Rac1基因真核表达质粒的构建及其对结肠癌细胞生物学功能的影响

目的：应用分子生物学技术构建Rac1基因真核表达质粒及小分子RNA（siRNA）干扰片段，通过调控其表达，研究Rac1蛋白对结肠癌细胞生物学功能的影响。方法从结肠癌细胞中扩增Rac1基因，构建pCDNA3.1(+)-Rac1和pEGFP-Rac1真核表达质粒实现过表达Rac1基因；通过小分子RNA干扰抑制Rac1基因表达。利用侵袭实验、划痕实验研究Rac1基因对结肠癌细胞侵袭和迁移能力的改变；通过Pull-Down实验，研究调控Rac1表达对癌细胞中GTPase活性的影响。结果成功构建Rac1基因真核表达质粒。通过调控Rac1蛋白的表达证实其与结肠癌细胞中Rac1 GTPase的活化程度，以及肿瘤细胞的迁移和侵袭能力呈正性关联。结论通过抑制Rac1的表达，可以有效阻止Rac1 GTPase的激活，从而抑制肿瘤细胞的迁移及侵袭，为抑制结肠癌进展提供新的干预靶点，也为进一步免疫生物过继治疗提供了必要的实验基础。

GTPase在肝癌细胞系中的表达和意义

目的:研究GTPase三个代表性蛋白在肝癌细胞系中的表达,探讨GTPase在肝癌发生发展中的意义.方法:用Western blot测定Rac1、Cdc42、RhoA蛋白在正常肝细胞系和几种肝癌细胞系中的表达水平.结果:与正常肝细胞系相对照,三种肝癌细胞系中Rac1、Cdc42、RhoA的蛋白表达水平均上调.结论:Rac1、CDC42、RhoA可能在肝癌的发生发展中起着重要的作用.

As a fundamental component of the host cellular cytoskeleton, actin is routinely engaged by infecting viruses. Furthermore, viruses from diverse groups, and infecting diverse hosts, have convergently evolved an array of mechanisms for manipulating the actin cytoskeleton for efifcacious infection. An ongoing chorus of research now indicates that the actin cytoskeleton is critical for viral replication at many stages of the viral life cycle, including binding, entry, nuclear localization, genomic transcription and reverse transcription, assembly, and egress/dissemination. Speciifcally, viruses subvert the force-generating and macromolecular scaffolding properties of the actin cytoskeleton to propel viral surifng, internalization, and migration within the cell. Additionally, viruses utilize the actin cytoskeleton to support and organize assembly sites, and eject budding virions for cell-to-cell transmission. It is the purpose of this review to provide an overview of current research, focusing on the various mechanisms and themes of virus-mediated actin modulation described therein.

支架蛋白IQGAP1与肿瘤的研究进展

IQGAPs(IQ motif containing GTPase activating proteins)是近年新发现的一个蛋白家族,其序列中含有类似于RasGAPs催化域的广泛序列和位于N端的4个可与钙调蛋白相互作用的IQ模体,在哺乳动物中有3个同源物IQGAP 1～3.IQGAP1是3个人类IQGAP同系物中发现早的1个~([1]),不同于IQGAP2和IQGAP3限制性地表达于肝和肠道等器官,其呈现出一种全身性地表达~([2-3]).