WHO Grade Of Malignancy Research Articles

Significance of Nestin and CD133 as cancer stem cell markers in diffuse glioma and association with p53 expression and IDH status.

Recent evidence suggests that the tumor stem cells that are responsible for the pathogenesis of gliomas have similar properties to those of neural stem cells. We have studied two of the most consistently expressed stem cell markers in gliomas, i.e., CD133 and Nestin, and compared them with respect to p53 expression and IDH status. To assess the level of expression of Nestin and CD133, and identify a correlation among various grades of diffuse glioma with IDH status and expression of p53. A cross-sectional retrospective study with 102 subjects for the expression of cancer stem cell markers; CD133 and Nestin and the correlation of their expression with that of p53 and IDH1 status in adult diffuse glioma. The study was conducted in the Departments of Pathology and Neurosurgery. The expression was assessed by immunohistochemistry on formalin-fixed paraffin-embedded sections. The scoring of expression of CD133 and Nestin was adapted from Zhang et al. The scoring for p53 was adopted from Aruna et al. Results: The diffuse gliomas were graded based on WHO into grade II (30.3%), grade III (28.4%), and grade IV (41.3%). Among WHO grade IV, 59.4% were primary, and 40.4% were secondary glioblastomas. 73% of the diffuse gliomas were IDH mutant, and p53 showed an overall expression of 76.4%. The expression of CD133 and Nestin were compared with the increasing grades of diffuse gliomas, which, when plotted on ROC curves, had AUCs of 0.6806 and 0.6119, respectively. Their expression showed a positive correlation with the IDH status of the tumor. Cancer stem cell markers CD133 and Nestin are expressed in diffuse glioma and have a higher expression with increasing WHO grade of malignancy. These cancer stem cell markers have shown significant association with the IDH-1 mutant status of diffuse gliomas. Hence, it can be inferred that diffuse gliomas with a higher expression of CD133 and Nestin have a poorer prognosis. Further, these cancer stem cell markers may be used as therapeutic targets in the future.

CD44-Mediated Poor Prognosis in Glioma Is Associated With M2-Polarization of Tumor-Associated Macrophages and Immunosuppression.

BackgroundGlioma is the most common primary brain tumor with a poor prognosis. Key genes that are negatively related to prognosis may provide the therapy targets to cure glioma. To clarify the role of CD44 in glioma, we explored its function at bulk-transcriptome, spatial and single-cell transcriptome levels.MethodsIn total, expression profiles with survival data of whole-grade glioma from The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA), RNA-seq data with anatomic information of glioblastoma (GBM) from the Ivy Glioblastoma Atlas Project, RNA-sequencing (RNA-seq) data from recurrent GBM receiving adjuvant anti-PD-1 immunotherapy accessed through GSE121810, and single-cell RNA-seq data of GBM under accession GSE103224 were enrolled in this study. CD44-specific findings were further analyzed by R language.ResultsCD44 is positively correlated with WHO grade of malignancy and is negatively related to prognosis in glioma. Meanwhile, CD44 predominantly expresses in GBM mesenchymal subtype, and gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses reveal that CD44 positively coexpressed genes are closely related to glioma immunity. Moreover, CD44+ cells mainly distribute in perinecrotic region with high expression of immune factors. At single-cell resolution, only malignant tumor cells, tumor-associated macrophages (TAMs), and T cells express CD44 in GBM. CD44+ malignant tumor cells are in mesenchymal-1-like (MES1-like) cellular state, and CD44+ TAMs are in M2 phenotype. CD44+ T cells have high expression of both PD-1 and PD-L1. CD44 and its directly interacted inhibitory immunomodulators are upregulated in patients with nonresponder recurrent GBM treated with PD-1 blockade therapy.ConclusionOur work demonstrates that CD44, a new M2 TAM biomarker, is involved in immune suppressor and promote glioma progression in glioma microenvironment. These results expand our understanding of CD44-specific clinical and immune features in glioma.

Large-Scale Analysis Reveals the Specific Clinical and Immune Features of DGCR5 in Glioma.

PurposeLong non-coding RNA DGCR5 plays different roles in different types of cancer. The purpose of this study was to investigate the clinicopathological features, potential biological functions and prognostic significance of DGCR5 in glioma in a large-scale study.Materials and MethodsA total of 697 RNA-seq data from The Cancer Genome Atlas (TCGA) and 301 mRNA microarray data from Chinese Glioma Genome Atlas (CGGA) were enrolled in this study. R language was used as the main tool for statistical analysis and graphical work.ResultsDGCR5 showed a negative correlation with the WHO grade of malignancy in glioma. Specifically, DGCR5 expression was significantly decreased in GBM and IDH wild-type glioma. Gene ontology analysis showed that DGCR5 was predominantly enriched in immune-related biological processes. Additionally, DGCR5 showed a significant correlation with stromal and immune cell populations, inflammatory activities and immune checkpoints. Clinically, patients with low-expression level of DGCR5 exhibited a worse overall survival.ConclusionDGCR5 expression is downregulated in glioma, and low DGCR5 independently predicts worse prognosis in glioma patients. Moreover, DGCR5 is significantly associated with immune response and immune infiltration. These findings suggest that DGCR5 is a promising immunotherapy target and a novel prognostic biomarker for glioma.

Value of 18F-FDG PET/computed tomography in predicting the simplified WHO grade of malignancy in thymic epithelial tumors.

To investigate the value of 18F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in predicting the simplified WHO grade of malignancy in thymic epithelial tumors. We retrospectively reviewed 81 patients with pathologically proven thymic epithelial tumors who underwent F-FDG PET/CT before surgical resection. Maximum standardized uptake value (SUVmax) and SUVmax/tumor size were measured on the primary lesion. A receiver operating characteristics (ROC) curve were performed for assessing the ability of F-FDG PET/CT as a predictor of the simplified WHO classification. There were 43 male patients (53.1%) and 38 female patients (46.9%), and the mean age was 55.6 ± 11.9 years. The mean tumor size was 53.2 ± 21.4 mm. There were 24 low-risk thymomas (29.6%) (A, AB, and B1), 29 high-risk thymomas (35.8%) (B2 and B3), and 28 thymic carcinomas (34.6%). The SUVmax and SUVmax/tumor size were found to be predictive factors that were useful to distinguish thymomas and thymic carcinomas, and area under the ROC curve were 0.820 and 0.691, respectively (P < 0.05), and the cutoff value for discriminating thymomas and thymic carcinomas was 5.34. In conclusion, a significant relationship was observed between SUVmax, SUVmax/tumor size and histological WHO classification of thymic epithelial tumors. F-FDG PET/CT may be useful for predicting the grade of malignancy in thymic epithelial.

Specific clinical and immune features of CD68 in glioma via 1,024 samples.

BackgroundThere is a growing recognition that tumor-associated macrophages (TAMs) are recruited to the glioma environment, facilitating tumor proliferation and migration by creating an immunosuppressive microenvironment. CD68 has been widely reported as a specific marker of TAMs in cancer.PurposeTo clarify the role of CD68 in glioma, we investigated its function at the transcriptome level and relationship with clinical practice.Patients and methodsIn total, 325 RNA-seq data from Chinese Glioma Genome Atlas (CGGA) and 697 RNA-seq data from The Cancer Genome Atlas (TCGA) network were enrolled in this study. CD68-specific findings were further analyzed with R language, and the prognostic impacts were validated through analyzing the overall survival (OS).ResultsCD68 showed a positive correlation with the WHO grade of malignancy in glioma. Meanwhile, CD68 was predominantly expressed in IDH wide type and mesenchymal subtype. Gene ontology (GO) analysis revealed that CD68-related genes were closely related to inflammatory response and immune response. Moreover, seven cultures of metagenes further confirmed that CD68 was a specific marker for macrophages in inflammatory response and played an important role in suppressing T-cell-mediated immunity. The Pearson correlation test suggested that CD68 showed robust correlation with other markers of macrophages and immune checkpoints, including PD-1 and TIM-3. Clinically, a high expression level of CD68 in tumors exhibited a poor survival in glioma patients.ConclusionOur results demonstrated that CD68 acted as an immune suppressor and contributed to glioma progression in the tumor microenvironment. These findings may expand our understanding of CD68-specific clinical and immune features in glioma.

Intraoperative fluorescence diagnostics in surgery of intracranial meningiomas: analysis of 101 cases

The study objective was to assess the sensitivity of 5-aminolevulinic acid-based (5-ALA) fluorescence diagnostics in surgery of brain meningiomas and to clarify the clinical and biological factors that may influence the fluorescent effect. The study consistently included 101 patients with intracranial meningiomas of various locations who were operated on using 5-ALA. There were 28 (27.72%) males and 73 (72.27%) females (median age, 54 years). In all patients, surgery was performed using an operating microscope equipped with a fluorescent module; in 24 of these, laser spectroscopy was used. For comparison of chances to observe the fluorescent effect of 5-ALA in patients having meningiomas with different WHO histological grades (Grade I vs Grade II-III), we performed a meta-analysis that included 10 studies (the largest series) on outcomes of surgical treatment of meningiomas using intraoperative fluorescence diagnostics. Of 101 patients included in this series, observable fluorescence was detected in 95 (94.1%) patients: weak fluorescence in 12 (11.9%), moderate fluorescence in 23 (22.8%) cases, and strong fluorescence in 60 (59.4%) patients. There was no statistically significant relationship (p>0.05) between the rate and intensity of observable fluorescence and the tumor growth pattern (primary/continued), location, WHO grade of malignancy, and histological subtype. In the absence of intraoperative bleeding, tumor fluorescence was statistically significantly brighter (p=0.02). Of 26 patients with hyperostosis, bone fluorescence was observed in 11 (42.3%) cases. There was no statistically significant relationship between administration of dexamethasone, its dose, administration of anticonvulsants, gastrointestinal tract diseases, as well as diabetes mellitus and the fluorescence intensity. There was also no significant relationship between the extent of tumor resection (Simpson scale) and the presence of fluorescence as well as its intensity. Comparison of the observable fluorescence intensity and the laser spectroscopy indicators revealed a significant correlation (r=0.75; p=0.005). Meningioma is a well fluorescent tumor, with the technique sensitivity being 94.1%. In some cases, the use of fluorescence diagnostics in surgery of meningiomas improves identification of residual tumor fragments and enables correction of a surgical approach. To assess the effect of fluorescence diagnostics on the recurrence rate and disease-free duration, further research is required.

Abstract IA08: An epigenome perspective of human tumor evolution

Abstract Cancers develop through a process of clonal evolution in which ongoing genetic and epigenetic diversification allows for repeated cycles of sub-clonal selection and expansion (Greaves and Maley, 2012; Nowell, 1976). As a result, human tumors can display substantial intratumoral heterogeneity, including discordant genetic alterations between the initial tumor and local recurrence or distant metastases (Gerlinger et al., 2012; Okosun et al., 2014; Wu et al., 2012; Yachida et al., 2010). As mutations accumulate over time, genomic profiling of spatially or temporally separated tumor samples can be used to reconstruct the evolutionary history and underlying clonal architectures of individual tumors (Gerlinger et al., 2014). In contrast to stable genetic events, epigenetic states are reversible and may change in response to the tumor microenvironment, prompting the question whether epigenetic information can similarly be used to discover tumor phylogeny. In low-grade glioma, the course of tumor evolution is particularly clinically significant. Low-grade gliomas are diffuse, infiltrative tumors that recur locally and may unpredictably undergo malignant progression to a higher grade with a worse prognosis (Sanai et al., 2011). Recurrences that progress to highly malignant WHO grade IV glioblastoma (GBM) acquire genetic alterations in the RB and AKT-mTOR pathways (Johnson et al., 2014; Louis, 2006). In fact, adjuvant treatment with alkylating chemotherapeutics such as temozolomide (TMZ) can induce hypermutation that emerges in recurrent tumors (Bodell et al, 2003; Hunter et al., 2006), and we recently linked treatment-associated driver mutations in these two pathways to malignant progression of grade II glioma to GBM (Johnson et al., 2014). The treatment associated malignant progression follows selection of tumor cells with epigenetic silencing of the DNA repair protein MGMT (van Thiujl et al, 2015). The critical role that epigenetic alterations play in the development and therapeutic response of gliomas is increasingly being appreciated (Fouse and Costello, 2009). Somatic mutations in IDH1 or IDH2 may be the first genetic driver in the development of many low-grade gliomas (Johnson et al., 2014; Lai et al., 2011; Watanabe et al., 2009). Genetic mutations in IDH genes induce a pattern of early epigenetic alterations known as the glioma CpG island methylator phenotype (G-CIMP) characterized by extensive remodeling of the DNA methylome (Hill et al., 2014; Noushmehr et al., 2010; Toyota et al., 1999; Turcan et al., 2012). The inactivation of other genes mutated in low-grade gliomas, such as ATRX (Jiao et al., 2012) and SMARCA4 (Johnson et al., 2014), is known to induce specific DNA methylation changes as well (Banine et al., 2005; Gibbons et al., 2000). Although there has been extensive characterization of tumor methylomes using a single sampling per tumor, little is known about intratumoral heterogeneity at the epigenetic level or of temporal evolution of the low-grade glioma methylome and its relationship to the genome. In this presentation, I will show that phylogenic analysis of spatial and temporal patterns of either reversible DNA methylation or irreversible somatic mutations independently yield remarkably similar evolutionary histories. I will also incorporate this inter-dependent evolution into a detailed model of brain tumorigenesis that extends from the first mutation and epimutations through tumor recurrence. Citation Format: Tali Mazor, Aleksandr Pankov, Jun Song, Joseph Costello. An epigenome perspective of human tumor evolution. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Sep 24-27, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2016;76(2 Suppl):Abstract nr IA08.

Value of 18F-FDG PET-CT in predicting the WHO grade of malignancy in thymic epithelial tumors

Objective To investigate the value of18F-FDG PET-CT in predicting the simplified WHO grade of malignancy in thymic epithelial tumors. Methods The 18F-FDG PET-CT imaging of forty-five patients with pathologically proven thymic epithelial tumors was analyzed retrospectively. The patients were subdivided into a low-risk group and a high-risk group based on the simplified WHO histological classification. Spearman rank correlation analysis was used to determine the relation between parameters of PET-CT and simplified WHO histological classification. An univariate logistic regression analysis and ROC curve were performed for assessing the ability of 18F-FDG PET-CT as a predictor of the simplified WHO classification. Results There were ten patients classified into low-risk group, and thirty-five patients classified into high-risk group. Both SUVmax and SUVmax / T showed significant relationship with patients subgroup (Spearman correlation coefficients were 0.577 and 0.621, respectively, P<0.000 1). The SUVmax and SUVmax /T were found to be predictive factors that were useful to distinguish high-risk tumor from low-risk tumor(area under the ROC curve were 0.888 and 0.917, respectively, P<0.000 1). Conclusions A significant relationship is observed between 18F-FDG PET-CT findings and histological WHO classification of thymic epithelial tumors. PET-CT may be useful for predicting the grad of malignancy in thymic epithelial tumors. Key words: Thymic epithelial tumors; Histological classification; Fluorodeoxyglucose F18; Positron-emission tomography

WHO grade related expression of TRAIL-receptors and apoptosis regulators in meningioma

Background and aimsThe expression of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors and key regulators of the extrinsic apoptosis pathway correlate with clinical features and the WHO grade of malignancy in some tumor entities. Expression of pro-apoptotic TRAIL receptors and executioners of apoptosis are a prerequisite for TRAIL-based therapies as a promising future targeted therapy. MethodsHuman meningioma tissues (n=24 WHO grade I, n=7 WHO grade II, n=6 WHO grade III) were immunohistochemically analyzed for the expression of TRAIL-R1, TRAIL-R2, TRAIL-R3, TRAIL-R4, caspase-8, cFLIP, Bcl-2, Bcl-XL, Mcl-1, Bax, and Bak. Staining intensities were quantified by an automated software-based algorithm. ResultsWhile TRAIL-R1 and TRAIL-R3 were nearly absent in meningiomas, TRAIL-R2 and TRAIL-R4 were abundantly expressed. However, only TRAIL-R4 expression correlated with the WHO grade of malignancy. Bcl-2 showed a non-significant upregulation in WHO grade III meningiomas. Bcl-XL and Mcl-1 expression was significantly higher in WHO grade II compared to grade I. Bcl-XL and TRAIL-R4 expression correlated with the mitotic activity (Ki67) of the tumor. Furthermore, TRAIL-R2 expression correlated with TRAIL-R4. Bak expression correlated with both, Bcl-XL and Mcl-1 expression. The expression patterns did neither correlate with the progression-free nor with the overall survival of the meningioma patients. ConclusionsApoptosis-inducing TRAIL-R2 and all key executioners of the extrinsic apoptosis pathway are abundantly expressed in meningioma. For some regulators of apoptosis with opposite functions, the expression of the pro-apoptotic protein significantly correlated with the expression level of the respective anti-apoptotic binding partner, possibly resulting in a steady-state of apoptosis. TRAIL-R2 might serve as a novel therapeutic target in meningioma.

Abstract 875: Genetic variation in the natural killer cell activating receptor NKG2D and its ligands in relation to glioma risk and outcome

Abstract Natural killer (NK) cells play a key role in the immune response to certain infections and neoplasms. A major activating receptor of NK lymphocytes is NKG2D. In cancer, NKG2D ligands on transformed cells transmit danger signals to NKG2D-activated NK T cells culminating in cytolysis of malignant cells. A role for NK host defense in glioma is suggested by the expression of NKG2D ligands on glioma cells though not normal brain and correlation of NKG2D ligand expression with increasing WHO grade of malignancy. Genetic variation in NKG2D and its ligands has been associated with susceptibility to cancer and autoimmune diseases. We examined single nucleotide polymorphisms (SNPs) in genes affecting NK cell-mediated immune response for association with glioma risk and outcome in a case-control study encompassing 563 newly diagnosed glioma cases (including 324 WHO grade IV glioblastomas (GBM); 145 WHO grade II or III astrocytomas and 94 oligoastrocytomas and oligodendrogliomas) and 629 healthy controls with no history of brain cancer. DNA was isolated from saliva samples. A total of 24 candidate SNPs were genotyped using the Illumina Goldengate assay in critical genes linked to NK immunosurveillance including KLRK1 (encoding NKG2D), key NKG2D ligands (MICA, MICB and RAET1E), and genes linked to tumor immunoresistance (IDO1, IDO2). Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for glioma risk in relation to individual SNPs adjusting for age and gender. Proportional hazards regression was used to estimate age and gender-adjusted hazard ratios (HR) for GBM-related death (203 deaths; median follow up: 11.2 months) for each examined SNP. A haplotype associated with low NK activity in peripheral lymphocytes, identified by SNPs in the NK complex gene region on 12p13-p12 and marked by rs1049174 in the 3’UTR of KLRK1 (minor allele frequency (MAF) in controls: 26%), was associated with an increased glioma risk (per variant “C” allele OR: 1.22; 95% CI: 1.02-1.46; p=0.030); associations with this SNP were most prominent among oligodendroglioma patients (per allele OR: 1.69; 95% CI: 1.20-2.38; p=0.0027). A putatively functional nonsynonymous SNP in MICA (rs1051794; Lys196Glu; MAF: 27%) had a borderline association with risk for GBM (per variant “A” allele OR: 1.24; 95% CI: 1.00-1.53; p=0.048) though not other glioma subtypes; the variant rs1051794 allele was associated with increased GBM mortality (per allele HR: 1.31; 95% CI: 1.04-1.65; p=0.020). An intronic SNP in IDO2 (rs2543072) associated with risk of astrocytic tumors (per variant “T” allele OR: 1.65; 95% CI: 1.19-2.30; p=0.003; MAF: 21%) was also associated with GBM mortality (per allele HR: 1.28; 95% CI: 1.00-1.62; p=0.046). These results provide evidence that genetic variation in NK immunosurveillance influences glioma susceptibility and may contribute to GBM aggressiveness. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 875. doi:10.1158/1538-7445.AM2011-875

Malignant Glioma Cells Counteract Antitumor Immune Responses through Expression of Lectin-Like Transcript-1

Glioblastoma, one of the most lethal tumors, is paradigmatic for tumor-associated immunosuppression. Lectin-like transcript-1 (LLT1) is a newly identified ligand for the inhibitory natural killer (NK) cell receptor CD161. Here, we report that glioma cells express LLT1 mRNA and protein in vitro and in vivo, whereas expression levels in normal brain are low. LLT1 expression in human gliomas increases with the WHO grade of malignancy. We further show that transforming growth factor-beta (TGF-beta) up-regulates the expression of LLT1 in glioma cells. Small interfering RNA (siRNA)-mediated down-regulation of LLT1 in LNT-229 and LN-428 cells promotes their lysis by NK cells. Thus, LLT1 acts as a mediator of immune escape and contributes to the immunosuppressive properties of glioma cells.

TGF- and metalloproteinases differentially suppress NKG2D ligand surface expression on malignant glioma cells

NKG2D ligands (NKG2DL) are expressed by infected and transformed cells. They transmit danger signals to NKG2D-expressing immune cells, leading to lysis of NKG2DL-expressing cells. We here report that the NKG2DL MHC class I-chain-related molecules A and B (MICA/B) and UL16-binding proteins (ULBP) 1-3 are expressed in human brain tumours in vivo, while expression levels are low or undetectable in normal brain. MICA and ULBP2 expression decrease with increasing WHO grade of malignancy, while MICB and ULBP1 are expressed independently of tumour grade. We further delineate two independent mechanisms that can explain these expression patterns: (i) transforming growth factor-beta (TGF-beta) is upregulated during malignant progression and selectively downregulates MICA, ULBP2 and ULBP4 expression, while MICB, ULBP1 and ULBP3 are unaffected. (ii) Cleavage of MICA and ULBP2 is reduced by inhibition of metalloproteinases (MP), whereas no changes in the expression levels of other NKG2DL were detected. Consequently, NKG2DL-dependent NK cell-mediated lysis is enhanced by depletion of TGF-beta or inhibition of MP. Thus, escape from NKG2D-mediated immune surveillance of malignant gliomas in vivo may be promoted by the inhibition of MICA and ULBP2 expression via an autocrine TGF-beta loop and by MP-dependent shedding from the cell surface. Loss of MICA and ULBP2, in contrast to other NKG2DL, may be particularly important in glioma immune escape, and differential regulation of human NKG2DL expression is part of the immunosuppressive properties of human malignant glioma cells.

Expression of tyrosine kinases FAK and Pyk2 in 331 human astrocytomas.

The progression of malignancy from astrocytomas to glioblastomas remains clinically as well as histopathologically unpredictable. The focal adhesion kinase (FAK) and the proline-rich tyrosine kinase (Pyk2) show a high expression in glioma cell lines and have an influence on increased cell proliferation and migration of glioma cells in vitro and in vivo. The aim of this study was to correlate the coexpression of FAK and Pyk2 to the WHO grade of malignancy in human astrocytomas. Immunohistochemical staining scores of FAK and Pyk2 were analyzed in 331 astrocytomas and correlated to each other and to the WHO grade. Significant coexpression of FAK and Pyk2 in astrocytomas was demonstrated. Pyk2 expression occurred much more frequently and with higher expression scores within the different WHO grades. Beyond this, a significant correlation between the WHO grade of malignancy of astrocytomas and the expression of FAK, as well as of Pyk2, was detected. This connection and the roles of these two tyrosine kinases in the progression of tumors should be confirmed by further studies.