维生素C衍生物对癌细胞浸润转移能力的抑制作用机理研究

前期研究表明Asc2P6P1m能够有效地抑制癌细胞的浸润转移。本文试图以Asc2P6P1m对人成纤维瘤细胞浸润转移作用探讨维生素C衍生物对癌细胞转移能力抑制的机理。对HT-1080细胞分别以50—300μmol/LAsc2P6P1m处理1h,随着Asc2P6P1m浓度的增大,细胞移动的数目明显减少,Asc2P6P1m对HT-1080细胞移动的抑制作用呈现出量效关系。Asc2P6P1m对ROS的清除作用,通过自旋捕集剂DMPO以电子自旋共振方法进行研究。HT-1080细胞经Asc2P6P1m处理后,细胞内的自由基水平与对照组相比有显著的降低。用F-actin的分子探针NBD研究表明,随处理时间延长,细胞内荧光强度与对照组相比显著降低。Western blots研究表明,细胞核内的RhoA蛋白量随Asc2P6P1m处理时间延长而逐渐增加。研究提示,Asc2P6P1m对癌细胞浸润转移能力的抑制作用是与抑制癌细胞内的ROS、提高细胞核内RhoA水平、降低细胞质内F-actin相关。

低浓度二甲双胍对肝癌细胞株Huh-7迁移、侵袭能力的影响及其机制

目的观察低浓度二甲双胍对肝癌(HCC)细胞株Huh-7细胞迁移、侵袭能力的影响,并探讨其机制。方法取对数生长期的Huh-7细胞,分别加入1、0 mmol/L二甲双胍干预(分别记为观察组和对照组),采用划痕实验评估二甲双胍对细胞迁移能力的影响,细胞侵袭实验评估二甲双胍对细胞侵袭能力的影响,葡萄糖代谢芯片评估二甲双胍对细胞PDK4 mRNA表达的影响,免疫印迹实验分析二甲双胍对细胞PDK4蛋白表达的影响。结果观察组干预24、48 h细胞迁移率分别为40.14%±2.40%、84.02%±3.85%,对照组分别为100.00%±0.00%、170.10±7.48%,两组比较,P均<0.05。观察组干预24 h细胞侵袭数为(183.20±17.13)个,对照组为(403.60±17.31)个,两组比较,P<0.05。观察组及对照组PDK4 mRNA相对表达量分别为1±0.01、1.84±0.01,两组比较,P<0.05。观察组及对照组PDK4蛋白相对表达量分别为0.53±0.01、0.44±0.01,两组比较,P<0.05。结论二甲双胍能抑制HCC Huh-7细胞的迁移和侵袭,机制可能与其可调控PDK4蛋白表达有关。

miR-142-3p通过调控S1PR3影响膀胱癌干细胞的干性

背景:研究发现miR-142-3p低表达于多种肿瘤组织和细胞系中,并且有研究发现TUG1/miR-142/ZEB2轴可抑制膀胱癌增殖并诱导其凋亡。目的:观察miR-142-3p在膀胱癌干细胞中的表达水平,探讨其对S1PR3的靶向调控作用及对膀胱癌干细胞干性的影响。方法:从新鲜人膀胱癌组织中分离培养原代膀胱癌细胞,采用流式细胞仪筛选出CD44^+细胞与CD44^-细胞,Western-blot检测2种细胞中Nanog、Oct4蛋白的表达,qRT-PCR检测2种细胞中miR-142-3p基因的表达。将miR-142-3p mimic(实验组)、miR对照质粒(对照组)分别转染至CD44^+细胞,48 h后,采用MTS实验检测细胞增殖能力,软琼脂克隆实验检测细胞克隆形成能力,Transwell小室实验检测各组细胞转移能力,Western-blot检测细胞中pPi3k和pAkt蛋白表达,qRT-PCR检测细胞中S1PR3基因表达。将稳定转染的2种细胞分别注射至裸鼠(购自北京维通利华实验动物技术有限公司)右侧腋下,4周后检测肿瘤体积。将S1PR3-突变型+miR-142-3p mimic、S1PR3-突变型+miR对照质粒、S1PR3-野生型+miR-142-3p mimic、S1PR3-野生型+miR对照质粒分别转染至CD44^+细胞,48h后检测各组荧光素酶活性。结果与结论:①CD44^+细胞中miR-142-3p基因表达显著低于CD44-细胞(P <0.05);CD44^+细胞中Nanog、Oct4蛋白表达显著高于CD44^-细胞,证实CD44^+细胞为膀胱癌干细胞;②实验组膀胱癌干细胞的增殖能力、克隆形成能力及转移能力明显低于对照组(P <0.05);③实验组膀胱癌干细胞中pPi3k和pAkt蛋白表达弱于对照组,S1PR3基因表达低于对照组(P <0.05);④实验组裸鼠体内肿瘤体积小于对照组(P <0.05);⑤与相比,S1PR3-突变型+miR-142-3p mimic组荧光素酶活性显著低于S1PR3-突变型+miR对照质粒组(P <0.05),S1PR3-野生型+miR对照质粒组和S1PR3-野生型+miR-142-3p mimic组荧光素酶活性无差异(P> 0.05);⑥结果表明,miR-142-3p在膀胱癌干细胞中低表达,其可能通过负调控S1PR3下调PI3K/AKT信号通路来抑制膀胱癌干细胞的干性。

EGFL7基因对人宫颈癌细胞Hela迁移与侵袭能力的影响

目的探究人表皮生长因子样结构域蛋白7(epidermal growth factor-like domain protein 7,EGFL7)基因在人宫颈癌细胞Hela中低表达对其迁移与侵袭能力的影响。方法将人宫颈癌细胞Hela分为实验组(Hela细胞转染EGFL7-siRNA)和对照组(Hela细胞转染Mock-siRNA),采用实时定量PCR法检测两组细胞中EGFL7 mRNA的含量;蛋白免疫印迹实验检测两组细胞EGFL7蛋白的表达量;利用细胞划痕愈合实验和transwell实验检测两组Hela细胞的迁移与侵袭能力。结果siRNA降低了人宫颈癌细胞Hela中EGFL7的蛋白表达;对照组Hela细胞划痕愈百分率为74.1%±6.8%,EGFL7表达降低后宫颈癌细胞划痕愈合百分率为42.0%±4.9%,划痕愈合能力明显下降(P<0.05);Transwell细胞转移结果显示,对照组Hela细胞成功转移的细胞数量为179.24±20.01,而低表达EGFL7的Hela细胞成功转移的细胞数量为79.22±13.16,转染EGFL7-siRNA的细胞转移能力显著下降(P<0.05);侵袭实验结果表明,对照组成功转移的细胞数量为79.35±8.04,EGFL7-siRNA组成功转移的细胞数量为26.98±6.24,低表达EGFL7的Hela细胞侵袭能力明显下降(P<0.05);低表达EGFL7的Hela细胞E-cad表达上调,MMP2/9蛋白的表达下调(均P<0.05)。结论EGFL7低表达会通过上皮间质转化(epithelial to mesenchymal transition,EMT)EMT降低人宫颈癌细胞Hela的迁移与侵袭能力。

Altered cytoskeletal structures in transformed cells exhibiting obviously metastatic capabilities

Oytoskeletal changes in transformed cells (LM-51) exhibiting obviously metastatie eapabilities were investigated by utilization of double-fluorescent labelling through combinations of:(1) tubulin indirect immunofluoresoenoe plus Khodamine-phalloidin staining of F-artins;(2) indirect immunofluorescent staining with α-aotinin polyolonal- and vinoulin monoclonal antibodies. The LM-51 cells which showed metastatic index of >50% were derived from lung metastasis in nude mice after subcutaneous inoculation of human highly metastatic tumor DNA transfected NIH3T3 cell transformants. The parent NIH3T3 cells exhibited well-organized miorotubu-les, prominent stress fibers and adhesion plaques while their transformants showed remarkable oytoskeletal alterations: (1) reduced microtubules but increased MTOC fluorescence; (2) disrupted stress fibers and fewer adhesion plaques with their protein components redistributed in the cytoplasm; (3) F-aotin-and α-actinin/vinculin aggregates appeared in the cytoplasm. These aggregates were dot-like, varied in size (0.1-0.4u,m) and number, located near the ventral surface of the cells. TPA-induced aotin/vinoulin bodies were studied too. Indications that aotin and α-actinin/vinoulin redistribution might be important alterations involved in the expression of metastatio capabilities of LM-51 transformed cells were discussed.

Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase

Human endogenous retrovirus W env(HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis(MS). These diseases are accompanied by immunological reactions in the central nervous system(CNS). Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter – nitric oxide(NO). NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases. In this study, we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env. Moreover, HERV-W env increased the expression and function of human inducible nitric oxide synthase(hi NOS) and enhanced the promoter activity of hi NOS. Microglial migration was also enhanced. These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS. Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases, including neuroinflammatory diseases, stroke, and neurodegenerative diseases.