The microbiome in pediatric oncology

The human microbiome comprises a diverse set of microorganisms, which play a mostly cooperative role in processes such as metabolism and host defense. Next-generation genomic sequencing of bacterial nucleic acids now can contribute a much broader understanding of the diverse organisms composing the microbiome. Emerging evidence has suggested several roles of the microbiome in pediatric hematology/oncology, including susceptibility to infectious diseases, immune response to neoplasia, and contributions to the tumor microenvironment as well as changes to the microbiome from chemotherapy and antibiotics with unclear consequences. In this review, the authors have examined the evidence of the role of the microbiome in pediatric hematology/oncology, discussed how the microbiome may be modulated, and suggested key questions in need of further exploration.     

非编码RNA在先天性心脏病中的研究进展

先天性心脏病是心血管结构及心电传导系统先天性畸形疾病的总称，是常见并且严重的出生畸形。随着最新分子生物学及遗传生物学的深入研究，越来越多的证据表明 非编码RNA 与先天性心脏病的发生、发展相关。本文将就目前国内、外非编码RNA 与先天性心脏病的关系的研究进展进行综述。     

HSP90β干扰和过表达慢病毒载体的构建及其在骨肉瘤细胞Saos-2中的表达

目的:获得热休克蛋白90β(HSP90β)基因干扰和过表达慢病毒表达系统，并检测其在人骨肉瘤细胞株Saos-2中的表达水平。方法:设计合成shRNA，以慢病毒表达质粒构建HSP90β干扰和过表达载体，酶切电泳、测序技术鉴定载体构建是否成功。重组病毒转染H1299细胞，以嘌呤霉素筛选稳定转染的Saos-2细胞，通过荧光显微镜观察计数获得转染效率。将感染好的细胞分为干扰NC组（NEG-shRNA）、干扰组（shRNA-HSP90β）、过表达NC对照组（NEG-pEZ）及过表达组（pEZ-HSP90β）。通过qRT-PCR 与Western blotting 分别从mRNA 和蛋白表达水平验证目的基因的干扰和过表达水平。结果:插入慢病毒表达载体的基因片段与目的基因的碱基序列完全一致。病毒包装成功后，嘌呤霉素最小致死浓度1 μg/ml，感染复数200，感染人Saos-2的感染效率达80%，其中shRNA-HSP90β组干扰效率为86.35%，pEZ-HSP90β组的mRNA相对表达量增加2.8倍。进一步研究发现，shRNA-HSP90β组较NEG-shRNA组中HSP90β蛋白表达明显降低，pEZ-HSP90β组较NEG-pEZ组HSP90β蛋白表达增加。结论:HSP90β基因干扰和过表达慢病毒载体构建成功，并能够在Saos-2中稳定表达。     

Consensus summary report for CEPI/BC March 12–13, 2020 meeting: Assessment of risk of disease enhancement with COVID-19 vaccines

A novel coronavirus (CoV), Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 in Wuhan, China and has since spread as a global pandemic. Safe and effective vaccines are thus urgently needed to reduce the significant morbidity and mortality of Coronavirus Disease 2019 (COVID-19) disease and ease the major economic impact. There has been an unprecedented rapid response by vaccine developers with now over one hundred vaccine candidates in development and at least six having reached clinical trials. However, a major challenge during rapid development is to avoid safety issues both by thoughtful vaccine design and by thorough evaluation in a timely manner. A syndrome of “disease enhancement” has been reported in the past for a few viral vaccines where those immunized suffered increased severity or death when they later encountered the virus or were found to have an increased frequency of infection. Animal models allowed scientists to determine the underlying mechanism for the former in the case of Respiratory syncytial virus (RSV) vaccine and have been utilized to design and screen new RSV vaccine candidates. Because some Middle East respiratory syndrome (MERS) and SARS-CoV-1 vaccines have shown evidence of disease enhancement in some animal models, this is a particular concern for SARS-CoV-2 vaccines. To address this challenge, the Coalition for Epidemic Preparedness Innovations (CEPI) and the Brighton Collaboration (BC) Safety Platform for Emergency vACcines (SPEAC) convened a scientific working meeting on March 12 and 13, 2020 of experts in the field of vaccine immunology and coronaviruses to consider what vaccine designs could reduce safety concerns and how animal models and immunological assessments in early clinical trials can help to assess the risk. This report summarizes the evidence presented and provides considerations for safety assessment of COVID-19 vaccine candidates in accelerated vaccine development.     

肝细胞癌患者血清外泌体mRNA表达谱及临床意义分析

背景与目的:外泌体是包含了复杂RNA和蛋白质的小膜泡,其中肿瘤细胞分泌的外泌体中的mRNA携带了大量肿瘤细胞遗传信息,因此对外泌体中特异性mRNA的分析,有望找到肿瘤诊断的新型分子标志物和治疗靶点。本研究通过高通量筛选与生物信息学方法探讨肝细胞癌(HCC)患者血清外泌体mRNA的表达特征及其潜在功能。方法:采集3例HCC患者及3例正常人的静脉血,用外泌体提取试剂盒提取血清外泌体,用Magen试剂盒提取外泌体RNA,对血清外泌体mRNA进行纯化、行反转录形成cDNA、PCR扩增、测序,最后将对所得数据质量进行评价后与参考数据进行比对,分析得到差异表达外泌体mRNA,并采用GO和KEGG通路富集分析对差异基因进行功能与通路注释。结果:与正常人比较,HCC患者有397个外泌体mRNA表达上调,192个外泌体mRNA表达下调;其中,NRGN、PF4、RGS18等17个基因表达明显上调,CXCL8、MORF4L2、SYCP1等14个基因显明显下调。GO富集分析显示,表达上调的外泌体mRNA的靶基因与蛋白质结合、蛋白质异二聚化活性、免疫系统过程的调节、胞外囊泡、细胞外细胞器、应激反应等有关,表达下调的外泌体mRNA的靶基因与嗅觉受体活性、细胞因子活性、CXCR趋化因子受体结合、中间丝、中间丝状细胞骨架等有关;KEGG通路分析显示,在上调的外泌体mRNA中,30条通路被显著富集,在下调的外泌体mRNA中9条通路被显著富集,其中,在上调的外泌体mRNA中,血小板激活、Rap 1信号通路、吞噬体、病毒致癌、肌动蛋白细胞骨架的调节与抗原处理和呈递等是最丰富和最有意义的通路;在下调的外泌体mRNA中,基础转录因子和细胞因子-细胞因子受体相互作用分别是最丰富和最有意义的通路。结论:HCC患者与正常人的血清外泌体mRNA表达特征存在较大差异,其与HCC发生、发展、转移可能密切相关,这为寻找新的诊断标志物及治疗靶点提供了依据。     

利用规律间隔成簇短回文重复序列/相关蛋白9系统敲减α2δ1对人肝癌细胞系Hep-12干性的影响

目的 通过规律间隔成簇短回文重复序列/相关蛋白9(CRISPR/Cas9)系统敲减人肝癌细胞系Hep12中电压依赖性钙离子通道 α2δ1的表达，观察α2δ1敲减后对肝癌细胞干性的影响。方法 设计3对靶向α2δ1的向导 (sgRNA)，长度为20 bp，构建到lenti CRISPRv2-puro载体上，然后在体外检测sgRNA切割活性，利用慢病毒包装系统包装含有sgRNA的重组质粒，将包装好的病毒感染Hep-12细胞，2 d后加入嘌呤霉素筛选。利用Western blotting验证α2δ1的敲减效果和干性相关基因的表达。通过成球实验检测其体外自我更新能力的变化。结果 测序结果显示，sgRNA成功插入载体质粒；体外切割实验显示，3条sgRNA均有切割活性；Western blotting结果显示，α2δ1基因的表达显著降低，干性相关基因B细胞特异性莫洛尼白血病病毒插入位点1(BMI1)和Nanog的表达显著被抑制；无血清培养基成球实验结果表明，敲减α2δ1导致Hep-12细胞的体外自我更新能力减弱。结论 利用CRISPR/Cas9技术成功构建敲除α2δ1基因的Hep-12细胞系；敲除α2δ1基因后能抑制Hep-12细胞肿瘤干细胞样特性。     

肺腺癌竞争内源性RNA网络的综合分析:基于肿瘤基因组图谱数据库

目的:基于肿瘤基因组图谱数据库（TCGA）架构肺腺癌（LUAD）竞争内源性RNA（ceRNA）网络，鉴定潜在的生存关联性生物标志物，并确定特异性治疗的小分子药物。方法:依据纳入研究标准，利用Edger软件筛选LUAD组织与正常组织(mRNA、lncRNA和miRNA)差异表达的基因。通过miRcode、miRDB、TargetScan和miRanda数据库对差异表达的RNA之间的关系进行分析，构建ceRNA网络。采用Kaplan-Meier方法分析ceRNA网络中的RNA表达量与生存预后的关系，通过富集分析对网络中的mRNA基因功能和调控通路进行分析。通过Cmap数据库筛选治疗LUAD的特异性小分子药物。利用D-lnc软件确定与关键的lncRNA相关的特异性小分子药物。结果:mRNAs(ELAVL2和PBK)、miRNAs(miR-13和miR-210)和lncRNAs(AP002478.1、DSCAM-AS1、LINC00269、LINC00470和LINC00483)与总生存期(OS)关系密切。喜树碱和甲萘醌有可能逆转LUAD的状态。卡铂、多西紫杉醇、帕比司他被确定为与关键lncRNA密切相关的药物。结论:ceRNA网络在LUAD中发挥重要作用，多种差异表达RNA与LUAD预后相关，可能成为潜在的肿瘤诊断标志物和治疗靶点。