基于随机森林的胃癌微阵列数据基因通路分析

将研究重点从单个基因转移到基因信号通路,结合随机森林与信号通路分析了一组胃癌微阵列数据。通过研究基因在通路中的情况以及通路中的基因对胃癌肠型、弥漫型和正常组织样本的分类能力,扩展了随机森林在生物学中的应用,为胃癌的研究提供了新的思路。     

非洲爪蟾BAFF及其信号通路相关基因的比较生物信息学分析

目的:对非洲爪蟾BAFF和BAFF信号通路相关基因进行了分析.方法:采用生物信息学方法对两栖类重要的模式生物-非洲爪蟾的基因组和EST数据库进行分析.结果:非洲爪蟾BAFF cDNA全长为557 bp,编码218个氨基酸.与人BAFF序列相似性为37.5％.该文一共得到了14个BAFF信号通路相关基因.通过与人BAFF信号通路进行比较,对非洲爪蟾这14个BAFF信号通路相关基因进行了分析.结论:BAFF和BAFF信号通路在进化过程中较为保守,这为进一步研究低等脊椎动物BAFF功能和信号通路具有重要的指导作用.     

胃癌多药耐药相关microRNA的筛选和鉴定

目的:研究胃癌多药耐药相关microRNA并对其进行鉴定、靶基因预测和预测靶基因的生物信息学分析。方法:运用microRNA芯片对胃癌多药耐药细胞SGC7901/ADR和其亲本细胞SGC7901进行microRNA表达谱分析;采用实时定量PCR的方法对差异表达的miRNA进行验证;再运用生物信息学方法对差异表达的miRNA进行靶基因预测;再对预测的靶基因进行GO和KEGG通路分析。结果:与SGC7901相比SGC7901/ADR表达上调超过2倍的miRNA有6个,表达下调超过2倍的有11个。实时定量PCR对共同差异表达的microRNA进行验证显示与芯片结果的一致性。对这17个差异表达的miRNA进行靶基因预测,再对预测得到的靶基因进行GO和KEGG通路分析显示预测的靶基因参与了肿瘤相关通路、MAPK通路、Focal Adhesion通路等。结论:我们初步筛选得到了胃癌多药耐药相关miRNA并对其进行了生物信息学分析,为进一步地探索miRNA在胃癌多药耐药中的作用及其分子机制奠定了基础。     

Nrf2/ARE信号通路与胃癌耐药关系的研究进展

胃癌是癌症死亡的第二大原因。化疗是胃癌治疗的主要方法之一,胃癌化疗失败的主要原因是对化疗药物的耐受。Nrf2/ARE信号通路与肿瘤耐药的关系是当前的研究热点。转录因子Nrf2作为抗氧化反应中的关键转录因子,可以与抗氧化反应元件ARE结合,正向调节II相解毒酶、抗氧化酶及某些药物转运泵基因等靶基因的表达,诱导胃癌耐药性的产生。该综述整理归纳了Nrf2/ARE信号通路与胃癌耐药之间的关系。     

胃癌发生及其耐药性形成中的相关信号通路

胃癌是常见的消化道恶性肿瘤,而化疗药物的耐药性严重影响晚期胃癌患者的化疗效果。本文总结了多种与胃癌的发生及耐药性产生相关的信号通路,包括rnTOR、Nrf2-ARE、Notch、Hedgehog和Wnt。这些信号通路不仅决定着胃癌等恶性肿瘤的发生、分化与转移,更影响着恶性肿瘤耐药性的产生,而耐药性正是目前肿瘤化疗的最大障碍。研究这些信号通路可以从分子水平研究癌症发生的机理从而阻断肿瘤的生长,从这些肿瘤相关信号通路中亦能了解到肿瘤耐药性产生的机制,为胃癌等恶性肿瘤研究和治疗提供新的思路。     

TRPS1在胃癌中的表达及生物信息学分析

目的探究转录抑制因子GATA结合基因1(TRPS1)在胃癌中的表达水平及其与表达相关基因的细胞功能及信号通路。方法通过筛选基因表达谱数据动态分析(GEPIA)、基因芯片表达谱公共数据库(GEO)数据,对TRPS1在胃癌组织中的数据进行Meta分析。采用实时荧光定量PCR技术(RT-qPCR)检测TRPS1在胃癌细胞中的表达水平。应用生物信息学分析TRPS1及表达相似基因的细胞功能和信号通路。结果在公共数据库中,TRPS1在胃癌组织中均呈高表达,合并标准均差SMD为0.40(95%CI:0.04～0.76,P=0.028),敏感性分析稳定,无发表偏倚。TRPS1在胃癌细胞HGC-27和MGC-803中呈高表达(均P0.01)。TRPS1和表达相关基因ESR1富集在多条功能通路中,与转录因子活性、序列特异性DNA结合等肿瘤相关通路密切相关;TRPS1与ESR1存在直接蛋白互作关联。结论 TRPS1在胃癌中可能是一个促癌因子,在胃癌的调控机制中有重要作用。     

MTA1调控基因网络在胃腺癌中的作用

本研究利用TCGA数据库提供的胃腺癌数据集,结合cBio Cancer Genomics Portal数据库和GeneCards数据库筛选出与肿瘤转移相关基因(MTA1)存在共表达和相互作用的83个基因。利用DAVID、STRING等分析软件发现这些基因主要富集在细胞周期、WNT通路、P53信号通路、胃癌和DNA修复等癌症相关通路上,并进一步利用String数据库和Cytoscape筛选出与MTA1紧密联系基因,同时结合大样本临床数据的生存曲线分析认为这些基因与胃腺癌生存率密切相关,MTA1可能与这些基因相互作用调控细胞增殖,影响胃腺癌细胞侵袭转移。通过研究胃腺癌组织中MTA1调控的基因网络,有助于揭示胃腺癌发病机制。找到有效生物学标记物组合作为胃癌的预测指标,可以为相关药物研发及临床诊断治疗提供新的思路和依据。     

棉铃虫Wnt1基因启动子活性研究

经典的Wnt信号通路是一条与生长发育密切相关的信号通路,经典Wnt信号通路在棉铃虫滞育蛹脑中受到抑制。本研究以棉铃虫Wnt1基因的转录调控为研究目标,对Wnt1启动子的活性进行了分析。首先,运用染色体步移的技术成功克隆了一段长为1566 bp的Wnt1启动子。然后,通过PCR扩增不同长度的启动子片段,构建到报告质粒,转染棉铃虫Hz Am1细胞并进行启动子活性分析,结果表明-1077~-1120以及-1120~-1140这两个区域对Wnt1基因的转录起着明显的激活作用。最后对这两个区域潜在的转录因子结合位点进行了预测。本研究从根本上了解棉铃虫滞育蛹脑中经典Wnt信号通路的调节机制打下了基础。     

牦牛miR-383的靶基因预测及生物信息学分析

MicroRNAs (miRNAs)是一类非编码的小分子单链RNA,通过与靶基因的mRNA结合,抑制mRNA的翻译,参与多种生物学过程.本实验室前期通过高通量测序发现90日龄牦牛胚胎的背最长肌中miR-383的表达量显著高于成年牦牛.为探究miR-383在牦牛骨骼肌发育中的分子功能和机制,本研究对miR-383的靶基因进行预测,并进行生物信息学分析.通过TargetScan、miRDB和miRanda 3个软件预测了miR-383的靶基因,然后合并miRTarbase数据库中已被证实的靶基因作为基因集,分别用DAVID和KOBAS3.0在线软件对基因集进行功能注释(GO分析)和Pathway信号通路富集分析.结果 表明,牦牛miR-383序列在各物种间高度保守,靶基因功能富集于CD8阳性T细胞增殖的调控、核糖核蛋白复合物定位和负调控T细胞分化等生物学过程.信号通路分析发现靶基因的信号通路显著富集于PI3K-Ak、AMPK、FoxO和Focal adhesion等与肌肉发育相关的信号通路中.该研究结果将为miR-383功能及调控机制的深入研究提供参考依据,也为解析牦牛肌肉发育的分子机制提供新的研究方向.     

Ras-mediated signaling pathway regulates the expression of a low-molecular-weight heat-shock protein in fission yeast.

In fission yeast, Schizosaccharomyces pombe, deficiency of ras1 gene causes an abnormal cell shape and abolishes mating ability. However, target genes of this signaling pathway are largely unknown because of the lack of an appropriate analysis system. To overcome this problem, we have started a novel project to categorize entire genes based on their expression levels under different growth conditions. Using this strategy, we screened genes whose expression levels were affected in the presence or absence of the ras1 gene product. For this purpose, we utilized high-density arrays of clones covering the entire genome of the fission yeast, and probed with labelled cDNA derived from various strains and growth conditions. Here, we demonstrate the detection of a low-molecular-weight heat-shock protein gene, hsp16, whose expression is very likely to be regulated by a ras-mediated signaling pathway, but not by the heat-shock response.     

小儿脓毒症休克相关基因的筛选及网络构建

为探究脓毒症休克与SIRS的差异表达基因及网络的构建,筛选潜在的核心基因,从GEO数据库下载相关基因表达谱GSE26378,数据分为脓毒症休克与SIRS各29个样本,通过在线软件GCBI对其进行标准化及差异基因筛选;对差异基因进行GO分析;基于KEGG进行功能通路分析以及基因信号网络分析;差异基因共表达网络分析。结果表明:两组中总共有1 456个基因被识别为差异基因(P0.05),与SIRS组相比,脓毒症休克组中有条859条下调基因,597条上调基因。GO功能富集分析显示差异基因主要参与了细胞周期、细胞免疫、细胞代谢。KEGG功能通路分析显示差异基因主要参与了MAPK信号通路、P53信号通路、wnt信号通路、细胞凋亡信号通路,细胞周期受体信号通路等。共表达分析发现基因CCNB1、NUSAP1、OIP5、SHCBP1、ZWINT、TOP2A、DLGAP5等位于网络中央部位,而基因信号网络分析发现基因PLCB1、PIK3CA、STAT3、CAMK2D、PRKCB、CREB1位于网络核心。基因芯片分析有助于发现脓毒症休克与SIRS患儿外周血单核细胞在转录组学上的改变,而生物信息学网络分析有助于发现潜在的靶点。     

A genome-wide survey of the genes for planar polarity signaling or convergent extension-related genes in Ciona intestinalis and phylogenetic comparisons of evolutionary conserved signaling components

Non-canonical Wnt signals similar to planar cell polarity (PCP) signaling in the fly control convergent extension (CE) of the dorsal mesoderm during gastrulation in vertebrates. Using the Ciona complete genome sequence and EST sequence data, we present here an initial and exhaustive search in non-vertebrate chordates, Ciona intestinalis for the family members as well as homologs or orthologs that are involved in PCP/CE signaling cascades. We clarified 7 cardinal gene families, including the MAPK, STE20 group kinase, Rho small GTPase, STAT, Glypican, Fz and Wnt gene families, as well as gene homologs or orthologs for known PCP/CE signaling components with their phylogenetic nature. As a result, we characterized 62 Ciona component genes. Among them, 59 genes were novel and functional genes which were supported by EST expressions and 15 genes belonged to PCP/CE component orthologs of other organisms or common ancestor genes. Moreover, from the phylogenetic point of view, we compared these components genome-widely with the PCP signaling components of fly and the CE signaling components of vertebrates. We then discovered not only that ascidians contain the basic ancestral signaling pathway components in chordates but also that several signaling components have not found in ascidian, indicating that ascidian CE pathway might have several gaps from vertebrate CE pathway. The present study provides an initial step for the subsequent analysis of CE in the non-vertebrate chordates, ascidians. In addition, this phylogenetic approach will help to facilitate understanding of the relationship between fly PCP signaling and the vertebrate CE pathway.     

Identification of novel metastasis suppressor signaling pathways for breast cancer

Cancer lethality is mainly caused by metastasis. Therefore, understanding the nature of the genes involved in this process has become a priority. Given the heterogeneity of mutations in cancer cells, considerable focus has been directed toward characterizing metastasis genes in the context of relevant signaling pathways rather than treating genes as independent and equal entities. One signaling cascade implicated in the regulation of cell growth, invasion and metastasis is the MAP kinase pathway. Raf kinase inhibitory protein (RKIP) functions as an inhibitor of the MAP kinase pathway and is a metastasis suppressor in different cancer models. By utilizing statistical analysis of clinical data integrated with experimental validation, we recently identified components of the RKIP signaling pathway relevant to breast cancer metastasis. Using the RKIP pathway as an example, we show how prior biological knowledge can be efficiently combined with genome-wide patient data to identify gene regulatory mechanisms that control metastasis.     

Identification of novel metastasis suppressor signaling pathways for breast cancer

Cancer lethality is mainly caused by metastasis. Therefore, understanding the nature of the genes involved in this process has become a priority. Given the heterogeneity of mutations in cancer cells, considerable focus has been directed toward characterizing metastasis genes in the context of relevant signaling pathways rather than treating genes as independent and equal entities. One signaling cascade implicated in the regulation of cell growth, invasion and metastasis is the MAP kinase pathway. Raf kinase inhibitory protein (RKIP) functions as an inhibitor of the MAP kinase pathway and is a metastasis suppressor in different cancer models. By utilizing statistical analysis of clinical data integrated with experimental validation, we recently identified components of the RKIP signaling pathway relevant to breast cancer metastasis. Using the RKIP pathway as an example, we show how prior biological knowledge can be efficiently combined with genome-wide patient data to identify gene regulatory mechanisms that control metastasis.     

单细胞测序分析人类胚胎干细胞神经分化的分子机制

目的 探讨人类胚胎干细胞(ESCs)分化为神经细胞的关键性靶基因及分子机制,为临床靶向治疗神经康复患者提供分子理论依据.方法 基于GEO数据平台芯片,采用单细胞测序方法(scRNA-seq),利用R语言从多分子维度(单细胞差异基因、蛋白互作网络和基因通路等)分析人类ESCs分化过程中的关键Marker基因并利用质控和数...     

长丝萝中的两个抗肿瘤活性成分的分离鉴定及对抑癌基因变化的验证

以长丝萝Dolichousnea longissima中分离得到的体外细胞毒活性较强的两个苯骈呋喃类化合物为实验材料,采用Affymetrix全表达谱基因芯片、GO分类、Pathway分析和实时荧光定量PCR技术对2种化合物处理前后的肝癌细胞株HepG2的差异表达基因进行分析和验证。结果表明,(Z)-2-乙酰基-5,5-二[2-(7-乙酰基-4,6-二羟基-3,5-二甲基苯骈呋喃基)]-4-羟基-2,4-戊二烯-1-醛筛选出明显变化的基因728个,其中上调基因有246个,下调基因有482个。PATHWAY分析与肿瘤相关的信号通路有细胞周期信号通路、内吞作用信号通路、癌细胞中信号通路、前列腺癌信号通路、p53信号通路、结肠直肠癌信号通路。GO分类显示差异基因共参与266个BP分类、68个CC分类和43个MF分类。4-[3-(7-乙酰基-4,6-二羟基-3,5-二甲基-2-氧代-2,3-二氢苯骈呋喃基)]-4-[2-(7-乙酰基-4,6-二羟基-3,5-二甲基苯骈呋喃基)]-3-氧代丁酸乙酯筛选出明显变化的基因112个,其中上调基因有8个,下调基因有104个。PATHWAY分析与肿瘤相关的信号通路有细胞周期信号通路、内吞作用信号通路。GO分类显示差异基因共参与109个BP分类、48个CC分类和15个MF分类。因此,以上两个苯骈呋喃类化合物均主要通过影响细胞周期信号通路和内吞作用信号通路使抑癌基因发生变化。