Analysis of Dual Class I Histone Deacetylase and Lysine Demethylase Inhibitor Domatinostat (4SC-202) on Growth and Cellular and Genomic Landscape of Atypical Teratoid/Rhabdoid.

Central nervous system atypical teratoid/rhabdoid tumors (ATRTs) are rare and aggressive tumors with a very poor prognosis. Current treatments for ATRT include resection of the tumor, followed by systemic chemotherapy and radiation therapy, which have toxic side effects for young children. Gene expression analyses of human ATRTs and normal brain samples indicate that ATRTs have aberrant expression of epigenetic markers including class I histone deacetylases (HDAC's) and lysine demethylase (LSD1). Here, we investigate the effect of a small molecule epigenetic modulator known as Domatinostat (4SC-202), which inhibits both class I HDAC's and Lysine Demethylase (LSD1), on ATRT cell survival and single cell heterogeneity. Our findings suggest that 4SC-202 is both cytotoxic and cytostatic to ATRT in 2D and 3D scaffold cell culture models and may target cancer stem cells. Single-cell RNA sequencing data from ATRT-06 spheroids treated with 4SC-202 have a reduced population of cells overexpressing stem cell-related genes, including SOX2. Flow cytometry and immunofluorescence on 3D ATRT-06 scaffold models support these results suggesting that 4SC-202 reduces expression of cancer stem cell markers SOX2, CD133, and FOXM1. Drug-induced changes to the systems biology landscape are also explored by multi-omics enrichment analyses. In summary, our data indicate that 4SC-202 has both cytotoxic and cytostatic effects on ATRT, targets specific cell sub-populations, including those with cancer stem-like features, and is an important potential cancer therapeutic to be investigated in vivo.

4SC-202 as a Potential Treatment for the Pediatric Brain Tumor Medulloblastoma.

This project involves an examination of the effect of the small molecule inhibitor 4SC-202 on the growth of the pediatric brain cancer medulloblastoma. The small molecule inhibitor 4SC-202 significantly inhibits the viability of the pediatric desmoplastic cerebellar human medulloblastoma cell line DAOY, with an IC50 = 58.1 nM, but does not affect the viability of noncancerous neural stem cells (NSC). 4SC-202 exposure inhibits hedgehog expression in the DAOY cell line. Furthermore, microarray analysis of human medulloblastoma patient tumors indicate significant upregulation of key targets in the Hedgehog signaling pathway and Protein Tyrosine Kinase (PTK7).

Therapeutic Targeting of PTK7 is Cytotoxic in Atypical Teratoid Rhabdoid Tumors.

Novel discoveries involving the evaluation of potential therapeutics are based on newly identified molecular targets for atypical teratoid rhabdoid tumors (ATRT), which are the most common form of infantile brain tumors. Central nervous system ATRTs are rare, aggressive, and fast growing tumors of the brain and spinal cord and carry a very poor prognosis. Currently, the standard of care for ATRT patients is based on surgical resection followed by systemic chemotherapy and radiotherapy, which result in severe side effects. As protein tyrosine kinases have proven to be actionable targets that reduce tumor growth in a number of cancers, we examined how inhibiting tyrosine kinases affected ATRT tumor growth. Here, we examine the therapeutic efficacy of the broad-spectrum tyrosine kinase inhibitor vatalanib in the treatment of ATRT. Vatalanib significantly reduced the growth of ATRT tumor cell lines, both in two-dimensional cell culture and in three-dimensional cell culture using a spheroid model. As vatalanib had a remarkable effect on the growth of ATRT, we decided to use a transcriptomic approach to therapy by examining new actionable targets, such as tyrosine kinases. Next-generation RNA-sequencing and NanoString data analysis showed a significant increase in PTK7 RNA expression levels in ATRT tumors. Inhibition of PTK7 by siRNA treatment significantly decreases the viability of ATRT patient-derived tumor cell lines.Implications: These studies provide the groundwork for future preclinical in vivo studies aiming to investigate the efficacy of PTK7 inhibition on ATRT tumor growth. Mol Cancer Res; 15(8); 973-83. ©2017 AACR.

Case report of an epidural cervical Onchocerca lupi infection in a 13-year-old boy.

A 13-year-old boy presented with fever and neck pain and stiffness, which was initially misdiagnosed as culture-negative meningitis. Magnetic resonance images of the brain and cervical spine demonstrated what appeared to be an intradural extramedullary mass at the C1-3 level, resulting in moderate cord compression, and a Chiari Type I malformation. The patient underwent a suboccipital craniectomy and a C1-3 laminectomy with intradural exploration for excisional biopsy and resection. The lesion containing the parasite was extradural, extending laterally through the C2-3 foramina. Inflammatory tissue secondary to Onchocerca lupi infection was identified, and treatment with steroids and doxycycline was initiated. At the 6-month follow-up, the patient remained asymptomatic, with MR images demonstrating a significant reduction in lesional size. However, 10 weeks postoperatively, the infection recurred, necessitating a second operation. The patient was treated with an additional course of doxycycline and is currently maintained on ivermectin therapy. This is the second reported case of cervical O. lupi infection in a human. In the authors' experience, oral doxycycline alone was insufficient in controlling the disease, and the addition of ivermectin therapy was necessary.

Cerebral peduncle tumor ablated by novel 3-mm laser tip.

BACKGROUND/OBJECTIVE: Decisions to use open surgery or radiotherapy in pediatric patients with familial neoplastic syndromes must consider not only the symptomatic benefits of treatment, but also future limitations these treatments may impose. Specifically, open surgical resection of noncurable tumors may preclude or encumber future lesion resections, while radiotherapy has detrimental effects on pediatric cognitive development and increases the risk of future malignancy development. We provide the first report of using a novel 3.0-mm diffusing laser tip with laser-induced thermal therapy (LiTT) to treat a pediatric patient with neurofibromatosis type 1 (NF-1). METHODS: A 12-year-old boy with NF-1 presented with a progressively enlarging lesion in the right midbrain. A stereotactic biopsy was performed, followed by LiTT with a novel 3.0-mm laser applicator. RESULTS: MRI 1 week after LiTT showed stable gross total ablation of the lesion with reduction in fluid-attenuated inversion recovery signal. The patient remained neurologically intact 6 months after his procedure, and follow-up MRI showed no evidence of recurrence. CONCLUSION: LiTT is a powerful adjunct to conventional open surgical and radiotherapy modalities in the treatment of patients with familial neoplastic syndromes or incurable lesions. The novel laser applicator tip described expands the treatment scope of this technique.

Wnt pathway in atypical teratoid rhabdoid tumors.

BACKGROUND: Atypical teratoid rhabdoid tumor (ATRT) is an aggressive pediatric brain tumor with limited therapeutic options. The hypothesis for this study was that the Wnt pathway triggered by the Wnt5B ligand plays an important role in ATRT biology. To address this hypothesis, the role of WNT5B and other Wnt pathway genes was analyzed in ATRT tissues and ATRT primary cell lines. METHODS: Transcriptome-sequencing analyses were performed using nanoString platforms, immunohistochemistry, Western blotting, quantitative reverse transcriptase PCR, immunoprecipitation, short interference RNA studies, cell viability studies, and drug dose response (DDR) assays. RESULTS: Our transcriptome-sequencing results of Wnt pathway genes from ATRT tissues and cell lines indicated that the WNT5B gene is significantly upregulated in ATRT samples compared with nontumor brain samples. These results also indicated a differential expression of both canonical and noncanonical Wnt genes. Imunoprecipitation studies indicated that Wnt5B binds to Frizzled1 and Ryk receptors. Inhibition of WNT5B by short interference RNA decreased the expression of FRIZZLED1 and RYK. Cell viability studies a indicated significant decrease in cell viability by inhibiting Frizzled1 receptor. DDR assays showed promising results with some inhibitors. CONCLUSIONS: These promising therapeutic options will be studied further before starting a translational clinical trial. The success of these options will improve care for these patients.

Concomitant achondroplasia and Chiari II malformation: A double-hit at the cervicomedullary junction.

We report the first case of a neonate with concurrent Chiari II malformation and achondroplasia. Although rare, both these conditions contribute to several deleterious anatomical changes at the cervicomedullary junction and thus predispose to acute hydrocephalus. Although our patient was initially asymptomatic, hydrocephalus ensued several weeks after birth and required cerebral spinal fluid diversion. We discuss the potential links between the two conditions, the pathophysiology, and the important clinical implications for the management of the increased risk of hydrocephalus.

Neuropsychiatric changes following penetrating head injury in children.

BACKGROUND: Penetrating head injuries demand the prompt attention of a neurosurgeon. While most neurosurgical centers are experienced in the acute management of these injuries, less is known about the long-term neuropsychiatric sequelae of penetrating head trauma. In adults, direct injury to the frontal lobe classically has been associated with mental status changes. However, there is less published data in children. CASE DESCRIPTION: We report the case of a 12-year-old boy who suffered a penetrating head injury to the frontal lobes secondary to a self-inflicted gunshot wound, and experienced subsequent resolution of pre-existing bipolar disorder and new onset of attention deficit hyperactivity disorder. CONCLUSION: Children with penetrating head injury require close multidisciplinary follow-up in order to monitor, and accordingly implement management strategies, for associated sequelae, including behavioral and neuropsychiatric changes.

Expression of the HOX genes and HOTAIR in atypical teratoid rhabdoid tumors and other pediatric brain tumors.

Pediatric brain tumors such as atypical teratoid rhabdoid tumors (ATRTs) are highly aggressive and predominantly occur in young children. A characteristic feature of ATRT is aberrations of the SMARCB1 (hSNF5/INI1) gene. Developmental gene defects may play an important role in the biology of pediatric brain tumors. HOX genes are transcription factors that play a pivotal role in anterior-posterior body axis patterning and are misexpressed in tumors such as lung carcinoma, neuroblastoma, and glioma. HOX genes are also known to be associated with long noncoding RNAs (lncRNAs) such as HOTAIR, which induces transcriptional silencing of the HOXD locus by recruiting polycomb repressive complex 2 to the HOXD locus. In this study, transcriptome analysis using the nanoString platform was performed, and expression of the HOX and HOTAIR genes was studied in pediatric tumors: 20 ATRTs, 10 ependymomas, 10 medulloblastomas, six glioblastoma multiforme, and nine juvenile pilocytic astrocytomas (JPAs). Results indicate that in ATRTs, medulloblastomas, and JPAs, the HOTAIR and HOXC genes are highly expressed; however, HOXD8-10 genes are not silenced. In ependymomas, there is low expression of the HOXC, HOTAIR, and HOXD8-10 genes. These interesting results need to be elucidated further so that the functions of these genes in pediatric tumors is understood.

Detection of an atypical teratoid rhabdoid brain tumor gene deletion in circulating blood using next-generation sequencing.

Circulating biomarkers such as somatic chromosome mutations are novel diagnostic tools to detect cancer noninvasively. We describe focal deletions found in a patient with atypical teratoid rhabdoid tumor, a highly aggressive early childhood pediatric tumor. First, we used magnetic resonance imaging (MRI) and histopathology to study the tumor anatomy. Next, we used whole genome sequencing (Next Gen Sequencing) and Bioinformatics interrogation to discover the presence of 3 focal deletions in tumor tissue and 2 of these 3 focal deletions in patient's blood also. About 20% of the blood DNA sequencing reads matched the tumor DNA reads at the SMARCB1 gene locus. Circulating, tumor-specific DNA aberrations are a promising biomarker for atypical teratoid rhabdoid tumor patients. The high percentage of tumor DNA detected in blood indicates that either circulating brain tumor cells lyse in the blood or that contents of brain tumor cells traverse a possibly compromised blood-brain barrier in this patient.

Clinical trials in cellular immunotherapy for brain/CNS tumors.

High-grade gliomas are the most common type of primary malignant brain/CNS tumor. There have been only modest advances in surgical techniques, radiotherapy and chemotherapy for high-grade gliomas over the past several decades. None of these have provided a major improvement in survival for patients. Recently, immunotherapy has been explored for the treatment of high-grade gliomas. Immunotherapy capitalizes on the specificity of the host immune system to selectively target tumor cells for destruction, while sparing normal brain parenchyma, thus making it a particularly attractive option. This article provides a comprehensive review of published clinical trials evaluating cellular immunotherapy in primary brain/CNS tumors.

Diffusion tensor tractography detection of functional pathway for the spread of epileptiform activity between temporal lobe and Rolandic region.

PURPOSE: The aim of the study was to assess the connectivity between magnetoencephalographic (MEG) dipoles in the temporal lobe and Rolandic region in children with temporal lobe epilepsy using diffusion tensor imaging (DTI) tractography. METHODS: Six pediatric patients with intractable focal epilepsy had MEG performed, which showed MEG dipoles over both temporal and Rolandic regions in a unilateral hemisphere. DTI tractography was performed on each patient. Six control subjects were studied for comparison. Two volumes of interest (VOIs) that encompassed the MEG dipoles were drawn, one placed in temporal lobe and the other in Rolandic region. Similar VOIs were placed in the contralateral side in the patients and on both sides in controls. Fractional anisotropy (FA) and trace of the external capsules were compared between patients and controls. RESULTS: In all patients, a tractography pathway traversing through the external capsule, connecting the temporal and Rolandic MEG dipoles, was visualized. However, on the contralateral hemisphere in each patient, there was no evidence of a similar fiber tract. There was no corresponding tractography pathway identified in either hemisphere within the controls. There were no significant differences in FA and trace between the seizure focus side and contralateral side in the patients. There was no significant difference in FA, but a difference in trace between patients and controls. CONCLUSION: We have found aberrant tractography pathway traversing through the external capsule, connecting two distant foci of epileptiform activity. Chronic interictal epileptogenic discharge could play a causal role in the de novo organization of these tracts.

Management of pediatric brainstem cavernous malformations: experience over 20 years at the hospital for sick children.

OBJECT: Because of their location and biological behavior, brainstem cavernous malformations (CMs) pose a formidable clinical challenge to the neurosurgeon. The optimal management of these lesions requires considerable neurosurgical judgment. Accordingly, the authors reviewed their experience with the management of pediatric brainstem CMs at the Hospital for Sick Children. METHODS: The authors performed a retrospective chart review of pediatric patients who had received diagnoses of a brainstem CM at the Hospital for Sick Children over the past 20 years. RESULTS: Twenty patients were diagnosed with brainstem CMs. The mean age at diagnosis was 10.1 +/- 5.4 years, and the patients included 13 boys and 7 girls. The mean maximal diameter of the CM was 14.3 +/- 11.2 mm. The lesions were evenly distributed on the right and left sides of the brainstem with 4 midbrain, 13 pontine, and 3 medullary lesions. Seven patients underwent surgery for the management of their CMs, with a mean age at presentation of 5.2 years, and a mean CM size of 21.0 mm. Of note from the surgical group, 2 patients had a family history of CMs, 2 lesions were medullary, the CM reached a pial surface in 6 of 7 patients, and 6 of 7 lesions were located on the right side. The mean age at presentation among the 13 patients in the nonsurgical group was 12.7 years, and the mean CM size was 10.6 mm. Seven of these patients had a prior history of radiation for tumor, and only 3 had lesions that reached a pial surface. CONCLUSIONS: The management of brainstem CMs in children is influenced by multiple factors. The majority of patients received conservative management and tended to be asymptomatic with smaller lesions. Patients with larger lesions and direct pial contact, in whom symptoms arose at a younger age were more likely to undergo surgical management. A history of familial CM was also a predictor for receiving surgical treatment. No patients with a prior history of radiation therapy underwent surgery for CMs. The presence of multiple lesions seemed to have no impact on the type of management chosen. Patients who underwent surgery did suffer morbidity related to the procedure, and tended to improve clinically over time. Conservative management was associated with new deficits arising in children, some of which improved with time. Consideration of many clinical and radiological parameters is thus prudent when managing the care of children with brainstem CMs.

Evidence for cardiomyocyte renewal in humans.

It has been difficult to establish whether we are limited to the heart muscle cells we are born with or if cardiomyocytes are generated also later in life. We have taken advantage of the integration of carbon-14, generated by nuclear bomb tests during the Cold War, into DNA to establish the age of cardiomyocytes in humans. We report that cardiomyocytes renew, with a gradual decrease from 1% turning over annually at the age of 25 to 0.45% at the age of 75. Fewer than 50% of cardiomyocytes are exchanged during a normal life span. The capacity to generate cardiomyocytes in the adult human heart suggests that it may be rational to work toward the development of therapeutic strategies aimed at stimulating this process in cardiac pathologies.

Neocortical neurogenesis in humans is restricted to development.

Stem cells generate neurons in discrete regions in the postnatal mammalian brain. However, the extent of neurogenesis in the adult human brain has been difficult to establish. We have taken advantage of the integration of (14)C, generated by nuclear bomb tests during the Cold War, in DNA to establish the age of neurons in the major areas of the human cerebral neocortex. Together with the analysis of the neocortex from patients who received BrdU, which integrates in the DNA of dividing cells, our results demonstrate that, whereas nonneuronal cells turn over, neurons in the human cerebral neocortex are not generated in adulthood at detectable levels but are generated perinatally.

Retrospective birth dating of cells in humans.

The generation of cells in the human body has been difficult to study, and our understanding of cell turnover is limited. Testing of nuclear weapons resulted in a dramatic global increase in the levels of the isotope 14C in the atmosphere, followed by an exponential decrease after 1963. We show that the level of 14C in genomic DNA closely parallels atmospheric levels and can be used to establish the time point when the DNA was synthesized and cells were born. We use this strategy to determine the age of cells in the cortex of the adult human brain and show that whereas nonneuronal cells are exchanged, occipital neurons are as old as the individual, supporting the view that postnatal neurogenesis does not take place in this region. Retrospective birth dating is a generally applicable strategy that can be used to measure cell turnover in man under physiological and pathological conditions.

Prospective feasibility study of outpatient stereotactic brain lesion biopsy.

OBJECTIVE: To assess the safety and feasibility of performing computed tomography-guided stereotactic brain lesion biopsy as an outpatient day-surgery procedure. METHODS: In late 1996, a prospective trial of outpatient stereotactic biopsies was initiated. The protocol consists of preadmission education of the patient, computed tomography-guided biopsy with local anesthesia (using a Brown-Roberts-Wells or Cosman-Roberts-Wells frame), postoperative observation in the postanesthetic care unit for 2 hours and in the day surgery unit for 2 hours, and then discharge home 4 hours after the procedure. RESULTS: Seventy-six patients constituted the intent-to-treat group, of whom two were not discharged on the same day (97.4% success rate). The two patients underwent inpatient admission because one required intravenous antibiotic treatment of a brain abscess and the other had a hard lesion in the brainstem that precluded biopsy needle penetration; admission for further investigation of the lesion was elected. Two patients experienced complications (2.6%), i.e., one small area of intraventricular hemorrhage that produced only a mild headache and one case of mild worsening of preexisting leg weakness, with negative computed tomographic results. CONCLUSION: Discharging patients home after 4 hours of observation after stereotactic biopsies seems to be a safe, well-tolerated practice. In this series, there was no major morbidity and no patient was disadvantaged by participating in this protocol. This approach would be expected to result in health care resource and cost savings, with a potential increase in patient satisfaction because of shorter hospital stays.