The Value of miR-296 and miR-517c in Evaluating the Prognosis of Patients with Glioma after Radiotherapy and Chemotherapy

Objective. To explore the value of miR-296 and miR-517c in evaluating the prognosis of patients with glioma after radiotherapy and chemotherapy. Methods. 732 patients with glioma were selected from January 2012 to January 2018. According to the effect of postoperative chemotherapy, the patients were divided into two groups: the effective group and the ineffective group. The serum miR-296, miR-517c, and clinicopathological parameters of the two groups before chemotherapy were compared. The factors affecting the sensitivity of radiotherapy and chemotherapy and the predictive efficacy of miR-296 and miR-517c on the prognosis of patients were analyzed. Results. The expression level of miR-296 in glioma tissue was significantly correlated with tumor pathological grade and depth of invasion ( P < 0.05 ), and the expression level of miR-296 in glioma tissue was significantly correlated with tumor pathological grade ( P < 0.05 ). Logistic regression analysis showed that tumor size, WHO grade, and serum miR-296 and miR-517c levels were all factors affecting chemosensitivity ( P < 0.05 ). The sensitivity, specificity, accuracy, and AUC of serum miR-296 prediction were 76.95%, 89.64%, 85.35%, and 0.891, respectively. The sensitivity, specificity, accuracy, and AUC of serum miR-517c prediction were 72.81%, 86.50%, 82.19%, and 0.739, respectively. Conclusion. miR-296 and miR-517c are closely related to the chemosensitivity and prognosis of glioma patients. High levels of miR-296 and miR-517c can enhance chemosensitivity and serve as reliable indexes to predict the prognosis of patients with glioma.

Somatic mitochondrial DNA mutations in different grades of glioma

Aim: Mitochondrial DNA (mtDNA) alterations play an important role in the multistep processes of cancer development. Gliomas are among the most diagnosed brain cancer. The relationship between mtDNA alterations and different grades of gliomas are still elusive. This study aimed to elucidate the profile of somatic mtDNA mutations in different grades of gliomas and correlate it with clinical phenotype. Materials & methods: Forty histopathologically confirmed glioma tissue samples and their matched blood were collected and subjected for mtDNA sequencing. Results & conclusion: About 75% of the gliomas harbored at least one somatic mutation in the mtDNA gene, and 45% of these mutations were pathogenic. Mutations were scattered across the mtDNA genome, and the commonest nonsynonymous mutations were located at complex I and IV of the mitochondrial respiratory chain. These findings may have implication for future research to determine the mitochondrial energetics and its downstream metabolomics on gliomas.

FLGS-04. Fluorescence lifetime imaging (FLIm) is a dye-free, high sensitivity approach for fluorescence guided surgery in high-grade and low-grade gliomas

INTRODUCTION Fluorescence-guided surgery can improve tumor identification and extent of surgical resection. 5-ALA is the standard for GBM, but is limited by lack of quantitative fluorescence, a need to work in the dark, and a lack of sensitivity for low grade tumors. We have developed a novel instrument for dye-free tissue autofluorescence lifetime imaging (FLIm) to identify glioma tissue during resection. This approach utilizes time-resolved autofluorescence measurements in narrow-band channels to assess markers of tissue metabolism. Compared to intensity-based imaging of exogenous fluorophores, FLIm has greater sensitivity without dependence on background lighting. The advantages of FLIm include quantitative tissue analysis, the ability to work under full light conditions, sensitivity for high and low grade gliomas, and the potential ability to identify IDH mutational status. In this study, we validated the use of FLIm for identification of glioma tissue at tumor resection margins. METHODS FLIm was used to image tissue margins during glioma resections and compared to microbiopsies from imaged regions to correlate fluorescence with histopathology. RESULTS FLIm was applied intraoperatively to 11 GBM and 5 LGG patients (7 imaged biopsies per patient). In GBM, tumor infiltration of cortex was associated with significantly decreased fluorescence lifetime (FL) in channels 2 (470/28nm;p&lt;0.05) and 3 (542/50nm;p&lt;0.002). In subcortical margins, FL was inversely proportional to the density of tumor in channels 2,3 (p&lt;0.05). When IDH wild-type GBMs were compared to IDH1-mutant tumors, FL was noted to be significantly longer in channel 1 (390/40nm;p&lt;0.05), and trended towards longer FL in channel 2, shorter FL in channel 3. In LGG, FL was significantly correlated with tumor density in channel 2 (p&lt;0.01). CONCLUSIONS FLIm is a dye-free, quantitative alternative to 5-ALA for fluorescence guided glioma resections with sensitivity to high and low-grade tumors, and the ability to predict IDH mutations in GBM. Further validation studies are on-going.

Circular RNA circNF1 siRNA Silencing Inhibits Glioblastoma Cell Proliferation by Promoting the Maturation of miR-340

It has been reported that circNF1, a type of circular RNA (circRNA), promotes gastric cancer. This study aimed to analyze the role of circNF1 in glioblastoma (GBM). The expression of circNF1, mature miR-340, and miR-340 precursor in paired GBM and non-cancer tissues from GBM patients (n = 50) was analyzed by RT-qPCR. GBM cells were transfected with circNF1 siRNA, followed by the analysis of the expression of mature miR-340 and miR-340 precursor, to study the effects of circNF1 knockdown on the maturation of miR-340. The CCK-8 assay was carried out to explore the role of circNF1 and miR-340 in the proliferation of GBM cells. circNF1 expression was found to be upregulated in GBM and was correlated with patient survival. In glioma tissue, circNF1 was inversely correlated with mature miR-340, but not with the miR-340 precursor. In GBM cells, circNF1 siRNA silencing resulted in the upregulation of mature miR-340, but not the miR-340 precursor. The cell proliferation assay showed that circNF1 siRNA silencing and miR-340 overexpression decreased the proliferation of GBM cells. In addition, the miR-340a inhibitor suppressed the role of circNF1 siRNA silencing in cell proliferation. Therefore, circNF1 siRNA silencing may inhibit GBM cell proliferation by promoting the maturation of miR-340.

miR-433-3p Targets AJUBA to Inhibit Malignant Progression of Glioma

<b><i>Introduction:</i></b> Glioma is the most aggressive and malignant type of tumors among primary intracranial tumors. miR-433-3p has been verified to be correlated with the formation and progression of many types of cancers. <b><i>Methods:</i></b> In this study, the effects of miR-433-3p and AJUBA on the proliferation, migration, and invasion of glioma and the molecular mechanisms were investigated. We analyzed bioinformatics databases and conducted cell biology experiments to determine that compared with adjacent tissue and normal cells, the expression level of miR-433-3p in glioma tissue and cells was lower, while the expression level of AJUBA was higher. Overexpressing miR-433-3p could significantly inhibit the proliferation, migration, and invasion of glioma cells and promote cell apoptosis. <b><i>Results:</i></b> In addition, after overexpressing miR-433-3p and AJUBA, it was found that overexpressing AJUBA could attenuate the inhibitory effect of overexpressing miR-433-3p on the proliferation, migration, and invasion of glioma cells, which suggested that miR-433-3p regulated the biological function of glioma by downregulating AJUBA expression. <b><i>Conclusion:</i></b> These results proved that miR-433-3p could target to inhibit the expression of AJUBA, thus inhibiting the biological function and malignant progression of glioma.

Yes-associated protein (YAP) promotes progression of glioma and poor prognosis of human

Background: Yes-associated protein(YAP) plays an important role in signal transduction and gene transcription regulation in 1 normal cells, with elevated and over-expressed YAP levels observed in various malignant tumors. The aim of this study was 2 to investigate the expression of YAP in malignant glioma, and to study the possible relationship of YAP expression with the 3 occurrence and development of malignant glioma. 4 Methods: Immunohistochemical staining was used to assess the expression of YAP and phosphor-YAP in malignant glioma 5 tissue and normal brain tissue, and their protein and mRNA levels were evaluated through Western blotting and reverse 6 transcription-polymerase chain reaction (RT-PCR), respectively. Normal brain tissue obtained from the functional lesion of 7 the epilepsy patients. After transfection of YAPsiRNA oligonucleotides or pcDNA3.1-hYAP plasmid, their effects on glioma 8 cells were investigated using western blot, cell proliferation, cycle, apoptosis and invasion, respectively. We conducted the 9 2 co-Immunoprecipitation to verify the combination of YAP and PPARγ, explore the mechanism of action. 10 Results: YAP-positive expression was found in 9 cases of normal brain and 60 cases of glioma. A significantly higher 11 expression of YAP in glioma tissue as compared with normal brain tissue at both protein and mRNA levels, and YAP proteins 12 mainly expressed and located in the nucleus and only a small percentage in the cytoplasm of glioma tissue. Phosphor-YAP 13 protein expression showed high staining of the cytoplasm, but no staining of the nuclear. While, with the enhancement of 14 the malignant degree, the cytoplasm YAP(p-YAP) expression is lower gradually than normal brain tissues. Further study in 15 glioma cell lines in which YAP was either overexpressed or depleted confirmed that YAP markedly promoted the cell 16 proliferation, cycle, invasion and inhibited the cell apoptosis. Moreover, YAP in company with PPARγ regulates the cell 17 proliferatin and effects the gliomagenesis. 18 Conclusion: These results indicate that YAP plays an important role in glioma and might be a useful therapeutic target of 19 glioma. 20

Immune Microenvironment Landscape in CNS Tumors and Role in Responses to Immunotherapy

Despite the important evolution of immunotherapeutic agents, brain tumors remain, in general, refractory to immune therapeutics. Recent discoveries have revealed that the glioma microenvironment includes a wide variety of immune cells in various states that play an important role in the process of tumorigenesis. Anti-tumor immune activity may be occurring or induced in immunogenic hot spots or at the invasive edge of central nervous system (CNS) tumors. Understanding the complex heterogeneity of the immune microenvironment in gliomas will likely be the key to unlocking the full potential of immunotherapeutic strategies. An essential consideration will be the induction of immunological effector responses in the setting of the numerous aspects of immunosuppression and evasion. As such, immune therapeutic combinations are a fundamental objective for clinical studies in gliomas. Through immune profiling conducted on immune competent murine models of glioma and ex vivo human glioma tissue, we will discuss how the frequency, distribution of immune cells within the microenvironment, and immune modulatory processes, may be therapeutically modulated to lead to clinical benefits.

CDK-associated Cullin 1 promotes Cell Proliferation and inhibits Cell Apoptosis in Human Glioblastoma

Background: Glioma is the most common intracranial primary tumour of adult humans, and its pathological mechanism and molecular characteristics are under investigation. CDK-associated cullin 1 (CACUL1) has been shown to regulate colorectal carcinoma, lung cancer and gastric cancer development. Objective: This study aims to explore the role of CACUL1 in the pathogenesis of human glioma. Methods: CACUL1 levels in human glioma tissue microarrays were detected by immunohistochemistry analysis. Two glioblastoma cell lines, namely, U87 and U251, were transfected with CACUL1 siRNA, and cell proliferation, cell cycle, cell apoptosis and regulating molecules including cyclin E1, cyclin A2, CDK2, p21, Bcl2 and Bax were assessed by CCK8, flow cytometry and Western blot. Results: CACUL1 expression in glioma tissue was significantly higher than that in normal brain tissue. CACUL1 knockdown impeded cell proliferation, induced cell apoptosis and caused G1/S transition arrest in glioblastoma cells. The cell cycle-related proteins CDK2, cyclin E1 and cyclin A2 were dramatically decreased in the CACUL1 siRNA group compared to the non-targeting siRNA group in both U87 and U251 cells, while the CDK inhibitory protein p21 was increased in U87 cells. Additionally, the Bcl-2/Bax ratio was significantly decreased. Conclusion: CACUL1 can promote cell proliferation and suppress apoptosis of glioma cells and might serve as a potential oncogene for gliomas.