CD147-dependent heterogeneity in malignant and chemoresistant properties of cancer cells.

CD147 (alias emmprin or basigin), an integral plasma membrane glycoprotein and a member of the Ig superfamily, is widespread in normal tissues, but highly up-regulated in many types of malignant cancer cells. CD147 is multifunctional, with numerous binding partners. Recent studies suggest that complexes of CD147 with the hyaluronan receptor CD44 and associated transporters and receptor tyrosine kinases are enriched in the plasma membrane of cancer stem-like cells. Here, we show that subpopulations of tumor cell lines constitutively expressing high levels of cell-surface CD147 exhibit cancer stem-like cell properties; that is, they exhibit much greater invasiveness, anchorage-independent growth, spheroid formation, and drug resistance in vitro and higher tumorigenicity in vivo than those constitutively expressing low levels of cell-surface CD147. Primary CD147-rich cell subpopulations derived from mouse mammary adenocarcinomas also exhibit high levels of invasiveness and spheroid-forming capacity, whereas CD147-low cells do not. Moreover, localization at the plasma membrane of CD44, the EGF receptor, the ABCB1 and ABCG2 drug transporters, and the MCT4 monocarboxylate transporter is elevated in cells constitutively expressing high levels of cell-surface CD147. These results show that CD147 is associated with assembly of numerous pro-oncogenic proteins in the plasma membrane and may play a fundamental role in properties characteristic of cancer stem-like cells.

Modulation of tumor tolerance in primary central nervous system malignancies.

Central nervous system tumors take advantage of the unique immunology of the CNS and develop exquisitely complex stromal networks that promote growth despite the presence of antigen-presenting cells and tumor-infiltrating lymphocytes. It is precisely this immunological paradox that is essential to the survival of the tumor. We review the evidence for functional CNS immune privilege and the impact it has on tumor tolerance. In this paper, we place an emphasis on the role of tumor-infiltrating myeloid cells in maintaining stromal and vascular quiescence, and we underscore the importance of indoleamine 2,3-dioxygenase activity as a myeloid-driven tumor tolerance mechanism. Much remains to be discovered regarding the tolerogenic mechanisms by which CNS tumors avoid immune clearance. Thus, it is an open question whether tumor tolerance in the brain is fundamentally different from that of peripheral sites of tumorigenesis or whether it simply stands as a particularly strong example of such tolerance.

Molecular Advances and Targeted Therapies for Pediatric Central Nervous System Tumors.

Central nervous system tumors are extremely rare in the pediatric population and molecularly heterogeneous. Growing scientific research and clinical practice experience are improving medical therapies to increase survival outcomes and quality of life and reduce side effects. The 2019 Neurobiology of Disease in Children Symposium, held in conjunction with the 48th annual meeting of the Child Neurology Society, aimed to (1) describe molecular advances in tumor classification, (2) better understand the evolution of targeted therapies, and (3) more clearly formulate a treatment plan for patients. The article summarizes the presentations and includes an edited transcript of a panel discussion.

Obesity related methylation changes in DNA of peripheral blood leukocytes.

BACKGROUND: Despite evidence linking obesity to impaired immune function, little is known about the specific mechanisms. Because of emerging evidence that immune responses are epigenetically regulated, we hypothesized that DNA methylation changes are involved in obesity induced immune dysfunction and aimed to identify these changes. METHOD: We conducted a genome wide methylation analysis on seven obese cases and seven lean controls aged 14 to 18 years from extreme ends of the obesity distribution and performed further validation of six CpG sites from six genes in 46 obese cases and 46 lean controls aged 14 to 30 years. RESULTS: In comparison with the lean controls, we observed one CpG site in the UBASH3A gene showing higher methylation levels and one CpG site in the TRIM3 gene showing lower methylation levels in the obese cases in both the genome wide step (P = 5 × 10(-6) and P = 2 × 10(-5) for the UBASH3A and the TRIM3 gene respectively) and the validation step (P = 0.008 and P = 0.001 for the UBASH3A and the TRIM3 gene respectively). CONCLUSIONS: Our results provide evidence that obesity is associated with methylation changes in blood leukocyte DNA. Further studies are warranted to determine the causal direction of this relationship as well as whether such methylation changes can lead to immune dysfunction.

Bone loss in survival motor neuron (Smn(-/-) SMN2) genetic mouse model of spinal muscular atrophy.

Spinal muscular atrophy (SMA) is characterized by degenerating lower motor neurons and an increased incidence of congenital bone fractures. Survival motor neuron (SMN) levels are significantly reduced due to deletions/mutations in the telomeric SMN1 gene in these patients. We utilized the Smn(-/-) SMN2 mouse model of SMA to determine the functional role for SMN in bone remodelling. microCT analysis of lumber vertebrae, tibia and femur bones from SMA mice revealed an osteoporotic bone phenotype. Histological analysis demonstrated a thin porous cortex of cortical bone and thin trabeculae at the proximal end of the growth plate in the vertebrae of SMA mice compared to wild-type mice. Histochemical staining of the vertebrae showed the presence of abundant activated osteoclasts on the sparse trabeculae and on the endosteal surface of the thin cortex in SMA mice. Histomorphometric analysis of vertebrae from SMA mice showed an increased number of osteoclasts. Serum TRAcP5b and urinary NTx levels were elevated, consistent with increased bone resorption in these mice. SMA mice showed a significant decrease in the levels of osteoblast differentiation markers, osteocalcin, osteopontin and osterix mRNA expression; however, there were no change in the levels of alkaline phosphatase expression compared to WT mice. SMA mouse bone marrow cultures revealed an increased rate of osteoclast formation (54%) and bone resorption capacity (46%) compared to WT mice. Pre-osteoclast cells from SMA mice showed constitutive up-regulation of RANK receptor signalling molecules critical for osteoclast differentiation. Our results implicate SMN function in bone remodelling and skeletal pathogenesis in SMA. Understanding basic mechanisms of SMN action in bone remodelling may uncover new therapeutic targets for preventing bone loss/fracture risk in SMA.

Targeting hyaluronan interactions in malignant gliomas and their drug-resistant multipotent progenitors.

PURPOSE: To determine if hyaluronan oligomers (o-HA) antagonize the malignant properties of glioma cells and treatment-resistant glioma side population (SP) cells in vitro and in vivo. EXPERIMENTAL DESIGN: A single intratumoral injection of o-HA was given to rats bearing spinal cord gliomas 7 days after engraftment of C6 glioma cells. At 14 days, spinal cords were evaluated for tumor size, invasive patterns, proliferation, apoptosis, activation of Akt, and BCRP expression. C6SP were isolated by fluorescence-activated cell sorting and tested for the effects of o-HA on BCRP expression, activation of Akt and epidermal growth factor receptor, drug resistance, and glioma growth in vivo. RESULTS: o-HA treatment decreased tumor cell proliferation, increased apoptosis, and down-regulated activation of Akt and the expression of BCRP. o-HA treatment of C6SP inhibited activation of epidermal growth factor receptor and Akt, decreased BCRP expression, and increased methotrexate cytotoxicity. In vivo, o-HA also suppressed the growth of gliomas that formed after engraftment of C6 or BCRP+ C6SP cells, although most C6SP cells lost their expression of BCRP when grown in vivo. Interestingly, the spinal cord gliomas contained many BCRP+ cells that were not C6 or C6SP cells but that expressed nestin and/or CD45; o-HA treatment significantly decreased the recruitment of these BCRP+ progenitor cells into the engrafted gliomas. CONCLUSIONS: o-HA suppress glioma growth in vivo by enhancing apoptosis, down-regulating key cell survival mechanisms, and possibly by decreasing recruitment of host-derived BCRP+ progenitor cells. Thus, o-HA hold promise as a new biological therapy to inhibit HA-mediated malignant mechanisms in glioma cells and treatment-resistant glioma stem cells.

Absence of decussation of the superior cerebellar peduncles in patients with Joubert syndrome.

Joubert syndrome (JS) is characterized by absence of decussation of both corticospinal tracts and superior cerebellar peduncles (SCP). Our hypothesis was that evidence for absence of SCP decussation may be found on routine brain MRI studies. Midsagittal T1-weighted images from 20 JS patients and 30 age-matched controls were retrospectively reviewed. An ill-defined area of lower T1 signal in the inferior midbrain was considered the sign of SCP decussation, and its presence or absence was noted. Fractional anisotropy (FA) maps were obtained in three JS patients and four controls. The SCP decussation was not visualized in any subject under 30 months of age. In subjects above 30 months of age the sign of the SCP decussation was absent in all 6 JS patients and present in all 16 controls. FA maps confirmed the absence of the SCP decussation in the JS patients. The SCP decussation is well seen on routine brain MRI studies in controls older than 30 months of age and absent in all JS patients, confirming the proposed lack of commissural fibers in JS, and accounting in part for the molar tooth sign.

Increased intracranial pressure in a case of pediatric multiple sclerosis.

A 15-year-old girl presented to our emergency department with dizziness, anorexia, nausea, and malaise. Clinical examination and magnetic resonance imaging studies showed characteristic features of multiple sclerosis. Surprisingly, a diagnostic lumbar puncture showed significant intracranial hypertension in addition to numerous oligoclonal bands, elevated immunoglobulin G index and immunoglobulin G/albumin ratio in the cerebrospinal fluid. It is proposed that a large burden of active demyelinating disease may cause increased intracranial pressure, thus providing an additional sound rationale for prompt therapeutic administration of intravenous high-dose steroids.

Evidence-based versus reported epilepsy management practices.

Evidence-based medicine practices are widely touted in medicine, although their adoption by busy practitioners is problematic and cumbersome. In this study, we examined published evidence underpinning 2 relevant clinical management questions in pediatric epilepsy: when to initiate an antiepileptic drug and when to prescribe the ketogenic diet. We surveyed practicing child neurologists who were attending their national meeting to determine whether their current practices aligned with the evidence. Clinical studies were evaluated using the Oxford Scale, which was adopted by the American Academy of Neurology. In addition, using a novel rating approach, we examined the impact on overall recommendations by scoring results from studies refuting a given practice. The data show that child neurologists' attitudes firmly adhere to evidence-based practice on when to initiate treatment with an antiepileptic drug, but not on when to prescribe the ketogenic diet. It seems clear that important differences in attitudes of practitioners toward different management strategies for epilepsy cannot be explained only by differences in the evidence. Safety and efficacy data suggest that the ketogenic diet should be more widely adopted as a management strategy in pediatric epilepsy.

Epileptic Encephalopathies: Clinical Aspects, Molecular Features and Pathogenesis, Therapeutic Targets and Translational Opportunities, and Future Research Directions.

Epileptic encephalopathies encompass a heterogeneous group of epilepsy syndromes that manifest with cognitive, behavioral, and neurologic deficits, seizures that are often intractable and multiform, aggressive electroencephalographic paroxysmal activity, and sometimes early death. As more is learned about the etiologies and manifestations of epileptic encephalopathies, progress has been made toward better treatment options. However, there is still a great need for further randomized controlled trials and research to help create clinically effective therapies. The 2015 Neurobiology of Disease in Children symposium, held in conjunction with the 44th annual meeting of the Child Neurology Society, aimed to (1) describe the clinical concerns involving diagnosis and treatment, (2) review the current status of understanding in the pathogenesis of epileptic encephalopathy, (3) discuss clinical management and therapies for epileptic encephalopathy, and (4) define future directions of research. This article summarizes the presentations and includes an edited transcript of question-and-answer sessions.

The face of Joubert syndrome: a study of dysmorphology and anthropometry.

Joubert syndrome (JS) is an autosomal recessive disorder characterized by cerebellar vermis hypoplasia, hypotonia, developmental delay, apnea/hypernea and ophthalmologic abnormalities. Since its description, most attention has focused on hindbrain malformations and the hallmark molar tooth sign (MTS) when visualized on axial magnetic resonance imaging (MRI). Few reports have described a characteristic clinical phenotype of JS and a large cohort of patients has not undergone dysmorphology examinations. In addition, very little is known about other conditions which share some of the clinical and radiological features of JS, including, Arima, Senior-Löken, Dekaban, COACH, and Varadi (OFD VI) syndromes. The purpose of this study was to document the morphologic characteristics of Joubert syndrome based upon detailed dysmorphology and anthropometric examinations in a large cohort of JS individuals to determine whether JS is associated with a specific pattern of malformation. Dysmorphology findings included long face, frontal prominence, bitemporal narrowing, ptosis, prominent nasal bridge and tip, prognathism, eyebrow abnormalities, trapezoid shaped mouth, lower lip eversion, and thick ear lobes. Anthropometric analyses showed several significant differences in measurements including bizygomatic, frontal, nasal, and mandibular dimensions. When compared to controls, younger JS patients had significantly increased facial widths whereas older patients had longer mandibular arc lengths. These data indicate that JS lacks a clear, specific recognizable pattern of malformation, despite being associated with several dysmorphic facial characteristics and distinct anthropometric facial patterns, which change with age. Variability and overlap of features in JS and other hindbrain syndromes makes clinical diagnosis difficult and probably reflects genetic heterogeneity within the cohort of patients with the MTS.

Spinal muscular atrophy: classification, diagnosis, management, pathogenesis, and future research directions.

Spinal muscular atrophy is an autosomal recessive neurodegenerative disorder that affects the motor neurons responsible for movement of the proximal muscles of the trunk and body. To date, the disease can be classified into 3 main categories based on severity and age of onset. During the October 18th symposium held in Pittsburgh, Pennsylvania, researchers met to (1) describe current diagnostic strategies, (2) discuss recent thoughts on pathogenesis, (3) review current therapies and clinical trials, and (4) define future research directions. In her opening remarks, Dr Story Landis, director of the National Institute of Neurological Disorders and Stroke, emphasized the degree to which the Neurobiology of Disease in Children conference series has broadened awareness of the many rare diseases affecting children, not only through the advancement of research but also by educating practitioners about diagnostic strategies. Dr Landis also discussed the role this conference may play in fostering research that seeks to develop a single mechanism of therapy for spinal muscular atrophy. She also discussed the current funding situation at the National Institutes of Health and addressed the crucial function of volunteer research organizations that sponsor research in further improving management of this condition. This article summarizes the presentations and includes the verbatim edited transcript of question-and-answer sessions.

Congenital bone fractures in spinal muscular atrophy: functional role for SMN protein in bone remodeling.

Spinal muscular atrophy is the second most common fatal childhood disorder. Core clinical features include muscle weakness caused by degenerating lower motor neurons and a high incidence of bone fractures and hypercalcemia. Fractures further compromise quality of life by progression of joint contractures or additional loss of motor function. Recent observations suggest that bone disease in spinal muscular atrophy may not be attributed entirely to lower motor neuron degeneration. The presence of the spinal muscular atrophy disease-determining survival motor neuron gene (SMN), SMN expression, and differential splicing in bone-resorbing osteoclasts was recently discovered. Its ubiquitous expression and the differential expression of splice variants suggest that SMN has specific roles in bone cell function. SMN protein also interacts with osteoclast stimulatory factor. Mouse models of human spinal muscular atrophy disease suggest a potential role of SMN protein in skeletal development. Dual energy x-ray absorptiometry analysis demonstrated a substantial decrease in total bone area and poorly developed caudal vertebra in the mouse model. These mice also had pelvic bone fractures. Studies delineating SMN signaling mechanisms and gene transcription in a cell-specific manner will provide important molecular insights into the pathogenesis of bone disease in children with spinal muscular atrophy. Moreover, understanding bone remodeling in spinal muscular atrophy may lead to novel therapeutic approaches to enhance skeletal health and quality of life. This article reviews the skeletal complications associated with spinal muscular atrophy and describes a functional role for SMN protein in osteoclast development and bone resorption activity.

Acute disseminated encephalomyelitis following infectious mononucleosis.

Two months following an Epstein-Barr virus infection, a 17-year-old white female presented with seizures, intermittent visual changes, and altered mental status. Magnetic resonance imaging showed white matter changes of acute disseminated encephalomyelitis with a predilection for posterior cerebral artery distributions but without radiological evidence of arteritis. Epstein-Barr virus titers and polymerase chain reaction analysis results for the virus were consistent with postinfectious acute disseminated encephalomyelitis. The symptoms and signs improved following treatment with high-dose corticosteroids and intravenous immunoglobulin. Although Epstein-Barr virus can cause acute viral encephalomyelitis, the authors report a case of acute disseminated encephalomyelitis months after acute Epstein-Barr virus infection.

Selective migration of neuralized embryonic stem cells to stem cell factor and media conditioned by glioma cell lines.

BACKGROUND: Pluripotent mouse embryonic stem (ES) cells can be induced in vitro to become neural progenitors. Upon transplantation, neural progenitors migrate toward areas of damage and inflammation in the CNS. We tested whether undifferentiated and neuralized mouse ES cells migrate toward media conditioned by glioma cell lines (C6, U87 & N1321) or Stem Cell Factor (SCF). RESULTS: Cell migration assays revealed selective migration by neuralized ES cells to conditioned media as well as to synthetic SCF. Migration of undifferentiated ES cells was extensive, but not significantly different from that of controls (Unconditioned Medium). RT-PCR analysis revealed that all the three tumor cell lines tested synthesized SCF and that both undifferentiated and neuralized ES cells expressed c-kit, the receptor for SCF. CONCLUSION: Our results demonstrate that undifferentiated ES cells are highly mobile and that neural progenitors derived from ES cells are selectively attracted toward factors produced by gliomas. Given that the glioma cell lines synthesize SCF, SCF may be one of several factors that contribute to the selective migration observed.

Oromotor and communication findings in joubert syndrome: further evidence of multisystem apraxia.

This study provides descriptive information in the areas of oromotor abilities and communication to better understand the spectrum of disability in individuals with Joubert syndrome. Participants included 21 individuals with the diagnosis of Joubert syndrome (mean age 10.45 years). Participants completed oromotor and receptive language measures. In addition, all of the participants' speech and gesture communication from a narrative task was coded and analyzed from videotape. Caregivers reported the participants' level of fine and gross motor function. The results show that individuals with Joubert syndrome exhibit a distinct oromotor pattern consistent with verbal and lingual apraxias. Despite significant motor skills deficits and oculomotor apraxia, persons with Joubert syndrome produced gestures when communicating, and those whose speech was less intelligible used a higher rate of gesture compared with those with greater verbal output. These findings suggest a new form of apraxia not previously described in the condition and are consistent with previous research that suggests that persons with Joubert syndrome typically do not exhibit classic symptoms of autism spectrum disorder.

Parenting stress and its relationship to the behavior of children with Joubert syndrome.

This study describes the relationship between parenting stress and behavior in children with Joubert syndrome, a rare genetic neurodevelopmental disorder. Parents (N = 43) reported severely impaired child adaptive behaviors. Most children did not show maladaptive behaviors, but a subset of approximately 20% displayed significant problems in areas such as inattention, overactivity, social withdrawal, and atypical behaviors. Mothers (59%) and fathers (40%) reported elevated levels of parenting stress. A hierarchical regression, including demographics, adaptive behavior, and maladaptive behavior, predicted 67% of the variance in mothers' stress and 40% of the variance in fathers' stress. Maladaptive behaviors uniquely contributed to maternal and paternal stress. The child's adaptive behavior level contributed significantly to parenting stress for mothers but not for fathers. Findings provide a better understanding of the impact of child behavior on parents caring for a child with Joubert syndrome.

Case of desmoplastic infantile ganglioglioma secreting ceruloplasmin.

Desmoplastic infantile ganglioglioma is a rare World Health Organization (WHO) grade I tumor commonly arising in early infancy and usually presenting with both solid and cystic components. We report a case of a large midline-enhancing desmoplastic infantile ganglioglioma in which newly formed cysts in communication with lateral ventricles contained highly proteinaceous fluid. Proteomic analysis of the fluid showed three proteins not normally found in cerebrospinal fluid. Immunohistochemical analysis of the tumor sample showed that the desmoplastic infantile ganglioglioma produced a high concentration of ceruloplasmin, which probably accounts for most of the 30- to 40-fold increase in protein compared with normal cerebrospinal fluid. To our knowledge, this is the first report of ceruloplasmin secretion by a brain tumor, and ongoing studies on the mechanism might yield novel approaches to reducing cyst production and protein content in an otherwise stable solid tumor.

Recent Advances in Understanding and Managing Autism Spectrum Disorders.

Autism spectrum disorder in children is a group of neurodevelopmental disorders characterized by difficulties with social communication and behavior. Growing scientific evidence in addition to clinical practice has led the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to categorize several disorders into the broader category of autism spectrum disorder. As more is learned about how autism spectrum disorder manifests, progress has been made toward better clinical management including earlier diagnosis, care, and when specific interventions are required. The 2014 Neurobiology of Disease in Children symposium, held in conjunction with the 43rd annual meeting of the Child Neurology Society, aimed to (1) describe the clinical concerns involving diagnosis and treatment, (2) review the current status of understanding in the pathogenesis of autism spectrum disorder, (3) discuss clinical management and therapies for autism spectrum disorder, and (4) define future directions of research. The article summarizes the presentations and includes an edited transcript of question-and-answer sessions.

Antisaccade-related brain activation in children with attention-deficit/hyperactivity disorder--A pilot study.

While antisaccade paradigms invoke circuitry associated with cognitive control and attention-deficit/hyperactivity disorder (ADHD), there is a dearth of functional magnetic resonance imaging (fMRI) investigations using antisaccade tasks among children with ADHD. Neural correlates associated with antisaccade performance were examined with fMRI in 11 children with ADHD (10 medicated) matched to 11 typically developing children. Significantly greater brain activation in regions in right dorsolateral prefrontal cortex and caudate nucleus was observed in children with ADHD relative to the control group. This pattern separated the children into their respective groups in a taxonomic manner. Sensitivity analyses probing comorbidity and medication-specific effects showed that results were consistent; however, the caudate nucleus difference was only detectable in the full sample, or in subsets with a more relaxed cluster threshold. Antisaccade performance did not significantly differ between the groups, perhaps as a result of greater brain activation or medication effects in the ADHD group. Thus, antisaccade paradigms may have sensitivity and specificity for the investigation of cognitive control deficits and associated neural correlates in ADHD, and may contribute towards the development of new treatment approaches for children with the disorder.