Brain tumors are the most common solid tumors in childhood. There is the need for biomarkers of residual disease, therapy response and recurrence. Cerebrospinal fluid (CSF) is a source of brain tumor ...biomarkers. We analyzed the proteome of waste CSF from extraventricular drainage (EVD) from 29 children bearing different brain tumors and 17 controls needing EVD insertion for unrelated causes. 1598 and 1526 proteins were identified by liquid chromatography-coupled tandem mass spectrometry proteomics in CSF control and brain tumor patients, respectively, 263 and 191 proteins being exclusive of either condition. Bioinformatic analysis revealed promising protein biomarkers for the discrimination between control and tumor (TATA-binding protein-associated factor 15 and S100 protein B). Moreover, Thymosin beta-4 (TMSB4X) and CD109, and 14.3.3 and HSP90 alpha could discriminate among other brain tumors and low-grade gliomas plus glyoneuronal tumors/pilocytic astrocytoma, or embryonal tumors/medulloblastoma. Biomarkers were validated by ELISA assay. Our method was able to distinguish among brain tumor vs non-tumor/hemorrhagic conditions (controls) and to differentiate two large classes of brain tumors. Further prospective studies may assess whether the biomarkers proposed by our discovery approach can be identified in other bodily fluids, therefore less invasively, and are useful to guide therapy and predict recurrences.
Neural tube defects are severe malformations affecting 1/1,000 live births. The planar cell polarity pathway controls the neural tube closure and has been implicated in the pathogenesis of neural ...tube defects both in animal models and human cohorts. In mouse disruption of
Dvl2
alone (
Dvl2
−/−
) or
Dvl2
and
Dvl3
(
Dvl2
−/−
;
Dvl3
+/−
,
Dvl2
+/−
;
Dvl3
−/−
) results in incomplete neurulation, suggesting a role for Disheveled in neural tube closure. Disheveled is a multifunctional protein that is involved in both the canonical Wnt signaling and the noncanonical planar cell polarity pathway. In this study, we analyzed the role of the human orthologs
DVL2
and
DVL3
in a cohort of 473 patients with neural tube defects. Rare variants were genotyped in 639 ethnically matched controls. We identified seven rare missense mutations that were absent in all controls analyzed. Two of these mutations, p.Tyr667Cys and p.Ala53Val, identified in
DVL2
were predicted to be detrimental in silico. Significantly, a 1-bp insertion (c.1801_1802insG) in exon 15 of
DVL2
predicted to lead to the truncation of the protein was identified in a patient with a complex form of caudal agenesis. In summary, we demonstrate a possible role for rare variants in
DVL2
gene as risk factors for neural tube defects.
Neural tube defects (NTDs) are severe congenital malformations affecting 1–2 in 1,000 live births, whose etiology is multifactorial, involving environmental and genetic factors. NTDs arise as ...consequence of the failure of fusion of the neural tube early during embryogenesis. NTDs' pathogenesis has been linked to genes involved in folate metabolism, consistent with an epidemiologic evidence that 70% of NTDs can be prevented by maternal periconceptional supplementation. However, polymorphisms in such genes are not linked in all populations, suggesting that other genetic factors and environmental factors could be involved. Animal models have provided crucial mechanistic information and possible candidate genes to explain susceptibility to NTDs. A crucial role has been assigned to the planar cell polarity (PCP) pathway, a highly conserved, non‐canonical Wnt‐frizzled‐dishevelled signaling cascade that plays a key role in establishing and maintaining polarity in the plane of the epithelium and in the process of convergent extension during gastrulation and neurulation in vertebrates. The Loop‐tail (Lp) mouse that develops craniorachischisis carry missense mutations in the PCP core gene Vangl2, that is the mammalian homolog of the Drosophila Strabismus/Van gogh (Stbm/Vang). The presence of mutations in human VANGL1 and VANGL2 genes encourages us to extend the investigation to other PCP genes that, with VANGL, play an essential role in neurulation during development.
Background
Neural tube defects (NTD) are among the most common defects affecting 1:1000 births. They are caused by a failure of neural tube closure during development. Their clinical presentation is ...diverse and dependent on the site and severity of the original defect on the embryonic axis. The etiology of NTD is multifactorial involving environmental factors and genetic variants that remain largely unknown.
Methods
We have conducted a whole exome sequencing (WES) study in five new NTD families and pooled the results with WES data from three NTD families and 43 trios that were previously investigated by our group. We analyzed the data using biased candidate gene and unbiased gene burden approaches.
Results
We identified four novel loss‐of‐function variants in three genes, MTHFR, DLC1, and ITGB1, previously associated with NTD. Notably, DLC1 carried two protein truncating variants in two independent cases. We also demonstrated an enrichment of variants in MYO1E involved in cytoskeletal remodeling. This enrichment reached borderline significance in a replication cohort supporting the association of this new candidate gene to NTD.
Conclusion
These data provide some key insights into the pathogenic mechanisms of human NTD and demonstrate the power of next‐generation sequencing in deciphering the genetics of this complex trait.
We have conducted a whole exome sequencing study in five new NTD families and pooled the results with WES data from three NTD families and 43 trios that were previously investigated by our group. We identified four novel loss‐of‐function variants in three genes, MTHFR, DLC1, and ITGB1, previously associated with NTD. Notably, DLC1 carried two protein truncating variants in two independent cases. We also demonstrated an enrichment of variants in MYO1E.
Genetic variants of enzymes involved in the folate pathway might be expected to have an impact on neural tube defect (NTD) risk. Given its key role in folate metabolism, the methylenetetrahydrofolate ...dehydrogenase 1 (MTHFD1) gene could represent an attractive candidate in NTD aetiology. In this study, the impact of the MTHFD1 1958G > A polymorphism on NTD risk in the Italian population was examined both by hospital-based case-control and family-based studies. The MTHFD1 1958G > A polymorphism was genotyped in 142 NTD cases, 125 mothers, 108 fathers and 523 controls. An increased risk was found for the heterozygous 1958G/A (OR = 1.69; P = 0.04) and homozygous 1958A/A (OR = 1.91; P = 0.02) genotypes in the children. Significant association was also found when combined 1958G/A and 1958A/A genotypes of cases were compared with the 1958G/G genotype (OR = 1.76; P = 0.02). The risk of an NTD-affected pregnancy of the mothers was increased 1.67-fold (P = 0.04) only when a dominant effect (1958G/A or 1958A/A vs 1958G/G) of the 1958A allele was analysed. The combined TDT/1-TDT (Z = 2.11; P = 0.03) and FBAT (Z = 2.4; P = 0.01) demonstrated a significant excess of transmission of the 1958A allele to affected individuals. In summary, our results indicate that heterozygosity and homozygosity for the MTHFD1 1958G > A polymorphism are genetic determinants of NTD risk in the cases examined.
The protocols of the 1990s omitted or delayed irradiation, using upfront chemotherapy to spare the youngest children with ependymoma the sequelae of radiotherapy (RT). We treated 41 children under ...the age of 3 years with intracranial ependymoma between 1994 and 2003.
After surgery, chemotherapy was given as follows: regimen I with four blocks of vincristine, high-dose methotrexate 5 g/m(2), and cyclophosphamide 1.5 g/m(2) alternating with cisplatin 90 mg/m(2) plus VP16 450 mg/m(2) for 14 months; subsequently, regimen II was used: VEC (VCR, VP16 300 mg/m(2), and cyclophosphamide 3 g/m(2)) for 6 months. Radiotherapy was planned for residual tumor after the completion of chemotherapy or for progression.
We treated 23 boys and 18 girls who were a median 22 months old; 14 were given regimen I, 27 were given regimen II; 22 underwent complete resection, 19 had residual tumor. Ependymoma was Grade 2 in 25 patients and Grade 3 in 16; tumors were infratentorial in 37 patients and supratentorial in 4. One child had intracranial metastases; 29 had progressed locally after a median 9 months. Event-free survival was 26% at 3 and 5 years and 23% at 8 years. One child died of sepsis, and another developed a glioblastoma 72 months after RT. Progression-free survival was 27% at 3, 5, and 8 years, and overall survival was 48%, 37%, and 28% at 3, 5, and 8 years, respectively. Of the 13 survivors, 6 never received RT; their intellectual outcome did not differ significantly in those children than in those without RT.
Our results confirm poor rates of event-free survival and overall survival for up-front chemotherapy in infant ependymoma. No better neurocognitive outcome was demonstrated in the few survivors who never received RT.
OBJECTIVE:To present the magnetic resonance imaging features, clinical findings, and possible embryologic bases for nonterminal myelocystoceles, a distinct subset of closed spinal dysraphisms.
...METHODS:We retrospectively analyzed imaging series and clinical records from five newborns and one older child with skin-covered soft tissue masses along the posterior midline spine. Spinal (6 patients) and brain (5 patients) magnetic resonance imaging was performed before surgical repair and compared with clinical findings, observations at surgery, and final lesion histology.
RESULTS:The lesions affected the cervical (n = 3), thoracic (n = 2), and lumbar (n = 1) regions. In each case, the dome of the mass was covered by thickened, dystrophic epithelium with no subcutaneous fat, whereas the base and lateral walls of the mass were covered by normal skin. All patients were neurologically intact at presentation. In three cases, a stalk emanated from the dorsal normal spinal cord, crossed a narrow posterior bony spina bifida, and coursed through a posterior meningocele to attach to the inner aspect of its dome. The other three cases showed dissection of a hydromyelic cavity into the stalk, converting it into a second "cyst" within the meningocele. Concurrent anomalies included focal hydromyelia immediately cranial to the origin of the posterior stalk (n = 2), mild Chiari II malformation (n = 3), triventricular hydrocephalus from aqueductal stenosis (n = 1), filar lipoma (n = 1), and presumed neurenteric cyst (n = 1). At surgery, the sac was resected in all cases, but intradural exploration and untethering was performed in only three children. Embryologic considerations indicate that the spectrum of these lesions likely arises from partial limited closure of the neural tube, failed disjunction of the cutaneous ectoderm, and variable degrees of hydromyelia.
CONCLUSION:The nonterminal myelocystocele is a distinct form of closed spinal dysraphism characterized by a skin-covered meningocele, which is either crossed by a fibroneurovascular stalk that extends from the dorsal aspect of the spinal cord to attach to the dome of the meningocele (abortive form, or myelocystocele manqué) or contains a hydromyelic cavity that is continuous with the ependymal canal of the spinal cord (complete form).
Aicardi–Goutières syndrome (AGS) is a rare interferon (IFN)‐related encephalopathy with onset during the first year of life. AGS, is clinically characterized by progressive microcephaly, bilateral ...basal ganglia calcification, cerebral atrophy, cerebrospinal fluid (CSF), lymphocytosis, delayed development of psychomotor abilities with pyramidal–extrapyramidal syndrome and mimics congenital viral infections. Microarray analysis examining the expression of 18 880 human genes has been applied to the CSF lymphocytes of 20 AGS cases (age 4.5 ± 4.4 years, mean ± standard deviation) characterized by high IFN‐alpha levels in CSF and 20 matched controls (age 4.4 ± 4.3 years, mean ± standard deviation). Gene‐expression data reveal significant differences between AGS cases and controls for all controls and 18 AGS cases. The two AGS cases unclassified as compared with controls were both older than 7 years. AGS cases presented upregulation of genes involved in IFN‐dependent pathways and lymphocyte functions, paralleled by the downregulation of genes encoding for angiopoietic activities. The cystatin F and DNAJ genes, having a negative feedback on IFN pathways, underwent a progressive age‐related increase in their expression. These gene‐expression signature parallels a progressive attenuation of clinical symptoms with age. Obtained results provide evidence that exposure to IFN‐alpha is harmful for developing brain.
Defects in the expression and/or function of the human leukocyte antigen (HLA) class I antigen-processing machinery (APM) components are found in many tumor types. These abnormalities may have a ...negative impact on the interactions of tumor cells with host's immune system and on the outcome of T cell-based immunotherapy. To the best of our knowledge, no information is available about APM component expression and functional characteristics in human medulloblastoma cells (Mb). Therefore, in the present study, we have initially compared the expression of APM components in Mb, an embryonal pediatric brain tumor with a poor prognosis, with that in noninfiltrating astrocytic pediatric tumors, a group of differentiated brain malignancies with favorable prognosis. LMP2, LMP7, calnexin, beta2-microglobulin-free heavy chain (HC) and beta2-microglobulin were down-regulated or undetectable in Mb lesions, but not in astrocytic tumors or normal fetal cerebellum. Two Mb cell lines (DAOI and D283) displayed similar but not superimposable defects in APM component expression as compared with primary tumors. To assess the functional implications of HLA class I APM component down-regulation in Mb cell lines, we tested their recognition by HLA class I antigen-restricted, tumor antigen (TA)-specific CTL, generated by stimulations with dendritic cells that had been transfected with Mb mRNA. The Mb cell lines were lysed by TA-specific CTL in a HLA-restricted manner. Thus, defective expression of HLA class I-related APM components in Mb cells does not impair their ability to present TA to TA-specific CTL. In conclusion, these results can contribute to optimize T cell-based immunotherapeutic strategies for Mb treatment.
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