Comprehensive profiling of myxopapillary ependymomas identifies a distinct molecular subtype with relapsing disease
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ABSTRACT: Myxopapillary ependymoma is a heterogeneous disease with respect to histopathology and clinical outcome. However, there are no diagnostic markers or clinical parameters that reliably predict the progression-free survival of the respective patients. We analyzed 185 tumors that classified as myxopapillary ependymoma based on global DNA methylation. Of these, 46 samples have been previously analyzed in GSE65362, GSE90496 or GSE109381. Using k-means clustering, our series split up into two distinct subtypes: MPE-A occurred in younger patients (median age 27 years) and were significantly enriched with tumors demonstrating papillary morphology and MGMT promoter methylation. Half of these tumors could not be totally resected, and 85% relapsed within 10 years. On the other hand, MPE-B occurred at a median age of 45 years. They included a significantly higher number of tumors with an initial diagnosis of WHO grade II and tanycytic morphology. Importantly, patients within this subgroup had a significantly better outcome with a relapse rate of only 33% in 10 years.
Project description:Ependymomas of the spinal cord are rare among children and adolescents, and the individual risk of disease progression is difficult to predict. This study aims at evaluating the prognostic impact of molecular typing of pediatric spinal cord ependymomas. Eighty-three patients with spinal ependymomas ≦ 22 years registered in the HIT-MED database between 1992 and 2022 were included. Forty-seven tumors were analyzed by DNA methylation array profiling. In six cases, HOXB13 and MYCN proteins were detected as surrogate markers for specific methylation classes. With a median follow-up time of 4.9 years (y), 5y- and 10y-overall survival (OS) were 100% and 86%, while 5y- and 10y-progression-free survival (PFS) were 65% and 54%. Myxopapillary ependymoma (SP-MPE, n=32, 63%) was the most common molecular type followed by spinal ependymoma (SP-EPN, n=17, 33%) and MYCN-amplified ependymoma (n=2, 4%). One case could not be molecularly classified, and one was reclassified as anaplastic pilocytic astrocytoma. 5y-PFS did not significantly differ between SP-MPE and SP-EPN (65% versus 78%, p=0.64). MYCN-amplification was associated with early relapses (<2.3y) in both cases and death in one patient. Patients with SP-MPE subtype B (n=9) showed a non-significant trend for better 5y-PFS compared to subtype A (n=18; 86% versus 56%, p=0.15). The extent of resection and WHO tumor grades significantly influenced PFS in a uni- and multivariate analysis.
Project description:The diagnosis of ependymoma has moved from a purely histopathological review with limited prognostic value to an integrated diagnosis, relying heavily on molecular information. However, as the integrated approach is still novel and some molecular ependymoma subtypes are quite rare, few studies have correlated integrated pathology and clinical outcome, often focusing on small series of single molecular types. We collected data from 2023 ependymomas as classified by DNA methylation profiling, consisting of 1736 previously published and 287 unpublished methylation profiles. Methylation data and clinical information were correlated, and an integrated model was developed to predict progression-free survival. Patients with EPN-PFA, EPN-ZFTA, and EPN-MYCN tumors showed the worst outcome with 10-year overall survival rates of 56%, 62%, and 32%, respectively. EPN-PFA harbored chromosome 1q gains and/or 6q losses as markers for worse survival. In supratentorial EPN-ZFTA, a combined loss of CDKN2A and B indicated worse survival, whereas a single loss did not. Twelve out of 200 EPN-ZFTA (6%) were located in the posterior fossa, and these tumors relapsed or progressed even earlier than supratentorial tumors with a combined loss of CDKN2A/B. Patients with MPE and PF-SE, generally regarded as non-aggressive tumors, only had a 10-year progression-free survival of 59% and 65%, respectively. For the prediction of the 5-year progression-free survival, Kaplan-Meier estimators based on the molecular subtype, a Support Vector Machine based on methylation, and an integrated model based on clinical factors, CNV data, and predicted methylation scores achieved balanced accuracies of 66%, 68%, and 73%, respectively. Excluding samples with low prediction scores resulted in balanced accuracies of over 80%.
Project description:Purpose: Myxopapillary ependymoma (MPE) is a distinct histological variant of ependymoma arising commonly in the spinal cord. Despite an overall favorable prognosis, distant metastases, subarachnoid dissemination, and late recurrences have been reported. Currently the only effective treatment for MPE is gross-total resection. We characterized the genomic and transcriptional landscape of spinal ependymomas in an effort to delineate the genetic basis of this disease and identify new leads for therapy. Experimental Design: Gene expression profiling was performed on 35 spinal ependymomas. Functional validation experiments were performed on tumour lysates consisting of assays measuring Pyruvate Kinase M activity (PKM), Hexokinase activity (HK), and lactate production. Results: At a gene expression level, we demonstrate that spinal Grade II and MPE are molecularly and biologically distinct. These findings are supported by specific copy number alterations occurring in each histological variant. Pathway analysis revealed that MPE are characterized by increased cellular metabolism, associated with up-regulation of HIF-1α. These findings were validated by western blot analysis demonstrating increased protein expression of HIF-1α, HK2, PDK1, and phosphorylation of PDHE1A. Functional assays were performed on MPE lysates, which demonstrated decreased PKM activity, increased HK activity, and elevated lactate production. Conclusions: Our findings suggest that MPE may be driven by a Warburg metabolic phenotype. The key enzymes promoting the Warburg phenotype: HK2, PKM2, and PDK are targetable by small molecule inhibitors/activators, and should be considered for evaluation in future clinical trials for MPE. RNA from 35 primary spinal ependymomas (fresh frozen) were isolated by pulverization in liquid nitrogen, and extraction using the Trizol Method (Invitrogen) [PMID:21840481]
Project description:Background: A methylation-based classification of ependymoma has recently found broad application. However, the diagnostic advantage and implications for treatment decisions remain unclear. Here, we retrospectively evaluate the impact of surgery and radiotherapy on outcome after molecular reclassification of adult intracranial ependymomas. Methods: Tumors diagnosed as intracranial ependymomas from 170 adult patients collected from eight diagnostic institutions were subjected to DNA methylation profiling. Molecular classes, patient characteristics, and treatment were retrospectively correlated with progression-free survival (PFS). Results: The classifier indicated an ependymal tumor in 73.5%, a different tumor entity in 10.6% and non-classifiable tumors in 15.9% of cases, respectively. The most prevalent molecular classes were posterior fossa ependymoma group B (EPN-PFB, 32.9%), posterior fossa subependymoma (PF-SE, 25.9%), and supratentorial ZFTA fusion-positive ependymoma (EPN-ZFTA, 11.2%). With a median follow-up of 60.0 months, the 5- and 10-year-PFS rates were 64.5% and 41.8% for EPN-PFB, 67.4% and 45.2% for PF-SE and 60.3% and 60.3% for EPN-ZFTA. In EPN-PFB, but not in other molecular classes, gross total resection (p=0.009) and postoperative radiotherapy (p=0.007) were significantly associated with improved PFS in multivariable analysis. Histological tumor grading (WHO 2 vs. 3) was not a predictor of prognosis within molecularly defined ependymoma classes. Conclusions: DNA methylation profiling improves diagnostic accuracy and risk stratification in adult intracranial ependymoma. The molecular class of PF-SE is unexpectedly prevalent among adult tumors with ependymoma histology and relapsed as frequently as EPN-PFB, despite the supposed benign nature. Gross total resection and radiotherapy may represent key factors in determining the outcome of EPN-PFB patients.
Project description:Ependymomas are glial tumors that share morphologic similarities with ependymal cells. Here we laser microdissected ependymoma cells of 15 infratentorial tumors and generated gene expression profiles. These profiles were compared to those of 7 laser microdissected ependymal tissues.
Project description:Genomic technologies have unmasked molecularly distinct subgroups among tumors of the same histological type; but understanding the biologic basis of these subgroups has proved difficult since their defining alterations are often numerous, and the cellular origins of most cancers remain unknown. We sought to decipher complex genomic data sets by matching the genetic alterations contained within these, with candidate cells of origin, to generate accurate disease models. Using an integrated genomic analysis we first identified subgroups of human ependymoma: a form of neural tumor that arises throughout the central nervous system (CNS). Validated alterations included amplifications and homozygous deletions of genes not yet implicated in ependymoma. Matching the transcriptomes of human ependymoma subgroups to those of distinct types of mouse radial glia (RG)—neural stem cells (NSCs) that we identified previously to be a candidate cell of origin of ependymoma - allowed us to select RG types most likely to represent cells of origin of disease subgroups. The transcriptome of human cerebral ependymomas that amplify EPHB2 and delete INK4A/ARF matched most closely that of embryonic cerebral Ink4a/Arf-/- RG: remarkably, activation of EphB2 signaling in this RG type, but not others, generated highly penetrant ependymomas that modeled accurately the histology and transcriptome of one human cerebral tumor subgroup (subgroup ‘D’). Further comparative genomic analysis revealed selective alterations in the copy number and expression of genes that regulate neural differentiation, particularly synaptogenesis, in both mouse and human subgroup ‘D’ ependymomas; pinpointing this pathway as a previously unknown target of ependymoma tumorigenesis. Our data demonstrate the power of comparative genomics to sift complex genetic data sets to identify key molecular alterations in cancer subgroups. [human mRNA] samples: 83 human ependynoma primary tumors were collected and clustered into distinct classes by unsupervised methods and then compared to mouse model data. [mouse mRNA] samples: 192 mouse tumors and cell lines were collected and clustered into distinct classes by unsupervised methods and then compared to human tumors. [human miRNA] samples: 64 human ependynoma primary tumors were collected and miRNA expression was assesed and compared to genomic expression
Project description:Mucuna pruriens extract MPE pretreatment may have a direct protective effect on heart (other than immunological neutralization of the venom neurotoxin and phospholipase A2 by the anti-MPE antibodies) that renders the heart more resistant to the toxic action of the venom The direct protective effect probably involves functional changes to the cardiac tissue that enable the heart to resist the reduction of contractility and rate induced by the cobra venom.To explore the possibility of the direct action of MPE pretreatment on heart and to understand the molecular events involved in the protection of MPE pretreatment against the lethal action of Naja sputatrix venom, gene expression studies were carried out using microarray analysis. Rats were divided into four groups (n=6): negative control (abbreviated as ‘negative’ group), MPE pretreated group (abbreviated as ‘MPE’ group), N. sputatrix venom-challenge group (abbreviated as ‘NS’ group) and N. sputatrix venom-challenge to MPE pretreated animals group (abbreviated as ‘MPE-NS’ group). In the ‘MPE’ group, rats were injected with MPE at a dose of 21 mg/kg (i.p.), on day 0, 7 and 14, and sacrificed on day 21. In the ‘negative’ group (the untreated, control group), rats were injected with saline of the same volume and sacrificed also on day 21. Hearts were then harvested immediately. In the N. sputatrix venom-challenge group (‘NS’ group), untreated rats were challenged with 1.5 LD50 (1.25 ?g/g) of N. sputatrix venom whereas in the venom challenge to MPE pretreated animals group (the ‘MPE-NS’ group), MPE pretreated rats were challenged with 1.5 LD50 (1.25 ?g/g) of N. sputatrix venom, both on day 21. For the ‘NS’ and ‘MPE-NS’ group, the rats were observed for 24 h after venom challenged and hearts were harvested as soon as death occurred or 24 h after the venom injection, whichever occurred first.
Project description:Ependymomas are glial tumors that share morphologic similarities with ependymal cells. Here we laser microdissected ependymoma cells of 15 infratentorial tumors and generated gene expression profiles. These profiles were compared to those of 7 laser microdissected ependymal tissues. 10 000 laser microdissected cells of each of the 15 different infratentorial ependymomas and seven ependymal autopsy tissues were lysed and gene expression profiles were generated. Expression profiles of ependymomas were compared to those of ependymal cells.
Project description:Purpose: Myxopapillary ependymoma (MPE) is a distinct histological variant of ependymoma arising commonly in the spinal cord. Despite an overall favorable prognosis, distant metastases, subarachnoid dissemination, and late recurrences have been reported. Currently the only effective treatment for MPE is gross-total resection. We characterized the genomic and transcriptional landscape of spinal ependymomas in an effort to delineate the genetic basis of this disease and identify new leads for therapy. Experimental Design: Gene expression profiling was performed on 35 spinal ependymomas. Functional validation experiments were performed on tumour lysates consisting of assays measuring Pyruvate Kinase M activity (PKM), Hexokinase activity (HK), and lactate production. Results: At a gene expression level, we demonstrate that spinal Grade II and MPE are molecularly and biologically distinct. These findings are supported by specific copy number alterations occurring in each histological variant. Pathway analysis revealed that MPE are characterized by increased cellular metabolism, associated with up-regulation of HIF-1α. These findings were validated by western blot analysis demonstrating increased protein expression of HIF-1α, HK2, PDK1, and phosphorylation of PDHE1A. Functional assays were performed on MPE lysates, which demonstrated decreased PKM activity, increased HK activity, and elevated lactate production. Conclusions: Our findings suggest that MPE may be driven by a Warburg metabolic phenotype. The key enzymes promoting the Warburg phenotype: HK2, PKM2, and PDK are targetable by small molecule inhibitors/activators, and should be considered for evaluation in future clinical trials for MPE.
Project description:Malignant pleural effusion (MPE) is indicative of terminal malignancy with uniformly fatal prognosis. Often, two distinct compartments of tumor microenvironment, the effusion and disseminated pleural tumors, co-exist in the pleural cavity, presenting a major challenge for therapeutic interventions and drug delivery. Clinical evidence suggests that MPE comprises abundant tumor associated myeloid cells with the tumor-promoting phenotype, impairing antitumor immunity. Here, we developed liposomal cyclic dinucleotide (LNP-CDN) for targeted activation of STING signaling in macrophages and dendritic cells and showed that, upon intrapleural administration, they induce drastic changes in the transcriptional landscape in MPE, mitigating the immune cold MPE in both the effusion and pleural tumors. Moreover, combination immunotherapy with blockade of PD-L1 potently reduced MPE volume and inhibited tumor growth not only in pleural cavity but also in lung parenchyma, conferring significantly prolonged survival of MPE-bearing mice. Furthermore, the LNP-CDN-induced immunological effects were also observed with clinical MPE samples, suggesting the potential of intrapleural LNP-CDN for clinical MPE immunotherapy.