High-throughput microRNA profiling of pediatric high-grade gliomas

Background

High-grade gliomas (HGGs) account for 15% of all pediatric brain tumors and are a leading cause of cancer-related mortality and morbidity. Pediatric HGGs (pHGGs) are histologically indistinguishable from their counterpart in adulthood. However, recent investigations indicate that differences occur at the molecular level, thus suggesting that the molecular path to gliomagenesis in childhood is distinct from that of adults. MicroRNAs (miRNAs) have been identified as key molecules in gene expression regulation, both in development and in cancer. miRNAs have been investigated in adult high-grade gliomas (aHGGs), but scant information is available for pHGGs.

Methods

We explored the differences in microRNAs between pHGG and aHGG, in both fresh-frozen and paraffin-embedded tissue, by high-throughput miRNA profiling. We also evaluated the biological effects of miR-17-92 cluster silencing on a pHGG cell line.

Results

Comparison of miRNA expression patterns in formalin versus frozen specimens resulted in high correlation between both types of samples. The analysis of miRNA profiling revealed a specific microRNA pattern in pHGG with an overexpression and a proliferative role of the miR-17-92 cluster. Moreover, we highlighted a possible quenching function of miR-17-92 cluster on its target gene PTEN, together with an activation of tumorigenic signaling such as sonic hedgehog in pHGG.

Conclusions

Our results suggest that microRNA profiling represents a tool to distinguishing pediatric from adult HGG and that miR-17-92 cluster sustains pHGG.     

An histologically atypical NF-type 1 patient with a new pathogenic mutation

Here we describe a case of Neurofibromatosis type 1 (NF1) associated with an atypical histiocytic lesion and a new pathogenic mutation. The genetic analysis revealed an heterozygous mutation in the 5′ splice site of intron 32, 6,084?+?1G?→?T. Histopathological findings are compatible with juvenile xanthogranuloma. The new, not already described, splicing mutation, is possibly partly responsible of the association between NF1 and the histiocitic lesion.     

Meso‐Rex bypass as an alternative technique for portal vein reconstruction at or after liver transplantation in children: Review and perspectives

de Ville de Goyet J, Lo Zupone C, Grimaldi C, D’Ambrosio G, Candusso M, Torre G, Monti L. Meso‐Rex bypass as an alternative technique for portal vein reconstruction at or after liver transplantation in children: Review and perspectives. Abstract: Direct portal revascularization can be achieved by interposing a vascular graft between the SMV and the Rex recessus (left portal vein system): the MRB. To review indications and results of the procedure in the setting of pediatric liver transplantation, reports were selected from the English literature. Previously reported series were updated to analyze long‐term outcome. A new series was added and analyzed as a complementary set of cases. A total of 51 cases were analyzed. With a 96% overall patient survival rate and a 100% long‐term patency rate when the IJV is used for the bypass, MRB achieves a very successful physiologic cure of chronic portal hypertension and restores the portal flow into and through the liver graft. It also has been used successfully for primary revascularization of liver grafts, as well as for managing early acute portal vein thrombosis episodes. The use of this procedure in conjunction with other strategies and techniques might be of interest for transplant surgeons, particularly those caring for children.     

Evolving of therapeutic strategies for CNS‐PNET

Background

A protocol for the intensive treatment of non‐cerebellar PNET (CNS‐PNET) combining chemotherapy and radiotherapy was launched in 2000. Efforts were subsequently made to improve the prognosis and to de‐escalate the treatment for selected patient groups.

Procedure

Twenty‐eight consecutive patients were enrolled for a high‐dose drug schedule (methotrexate, etoposide, cyclophosphamide, and carboplatin ± vincristine), followed by hyperfractionated accelerated CSI (HART‐CSI) at total doses of 31–39 Gy, depending on the patient's age, with two high‐dose thiotepa courses following CSI. After the first 15 patients had been treated, craniospinal irradiation (CSI) was replaced with focal radiotherapy (RT) for selected cases (non‐metastatic and not progressing during induction chemotherapy). Eight of the 28 children received the same chemotherapy but conventionally fractionated focal RT at 54 Gy.

Results

The 5‐year progression‐free survival (PFS), event‐free survival (EFS), and overall survival (OS) rates were 62%, 53%, and 52%, respectively, for the whole series, and 70%, 70%, and 87% for the eight focally irradiated children. Residual disease and metastases were not prognostically significant. In children with residual disease, response to RT was significant (5‐year PFS 59% vs. 20%, P = 0.01), while the total dose of CSI was not. There were three treatment‐related toxic events. Relapses were local in seven cases (including two of the eight focally irradiated patients), and both local and disseminated in 2.

Conclusions

This intensive schedule enabled treatment stratification for the purposes of radiation, thereby sparing some children full‐dose CSI. Local control is the main goal of treatment for CNS‐PNET. Pediatr Blood Cancer 2013;60:2031–2035. © 2013 Wiley Periodicals, Inc.     

Intracranial neuromuscular choristoma: Report of a case with literature review

Neuromuscular choristoma (NMC), also called neuromuscular hamartoma or nerve rhabdomyoma, is a rare lesion of the spinal and cranial nerves composed of skeletal muscle intimately associated with nerve fibers. Its origin has not been precisely clarified and a malformative event, resulting from aberrant differentiation or a true neoplastic growth, have been proposed by authors. We hereby present a cerebellopontine angle NMC enlarging the eighth cranial nerve in a 3‐year‐old child, that histologically appeared composed of a large amount of striated muscle mixed with nerve fibers. We also provide a review of the intracranial NMC cases reported in the literature and an analysis of proposed hypotheses to explain the presence of muscle cells in nerve trunks.     

Aflatoxin M1 in Cow’s Milk: Method Validation for Milk Sampled in Northern Italy

Aflatoxins (AFs) are mycotoxins produced by some species of Aspergillus. In dairy cows, ingested AFB1 is metabolized into carcinogenic AFM1 which is eliminated through milk, thus posing a risk for consumer health. Here we describe the set, validation, and application of screening (ELISA) and confirmatory (HPLC) tests carried out on milk samples collected through official control of mycotoxin levels in northern Italy over a three-year period (2012–2014). The limit of detection (LOD) was set at 5 ppt (ng/kg) and 2 ppt for ELISA and HPLC, respectively, and the limit of quantification (LOQ) was 10 ppt for confirmatory HPLC. A total of 1668 milk samples were analyzed: ELISA identified 36 (2.2%) positive milk samples that were subsequently confirmed by HPLC. The level of AFM1 in the positive samples ranged between 18 ± 2 and 208 ± 27 ppt. Of the total samples, only eight (0.5%) were found non-compliant with the EU regulatory limit (50 ppt; range 74 ± 10 to 208 ± 27 ppt). Use of ELISA and HPLC tests in series allows for high-volume analysis of samples, thus saving time and money while guaranteeing high analytical precision and accuracy.     

Genetic Alterations in Gliosarcoma and Giant Cell Glioblastoma

The majority of glioblastomas develop rapidly with a short clinical history (primary glioblastoma IDH wild‐type), whereas secondary glioblastomas progress from diffuse astrocytoma or anaplastic astrocytoma. IDH mutations are the genetic hallmark of secondary glioblastomas. Gliosarcomas and giant cell glioblastomas are rare histological glioblastoma variants, which usually develop rapidly. We determined the genetic patterns of 36 gliosarcomas and 19 giant cell glioblastomas. IDH1 and IDH2 mutations were absent in all 36 gliosarcomas and in 18 of 19 giant cell glioblastomas analyzed, indicating that they are histological variants of primary glioblastoma. Furthermore, LOH 10q (88%) and TERT promoter mutations (83%) were frequent in gliosarcomas. Copy number profiling using the 450k methylome array in 5 gliosarcomas revealed CDKN2A homozygous deletion (3 cases), trisomy chromosome 7 (2 cases), and monosomy chromosome 10 (2 cases). Giant cell glioblastomas had LOH 10q in 50% and LOH 19q in 42% of cases. ATRX loss was detected immunohistochemically in 19% of giant cell glioblastomas, but absent in 17 gliosarcomas. These and previous results suggest that gliosarcomas are a variant of, and genetically similar to, primary glioblastomas, except for a lack of EGFR amplification, while giant cell glioblastoma occupies a hybrid position between primary and secondary glioblastomas.     

A case report of pityriasis lichenoides in a patient with chronic hepatitis C

The authors describe a case of chronic hepatitis C associated with pityriasis lichenoides. The association and evolution during antiviral treatment of these two diseases in this patient point to a possible pathogenetic link between chronic C virus infection and pityriasis lichenoides.     

Carrier Screening for β Thalassemia in Pregnant Indian Women: Experience at a Single Center in Madhya Pradesh

To study the prevalence of β thalassemia trait in pregnancy in urban population screening for β thalassemia in pregnant women at a single center in Indore (MP) has been conducted for a period of 2 year. Blood samples were tested for complete blood count and hemoglobin electrophoresis. During the 2 year period a total of 1,006 women were screened; 28 women who carried abnormal pattern were detected. The mean gestational age for screening was 13 ± 4 weeks. The prevalence of carriers was 2.78 %. As much as 99 % of pregnant women undergoing screening were willing for prenatal diagnosis if required. The economic burden to the society for treating thalassemic patients is huge. The institution of prevention programs like carrier screening has proven costeffective in populations with a high frequency of carriers. Screening of pregnant women early in pregnancy followed by prenatal diagnosis is acceptable and effective strategy for control of thalassemia in developing countries like India.     

Claudin-6 is of limited sensitivity and specificity for the diagnosis of atypical teratoid/rhabdoid tumors

Recent gene expression microarray analyses have indicated that claudin-6 is specifically expressed in atypical teratoid rhabdoid tumors (AT/RTs), suggesting a role as a positive diagnostic marker in addition to SMARCB1 (INI1) loss, which is encountered in the majority of AT/RTs. In order to investigate the potential of claudin-6 as a diagnostic marker, expression was investigated in 59 AT/RTs and 60 other primary central nervous system (CNS) tumors, including primitive neuroectodermal tumors, medulloblastomas, choroid plexus tumors, and both pediatric and adult low- and high-grade gliomas using immunohistochemistry. Claudin-6 was expressed in 17/59 AT/RTs (29%), but also in a variety of other primary CNS tumors, including 60% of medulloblastomas and 21% of malignant gliomas. Even though high staining scores (2+ or 3+) were more often encountered in AT/RTs (Chi-square 4.177; P=0.041), the overall frequency of claudin-6 staining was not significantly higher in AT/RTs as compared with the other tumors (17/59 vs. 16/60; Chi-square=0.328; P=0.567). In a subgroup of 43 AT/RT patients, of which follow-up data were available, claudin-6 expression did not show any correlation with survival. In conclusion, claudin-6 immunohistochemistry is of limited sensitivity and specificity for the diagnosis of AT/RT and does not correlate with clinical behavior.