AKT1负性调控乳腺癌细胞迁移的机制研究

目的:明确AKT1负性调控乳腺癌细胞迁移的分子机制,为乳腺癌转移的防治提供新思路和新靶点。方法:以乳腺癌MCF-7细胞和MDA-MB-231细胞为研究对象,采用RNA干扰技术敲减AKT1的表达,Western blot检测AKT1总蛋白、β-连环蛋白(β-catenin)总蛋白和核蛋白的表达,免疫荧光检测β-catenin在乳腺癌细胞中的定位,Transwell迁移实验探究β-catenin的核转位是否参与AKT1负性调控乳腺癌细胞迁移的过程。结果:敲减AKT1表达后,β-catenin总蛋白与核蛋白的表达明显上调,乳腺癌MCF-7细胞和MDA-MB-231细胞的迁移能力也明显增强,使用XAV-939抑制β-catenin的核移位后,敲减AKT1表达引起的乳腺癌细胞迁移能力的增强也明显下降。结论:AKT1对乳腺癌细胞迁移的负性调控可能是由β-catenin核转位介导的。     

RARG对胃癌细胞活力和迁移能力的影响

目的:探讨视黄酸受体γ(retinoic acid receptor gamma,RARG)对胃癌细胞活力和迁移能力的影响及其机制。方法:采用生物信息学技术分析在线数据库中胃癌和正常胃组织的RARG表达水平及其与胃癌患者总生存率的相关性;利用过表达质粒转染和RNA干扰技术,在体外促进和抑制胃癌细胞中RARG的表达,并采用MTT和Transwell实验检测RARG对胃癌细胞活力和迁移能力的影响;通过Western blot和TOP/FOP双萤光素酶报告基因检测RARG对Wnt/β-catenin信号通路的调控;利用免疫共沉淀和免疫荧光共定位实验检测RARG与β-catenin蛋白的相互作用情况。结果 :过表达RARG能够增强胃癌细胞SGC7901的活力和迁移能力(P0.05),敲减RARG能够减弱胃癌细胞MGC-803的活力和迁移能力(P0.05)。同时,过表达RARG能够增加β-catenin、c-Myc、cyclin D1、Twist和Snail的蛋白表达水平(P0.05),以及TOP/FOP双萤光素酶报告基因活性(P0.05)。另外,RARG与β-catenin蛋白存在相互作用。结论 :RARG通过激活Wnt/β-catenin信号通路促进胃癌细胞的活力和迁移能力,其基因在胃癌的发生发展中扮演着癌基因的角色。     

长链非编码RNA PVT1调控miR-551通过Wnt信号通路对卵巢癌迁移和侵袭的影响

目的:探讨长链非编码RNA PVT1在卵巢癌组织中的表达情况及其在卵巢癌细胞迁移和侵袭过程中的作用及机制。方法:q PCR检测卵巢癌和正常卵巢组织及不同卵巢癌细胞中PVT1的表达情况;Transwell侵袭实验和细胞划痕实验分别检测沉默PVT1后卵巢癌细胞侵袭和迁移能力的变化;双萤光素酶报告基因检测PVT1与微小RNA(miR)-551的相互作用;Transwell侵袭实验和细胞划痕实验分别检测沉默PVT1后miR-551-inhibitor对卵巢癌细胞侵袭和迁移能力的影响;Western blot法检测沉默PVT1后Wnt信号通路相关蛋白的表达情况。裸鼠皮下成瘤实验检测沉默PVT1对卵巢癌成瘤重量及体积的影响。结果:与正常卵巢组织相比,卵巢瘤组织中PVT1表达明显增高(P0.05);卵巢癌细胞株ES-2中PVT1表达水平最高(P0.05);沉默PVT1可以抑制卵巢癌细胞侵袭和迁移能力;PVT1能与miR-551的位点特异性结合;沉默PVT1后,miR-551-inhibitor可以促进卵巢癌细胞侵袭和迁移能力;沉默PVT1后Wnt信号通路蛋白的表达相应下调;与阴性对照组相比,PVT1-siRNA组荷瘤小鼠肿瘤体积和重量都明显减小(P0.05)。结论:PVT1在卵巢癌发生发展过程中起重要作用,它可以靶向调节miR-551,通过Wnt信号通路调控卵巢癌细胞的侵袭和迁移能力。     

转染胃动蛋白2基因抑制人胃癌细胞系MKN28增殖、迁移和侵袭

目的检测胃癌、癌旁组织和胃癌远端胃黏膜组织中胃动蛋白2(GKN2)的表达;分析GKN2转染人胃癌MKN28细胞系后对增殖、迁移和侵袭的影响。方法免疫组织化学技术检测胃癌、癌旁组织和胃癌远端胃黏膜中GKN2蛋白的表达;将GKN2基因真核表达载体(Xhol_GKN3SP-h GKN2-TEV-SBP_Xhol)转入人胃癌MKN28细胞,经G418筛选后获得稳转细胞株,Western blot确定GKN2在MKN28细胞中表达;MTT法测定MKN28细胞增殖;Transwell迁移实验和侵袭实验检测细胞迁移和侵袭。结果 GKN2在胃癌组织中的表达少于胃癌远端胃黏膜和癌旁胃组织(P<0.05)。GKN2转染人胃癌MKN28细胞后吸光度值(A值)显著低于未转染组和空载体组(P<0.05)。与未转染组及空载体组相比,GKN2过表达致使迁移细胞数(P<0.05)和侵袭细胞数均明显下调(P<0.05)。结论 GKN2表达减低与胃癌的发生有关;GKN2过表达显然可阻抑人胃癌MKN28细胞的增殖、迁移和侵袭。     

骨桥蛋白对骨髓间充质干细胞核力学特性的影响及相关分子机制

目的研究骨桥蛋白(osteopontin,OPN)对骨髓间充质干细胞(bone marrow-derived mesenchymal stem cells,BMSCs)核力学特性的影响及相关分子机制。方法采用Transwell法分析BMSCs迁移能力。利用原子力显微镜(atomic force microscope,AFM)检测细胞核弹性模量,分析OPN作用下BMSCs细胞核硬度的变化。通过Western blot技术检测OPN作用对黏着斑激酶(focal adhesion kinase,FAK)和胞外信号调节激酶1/2(extracellular signal-regulated kinase 1/2,ERK 1/2)的影响,并利用FAK或ERK1/2抑制剂考察FAK-ERK1/2信号通路在OPN影响BMSCs核力学特性中的作用。通过RT-PCR和Western blot技术检测OPN作用下核纤层蛋白Lamin A/C的表达变化。结果 OPN处理组细胞核弹性模量与对照组相比明显降低。OPN作用显著上调FAK、ERK1/2磷酸化水平,加入FAK或ERK1/2抑制剂在一定程度上回救OPN降低的细胞核弹性模量,并显著抑制BMSCs迁移。OPN处理BMSCs后Lamin A/C mRNA和蛋白水平的表达出现下调,但FAK或ERK1/2抑制剂能够抑制OPN诱导的Lamin A/C表达下调。结论 OPN可能通过FAK-ERK1/2信号通路下调BMSCs核骨架蛋白Lamin A/C表达,降低细胞核硬度,促进BMSCs迁移。该研究结果为深入认识OPN调控BMSCs迁移行为的机制及其临床应用提供了实验依据。     

Activation and Migration of Adventitial Fibroblasts Contributes to Vascular Remodeling

The rat carotid artery balloon injury model was used to prove the activation and migration of adventitial fibroblasts. We found that at day 7 after injury, adventitial fibroblasts proliferated, transformed into myofibroblasts under transmission electron microscopy in the model group. Simultaneously, we proved that the adventitial cells migrated to the media and intima on seventh day after injury by directly labeled the adventitial cells by the in vivo gene transfer technique. Moreover, we captured the precise moment when the adventitial fibroblasts migrated from the adventitia to the media through the external elastic plate under transmission electron microscope. This study provides direct evidences that adventitial fibroblasts activate and migrate to the media and intima, then actively take part in revascularization. Anat Rec, 301:1216–1223, 2018. © 2018 Wiley Periodicals, Inc.     

The Permian reptile Opisthodontosaurus carrolli: a model for acrodont tooth replacement and dental ontogeny

Continuous tooth replacement is common for tetrapods, but some groups of acrodont lepidosaurs have lost the ability to replace their dentition (monophyodonty). Acrodonty, where the tooth attaches to the apex of the jawbone, is an unusual form of tooth attachment that has been associated with the highly autapomorphic condition of monophyodonty. Beyond Lepidosauria, very little is known about the relationship between acrodonty and monophyodonty in other amniotes. We test for this association with a detailed study of the dentition of Opisthodontosaurus, an unusual Early Permian captorhinid eureptile with acrodont dentition. We provide clear evidence, both histological and morphological, that there were regular tooth replacement events in the lower jaw of Opisthodontosaurus, similar to its captorhinid relatives. Thus, our study of the oldest known amniote with an acrodont dentition shows that acrodonty does not inhibit tooth replacement, and that many of the characteristics assigned to lepidosaurian acrodonty are actually highly derived features of lepidosaurs that have resulted secondarily from a lack of tooth replacement. In the context of reptilian dental evolution, we propose the retention of the simple definition of acrodonty, which only pertains to the relative position of the tooth at the apex of the jaw, where the jaw possesses equal lingual and labial walls. This definition of implantation therefore focuses solely on the spatial relationship between the tooth and the jawbone, and separates this relationship from tooth development and replacement.