Atypical teratoid/rhabdoid tumors: challenges and search for solutions

Radiation-induced malignant rhabdoid tumour of the hypothalamus in an adult: A case report

BACKGROUND

Rhabdoid tumours of the central nervous system are highly malignant and extremely rare in adults. To the best of our knowledge, only 87 cases of malignant rhabdoid tumour have been reported to date, inclusive of 4 cases with presumed radiation-induced aetiology. We report a case of malignant rhabdoid tumour in an adult with presumed radiation-induced aetiology to enrich the armamentarium of this disease entity, which may have some implications for early diagnosis and treatment of this rare disease in the future.

CASE SUMMARY

A 27-year-old male, who was exposed to cranial irradiation at the age of 4 years as part of the treatment for acute lymphoblastic leukaemia, presented with symptoms of raised intracranial pressure for one week. Brain magnetic resonance imaging revealed a heterogeneously enhancing lesion at the hypothalamus. Stereotactic biopsy was performed. Histopathological examination of the lesion showed malignant rhabdoid tumour. The disease progressed rapidly, with manifestation of leptomeningeal spread. He was started on craniospinal irradiation but treatment was suspended after 5.4 Gy, as he developed myelosuppression. His clinical condition deteriorated rapidly, and he succumbed to his illness within 2 mo.

CONCLUSION

This fifth case of radiation-induced central nervous system rhabdoid tumour re-enforces the aggressive nature of this disease with poor prognosis.

Nonviral polymeric nanoparticles for gene therapy in pediatric CNS malignancies

Together, medulloblastoma (MB) and atypical teratoid/rhabdoid tumors (AT/RT) represent two of the most prevalent pediatric brain malignancies. Current treatment involves radiation, which has high risks of developmental sequelae for patients under the age of three. New safer and more effective treatment modalities are needed. Cancer gene therapy is a promising alternative, but there are challenges with using viruses in pediatric patients. We developed a library of poly(beta-amino ester) (PBAE) nanoparticles and evaluated their efficacy for plasmid delivery of a suicide gene therapy to pediatric brain cancer models-specifically herpes simplex virus type I thymidine kinase (HSVtk), which results in controlled apoptosis of transfected cells. In vivo, PBAE-HSVtk treated groups had a greater median overall survival in mice implanted with AT/RT (P = 0.0083 vs. control) and MB (P < 0.0001 vs. control). Our data provide proof of principle for using biodegradable PBAE nanoparticles as a safe and effective nanomedicine for treating pediatric CNS malignancies.

Intrinsic Disorder of the BAF Complex: Roles in Chromatin Remodeling and Disease Development

The two-meter-long DNA is compressed into chromatin in the nucleus of every cell, which serves as a significant barrier to transcription. Therefore, for processes such as replication and transcription to occur, the highly compacted chromatin must be relaxed, and the processes required for chromatin reorganization for the aim of replication or transcription are controlled by ATP-dependent nucleosome remodelers. One of the most highly studied remodelers of this kind is the BRG1- or BRM-associated factor complex (BAF complex, also known as SWItch/sucrose non-fermentable (SWI/SNF) complex), which is crucial for the regulation of gene expression and differentiation in eukaryotes. Chromatin remodeling complex BAF is characterized by a highly polymorphic structure, containing from four to 17 subunits encoded by 29 genes. The aim of this paper is to provide an overview of the role of BAF complex in chromatin remodeling and also to use literature mining and a set of computational and bioinformatics tools to analyze structural properties, intrinsic disorder predisposition, and functionalities of its subunits, along with the description of the relations of different BAF complex subunits to the pathogenesis of various human diseases.

Zeolitic Imidazolate Framework-8 as pH-Sensitive Nanocarrier for "Arsenic Trioxide" Drug Delivery

Previous results revealed that arsenic trioxide might be used as promising therapeutic agent for the treatment of some solid tumours as atypical teratoid rhabdoid tumours (ATRT). However, in order to become an approved drug for solid tumour treatment, the active formulation has to get more efficient and feasible-but at the same time less toxic. One of the possibilities to achieve this dichotomy is to use nanomedicine tools. Herein, we report on the Zn-based metal-organic framework ZIF-8 (Zeolitic Imidazolate Framework-8) which turned out to be a promising candidate for the delivery of AsIII species. It conjointly features a high drug loading capacity and a prominent pH-triggered release behaviour. AsIII -loaded ZIF-8 nanoparticles coated and non-coated with polyethylene glycol were studied by XRPD, IR, Raman, TGA, TEM, EDX, CHN-elemental analysis, sorption analysis and ICP-OES, and their cytotoxicity was evaluated in vitro.

Coopted temporal patterning governs cellular hierarchy, heterogeneity and metabolism in Drosophila neuroblast tumors

It is still unclear what drives progression of childhood tumors. During Drosophila larval development, asymmetrically-dividing neural stem cells, called neuroblasts, progress through an intrinsic temporal patterning program that ensures cessation of divisions before adulthood. We previously showed that temporal patterning also delineates an early developmental window during which neuroblasts are susceptible to tumor initiation (Narbonne-Reveau et al., 2016). Using single-cell transcriptomics, clonal analysis and numerical modeling, we now identify a network of twenty larval temporal patterning genes that are redeployed within neuroblast tumors to trigger a robust hierarchical division scheme that perpetuates growth while inducing predictable cell heterogeneity. Along the hierarchy, temporal patterning genes define a differentiation trajectory that regulates glucose metabolism genes to determine the proliferative properties of tumor cells. Thus, partial redeployment of the temporal patterning program encoded in the cell of origin may govern the hierarchy, heterogeneity and growth properties of neural tumors with a developmental origin.

Atypical teratoid/rhabdoid tumor presenting with subarachnoid and intraventricular hemorrhage

Background:

Sellar masses comprise 14–18% of all intracranial tumors. Pituitary adenomas account for 85% of these lesions, while 15% of sellar masses stem from other etiologies. Intratumoral hemorrhage (apoplexy), while not exceptionally common, can be discovered at presentation. While the hemorrhage pattern is typically contained within the tumor, an extension of bleeding beyond the sella has been reported.

Case Description:

A 55-year-old female presented with an anterior interhemispheric subarachnoid hemorrhage and extensive intraventricular hemorrhage (IVH). Initially, the IVH was thought to be due to a ruptured aneurysm. After further workup, a hemorrhagic sellar mass was diagnosed. The patient underwent transsphenoidal resection of a pituitary adenoma. The patient returned to the emergency department6 weeks later with an atypical rapidly expanding sellar mass. After tumor debulking, the pathology revealed an atypical teratoid/rhabdoid tumor (ATRT). Here, we reviewed this and other such cases of sellar ATRT.

Conclusion:

The early diagnosis of sellar ATRT with lack of integrase interactor 1 expression and elevated Ki67 proliferation indices can prompt more aggressive attempted gross total resection, chemotherapy, and radiation treatments.

Pediatric primary spinal atypical teratoid rhabdoid tumor: a case series and review of the literature

Atypical teratoid rhabdoid tumors (ATRTs) are rare malignant central nervous system tumors, commonly occurring before 3 years of age. Median overall survival (OS) of patients with these tumors is about 1 year, despite aggressive multimodal therapy. Pediatric primary spinal ATRTs are even more rare, with fewer than 50 cases reported. The authors present a series of four patients who were treated at Ann and Robert H. Lurie Children's Hospital of Chicago in the period from 1996 to 2017.These patients, with ages 2-11 years, presented with pain and a decline in motor functions. They were found to have lesions in the lumbar, thoracic, and/or cervical spine. One patient's tumor was intramedullary with exophytic components, while another patient's tumor had both intra- and extradural components. All patients underwent resection followed by chemotherapy (systemic and intrathecal). Two patients had fractionated radiation therapy and one had an autologous stem cell transplant. Three patients are known to be deceased (OS 8.5-45 months). The fourth patient was in remission 19 years after her initial diagnosis. To the authors' knowledge, this is the largest series of pediatric primary spinal ATRTs documented at a single institution. These cases illustrate a variety of presentations of spinal ATRT and add to the body of literature on this aggressive pathology.A systematic MEDLINE search was also conducted using the keywords "atypical teratoid rhabdoid tumor," "pediatric spinal rhabdoid tumor," and "malignant rhabdoid tumor spine." Reports were included for patients younger than 21 years, without evidence of intracranial or systemic disease at the time of diagnosis. Clinical characteristics and outcomes of the four institutional cases were compared to those in the literature. This review yielded an additional 48 cases of primary pediatric spinal ATRTs reported in the English-language literature. Patients (ages 2 months to 19 years) presented with symptoms of pain, regression of motor function, and spinal cord compression. The majority of tumors were intradural (14 extramedullary, 8 intramedullary, 1 both). Eleven cases in the literature described tumors limited to extradural structures, while 10 tumors involved the intra- and extradural spine. Four reports did not specify tumor location. Although rare, spinal ATRT should be considered in the differential diagnosis of pediatric patients presenting with a new spinal mass.

Incidence of metastatic disease and survival among patients with newly diagnosed primary CNS tumors in the United States from 2004-2013

Background: Population-based estimates of the incidence and prognosis of metastatic disease at the initial diagnosis of primary central nervous system (CNS) tumors are currently lacking.

Methods: A total of 43,455 patients diagnosed with a primary CNS tumor were enrolled to evaluate metastatic rates utilizing the data from the Surveillance, Epidemiology, and End Results (SEER) program. We used multivariate logistic regression to analyze the risk factors associated with the presence of metastasis at the first visit of patients with metastatic medulloblastoma (MB), atypical teratoid/rhabdoid tumor (ATRT), glioblastoma multiforme (GBM), or pilocytic astrocytoma (PA). Hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer-specific death (CSD) of patients with these four CNS tumors were analyzed using multivariate Cox regression.

Results: In patients with primary CNS embryonal tumors, the metastatic rates of patients with MB and ATRT were 14.51% and 19.25%, respectively. The metastatic rate for MB patients aged 0 to 18 years was 16.69%. In the patients with glioma, the metastatic rates of patients with PA and GBM were 1.55% and 1.39%, respectively. On multivariate logistic regression among patients with glioma, GBM (vs PA; OR, 2.12; 95% CI, 1.37 to 3.30; P=0.001) was associated with greater odds of having metastatic disease at diagnosis. On multivariate logistic regression among patients with GBM, MB, or ATRT, MB (vs GBM; OR, 4.66; 95% CI, 2.81 to 7.72; P<0.001) and ATRT (vs GBM; OR, 5.65; 95% CI, 3.27 to 9.75; P<0.001) were associated with greater odds of having metastatic disease at diagnosis. In the multivariate Cox proportional hazards model for CSD among patients with metastatic GBM or MB at diagnosis, gross total resection/total lobectomy (vs partial resection/partial lobectomy) was not related to a decreased or an increased risk of CSD. In patients with metastatic ATRT, compared to no surgery, gross total resection/total lobectomy or partial resection/partial lobectomy was not associated with a decreased risk of CSD.

Conclusions: The findings in this study provide a population-based estimate of the incidence and prognosis of metastatic disease at the initial diagnosis of primary CNS tumors. These survival outcomes are relevant because they will help to prioritize future research directions to improve the treatment strategies of these metastatic CNS tumors.

Factors Influencing Survival of Children with Atypical Teratoid/Rhabdoid Tumors: A Single-Institute Experience in a Developing Country

BACKGROUND

We evaluated the factors influencing overall survival (OS) and event-free survival (EFS) in children with atypical teratoid/rhabdoid tumors (ATRTs).

METHODS

We performed a retrospective study of children aged <16 years and tumor histological diagnosis of ATRT. Univariate and multivariate analyses were performed to determine the effect of individual and interdependent variables and survival.

RESULTS

A total of 34 children had undergone surgery, with a male/female ratio of 1.8:1. On univariate analysis, the factors with statistically significant influence on OS and EFS were the extent of resection (P = 0.012 and P = 0.015, respectively), adjuvant therapy (P ≤ 0.001 and P = 0.001, respectively), and rhabdoid cell percentage (P = 0.004 and P = 0.005, respectively). On survival analysis, the median OS and EFS were better for those who had completed adjuvant therapy versus those who had not received adjuvant therapy (OS, 22.7 months vs. 3.5 months; EFS, 10.9 months vs. 3.5 months), those who had undergone gross total resection versus those who had undergone partial decompression (OS, 10.9 months vs. 2 months; EFS, 8.9 months vs. 2.5 months), and those with <50% rhabdoid cells in the biopsy specimen versus those with >50% rhabdoid cells (OS, 10.9 months vs. 3.7 months; EFS, 8.9 months vs. 3.5 months). On multivariate analysis, only the extent of resection and adjuvant therapy status had a significant influence on OS and EFS.

CONCLUSION

Achieving gross total resection should be the aim of surgery, depending on the tumor location, and these children should undergo upfront adjuvant treatment.

[Central nervous system atypical teratoid/rhabdoid tumor without loss of nuclear expression of INI1]

The paper describes a clinical case of atypical teratoid/rhabdoid tumor with preserved INI1 expression and SMARCA4 gene mutations in an 8-month-old girl. Genome-wide DNA methylation, hierarchical clustering, and next-generation sequencing were used to make a tumor diagnosis. However, BRG1 immunohistochemical examination may be recommended in the routine practice of diagnosis and study of childhood CNS malignant tumors.

Comprehensive Analysis of Chromatin States in Atypical Teratoid/Rhabdoid Tumor Identifies Diverging Roles for SWI/SNF and Polycomb in Gene Regulation

Biallelic inactivation of SMARCB1, encoding a member of the SWI/SNF chromatin remodeling complex, is the hallmark genetic aberration of atypical teratoid rhabdoid tumors (ATRT). Here, we report how loss of SMARCB1 affects the epigenome in these tumors. Using chromatin immunoprecipitation sequencing (ChIP-seq) on primary tumors for a series of active and repressive histone marks, we identified the chromatin states differentially represented in ATRTs compared with other brain tumors and non-neoplastic brain. Re-expression of SMARCB1 in ATRT cell lines enabled confirmation of our genome-wide findings for the chromatin states. Additional generation of ChIP-seq data for SWI/SNF and Polycomb group proteins and the transcriptional repressor protein REST determined differential dependencies of SWI/SNF and Polycomb complexes in regulation of diverse gene sets in ATRTs.

Metal-organic framework nanoparticles for arsenic trioxide drug delivery

Arsenic trioxide is a double-edged sword: On the one hand it is known as a poison, on the other hand it is used as an anticancer drug. Though effective in the treatment of leukaemia, arsenic trioxide has not been able to be introduced into the treatment of solid tumour entities yet due to its dose-limiting toxicity. However, different in vitro and in vivo studies revealed arsenic trioxide to be a potent agent against different solid tumour entities, including atypical teratoid rhabdoid tumours (ATRT), a paediatric brain tumour entity with a very poor prognosis. To improve the pharmacokinetics and therapeutic efficacy of arsenic trioxide and to reduce its toxic side effects, we propose to use a metal-organic framework (MOF) as a drug carrier material. Herein we report on using a MOF called MFU-4l (Metal-Organic Framework Ulm University), consisting of Zn(ii) ions and bis(1H-1,2,3-triazolo[4,5-b],[4',5'-i])dibenzo[1,4]dioxin ligands, to deliver arsenic trioxide in a form of dihydrogen arsenite anions. The H₂AsO₃ ^- anions were introduced to the MOF in a nanoparticle formulation via a postsynthetic side ligand exchange. The prepared material was characterised by IR, TGA, XRPD, SEM-EDX, TEM, DLS, ICP-OES and adsorption analysis. The drug release studies at different pH values were carried out as well as cytotoxicity tests with different ATRT cell lines and non-tumorous-control cell lines. The MOF-based material was shown to be a promising candidate for arsenic trioxide drug delivery.

Embryonal Tumors of the Central Nervous System: From the Radiologic Pathology Archives

Embryonal tumors of the central nervous system (CNS) are highly malignant undifferentiated or poorly differentiated tumors of neuroepithelial origin and have been defined as a category in the World Health Organization (WHO) classification since the first edition of the "Blue Book" in 1979. This category has evolved over time to reflect our ever-improving understanding of tumor biology and behavior. With the most recent update in 2016, many previous histologic diagnoses incorporate molecular parameters for the first time (genetically defined entities). While medulloblastoma and atypical teratoid/rhabdoid tumor are familiar carryovers from the 2007 CNS WHO classification, there are major changes to the embryonal tumor category: for example, elimination of the term CNS primitive neuroectodermal tumor and addition of a new genetically defined entity, embryonal tumor with multilayered rosettes, C19MC-altered. The purpose of this article is to discuss both the radiologic-pathologic features of CNS embryonal tumors and the new molecularly defined types/subtypes that will become the standard classification/terminology for future diagnoses and tumor research.

Oncolytic Viruses as Therapeutic Tools for Pediatric Brain Tumors

In recent years, we have seen an important progress in our comprehension of the molecular basis of pediatric brain tumors (PBTs). However, they still represent the main cause of death by disease in children. Due to the poor prognosis of some types of PBTs and the long-term adverse effects associated with the traditional treatments, oncolytic viruses (OVs) have emerged as an interesting therapeutic option since they displayed safety and high tolerability in pre-clinical and clinical levels. In this review, we summarize the OVs evaluated in different types of PBTs, mostly in pre-clinical studies, and we discuss the possible future direction of research in this field. In this sense, one important aspect of OVs antitumoral effect is the stimulation of an immune response against the tumor which is necessary for a complete response in preclinical immunocompetent models and in the clinic. The role of the immune system in the response of OVs needs to be evaluated in PBTs and represents an experimental challenge due to the limited immunocompetent models of these diseases available for pre-clinical research.

Multimodal treatments combined with gamma knife surgery for primary atypical teratoid/rhabdoid tumor of the central nervous system: a single-institute experience of 18 patients

OBJECTIVES

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, highly malignant tumor of the central nervous system with poor prognosis. Nowadays, multimodal management, including surgery, chemotherapy (CMT), and radiation therapy (RT), is advocated. However, AT/RT treatment with gamma knife surgery (GKS) was rarely reported. The aim of this study was to assess the efficacy and safety of GKS for the treatment of AT/RT.

PATIENTS AND METHODS

Medical records of AT/RT patients who underwent surgery from 2007 to 2014 at the West China Hospital were retrospectively reviewed and statistically analyzed.

RESULTS

Eighteen patients (12 males and 6 females) were presented with AT/RTs. Median age during presentation was 20.5 months (range, 4-179 months). Twelve patients were < 3 years and six patients were > 3 years. Tumor location was supratentorial in seven patients, infratentorial in ten patients, and center area of the brain in one patient. Treatments performed were as follows: surgery alone in two patients, surgery+RT in two patients, surgery+CMT in five patients, surgery+CMT+RT in two patients, and surgery+CMT+RT+GKS in seven patients. The 2-year overall survival (OS) rate and event-free survival (EFS) rate for all 18 consecutive patients were 33.3 and 27.8%, respectively. Cox regression analyses showed that multimodal management combined with GKS was an independent positive prognostic factor for OS.

CONCLUSIONS

Although AT/RTs are lethal cancer types, the OS of the disease was improved by using multimodal therapeutic strategies, including surgery, CMT, and RT, combined with GKS.

Posterior fossa medulloblastoma in an atypical extra-axial location: A case report

Medulloblastoma is the most common posterior fossa tumor of childhood typically within the fourth ventricle. However, extra-axial medulloblastoma in posterior fossa is an uncommon diagnosis. We report a case in a 33-month-old male who presented with repeated complaints of abdominal pain, intermittent emesis, and diarrhea, and diagnosed with right cerebellar extra-axial medulloblastoma, which was surgically resected. Majority of the reported extra-axial medulloblastoma in posterior fossa in the United States are located in the cerebellopontine angle. However, to the best of our knowledge, our case is the first to document medulloblastoma occurring exclusively in the cerebellar hemispheric extra-axial space rather than the cerebellopontine angle. Although the diagnosis can present as a radiological dilemma, a systematic multimodality imaging approach can aid in narrowing the differential diagnosis and timely management. In this case report, we will discuss the imaging characteristics, differential diagnosis, and management strategies, alongside a brief review of the world literature of extra-axial medulloblastoma.