低氧模拟剂氯化钴对胃癌细胞BGC823中S100A4基因表达的影响

摘要: S100A4基因是肿瘤侵袭转移相关的重要基因, 该基因高表达与胃癌浸润、淋巴结转移及胃癌细胞体外侵袭力密切相关。为探讨S100A4基因高表达的机制, 文章应用低氧模拟剂氯化钴处理胃癌细胞BGC823, RT-PCR、免疫组化、免疫荧光及Western blotting方法分别检测BGC823细胞中S100A4 mRNA及蛋白表达情况。结果显示, 氯化钴处理胃癌BGC823细胞后, S100A4 mRNA及蛋白表达明显增加。提示低氧模拟剂氯化钴可促进胃癌细胞BGC823中S100A4 基因表达。     

S100A4 在胰腺癌中的研究进展

胰腺癌最重要的生物学特性是容易发生转移和侵袭,致使很多患者无法得到根治性治疗。外科手术是胰腺癌惟一可能治愈的手段,但仅有10-20%的患者有机会手术治疗。错过早期诊断、常规疗法普遍不明显及快速肿瘤扩散共同导致患者的预后不良。胰腺癌的发生、发展受多基因调控。S100A4基因是近几年发现的一种具有促肿瘤作用的基因,目前研究认为该蛋白在胰腺癌的侵袭和转移中起重要作用.本文主要就S100A4与胰腺癌的有关研究进展加以综述。     

RAB5A基因对肺腺癌细胞微丝的影响

为研究RAB5A基因对肺腺癌细胞中微丝的影响,通过FITC标记的鬼笔环肽对AGZY83-a细胞骨架中的微丝特异染色,利用共聚焦激光扫描显微镜发现RAB5A过表达后微丝束变密。经Superarray肿瘤转移相关基因微芯片分析RAB5A对肿瘤转移相关基因的表达影响．发现了3个与细胞骨架调节相关基因表达发生变化,NM23H1与Rac1的表达受到抑制．同时S100A4的表达增加。以前有研究认为S100A4基因可抑制NM23H1基因表达,为验证NM23H1基因的表达降低是否由于S100肖4表达增高所致,利用RNAi沉默AGZY83-a细胞中S100A4基因的表达,发现NM23H1基因表达增高,由此推断RAB5A基因可能通过上调S100A4基因表达来抑制NM23H1基因表达。     

S100A4在胰腺癌中的研究进展

胰腺癌最重要的生物学特性是容易发生转移和侵袭,致使很多患者无法得到根治性治疗。外科手术是胰腺癌惟一可能治愈的手段,但仅有10-20%的患者有机会手术治疗。错过早期诊断、常规疗法普遍不明显及快速肿瘤扩散共同导致患者的预后不良。胰腺癌的发生、发展受多基因调控。S100A4基因是近几年发现的一种具有促肿瘤作用的基因,目前研究认为该蛋白在胰腺癌的侵袭和转移中起重要作用.本文主要就S100A4与胰腺癌的有关研究进展加以综述。     

长链非编码RNA在调控EMT及肿瘤侵袭转移中的作用

上皮–间充质转化(EMT)是指在某些因素的作用下,上皮细胞失去极性,细胞紧密连接性丧失,转变成具有迁移能力的间充质细胞的生物学过程。EMT在肿瘤的侵袭转移过程中发挥着重要的作用。长链非编码RNA(lncRNA)在许多癌症中异常表达,在肿瘤的发生发展中发挥了重要的作用, lncRNA亦参与肿瘤侵袭转移,近年来越来越多的研究发现, lncRNA参与调控EMT进程,进而影响肿瘤的侵袭转移,逐渐成为临床肿瘤诊断及治疗的潜在靶点。该文将对lncRNA在调控EMT及肿瘤侵袭转移中的作用机制及相关临床治疗研究进行综述。     

S100A4蛋白与肿瘤血管生成的研究进展

肿瘤血管生成是指肿瘤细胞诱导的微血管生长以及肿瘤中血液循环建立的过程。重要脏器的转移是恶性肿瘤致死的主要原因,而肿瘤生长、转移和复发都依赖于肿瘤血管生成.S100A4基因是近几年发现的一种具有促肿瘤作用的基因,该基因编码一种钙离子结合调节蛋白,通过与钙离子结合在肿瘤发生和发展中起重要作用。目前研究认为该蛋白在肿瘤的侵袭和转移中有促血管生成作用.本文主要就S100A4与肿瘤血管生成的有关研究进展加以综述。     

S100A4原核表达载体的构建以及蛋白的表达和纯化

S100A4是S100蛋白家族的成员,在细胞的增殖、分化、损伤修复以及肿瘤细胞转移等方面发挥重要的调控作用.本研究将S100A4全长基因构建到pET28a原核表达载体上,利用大肠杆菌表达系统表达和纯化出高纯度的重组人S100A4.通过试验证明,重组人S100A4蛋白在体外可以有效地增强黑色素瘤细胞A375-S2的增殖.重组人S100A4原核表达与纯化方法的建立将促进其结构和生物学功能研究,并且对于S100蛋白家族其它蛋白的表达与纯化具有重要的参考意义.     

人类S100A8/A9基因的转录调控

S100蛋白以其在中性条件下能溶解于100%饱和硫酸铵中而得名,是一个酸性的钙离子结合蛋白家族。S100A8和S100A9均为S100蛋白家族成员。S100A8/A9形成的异源二聚体蛋白即钙卫蛋白,在抗感染、抗肿瘤等过程中发挥了重要的功能。S100A8/A9基因启动子受许多转录因子如C/EBPα、C/EBPβ等的调控。炎性因子如白细胞介素、干扰素γ、肿瘤坏死因子α、脂多糖等可以上调S100A8/A9基因的表达,众多的细胞信号通路也参与了S100A8/A9基因的表达调控。表观遗传因素在S100A8/A9基因的表达过程中也发挥了重要的调控作用。本文概述了人类S100A8/A9基因的转录调控进展,对该领域的研究趋势进行了展望。     

Ezrin蛋白信号转导通路及其对肿瘤侵袭转移的最新进展

肿瘤转移是一个多阶段、多途径、涉及多基因及其信号通路变化的一系列复杂过程。了解肿瘤转移相关基因的信号传导通路以及对肿瘤转移的作用机制,为寻找抑制肿瘤转移的关键靶点具有重要的意义。Ezrin高表达与肿瘤转移密切相关,它可通过改变肿瘤细胞极性及细胞运动、调节肿瘤细胞间黏附及细胞与细胞外基质黏附、参与肿瘤细胞内信号转导而影响恶性肿瘤转移。Ezrin过度表达可以破坏正常细胞内信号传递网络的平衡,其中主要涉及的为细胞信号转导相关分子(Rho)及受体酪氨酸蛋白激酶等信号传导途径。Ezrin借助于细胞内错综复杂的信号转导网络调控细胞的形态构成、黏附、吞噬、运动、血管形成等一系列的生物学过程,最终实现肿瘤细胞的侵袭和转移。本文就Ezrin蛋白的信号转导通路及其对肿瘤转移作用的研究进展做一综述。     

S100A4基因在结肠癌中的表达及意义

目的：通过检测S100A4基因在结肠癌细胞系及结肠癌组织中的表达,探讨其与结肠癌的关系。方法：运用RT-PCR法检测不同结肠癌细胞系中S100A4基因的表达情况;通过原位杂交和免疫组化方法检测61例结肠癌标本中S100A4基因的表达。结果：结肠癌细胞系Lovo及HT29均有S100A4基因表达。S100A4蛋白和RNA在结肠癌中表达率分别为36．1％和34.4％,而在正常结肠组织中不表达（p〈0．05）。临床分期晚比临床分期早的患者S100A4表达明显增高（p〈0.05）;有淋巴结转移的患者比无淋巴结转移的患者S100A4表达明显增高（p〈0．05）。此外,S100A4表达还与肿瘤大小,病理学分级,肉眼分型等相关。结论：结肠癌中S100A4基因表达增高,而且与肿瘤的侵袭及转移密切相关,是判断结肠癌生物学行为及预后的有价值的指标。     

S100A4 mediated cell invasion and metastasis of esophageal squamous cell carcinoma via the regulation of MMP-2 and E-cadherin activity

It is well documented that S100A4 is upregulated in a large amount of invasive tumors and plays a pivotal role in tumor invasion and metastasis. However, the precise role and mechanism S100A4 exerts in the invasion and metastasis of esophageal squamous cell carcinoma (ESCC) have not been fully elucidated to date. Our data demonstrated that S100A4 was overexpressed in human ESCC tissues, especially in ESCC with poor differentiation, deep invasion and lymph node metastasis. Subsequently, the knockdown of S100A4 by RNAi in ESCC cell line (EC-1) could reduce cell invasion, metastasis and proliferation ability in vitro. Most importantly, S100A4 regulated MMP-2 positively and E-cadherin negatively in vivo and in vitro to some extent. Our results suggest that S100A4 is an important factor in the invasion, metastasis and proliferation of ESCC and may control invasion and metastasis at least in part through the regulation of MMP-2 and E-cadherin activity. S100A4 may serve as a biomarker for progression of ESCC and a potential molecular target for biotherapy of ESCC.     

Role of fibulin-5 in metastatic organ colonization

The tumor microenvironment is now recognized as a major factor in determining the survival and growth of disseminated tumor cells at potential metastatic sites. Tumor cells send signals to stroma cells and stimulate them to produce factors that in turn create favorable conditions for tumor cell metastasis. Activated fibroblasts constitute an important component of the tumor-associated stroma. We have previously shown that S100A4 protein produced by stromal fibroblasts in the primary tumor stimulates metastasis formation. Here we show that activated fibroblasts also stimulate the formation of metastases independently of S100A4 expression during organ colonization. To identify genes that could potentially interfere with fibroblast-driven metastasis, we used gene expression profiling of S100A4-deficient fibroblasts treated with and without tumor cell-conditioned media. Five differentially expressed genes encoding cell surface and secreted proteins with potential metastasis-modulating activity were selected. Expression of lymphocyte antigen 6 complex (Ly6c) and matrix metalloproteinase 3 (Mmp3) was upregulated in fibroblasts in response to tumor-conditioned medium, whereas expression of cadherin-16 (Cdh16), Ccn2, and fibulin-5 (Fbln5) was downregulated. Further analysis showed that Fibulin-5 is able to suppress the metastatic colonization of lungs and liver. Additional studies suggest a mechanism in which Fibulin-5 suppresses metastasis formation by inhibiting production of matrix metalloproteinase 9 (MMP9) and reducing the invasive behavior of fibroblasts. Together our data are consistent with the notion that tumors secrete factors that downregulate expression of Fbln5 in fibroblasts at sites of metastatic colonization, in turn upregulating Mmp9 expression and stimulating metastatic organ colonization.