Neuroblastoma: a master of disguise and a challenge to cure

Neuroblastoma is one of the commonest childhood cancers and typically affects very young children. It is characterized by a very broad spectrum of clinical presentation and outcome, driven by the biology of the tumour. This ranges from ‘low risk’ tumours, most commonly found in infants, which may spontaneously regress and have an excellent prognosis with minimal or no treatment, to ‘high risk’ disease, which carries a poor prognosis despite intensive multi-modal treatment. Although particular presentations may be associated with favourable or unfavourable outcome, the clinical features may mask the underlying biology of the tumour and a full assessment of the clinical and biological features is required to determine appropriate treatment. The International Neuroblastoma Risk Group classification, based on the age of the patient and the stage, grade and genetics of the tumour, is used to stratify treatment according to risk factors. This review provides an overview of current neuroblastoma management, focusing on how classification is applied in practice, and how this is used to determine individual patient treatment. The challenges that remain in treating patients with high-risk disease are discussed.     

Japanese version of The Cancer Genome Atlas,JCGA, established using fresh frozen tumors obtained from 5143 cancer patients

This study aimed to establish the Japanese Cancer Genome Atlas (JCGA) using data from fresh frozen tumor tissues obtained from 5143 Japanese cancer patients, including those with colorectal cancer (31.6%), lung cancer (16.5%), gastric cancer (10.8%) and other cancers (41.1%). The results are part of a single‐center study called “High‐tech Omics‐based Patient Evaluation” or “Project HOPE” conducted at the Shizuoka Cancer Center, Japan. All DNA samples and most RNA samples were analyzed using whole‐exome sequencing, cancer gene panel sequencing, fusion gene panel sequencing and microarray gene expression profiling, and the results were annotated using an analysis pipeline termed “Shizuoka Multi‐omics Analysis Protocol” developed in‐house. Somatic driver alterations were identified in 72.2% of samples in 362 genes (average, 2.3 driver events per sample). Actionable information on drugs that is applicable in the current clinical setting was associated with 11.3% of samples. When including those drugs that are used for investigative purposes, actionable information was assigned to 55.0% of samples. Germline analysis revealed pathogenic mutations in hereditary cancer genes in 9.2% of samples, among which 12.2% were confirmed as pathogenic mutations by confirmatory test. Pathogenic mutations associated with non–cancerous hereditary diseases were detected in 0.4% of samples. Tumor mutation burden (TMB) analysis revealed 5.4% of samples as having the hypermutator phenotype (TMB ≥ 20). Clonal hematopoiesis was observed in 8.4% of samples. Thus, the JCGA dataset and the analytical procedures constitute a fundamental resource for genomic medicine for Japanese cancer patients.     

Wolf-Hirschhorn综合征4例及文献复习

目的　探讨Wolf-Hirschhorn综合征（WHS）临床特征及基因突变。方法　回顾分析2017-11-20—2018-05-26南京医科大学附属儿童医院收治的4例发育延迟及智力低下患儿的临床资料，临床拟诊为WHS。应用染色体微阵列芯片分析技术进行基因检测，并复习相关文献总结疾病特点。结果　2例男性和2例女性患儿因生后特殊面容（希腊头盔样面容）、智力低下、发育延迟、肌张力低下、癫痫，应用染色体微阵列芯片分析技术发现患儿4p16.3区域2.24～3.8 Mb的缺失，确诊WHS，给予抗癫痫及康复治疗并定期随访。结论　尽早完善染色体芯片技术检查有助于早期诊断WHS，且能判断预后。染色体微阵列芯片分析与传统细胞遗传学分析方法相比，具有高分辨和高准确度的优点，可为产前遗传学诊断提供更详细信息。     

基因组时代产前诊断面临的机遇和挑战

        自20世纪70年代开始，染色体核型分析技术作为诊断胎儿染色体异常的金标准已使用多年，但该技术存在分辨率较低（5~10Mb）、培养周期长、检测通量低及有培养失败风险等局限性。随后，靶向诊断技术（FISH、QF-PCR、MLPA）的出现，大大缩短了检测时间，与染色体核型技术联合应用，可早期诊断常见的胎儿染色体异常。此外，Sanger测序作为基因变异检测的金标准，可用于明确致病的单基因疾病的产前诊断。然而，以上技术均无法实现在全基因组范围内进行快速、高分辨率地诊断胎儿致病性变异。 浏览更多请关注微信公众号及当期杂志。     

Frequency and clinical manifestation of prenatal cytogenetic diagnosis of chromosomal polymorphisms in Northeast China

ObjectiveTo retrospectively analyze the incidence of chromosomal polymorphisms in prenatal cytogenetic diagnostic cases and the effect of the clinical manifestation of these fetuses.Materials and methods490 fetuses with chromosomal polymorphisms among 9996 pregnant women who underwent prenatal cytogenetic diagnosis were included in this study and were set as group 1. Other 500 pregnant women, whose fetuses were with normal karyotypes, were randomly selected from the remaining pregnant women and set as group 2. Clinical information and outcomes and maternal serum screening results of group 1 were compared with group 2.ResultsThe frequency of fetal chromosomal polymorphism was 4.90% (490/9996). The most common variants observed were 1/9/16 qh± (2.27%, 227/9996), followed by inv(9) (0.90%, 90/9996). 94.62% (264/279) of fetal chromosomal variants were inherited from parents. No statistical difference was found in clinical information and outcomes and maternal serum screening results between group 1 and group 2.ConclusionThe fetus with chromosomal polymorphism has no impact on serum markers of second trimester screening and does not play an important role for the clinical outcome of the current pregnancy either, whether it is inherited from the parents or a de novo mutation.     

Chromosomal DNA damage in APOE ɛ4 carriers and noncarriers does not appear to be different

DNA damage may play a key role in promoting disease‐onset and accelerated disease progression in Alzheimer's disease (AD) by increasing the rates of neuronal cell death. The ?4 allele of the APOE gene is the best characterised genetic risk factor for AD, however, it is unknown if APOE ?4 carriers exhibit increased levels of DNA damage which may contribute to increased AD risk. 175 healthy participants (aged 34–67 years old) from South Australia were recruited into the study and provided a single blood sample for the isolation of peripheral blood lymphocytes, APOE genotyping and lymphocyte chromosomal DNA damage analysis using the Cytokinesis‐Block micronucleus cytome (CBMN‐Cyt) assay with the micronucleus index being the primary outcome measure. When compared to non‐APOE ?4 carriers, APOE ?4 carriers did not exhibit altered rates of i) cell division, represented by the nuclear division index (NDI, P = 0.372), ii) cell death as represented by apoptotic (P = 0.457) and necrotic (P = 0.393) frequencies and iii) chromosomal DNA damage as indicated by the number of micronuclei (MNi, P = 0.795), nucleoplasmic bridges (NPBs, P = 0.221) or nuclear buds (NBUDs, P = 0.293) scored in binucleated cells. In conclusion, although we and others have previously shown that rates of chromosomal DNA damage measured using the CBMN‐Cyt assay are elevated in individuals with cognitive impairment, in this South Australian cohort the frequency of genome instability is not substantially influenced by the presence of the APOE ?4 allele. Environ. Mol. Mutagen. 56:694–708, 2015. © 2015 Wiley Periodicals, Inc.     

Chromosomal instability triggers cell death via local signalling through the innate immune receptor Toll

Chromosomal instability (CIN) is a hallmark of cancer and has been implicated in cancer initiation, progression and the development of resistance to traditional cancer therapy. Here we identify a new property of CIN cells, showing that inducing CIN in proliferating Drosophila larval tissue leads to the activation of innate immune signalling in CIN cells. Manipulation of this immune pathway strongly affects the survival of CIN cells, primarily via JNK, which responds to both Toll and TNFα/Eiger. This pathway also activates Mmp1, which recruits hemocytes to the CIN tissue to provide local amplification of the immune response that is needed for effective elimination of CIN cells.     

Assessment of systemic genetic damage in pediatric inflammatory bowel disease

The etiology of distal site cancers in inflammatory bowel disease (IBD) is not well understood and requires further study. We investigated whether pediatric IBD patients' blood cells exhibit elevated levels of genomic damage by measuring the frequency of mutant phenotype (CD59-/CD55-) reticulocytes (MUT RET) as a reporter of PIG-A mutation, and the frequency of micronucleated reticulocytes (MN-RET) as an indicator of chromosomal damage. IBD patients (n = 18 new-onset disease, 46 established disease) were compared to age-matched controls (constipation or irritable bowel syndrome patients from the same clinic, n = 30) and young healthy adults age 19–24 (n = 25). IBD patients showed no indication of elevated MUT RET relative to controls (mean ± SD = 3.1 ± 2.3 × 10⁻⁶ vs. 3.6 ± 5.6 x 10⁻⁶, respectively). In contrast, 59 IBD patients where %MN-RET measurements were obtained, 10 exceeded the upper bound 90% tolerance interval derived from control subjects (i.e., 0.42%). Furthermore, each of the 10 IBD patients with elevated MN-RET had established disease (10/42), none were new-onset (0/17) (p = .049). Interestingly, each of the subjects with increased chromosomal damage was receiving anti-TNF based monotherapy at the time blood was collected (10/10, 100%), whereas this therapy was less common (20/32, 63%) among patients that exhibited ≤0.42% MN-RET (p = .040). The results clearly indicate the need for further work to understand whether the results presented herein are reproducible and if so, to elucidate the causative factor(s) responsible for elevated MN-RET frequencies in some IBD patients.