraction ◽  
Slight Modification ◽  
Low Grade ◽  
Normal Brain ◽  
Sox9 Expression ◽  
Sox9 Gene

Introduction: SOX9, a members of SOX family, plays a significant roles in developmental processes during embryogenesis, including brain tissue. Few studies have shown that SOX9 has been involved in tumourigenesis of several types of cancer including brain tumour. However, such studies are still lacking in the Malaysian population. The aim of this study was to determine SOX9 expression level in several types of brain tumours in East Coast Malaysia. Materials and Methods: Five formalin-fixed pariffin-embedded brain tumour samples of Malay descendants were sectioned by using microtome. RNA extraction was performed with slight modification by adding Trizol during tissue lysis. The RNA was converted to cDNA using reverse transcription technique before SOX9 expression was detected using RT q-PCR assay in brain tumours normalized to non-neoplastic brain tissues. Results: Overall results displayed that SOX9 gene in all samples were up-regulated. SOX9 overexpression was found in both high and low grade glioma (anaplastic and pilocytic astrocytoma respectively). This is consistence with both low grade (benign) and atypical meningioma. Secondary brain tumour also showed up-regulation when compared to normal brain tissue. Conclusion: Up-regulation in SOX9 expression in selected brain tumours in Malay patients revealed its significant roles in brain tumourigenesis. Functional studies should be carried out to observe the SOX9 functions and mechanism whether they should reflect their diverse roles in Malaysia population.

scholarly journals Quantitative fluorescence in intracranial tumor: implications for ALA-induced PpIX as an intraoperative biomarker

2011 ◽  
Vol 115 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Pablo A. Valdés ◽  
Frederic Leblond ◽  
Anthony Kim ◽  
Brent T. Harris ◽  
Brian C. Wilson ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Fluorescence Imaging ◽  
Low Grade ◽  
Normal Brain ◽  
Intracranial Tumors ◽  
Neoplastic Tissue ◽  
Fluorescence Measurements ◽  
Significant Difference ◽  
Quantitative Fluorescence

Object Accurate discrimination between tumor and normal tissue is crucial for optimal tumor resection. Qualitative fluorescence of protoporphyrin IX (PpIX), synthesized endogenously following δ-aminolevulinic acid (ALA) administration, has been used for this purpose in high-grade glioma (HGG). The authors show that diagnostically significant but visually imperceptible concentrations of PpIX can be quantitatively measured in vivo and used to discriminate normal from neoplastic brain tissue across a range of tumor histologies. Methods The authors studied 14 patients with diagnoses of low-grade glioma (LGG), HGG, meningioma, and metastasis under an institutional review board–approved protocol for fluorescence-guided resection. The primary aim of the study was to compare the diagnostic capabilities of a highly sensitive, spectrally resolved quantitative fluorescence approach to conventional fluorescence imaging for detection of neoplastic tissue in vivo. Results A significant difference in the quantitative measurements of PpIX concentration occurred in all tumor groups compared with normal brain tissue. Receiver operating characteristic (ROC) curve analysis of PpIX concentration as a diagnostic variable for detection of neoplastic tissue yielded a classification efficiency of 87% (AUC = 0.95, specificity = 92%, sensitivity = 84%) compared with 66% (AUC = 0.73, specificity = 100%, sensitivity = 47%) for conventional fluorescence imaging (p < 0.0001). More than 81% (57 of 70) of the quantitative fluorescence measurements that were below the threshold of the surgeon's visual perception were classified correctly in an analysis of all tumors. Conclusions These findings are clinically profound because they demonstrate that ALA-induced PpIX is a targeting biomarker for a variety of intracranial tumors beyond HGGs. This study is the first to measure quantitative ALA-induced PpIX concentrations in vivo, and the results have broad implications for guidance during resection of intracranial tumors.

scholarly journals P11.49 An electrophysiological signature of glioma infiltration in the ex vivo human brain

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii54-iii54
Author(s):  
A J Kirby ◽  
J P Lavrador ◽  
C Brogna ◽  
F Vergani ◽  
C Chandler ◽  
...  
Keyword(s):  
Human Brain ◽  
Brain Tissue ◽  
Brain Slices ◽  
Glioma Cells ◽  
Low Grade ◽  
Tissue Preparation ◽  
High Grade ◽  
Spontaneous Seizure ◽  
Human Brain Tissue ◽  
The Brain

Abstract BACKGROUND Invading glioma cells affect the physiological function of the peritumoural cortex. This may manifest clinically as seizures. Here, we investigate the effect the invading glioma cells on the electrophysiological signalling of the peritumoral cortex using living human brain tissue donated by people having a craniotomy for glioma resection (REC approval, 18/SW/002). MATERIAL AND METHODS The brain tissue was cut into thin slices, which preserved the architecture of the glioma and the adjacent healthy brain. The brain slices were incubated in 5-aminolevulinic acid to make the glioma cells fluorescent. We observed 5-ALA induced fluorescence in both low-grade and high-grade gliomas. This enabled us to make electrophysiological recordings of brain activity across the boundary between glioma and brain. RESULTS We recorded from brain slices of 5 participants with glioblastoma and 4 participants with oligodendroglioma (WHO grade II - III). Spontaneous “seizure-like” discharges were recorded in brain slices from 5/8 participants (3 GBM, 2 oligodendroglioma) who reported seizures and from one participant (GBM) who had not had any clinical seizures. Further analysis of the electrical discharges revealed that they could be subdivided into two distinct types based on the major frequencies in the discharge. CONCLUSION We concluded that human brain slices from people with either a low-grade or a high-grade glioma can generate spontaneous seizure-like discharges. This electrophysiological signature will be compared to infiltration and grade of the glioma cells in the donated sample. The living human brain tissue preparation gives us a platform to study the mechanisms of tumour-associated seizures and how abnormal neural activity affects glioma growth.

TAMI-47. MIR-542-3P CONTRIBUTES TO THE HK2-MEDIATED HIGH GLYCOLYTIC PHENOTYPE IN HUMAN GLIOMA CELLS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi208-vi208
Author(s):  
Junhyung Kim ◽  
Min Woo Park ◽  
Ju Won Ahn ◽  
Jeong Min Sim ◽  
Suwan Kim ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Cellular Proliferation ◽  
Glioma Cells ◽  
Low Grade ◽  
High Grade ◽  
Human Glioma ◽  
Human Glioma Cells ◽  
Glycolytic Activity ◽  
High Grade Gliomas ◽  
Glycolytic Phenotype

Abstract BACKGROUND The elevation of glucose metabolism is linked to high-grade gliomas such as glioblastoma multiforme (GBM). The high glycolytic phenotype is associated with cellular proliferation and resistance to treatment with chemotherapeutic agents in GBM. MicroRNA-542-3p (miR-542-3p) has been implicated in several tumors including gliomas. However, the role of miR-542-3p in glucose metabolism in human gliomas remains unclear. METHODS We measured the levels of cellular proliferation in human glioma cells. We measured the glycolytic activity in miR-542-3p knockdown and over-expressed human glioma cells. We measured the levels of miR-542-3p and HK2 in glioma tissues from patients with low- and high-grade gliomas using imaging analysis. RESULTS We show that knockdown of miR-542-3p significantly suppressed cellular proliferation in human glioma cells. Knockdown of miR-542-3p suppressed HK2-induced glycolytic activity in human glioma cells. Consistently, over-expression of miR-542-3p increased HK2-induced glycolytic activity in human glioma cells. The levels of miR-542-3p and HK2 were significantly elevated in glioma tissues of patients with high-grade gliomas relative to that in low-grade gliomas. The elevation of HK2 levels in patients with high-grade gliomas were positively correlated with the high levels of miR-542-3p in GBM and low-grade gliomas (LGG) based on the datasets from the Cancer Genome Atlas (TCGA) database. Moreover, the high levels of miR-542-3p were associated with poor survival rate in the TCGA database. CONCLUSIONS miR-542-3p contributes to the HK2-mediated high glycolytic phenotype in human glioma cells.

scholarly journals Enrichment of Aldolase C Correlates with Low Non-Mutated IDH1 Expression and Predicts a Favorable Prognosis in Glioblastomas

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1238 ◽  
Author(s):  
Chang ◽  
Tsai ◽  
Huang ◽  
Chen ◽  
Hsiao ◽  
...  
Keyword(s):  
Protein Expression ◽  
Mrna Expression ◽  
Brain Tissue ◽  
Low Grade ◽  
Normal Brain ◽  
Normal Brain Tissue ◽  
Expression Levels ◽  
Glioblastoma Patient ◽  
Favorable Prognosis ◽  
Aldolase C

The aldolases family is one of the main enzymes involved in the process of glycolysis. Aldolase C (ALDOC), which belongs to the aldolase family, is found in normal brain tissue and is responsible for the repair of injured tissue. However, the role of ALDOC in glioblastoma remains unclear. In this study, we data-mined in silico databases to evaluate aldolase family members’ mRNA expression in glioblastoma patient cohorts for determining its prognostic values. After that, we also performed immunohistochemical stain (IHC) analysis to evaluate protein expression levels of ALDOC in glioblastoma tissues. From The Cancer Genome Atlas (TCGA) database analyses, higher mRNA expression levels in normal brain tissue compared to glioblastoma was observed. In addition, compared to low-grade glioma, ALDOC expression was significantly downregulated in high-grade glioblastoma. Besides, the expression level of ALDOC was associated with molecular subtypes of glioblastomas and recurrent status in several data sets. In contrast, aldolase A (ALDOA) and aldolase B (ALDOB) revealed no significant prognostic impacts in the glioblastoma cohorts. Furthermore, we also proved that ALDOC mRNA and protein expression inversely correlated with non-mutated IDH1 expressions in glioblastoma patient cohorts. Additionally, the concordance of low ALDOC and high non-mutated IDH1 expressions predicted a stronger poor prognosis in glioblastoma patients compared to each of above tests presented alone. The plausible ALDOC and IDH1 regulatory mechanism was further elucidated. Our results support high ALDOC expression in glioblastomas that might imply the mutated status of IDH1, less possibility of mesenchymal subtype, and predict a favorable prognosis.

scholarly journals Ex Vivo Raman Spectrochemical Analysis Using a Handheld Probe Demonstrates High Predictive Capability of Brain Tumour Status

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 49 ◽  
Author(s):  
Danielle Bury ◽  
Camilo Morais ◽  
Katherine Ashton ◽  
Timothy Dawson ◽  
Francis Martin
Keyword(s):  
Gold Nanoparticles ◽  
Brain Tissue ◽  
Brain Tumour ◽  
Sensitivity And Specificity ◽  
Brain Tumours ◽  
Ex Vivo ◽  
Diagnostic Tools ◽  
Low Grade ◽  
Normal Brain ◽  
Raman Probe

With brain tumour incidence increasing, there is an urgent need for better diagnostic tools. Intraoperatively, brain tumours are diagnosed using a smear preparation reported by a neuropathologist. These have many limitations, including the time taken for the specimen to reach the pathology department and for results to be communicated to the surgeon. There is also a need to assist with resection rates and identifying infiltrative tumour edges intraoperatively to improve clearance. We present a novel study using a handheld Raman probe in conjunction with gold nanoparticles, to detect primary and metastatic brain tumours from fresh brain tissue sent for intraoperative smear diagnosis. Fresh brain tissue samples sent for intraoperative smear diagnosis were tested using the handheld Raman probe after application of gold nanoparticles. Derived Raman spectra were inputted into forward feature extraction algorithms to build a predictive model for sensitivity and specificity of outcome. These results demonstrate an ability to detect primary from metastatic tumours (especially for normal and low grade lesions), in which accuracy, sensitivity and specificity were respectively equal to 98.6%, 94.4% and 99.5% for normal brain tissue; 96.1%, 92.2% and 97.0% for low grade glial tumours; 90.3%, 89.7% and 90.6% for high grade glial tumours; 94.8%, 63.9% and 97.1% for meningiomas; 95.4%, 79.2% and 98.8% for metastases; and 99.6%, 88.9% and 100% for lymphoma, based on smear samples (κ = 0.87). Similar results were observed when compared to the final formalin-fixed paraffin embedded tissue diagnosis (κ = 0.85). Overall, our results have demonstrated the ability of Raman spectroscopy to match results provided by intraoperative smear diagnosis and raise the possibility of use intraoperatively to aid surgeons by providing faster diagnosis. Moving this technology into theatre will allow it to develop further and thus reach its potential in the clinical arena.

scholarly journals P04.15 Impact of histone lysine methyltransferases SETDB1, SETD2, SUV39H1, MLL2, EZH2and their corresponding histone marks in pediatric astrocytomas

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii32-iii32
Author(s):  
A Klonou ◽  
P Korkolopoulou ◽  
A N Gargalionis ◽  
M Themistocleous ◽  
S Sgouros ◽  
...  
Keyword(s):  
Gene Expression ◽  
Low Grade ◽  
Normal Brain ◽  
Nuclear Staining ◽  
High Grade ◽  
Cytoplasmic Staining ◽  
Histone Marks ◽  
Histone Lysine ◽  
Lysine Methyltransferases ◽  
Histone Lysine Methyltransferases

Abstract BACKGROUND Pediatric brain tumors are characterized by altered epigenetic profiles and deregulated chromatin remodelling that affects gene expression. Histone lysine methylation has emerged as important chromatin function regulator, with potential role in glioma formation. Τhis study investigates the expression of histone lysine methyltransferases (SETDB1, SUV39H1, EZH2, MLL2, SETD2) and their corresponding methylation marks (H3K9me3, H3K27me3, H3K4me2/3, H3K36me3) in pediatric astrocytomas. MATERIAL AND METHODS Thirty-four (34) archival pediatric astrocytomas [27 low grade (I/II) and 7 high grade (III/IV) tumors; 21 males, 13 females; 1–15 years old] and 5 postmortem normal brain samples were studied. Methyltransferases expression and histone marks were detected by immunohistochemistry as H-score (intensity multiplied with cell percentage, 0–300) and validated by western blot. RESULTS Elevated nuclear SETD2 and SETDB1 staining was observed in all astrocytomas (median H-score:165 and 110, respectively). SETDB1 and SETD2 expression levels were positively associated (p=0.004), being higher in high grade compared to lower grade tumors (p=0.001, p=0.027, respectively). Furthermore, SETDB1 staining was significantly increased in male children (p=0.051) and negatively associated with patients age (p=0.028). A moderate nuclear and cytoplasmic staining was obtained for MLL2 at low grade (median H-score:84) compared to high grade tumors (median H-score:144). In accordance, lower SUV39H1 nuclear and cytoplasmic expression was detected in low grade tissues (median H score:85) compared to high grade (median H-score:160). EZH2 presented no significant nuclear expression. Increased nuclear staining of H3K9me3 and H4K20me3 repressive marks was observed in astrocytomas (median H-score:297 and 270, respectively), being positively associated (p=0.02). Elevated nuclear staining of H3K4me3 active mark (median H-score:210) was detected in astrocytomas, being significantly higher in high grade tumors (p=0.025) and in male children (p=0.036). CONCLUSION SETDB1, SETD2, SUV39H1 and MLL2 may play a significant role in modulating gene expression in pediatric astrocytomas. Increased presence of H3K9me3, H4K20me3 and H3K4me3 histone marks signifies their possible participation in gliomagenesis. Larger cohort studies need to elucidate the functional significance and underlying molecular mechanisms of these chromatin-modifying enzymes and respective histone changes in pediatric astrocytomas.

scholarly journals PATZ1 Is Overexpressed in Pediatric Glial Tumors and Correlates with Worse Event-Free Survival in High-grade Gliomas

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1537
Author(s):  
Annalisa Passariello ◽  
Maria Elena Errico ◽  
Vittoria Donofrio ◽  
Manuela Maestrini ◽  
Alia Zerbato ◽  
...  
Keyword(s):  
Mrna Level ◽  
Young Patients ◽  
Molecular Heterogeneity ◽  
Low Grade ◽  
Normal Brain ◽  
High Grade ◽  
Event Free Survival ◽  
Free Survival ◽  
Glial Tumors ◽  
High Grade Gliomas

Glial tumors are the leading cause of cancer-related death and morbidity in children. Their diagnosis, mainly based on clinical and histopathological factors, is particularly challenging because of their high molecular heterogeneity. Thus, tumors with identical histotypes could result in variable biological behaviors and prognoses. The PATZ1 gene has been recently shown to be expressed in adult gliomas, including glioblastomas, where it correlates with the proneural subtype and with a better prognosis. Here, we analyzed the expression of PATZ1 in pediatric gliomas, first at mRNA level in a public database, and then at protein level, by immunohistochemistry, in a cohort of 52 glial brain tumors from young patients aged from 6 months to 16 years. As for adult tumors, we show that PATZ1 is enriched in glial tumors compared to the normal brain, where it correlates positively and negatively with a proneural and mesenchymal signature, respectively. Moreover, we show that PATZ1 is expressed at variable levels in our cohort of tumors. Higher expression was detected in high-grade than low-grade gliomas, suggesting a correlation with the malignancy. Among high-grade gliomas, higher levels of PATZ1 have consistently been found to correlate with worse event-free survival. Therefore, our study may imply new diagnostic opportunities for pediatric gliomas.

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