壳寡糖对HeLa细胞和A549细胞自噬性死亡的影响

为了探讨壳寡糖(COS)对He La细胞和A549细胞自噬性死亡的影响,利用不同浓度COS处理细胞后MTT法检测细胞的增殖抑制情况,采用MDC染色法观察自噬泡的形成,免疫荧光法检测LC3在细胞内的表达,Western-blot分析COS处理He La和A549细胞不同时间后细胞内LC3-Ⅱ/LC3-Ⅰ变化。结果表明,5.0 mg·m L-1COS对两种细胞的增殖抑制率最大,分别为52.15%和57.63%(P0.01)。与阴性对照相比,经COS处理后的细胞MDC染色细胞内荧光强度增加,且阳性信号聚集于核周区域;免疫荧光检测发现LC3阳性颗粒数明显增加,表明细胞内自噬体的数量增多。Western-blot检测分析随着COS处理细胞时间延长,LC3-Ⅱ/LC3-Ⅰ比值逐渐增大,显示细胞内自噬活性增强。由此推测COS能够通过诱导He La和A549细胞的自噬性死亡来抑制细胞增殖,为COS的抗肿瘤作用机制的研究提供理论依据。     

Mapping and characterization of two relevance networks from SNP and gene levels

Variations of gene expression and DNA sequence are genetically associated. The goal of this study was to build genetic networks to map from SNPs to gene expressions and to characterize the two different kinds of networks. We employed mutual information to evaluate the strength of SNP–SNP and gene–gene associations based on SNPs identity by descent (IBD) data and differences of gene expressions. We applied the approach to one dataset of Genetics of Gene Expression in Humans, and discovered that both the SNP relevance network and the gene relevance network approximated the scale-free topology. We also found that 12.09% of SNP–SNP interactions matched 24.49% of gene–gene interactions, which was consistent with that of the previous studies. Finally, we identified 49 hub SNPs and 115 hub genes in their relevance networks, in which 27 hub SNPs were associated with 25 hub genes.     

基于分层网络和反馈机制的细胞重编程

在多潜能细胞分化并最终形成相应的谱系结构的过程中, 多潜能细胞可能发生重编程.主要研究细胞分化过程中由双重负反馈回路的层级网络如何产生细胞重编程. 通过建立数学模型对整个系统的分叉进行分析, 揭示分层网络以及反馈机制产生细胞重编程的机理.     

钙调素对肿瘤细胞周期的调节作用

利用钙调素拮抗剂三氟拉嗪(TFP)研究了钙调素对HeLa细胞周期进程的影响,TFP处理的细胞被阻抑在G_1/S,使S期群体及DNA合成下降,G_2期群体增加.有丝分裂(M)前期细胞减少,中期细胞增加.结果表明钙调素对G_1至S期.G_2至M期和M中期至M后期具有调节作用,钙调素通过细胞周期中上述3个位点对肿瘤细胞增殖进行调节.     

电化学对人宫颈癌细胞系HeLa-S3细胞周期进程的影响

为了解电化学治疗（ＥＣＴ）是否对人宫颈癌细胞的生物学行为有影响，用体外实验和放射自显影技术，观察不同电压和电量组合的ＥＣＴ对人宫颈癌细胞系（ＨｅＬａ－Ｓ３）的细胞增殖周期影响。结果是ＥＣＴ对ＨｅＬａ细胞的ＤＮＡＧ１－Ｓ期和有丝分裂期有明显抑制作用。     

PKA和PKC对HeLa细胞G_2/M/G_1进程的影响

为了研究PKA和PKC对HeLa细胞G2 →M期和M→G1期进程的影响 ,用PKA和PKC抑制剂分别处理同步的G2 期和M期的HeLa细胞后 ,测定了细胞有丝分裂指数和PKA ,PKC与CDC2激酶的活性 .结果表明 ,PKAⅢ型抑制剂在促进HeLa细胞G2 /M /G1进程的同时 ,刺激了PKC的活性 ,反之 ,PKC的抑制剂GF 10 92 0 3X在阻抑HeLa细胞G2 /M /G1进程的同时 ,激活了PKA的活性 ,与其相关的CDC2激酶活性也发生了相应的变化 .实验表明 ,PKA和PKC分别负调和正调HeLa细胞G2 /M/G1进程 ,两者表现出拮抗关系 .     

Ar^＋激光辐照对吖啶橙敏化人体宫颈癌细胞的生物学效应

用不同剂量的氩离子激光照射经吖啶橙敏化的人体宫颈癌细胞后,与对照组细胞比较,观察到其生长曲线下降、死亡率曲线上升、酸性磷酸酶迅速失活以及细胞显微结构与亚显微结构的受损退行性变等效应,并对上述结果进行了讨论分析。     

Identifying disease feature genes based on cellular localized gene functional modules and regulation networks

Using data mining methods to identify disease-rele- vant genes and functional modules via high throughput gene expression profiles is of critical importance for studying complex disease mechanisms and predicting disease phenotypes[1,2]. Genes do not behav…     

钙调素在细胞增殖中的调节作用

钙调素通过促进细胞周期的进程，实现其对细胞增殖的调节。     

microRNA-16 expression in HeLa cells is upregulated in cell-cycle and drug dependent manner

microRNAs are single-stranded, non-coding RNAs that regulate gene expression. The microRNA-16 family has been reported to be involved in cell-cycle regulation, which could also downregulate expression of multiple pro-proliferation genes. The present results demonstrated that miR-16 expression in HeLa cells increased when the cells were arrested during S-phase under methyl methanesulfate (MMS) treatment. This further resulted in downregulation of a target protein CDC25A, whereas miR-16 expression did not increase when HeLa cells were arrested during the MMS-treated G₀/G₁ or G₂/M phase. Furthermore, when HeLa cells were arrested during S-phase with hydroxyurea treatment, miR-16 expression did not increase. These results suggest that expression levels of microRNAs in mammalian cells are delicately regulated under variable cellular conditions.     

真核细胞基因转录抑制机制的研究

真核细胞的基因转录抑制受多方面的调节,目前的研究已经揭示了转录因子产生转录抑制的分子机制,蛋白之间的相互作用产生的转录抑制等几方面的作用机制.研究了全酶与基因的转录、染色质与真核基因转录抑制、干扰激活因子活性等,在真核细胞基因转录抑制中起的作用.     

Cell cycle and cell signal transduction in marine phytoplankton

tAs unicellular phytoplankton, the growth of a marine phytoplankton population results directly from the completion of a cell cycle, therefore, cell-environment communication is an important way which involves signal transduction pathways to regulate cell cycle progression and contribute to growth, metabolism and primary production and respond to their surrounding environment in marine phytoplankton. Cyclin-CDK and CaM/Ca²⁺ are essentially key regulators in control of cell cycle and signal transduction pathway, which has important values on both basic research and applied biotechnology. This paper reviews progress made in this research field, which involves the identification and characterization of cyclins and cell signal transduction system, cell cycle-control mechanisms in marine phytoplankton cells, cell cycle proteins as a marker of a terminal event to estimate the growth rate of phytoplankton at the species level, cell cycle-dependent toxin production of toxic algae and cell cycle progression regulated by environmental factors.     

EC109细胞株细胞周期DNA代谢和形态改变的研究

人食管癌细胞株 EC109以显微分光光度计测定癌细胞核 DNA 含量,以放射自显影测定细胞核摄取~3H-TdR 和扫描电镜检查细胞表面的超微结构.大多数 EC109瘤细胞间期细胞核的 DNA 含量增加,主要干系细胞 DNA 含量为2 C,属 G_1期,也可见低于四倍体(3 C),高于四倍体(>4 C).甚至多倍体(>8 C)的瘤细胞.~3H-TdR 加入培养基10分钟后,许多瘤细胞核有银粒出现(S 期细胞).大量细胞进入细胞周期反映其恶性程度高.扫描电镜可见 EC109在细胞周期不同阶段其细胞大小形状和微绒毛也不同.本文结果说明用细胞核 DAN 含量测定,~3H-TdR 掺入和细胞表面超微结构可测定肿瘤周期.也可用这些方法判定瘤细胞的恶性程度.     

立方形递归网络中的Hamilton圈

立方形递归网络是一类具有良好拓扑性质的互连网络模型.运用立方形递归网络结构的递归性,证明了立方形递归网络存在Hamilton圈,同时给出了立方形递归网络中构造Hamilton圈的方法.     

一种应用于多跳网络的可调占空比固定时延MAC协议

针对Ad Hoc网络、无线传感器网络等类型的多跳网络中使用传统的基于低占空比的MAC协议会使数据传输的时延随转发节点的增加而变大的问题,提出一种固定时延的MAC协议(FDS-MAC).该协议针对不同跳数的源节点,由汇聚节点通过改变占空比来设置合理的固定时延值并将其放在调度表中,源节点通过改变监听调度表的占空比达到固定时延的目的;当节点跳数较多时,可通过物理分簇配合FDS-MAC有效降低固定时延的值.理论分析和仿真结果表明,该协议可获得合理的固定时延和良好的耗能特性,在很多场景可获应用.     

Cell adhesion receptors and cancer

Cell-to-cell and cell-to-extracellular matrix (ECM) interactions in the functions of cell adhesion and signal transduction are important in global control of cell phenotypes and cell behavior and are crucial for maintenance of homeostasis and structural/functional stabilization of tissues and organs. Cell adhesion receptors are recognized as the molecular basis of cell adhesion. Cadherin and Integrin are widely expressed adhesion receptors in most tissues. They are transmembrane glycoproteins which, through their cytoplasmic domain, bind to many proteins at the inner surface of cell membrane to form molecule-linkage complexes and then connect with the cytoskeleton. Through cell adhesion receptors a network functioning as cell adhesion and signal transduction is organized between tissue cells and cell-ECM. In this regard cell adhesion receptors play an important role in regulation of morphogenesis, cell-cell recognition, cell migration, cell sorting and the determination of cell's fate in development. They mediate cell functions and their fault expression is intimately correlated with development of disorders like cancer. Several isoforms of Integrin were found to have tumor suppressor effect. Some components in the molecule-linkage of focal contact are actin-binding proteins as well as substrates of kinase in the Integrin initiated signal pathway to play a role as signal transducer. Some of these molecules exhibited tumor suppressor effect too. Decreased expression of E-Cadherin has been demonstrated in many epithelium originated carcinomas. Cadherin associated membrane adhesion plaque molecule β-Catenin is also involved in the oncogene Wnt signal pathway. Both E-Cadherin and β-Catenin were proved respectively with tumor suppressor effect against invasiveness and metastasis. That Cadherin is important for the posttranslationally functional expression of Connexin has been supported by evidence from developmental biology and cancer cell differentiation studies to suggest that some sort of interrelation feedback control exists between the two signal pathways.     

亚历山大藻细胞周期中毒素含量及组成的变化

用细胞同步化培养的方法,研究了塔玛亚历山大藻A.tamarenseCI01株不同细胞周期细胞中毒素含量与组成的变化.结果表明,A.tamarenseCI01细胞分裂主要发生在早上6时至8时,细胞密度在6 h内增加近一倍.细胞内毒素合成主要在细胞周期的G1期,由光诱导合成,毒素含量（fmol/cell,Qt）在光周期前8 h内从17 fmol/cell增加到分裂前的24 fmol/cell,而在其它细胞周期细胞内毒素含量稳定,基本不合成毒素.比较分析单细胞C1,2毒素和GTX2,3毒素合成时间及速率,推测在A.tamarenseCI01中细胞首先合成GTX2,3,在其它修饰酶的作用下再转化为C1,2.     

细胞维持离子高(或低)浓度的随机过程论模型

本文建立了细胞维持离子高(或低)浓度的随机过程论模型。模型的随机差分方程是: 其中对于对于作者根据此模型,对细胞内离子浓度的均值和涨落做了计算。该模型是与实验事实相吻合的,同时它还揭示出细胞的自组织功能。本文工作是建立离子运动模型研究的一个新方向。     

细胞周期调控的分子机制与关卡调控

通过对真核生物细胞增殖过程中细胞周期调控的分析, 归纳综合了以cyclin-CDK复合物为核心的细胞周期调控分子机制和以CKI、ATM、p53、Rb等为作用因子的关卡调控.此外, 外源性信号也对真核生物细胞周期起间接调控作用.