Prognosis Of Medulloblastoma Research Articles

Effect of FAT1 gene expression on the prognosis of medulloblastoma in children: A protocol for systematic review and meta-analysis.

Background:It was reported that cloning human adipose atypical cadherin 1 (FAT1) has an effect on the prognosis of medulloblastoma (MB), while the conclusion still needs to be further proved. Therefore, this study attempted to explore the effect of the high expression of FAT1 on the prognosis of MB children.Methods:The database was retrieved from China National Knowledge Infrastructure (CNKI), Chinese Biomedical literature Database (CBM), Chinese Scientific and Journal Database (VIP), Wan Fang database, PubMed, and EMBASE. Hazard ratios (HRs) and its 95% confidence intervals (CIs) were applied to assess the prognostic effect of FAT1 on overall survival (OS) and disease-free survival (DFS). RevMan 5.3 and STATA 16.0 software were used to perform the meta-analysis.Results:The results of the study would be published in peer-reviewed journals or at relevant meetings.Conclusion:Our findings revealed the effect of the high expression of FAT1 on the prognosis of MB children. Such studies may find a new prognostic marker for MB children and help clinicians and health professionals make clinical decisions.OSF Registration Number:DOI 10.17605/OSF.IO/5FN8M.

Construction and Validation of a 13-Gene Signature for Prognosis Prediction in Medulloblastoma.

Background: Recent studies have identified several molecular subgroups of medulloblastoma associated with distinct clinical outcomes; however, no robust gene signature has been established for prognosis prediction. Our objective was to construct a robust gene signature-based model to predict the prognosis of patients with medulloblastoma.Methods: Expression data of medulloblastomas were acquired from the Gene Expression Omnibus (GSE85217, n = 763; GSE37418, n = 76). To identify genes associated with overall survival (OS), we performed univariate survival analysis and least absolute shrinkage and selection operator (LASSO) Cox regression. A risk score model was constructed based on selected genes and was validated using multiple datasets. Differentially expressed genes (DEGs) between the risk groups were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and protein–protein interaction (PPI) analyses were performed. Network modules and hub genes were identified using Cytoscape. Furthermore, tumor microenvironment (TME) was evaluated using ESTIMATE algorithm. Tumor-infiltrating immune cells (TIICs) were inferred using CIBERSORTx.Results: A 13-gene model was constructed and validated. Patients classified as high-risk group had significantly worse OS than those as low-risk group (Training set: p < 0.0001; Validation set 1: p < 0.0001; Validation set 2: p = 0.00052). The area under the curve (AUC) of the receiver operating characteristic (ROC) analysis indicated a good performance in predicting 1-, 3-, and 5-year OS in all datasets. Multivariate analysis integrating clinical factors demonstrated that the risk score was an independent predictor for the OS (validation set 1: p = 0.001, validation set 2: p = 0.004). We then identified 265 DEGs between risk groups and PPI analysis predicted modules that were highly related to central nervous system and embryonic development. The risk score was significantly correlated with programmed death-ligand 1 (PD-L1) expression (p < 0.001), as well as immune score (p = 0.035), stromal score (p = 0.010), and tumor purity (p = 0.010) in Group 4 medulloblastomas. Correlations between the 13-gene signature and the TIICs in Sonic hedgehog and Group 4 medulloblastomas were revealed.Conclusion: Our study constructed and validated a robust 13-gene signature model estimating the prognosis of medulloblastoma patients. We also revealed genes and pathways that may be related to the development and prognosis of medulloblastoma, which might provide candidate targets for future investigation.

Preoperative Neutrophil to Lymphocyte Ratio and Platelet to Lymphocyte Ratio are Associated with the Prognosis of Group 3 and Group 4 Medulloblastoma

Inflammation and immunoreaction markers were correlated with the survival of patients in many tumors. However, there were no reports investigating the relationships between preoperative hematological markers and the prognosis of medulloblastoma (MB) patients based on the molecular subgroups (WNT, SHH, Group 3, and Group 4). A total 144 MB patients were enrolled in the study. The differences of preoperative hematological markers among molecular subgroups of MB were compared by One-way ANOVA method. Kaplan-Meier method was used to calculate the curves of progression free survival (PFS) and overall survival (OS). The comparison of survival rates in different groups were conducted by the Log-rank test. Multivariate analysis was used to evaluate independent prognostic factors. Increased preoperative NLR (neutrophil-to-lymphocyte ratio, PFS, P = 0.004, OS, P < 0.001) and PLR (platelet-to-lymphocyte ratio, PFS, P = 0.028, OS, P = 0.003) predicted poor prognosis in patients with MB, while preoperative MLR (monocyte-to-lymphocyte ratio), MPV (mean platelet volume), PDW (platelet distribution width), and AGR (albumin-to-globulin ratio) were revealed no predictive value on the prognosis of patients with MB. Furthermore, high preoperative NLR and PLR predicted unfavorable prognosis in childhood MB patients. However, preoperative NLR and PLR were not associated with the prognosis in adult MB patients. Multivariate analysis demonstrated preoperative NLR (PFS, P = 0.029, OS, P = 0.005) and PLR (PFS, P = 0.023, OS, P = 0.005) were the independent prognostic factors in MB patients. Emphatically, the levels of preoperative NLR and PLR in Group 3 MB were significantly higher than those in WNT MB. High preoperative NLR was associated with unfavorable OS in Group 3 (P = 0.032) and Group 4 (P = 0.027) tumors. Similarly, increased preoperative PLR predicted poor PFS (P = 0.012) and OS (P = 0.009) in Group 4 tumors. Preoperative NLR and PLR were the potential prognostic markers for MB patients. Preoperative NLR and PLR were significantly associated with the survival of Group 3 and Group 4 tumors.

A simplified approach using Taqman low-density array for medulloblastoma subgrouping

Next-generation sequencing platforms are routinely used for molecular assignment due to their high impact for risk stratification and prognosis in medulloblastomas. Yet, low and middle-income countries still lack an accurate cost-effective platform to perform this allocation. TaqMan Low Density array (TLDA) assay was performed using a set of 20 genes in 92 medulloblastoma samples. The same methodology was assessed in silico using microarray data for 763 medulloblastoma samples from the GSE85217 study, which performed MB classification by a robust integrative method (Transcriptional, Methylation and cytogenetic profile). Furthermore, we validated in 11 MBs samples our proposed method by Methylation Array 450 K to assess methylation profile along with 390 MB samples (GSE109381) and copy number variations. TLDA with only 20 genes accurately assigned MB samples into WNT, SHH, Group 3 and Group 4 using Pearson distance with the average-linkage algorithm and showed concordance with molecular assignment provided by Methylation Array 450 k. Similarly, we tested this simplified set of gene signatures in 763 MB samples and we were able to recapitulate molecular assignment with an accuracy of 99.1% (SHH), 94.29% (WNT), 92.36% (Group 3) and 95.40% (Group 4), against 97.31, 97.14, 88.89 and 97.24% (respectively) with the Ward.D2 algorithm. t-SNE analysis revealed a high level of concordance (k = 4) with minor overlapping features between Group 3 and Group 4. Finally, we condensed the number of genes to 6 without significantly losing accuracy in classifying samples into SHH, WNT and non-SHH/non-WNT subgroups. Additionally, we found a relatively high frequency of WNT subgroup in our cohort, which requires further epidemiological studies. TLDA is a rapid, simple and cost-effective assay for classifying MB in low/middle income countries. A simplified method using six genes and restricting the final stratification into SHH, WNT and non-SHH/non-WNT appears to be a very interesting approach for rapid clinical decision-making.

Combined BET bromodomain and CDK2 inhibition in MYC-driven medulloblastoma

Medulloblastoma (MB) is the most common malignant brain tumor in children. MYC genes are frequently amplified and correlate with poor prognosis in MB. BET bromodomains recognize acetylated lysine residues and often promote and maintain MYC transcription. Certain cyclin-dependent kinases (CDKs) are further known to support MYC stabilization in tumor cells. In this report, MB cells were suppressed by combined targeting of MYC expression and MYC stabilization using BET bromodomain inhibition and CDK2 inhibition, respectively. Such combination treatment worked synergistically and caused cell cycle arrest as well as massive apoptosis. Immediate transcriptional changes from this combined MYC blockade were found using RNA-Seq profiling and showed remarkable similarities to changes in MYC target gene expression when MYCN was turned off with doxycycline in our MYCN-inducible animal model for Group 3 MB. In addition, the combination treatment significantly prolonged survival as compared to single-agent therapy in orthotopically transplanted human Group 3 MB with MYC amplifications. Our data suggest that dual inhibition of CDK2 and BET bromodomains can be a novel treatment approach for suppressing MYC-driven cancer.

Survival and Prognostic Factors in Pediatric Patients with Medulloblastoma in Southern Thailand.

Background:The current prognosis of medulloblastoma in children is better because of technological advancements and improvements in treatment strategies and genetic investigations. However, there is a lack of studies that focus on medulloblastoma in Thailand. The aims of our study were to conduct a survival analysis and to identify the prognostic factors of pediatric medulloblastoma.Materials and Methods:Fifty-five children, with medulloblastoma, were eligible for analysis between 1991 and 2015. We retrospectively reviewed both the clinical and the histological data. Survival curves were constructed using the Kaplan–Meier method. For comparisons of dichotomous factors, between groups, the log-rank test was used to determine survival. The Cox proportional hazard regression model was used to identify the univariate and multivariate survival predictors.Results:The mortality rate was 49.1% in this study. The median follow-up time was 68.8 months (range: 1–294 months). The 5-year overall survival rate and median survival time were 53.8% (95% CI 38.7–66.7) and 80 months (95% CI 23–230), respectively. Univariate analysis revealed children <3 years of age, hemispheric tumor location, high risk according to risk stratification, and patients who did not receive radiation therapy affected the prognosis. In multivariable analysis, hemispheric tumors (hazard ratio [HR] 2.54 [95% CI 1.11–5.80]; P = 0.01)and high risk groups (HR 3.86 [95% CI 1.28–11.60]; P = 0.01) influenced death. Finally, using conditional inference trees, the study showed that hemispheric tumor locations are truly aggressive in behavior, whereas risk stratification is associated with the prognosis of midline tumors.Conclusions:Hemispheric medulloblastoma and high-risk groups according to risk stratification were associated with poor prognosis.

Understanding medulloblastoma.

Brain tumors are the most common solid tumor malignancies in childhood, and among them, medulloblastoma occurs with the greatest frequency. Because medulloblastomas occur in the posterior fossa, the presenting symptoms often are vague complaints and diagnosis may be delayed. Between 70% and 80% of patients who are diagnosed before metastatic dissemination survive, compared with 30% to 40% of those in higher risk groups. This article reviews the diagnosis, treatment, and prognosis for medulloblastoma.

A Retrospective Study of Progression-Free and Overall Survival in Pediatric Medulloblastoma Based on Molecular Subgroup Classification: A Single-Institution Experience.

Medulloblastoma (MB) has been classified into four core subgroups according to the transcriptional profile in recent years. However, some disagreement among researchers remains regarding the prognoses and most effective treatments of the different subgroups with different age distributions. The objective of this study was to analyze MB prognosis in children population based on the classification of four molecular subgroups. From January 2011 to January 2013, 84 consecutive MB patients aged underwent tumor removal at Beijing Tiantan Hospital. A total of 55 patients who ranged in age from 4 to 18 years underwent detailed follow-up. Molecular subgrouping was performed using RT-PCR. The 2-year progression-free survival (PFS) and overall survival (OS) rates for the entire cohort were 76.2 ± 5.8 and 81.8 ± 5.2%, respectively. Univariate analysis revealed that the Group 4 patients had a better survival (2-year OS, 90.6 ± 5.2%) than the SHH subgroup (P = 0.002) and Group 3 patients (P = 0.008). Only two of the 23 non-metastasized Group 4 patients relapsed, and chemotherapy did significantly affect these patients (PFS, P = 0.685). One out of five WNT patients had tumor relapse and died at last. Large cell/anaplastic (LC/A) histology and chemotherapy were independent risk factors in multivariate analysis. In our study, the non-metastasized Group 4 patients had an excellent prognosis. The SHH subgroup and Group 3 patients had worst prognoses. LC/A histology had a dismal prognosis in our cohorts, which warrants intensive treatment.

PLK1-associated microRNAs are correlated with pediatric medulloblastoma prognosis.

Medulloblastoma (MB) is the most common malignant tumor of the central nervous system (CNS) in children. Despite its relative good survival rates, treatment can cause long time sequels and may impair patients' lifespan and quality, making the search for new treatment options still necessary. Polo like kinases (PLKs) constitute a five-member serine/threonine kinases family (PLK 1-5) that regulates different stages during cell cycle. Abnormal PLKs expression has been observed in several cancer types, including MB. As gene regulators, miRNAs have also been described with variable expression in cancer. We evaluated gene expression profiles of all PLK family members and related miRNAs (miR-100, miR-126, miR-219, and miR-593*) in MB cell lines and tumor samples. RT-qPCR analysis revealed increased levels of PLK1-4 in all cell lines and in most MB samples, while PLK5 was found underexpressed. In parallel, miR-100 was also found upregulated while miR-129, miR-216, and miR-593* were decreased in MB cell lines. Variable miRNAs expression patterns were observed in MB samples. However, a correlation between miR-100 and PLK4 expression was observed, and associations between miR-100, miR-126, and miR-219 expression and overall and event free survival were also evinced in our cohort. Moreover, despite the lack of association with clinico-pathological features, when comparing primary tumors to those relapsed, we found a consistent decrease on PLK2, miR-219, and miR-598* and an increase on miR-100 and miR-126. Specific dysregulation on PLKs and associated miRNAs may be important in MB and can be used to predict prognosis. Although miRNAs sequences are fundamental to predict its target, the cell type may also be consider once that mRNA repertoire can define different roles for specific miRNA in a given cell.

Expression and significance of growth factor receptor binding protein 2-associated binding protein-1 and glioma-associated oncogene homologue-1 in pediatric medulloblastoma

Objective To explore the expressions of growth factor receptor binding protein 2-associated bin-ding protein-1(Gab-1) and glioma-associated oncogene homologue-1(Gli-1) in pediatric medulloblastoma, and to analyze their correlation between clinical and pathological characteristics and prognosis in pediatric medulloblastoma. Methods Elivision immunohistochemistry was used to detect the expressions of Gab-1 and Gli-1 protein in tissue microarray of 40 paraffin embedded pediatric medulloblastoma specimens.Chi-square test or Fisher exact test was used to analyze the correlation between Gab-1 and Gli-1 protein expressions with gender, age, tumor location and pathological subtypes.Follow-up data were handled by using Kaplan-Meier survival analysis and Cox regression analysis. Results Positive expression ratios of Gab-1 and Gli-1 protein in 40 pediatric medulloblastoma were 35.0% and 55.0%, respectively.The positive expression rate of Gab-1 in medulloblastoma tissues had no statistical significance between different genders[male: 30.4%(7/23 cases) vs.female: 41.2%(7/17 cases)], age[ 0.05). There were statistical differences of positive expression rate of Gli-1 protein in different age groups[ 0.05). Kaplan-Meier survival analysis showed that the age, the expressions of Gab-1 and Gli-1 protein were correlated with prognosis of pediatric medulloblastoma(all P<0.05). Cox regression indicated that the age, pathological subtypes and the expression of Gli-1 protein were independent prognostic indicators in pediatric medulloblastoma(all P<0.05). Conclusion Expression of Gab-1 and Gli-1 protein is significantly correlated with the prognosis of medulloblastoma, and the positive expression is a marker of unfavorable prognosis. Key words: Growth factor receptor binding protein 2-associated binding protein-1; Glioma-associated oncogene homologue-1; Child; Medulloblastoma; Prognosis

Erratum to: The DNA methyltransferase inhibitor zebularine exerts antitumor effects and reveals BATF2 as a poor prognostic marker for childhood medulloblastoma.

Medulloblastoma (MB) is the most common solid tumor among pediatric patients and corresponds to 20 % of all pediatric intracranial tumors in this age group. Its treatment currently involves significant side effects. Epigenetic changes such as DNA methylation may contribute to its development and progression. DNA methyltransferase (DNMT) inhibitors have shown promising anticancer effects. The agent Zebularine acts as an inhibitor of DNA methylation and shows low toxicity and high efficacy, being a promising adjuvant agent for anti-cancer chemotherapy. Several studies have reported its effects on different types of tumors; however, there are no studies reporting its effects on MB. We analyzed its potential anticancer effects in four pediatric MB cell lines. The treatment inhibited proliferation and clonogenicity, increased the apoptosis rate and the number of cells in the S phase (p < 0.05), as well as the expression of p53, p21, and Bax, and decreased cyclin A, Survivin and Bcl-2 proteins. In addition, the combination of zebularine with the chemotherapeutic agents vincristine and cisplatin resulted in synergism and antagonism, respectively. Zebularine also modulated the activation of the SHH pathway, reducing SMO and GLI1 levels and one of its targets, PTCH1, without changing SUFU levels. A microarray analysis revealed different pathways modulated by the drug, including the Toll-Like Receptor pathway and high levels of the BATF2 gene. The low expression of this gene was associated with a worse prognosis in MB. Taken together, these data suggest that Zebularine may be a potential drug for further in vivo studies of MB treatment.

The DNA methyltransferase inhibitor zebularine exerts antitumor effects and reveals BATF2 as a poor prognostic marker for childhood medulloblastoma.

Medulloblastoma (MB) is the most common solid tumor among pediatric patients and corresponds to 20% of all pediatric intracranial tumors in this age group. Its treatment currently involves significant side effects. Epigenetic changes such as DNA methylation may contribute to its development and progression. DNA methyltransferase (DNMT) inhibitors have shown promising anticancer effects. The agent Zebularine acts as an inhibitor of DNA methylation and shows low toxicity and high efficacy, being a promising adjuvant agent for anti-cancer chemotherapy. Several studies have reported its effects on different types of tumors; however, there are no studies reporting its effects on MB. We analyzed its potential anticancer effects in four pediatric MB cell lines. The treatment inhibited proliferation and clonogenicity, increased the apoptosis rate and the number of cells in the S phase (p < 0.05), as well as the expression of p53, p21, and Bax, and decreased cyclin A, Survivin and Bcl-2 proteins. In addition, the combination of zebularine with the chemotherapeutic agents vincristine and cisplatin resulted in synergism and antagonism, respectively. Zebularine also modulated the activation of the SHH pathway, reducing SMO and GLI1 levels and one of its targets, PTCH1, without changing SUFU levels. A microarray analysis revealed different pathways modulated by the drug, including the Toll-Like Receptor pathway and high levels of the BATF2 gene. The low expression of this gene was associated with a worse prognosis in MB. Taken together, these data suggest that Zebularine may be a potential drug for further in vivo studies of MB treatment.

Clinical characteristics and abandonment and outcome of treatment in 67 Chinese children with medulloblastoma.

OBJECT The purpose of this study was to explore the clinical features and outcome of medulloblastoma in Chinese children. The authors analyze the reasons that treatment is abandoned and attempt to provide evidence-based recommendations for improving the prognosis of medulloblastoma in this population. METHODS A total of 67 pediatric cases of newly diagnosed medulloblastoma were included in this study. All of the children were treated at Xinhua Hospital between January 2007 and June 2013. The authors retrospectively analyzed the clinical data, treatment modalities, and outcome. The male-to-female ratio was 2:1, and the patients' median age at diagnosis was 51.96 months (range 3.96-168.24 months). The median duration of follow-up was 32 months (range 3-70 months). RESULTS At the most recent follow-up date, 31 patients (46%) were alive, 30 (45%) had died, and 6 (9%) had been lost to follow-up. The estimated 3-year overall survival and progression-free survival, based on Kaplan-Meier analysis, were 55.1% ± 6.4% and 45.6% ± 6.7%, respectively. Univariate analysis showed that standard-risk group (p = 0.009), postoperative radiotherapy (RT) combined with chemotherapy (p < 0.001), older age (≥ 3 years) at diagnosis (p = 0.010), gross-total resection (p = 0.012), annual family income higher than $3000 (p = 0.033), and living in urban areas (p = 0.008) were favorable prognostic factors. Multivariate analysis revealed that postoperative RT combined with chemotherapy was an independent prognostic factor (p < 0.001). The treatment abandonment rate in this cohort was 31% (21 of 67 cases). CONCLUSIONS There was a large gap between the outcome of medulloblastoma in Chinese children and the outcome in Western children. Based on our data, treatment abandonment was the major cause of therapeutic failure. Parents' misunderstanding of medulloblastoma played a major role in abandonment, followed by financial and transportation difficulties. Establishment of multidisciplinary treatment teams could improve the prognosis of medulloblastoma in Chinese children.

Abstract 853: The role of germline microRNA-related polymorphisms on pediatric medulloblastoma prognosis and survival

Abstract Background: Five-year survival for pediatric medulloblastoma is between 60-80%, which remains far from ideal. While the molecular features of these tumors are being used to improve risk stratification, novel markers are needed to identify those at the greatest risk of recurrence and poor survival. MicroRNAs (miRNA) regulate gene expression and may play a major role in regulatory networks related to cancer therapy. Because of that, single nucleotide polymorphisms (SNPs) within these regions (miR-SNPs), which have the ability to alter normal miRNA function, are being evaluated in terms of cancer prognosis and survival. However, to our knowledge, miR-SNPs have not been evaluated in terms of outcomes (recurrence and survival) among those with pediatric medulloblastoma. Methods: Patients with medulloblastoma (n = 100) treated at Texas Children's Cancer Center and MD Anderson Cancer Center between 1982 and 2009 who had existing genotype data from the Illumina Omni1 array were included in this analysis. We selected 25 miR-SNPs within 24 genes with a minor allele frequency (MAF) greater than 5%. Variants were selected from within pri- or pre-miRNAs, miRNA processing machinery, or within binding sites identified in the literature as related to tumorigenesis. The remaining variants were predicted to create or destroy miRNA binding sites per the prediction algorithm PolymiRTS 3.0. Adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) were calculated using Cox regression under log-additive or dominant genetic models (if the MAF fell between 5-15%) to estimate the association between miR-SNPs and progression-free and overall survival (OS) times. All models were adjusted for sex (reference = male), race (reference = white), and age at diagnosis (continuous). Clinical variables including risk group, and craniospinal radiation were also analyzed. Multiple comparisons were adjusted for using the false discovery rate method. Results: The median follow-up time among 88 survivors was 8.33 years (range 1.16 - 25.83 years). Individuals who carry a copy of the minor allele of KIAA0423 (rs1053667), which is located within a putative miR-19a/b binding site, experienced 2.93 times the hazard of progression (CC+CT vs. TT: aHR = 2.93; 95% CI: 1.10-7.83). For overall survival, carriers of a copy of the minor allele experienced 3.96 times the hazard of death (CC+CT vs. TT: aHR = 3.96; 95% CI: 1.12-14.02). While these data point to a potentially strong effect, the results did not remain significant after adjustment for multiple comparisons. Conclusions: This preliminary analysis suggests that certain miR-SNPs may be associated with pediatric medulloblastoma recurrence and survival; however our findings must be validated in a larger population. Validated miR-SNPs may potentially be used for refined risk stratification for those diagnosed with childhood cancers or may be informative for targeted therapies. Citation Format: Erin C. Peckham, Philip J. Lupo, Austin L. Brown, Mehmet Fatih Okcu, Ching C. Lau, Surya Rednam, Michael E. Scheurer. The role of germline microRNA-related polymorphisms on pediatric medulloblastoma prognosis and survival. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 853. doi:10.1158/1538-7445.AM2015-853

Molecular subgrouping and characterization analysis of medulloblastomas in a cohort of Japanese patients

Medulloblastoma is the most common solid malignancy and cause of oncologic death among children. Recent advances in genomic analysis obtained through international large-scale collaborations, Medulloblastoma Advanced Genomics International Consortium(MAGIC), have revealed that medulloblastomas can be classified into at least four distinct subgroups depending on their molecular expression profiles. These studies showed that the prognosis, age distributions, and molecular mechanisms of these subgroups of medulloblastomas completely differ from each other. Here we report the first analysis of molecular subgroups of medulloblastoma in Japanese patients(Shizuoka cohort). Molecular subgroups were predicted for 18 medulloblastomas;and age distributions, radiographic features, and histological characteristics were analyzed. It was predicted that 11% of the medulloblastomas were of the WNT type, 50% of the SHH type, 6% of the group 3 type, and 33% of the group 4 type. The percentage of group 3 type medulloblastomas was smaller than in the MAGIC study, while the percentage of the SHH type was larger. However, age distribution, recurrence-free survival, and overall survival for each group were quite similar to the MAGIC study. In addition, in an imaging study, 78% of patients with medulloblastomas of the SHH type presented tumors in the cerebellar hemispheres. The classical pathohistological hallmarks that may predict medulloblastoma prognosis were mainly seen in tumors of the SHH type. Molecular subgrouping of medulloblastomas could be important in the future, not only for prediction of prognosis, but also for decision making regarding the use of future new treatments such as molecular targeting therapy. The establishment of a public molecular analysis system of medulloblastomas in Japan is greatly desired, and it is currently under development;this database will help establish the molecular diagnosis of medulloblastomas in Japan.

Paired box gene 8 (PAX8) expression is associated with sonic hedgehog (SHH)/wingless int (WNT) subtypes, desmoplastic histology and patient survival in human medulloblastomas.

The paired box gene 8 (PAX8) plays crucial roles in organ patterning and cellular differentiation during development and tumorigenesis. Although its function is partly understood in vertebrate development, there is poor data concerning human central nervous system (CNS) development and brain tumours. We investigated developing human (n = 19) and mouse (n = 3) brains as well as medulloblastomas (MBs) (n = 113) for PAX8 expression by immunohistochemistry. Human MB cell lines were assessed for PAX8 expression using polymerase chain reaction and immunoblotting and analysed for growth and migration following PAX8 knock-down by small interfering ribonucleic acid (siRNA). PAX8 protein expression was associated with germinal layers in human and murine forebrain and hindbrain development. PAX8 expression significantly decreased over time in the external granule cell layer but increased in the internal granule cell layer. In MB subtypes, we observed an association of PAX8 expression with sonic hedgehog (SHH) and wingless int subtypes but not with group 3 and 4 MBs. Beyond that, we detected high PAX8 levels in desmoplastic MB subtypes. Univariate analyses revealed high PAX8 levels as a prognostic factor associated with a significantly better patient prognosis in human MB (overall survival: Log-Rank P = 0.0404, Wilcoxon P = 0.0280; progression-free survival: Log-Rank P = 0.0225; Wilcoxon P = 0.0136). In vitro assays revealed increased proliferation and migration of MB cell lines after PAX8 siRNA knock-down. In summary, high PAX8 expression is linked to better prognosis in MBs potentially by suppressing both proliferative and migratory properties of MB cells. The distinct spatio-temporal expression pattern of PAX8 during brain development might contribute to the understanding of distinct MB subtype histogenesis.

A prognostic analysis of pediatrics central nervous system small cell tumors: evaluation of EGFR family gene amplification and overexpression.

BackgroundCentral nervous system (CNS) tumors are the most common solid tumors that occur in children, however there were few big-data follow-up analysis published in China. Overexpression of epidermal growth factor receptor (EGFR) family members was reported on glioblastoma (GBM) and medulloblastoma (MB) before. However, the correlation between EGFR family members expression with prognosis of MB, supratentorial primitive neuroectodermal tumor (PNET) and small cell GBM is unclear in Chinese children.MethodsA retrospective and survival analysis was performed on children (age ≤ 16 years) diagnosed as CNS primary small cell tumors in the Affiliated Provincial Hospital, Shandong University from 2000 to 2012, including MB (n = 44), PNET (n = 8) and small cell GBM (n = 19). The expression of EGFR, ERBB-2, ERBB-3 and ERBB-4 were detected by immunohistochemistry (IHC). The fluorescence in situ hybridization (FISH) was used to observe the amplification of EGFR and ERBB-2 gene.ResultsMedian survival times of MBs, small GBMs and PNETs were 23 ± 6.7 months, 8 ± 4.7 months and 10 ± 1.4 months. Expression and amplification of ERBB-2, ERBB-3 and ERBB-4 were not observed in all tumor samples. The multiply Cox regression suggested the overexpression and amplification of EGFR were negative prognostic factors for MB. Radiotherapy had the positive function for all pediatric patients.ConclusionOverexpression of EGFR predicts poor outcomes of MBs, small cell GBMs and PNETs, suggesting those three CNS tumor subtypes can be considered as one group for the potential common mechanism. The current individual treatment and big data analysis of pediatric CNS embryonal tumors and GBM continues to be very challenging in China.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7649640001237474

Epigenetic silencing of miRNA-9 is associated with HES1 oncogenic activity and poor prognosis of medulloblastoma

Background:microRNA-9 is a key regulator of neuronal development aberrantly expressed in brain malignancies, including medulloblastoma. The mechanisms by which microRNA-9 contributes to medulloblastoma pathogenesis remain unclear, and factors that regulate this process have not been delineated.Methods:Expression and methylation status of microRNA-9 in medulloblastoma cell lines and primary samples were analysed. The association of microRNA-9 expression with medulloblastoma patients' clinical outcome was assessed, and the impact of microRNA-9 restoration was functionally validated in medulloblastoma cells.Results:microRNA-9 expression is repressed in a large subset of MB samples compared with normal fetal cerebellum. Low microRNA-9 expression correlates significantly with the diagnosis of unfavourable histopathological variants and with poor clinical outcome. microRNA-9 silencing occurs via cancer-specific CpG island hypermethylation. HES1 was identified as a direct target of microRNA-9 in medulloblastoma, and restoration of microRNA-9 was shown to trigger cell cycle arrest, to inhibit clonal growth and to promote medulloblastoma cell differentiation.Conclusions:microRNA-9 is a methylation-silenced tumour suppressor that could be a potential candidate predictive marker for poor prognosis of medulloblastoma. Loss of microRNA-9 may confer a proliferative advantage to tumour cells, and it could possibly contribute to disease pathogenesis. Thus, re-expression of microRNA-9 may constitute a novel epigenetic regulation strategy against medulloblastoma.

ID3 contributes to cerebrospinal fluid seeding and poor prognosis in medulloblastoma

BackgroundThe inhibitor of differentiation (ID) genes have been implicated as promoters of tumor progression and metastasis in many human cancers. The current study investigated the expression and functional roles of ID genes in seeding and prognosis of medulloblastoma.MethodsID gene expression was screened in human medulloblastoma tissues. Knockdown of ID3 gene was performed in medulloblastoma cells in vitro. The expression of metastasis-related genes after ID3 knockdown was assessed. The effect of ID3 knockdown on tumor seeding was observed in an animal model in vivo. The survival of medulloblastoma patients was plotted according to the ID3 expression levels.ResultsSignificantly higher ID3 expression was observed in medulloblastoma with cerebrospinal fluid seeding than tumors without seeding. Knockdown of ID3 decreased proliferation, increased apoptosis, and suppressed the migration of D283 medulloblastoma cells in vitro. In a seeding model of medulloblastoma, ID3 knockdown in vivo with shRNA inhibited the growth of primary tumors, prevented the development of leptomeningeal seeding, and prolonged animal survival. High ID3 expression was associated with shorter survival of medulloblastoma patients, especially in Group 4 medulloblastomas.ConclusionsHigh ID3 expression is associated with medullolbastoma seeding and is a poor prognostic factor, especially in patients with Group 4 tumors. ID3 may represent the metastatic/ aggressive phenotype of a subgroup of medulloblastoma.

Inhibition of SIRT1 Transcription in Resveratrol-differentiated Medulloblastoma Cells

Backgrounds: Medulloblastoma (MB) is the commonest brain malignancy in childhood with poor prognosis, because of its rapid aggressive growth and frequent occurrence. The current chemotherapeutic regimens for medulloblastoma patients involve a combination of lomustine, cisplatin, carboplatin, vincristine or cyclophosphamide, which have distinct short- and long-term side-effects. It is therefore in urgent need to explore safer and more effective adjuvant approach(s). Resveratrol, a polyphenol rich in numerous plants, has multiple biological activities including anticancer effects. Our previous data confirmed that resveratrol inhibited proliferation and induced differentiation and apoptosis of medulloblastoma cells. SIRT1 is a deacetylase of class III HDACs and the supposed molecular effecter of resveratrol. SIRT1 involves in aging prevention and cancer formation in a cell-context specific manner. Nevertheless, the datum concerning the role(s) of SIRT1 in formation and prognosis of medulloblastoma is still missing.Objective: The present study aimed to address the expression patterna of SIRT1 in medulloblastoma tissues and non-cancerous counterparts and to explore whether resveratrol exerts its anti-medulloblastoma effects via regulating SIRT1 expression and bioactivity.Methods: The expression of SIRT1 in medulloblastoma and non-cancerous counterparts was elucidated by immunohistochemical ataining (IHC). To clarify the function of SIRT1 in medulloblastomas, SIRT1 expression in UW228-3 medulloblastoma cells were suppressed by RNA interference (RNAi). The influence of resveratrol in SIRT1 expressions in UW228-3 cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry (ICC) and Western blotting (WB). The catalytic activity of deacetylase SIRT1 was examined by measuring the acetylation of the main substrate p53.Results: IHC staining revealed that SIRT1 was expressed in 64.17% of MB tissues, which was higher than that in noncancerous cerebellum tissues (14.29%). The frequencies of SIRT1 expression in the nodular MB (22.22%) with better prognosis is lower than that in anaplastic MB (79.07% ) and classic MB (60.29 %; P&lt;0.05). The proliferation of UW228-3 cells was remarkably suppressed after being transfected with SIRT1 siRNA, accompanied with extensive cell death. The results of RT-PCR and WB showed that after 48 hours 100 M resveratrol treatment, SIRT1 expression in UW228-3 cells was down-regulated at both transcriptional and translational levels. However, resveratrol has no effect on the deacetylase activity of SIRT1.Conclusion: The above findings suggested that SIRT1 expression is corrected with the formation and prognosis of human MB. Resveratrol influences SIRT1 functioning in human MB cells through inhibiting SIRT1 expression rather than modulating its acetylation activity.Keywords: resveratrol, SIRT1, RNA interference, deacetylase, medulloblastoma