LincRNA-p21敲减对胃癌细胞生长和转移的影响及其作用机制

目的：探讨LincRNA-p21敲减对胃癌细胞增殖、迁移与侵袭的影响,并阐明其作用机制。方法：采用实时荧光定量聚合酶链反应（RT-qPCR）法检测胃癌组织、癌旁组织以及3种胃癌细胞（MGC-803、MKN-45和SGC-790）和正常胃黏膜上皮细胞GES-1中LincRNA-p21mRNA表达水平。以MGC-803细胞作为研究对象,实验分为sh-NC组、sh-LincRNA-p21组和AG490+sh-LincRNA-p21组。sh-NC组MGC-803细胞采用慢病毒感染sh-NC;sh-LincRNA-p21组MGC-803细胞采用慢病毒感染sh-LincRNA-p21;AG490+sh-LincRNA-p21组MGC-803细胞采用慢病毒感染sh-LincRNA-p21后,再采用10 μg·L^-1 AG490处理细胞。采用5-乙炔基-2'-脱氧尿苷（EdU）掺入法检测各组MGC-803细胞EdU掺入百分比,CCK-8法检测各组MGC-803细胞活性,Transwell法检测各组MGC-803细胞迁移数和侵袭数,Western blotting法检测sh-NC组和sh-LincRNA-p21组MGC-803细胞中p-JAK1、p-STAT3和p-STAT5蛋白表达水平。将sh-NC组和sh-LincRNA-p21组MGC-803细胞移植入BALB/c裸鼠颈部皮下成瘤,检测瘤体体积和质量。结果：与癌旁组织比较,胃癌组织中LincRNA-p21mRNA表达水平明显降低（P<0.01）;与GES-1细胞比较,MGC-803、MKN-45和SGC-790细胞中LincRNA-p21表达水平均明显降低（P<0.01）。与sh-NC组比较,sh-LincRNA-p21组MGC-803细胞EdU掺入百分比、细胞活性、细胞迁移数和侵袭数、p-JAK1、p-STAT3和p-STAT5蛋白表达水平均明显升高（P<0.05或P<0.01）;与sh-LincRNA-p21组小鼠比较,AG490+sh-LincRNA-p21组MGC-803细胞活性、细胞迁移数和侵袭数均明显降低（P<0.05或P<0.01）。裸鼠成瘤实验,与sh-NC组比较,sh-LincRNA-p21组小鼠瘤体体积和质量均明显增加（P<0.05或P<0.01）。结论：敲减LincRNA-p21可明显促进胃癌细胞的生长与转移,且该促进作用可能与其促进JAK-STAT信号通路活性有关。     

虫草素对人肝癌细胞迁移及侵袭的机制研究

目的 研究虫草素对人肝癌细胞Bel-7402迁移和侵袭的影响,并探讨其作用机制。方法 以人肝癌细胞Bel-7402为研究对象,虫草素处理Bel-7402细胞。MTT法检测细胞活力;划痕实验检测细胞迁移能力;侵袭小室实验检测细胞侵袭能力;实时荧光定量聚合酶链反应（qRT-PCR）检测MMP-2和MMP-9 mRNA 表达情况;Western blotting实验检测MMP-2、MMP-9、ERK、p-ERK、EGFR及p-EGFR蛋白表达水平。结果 虫草素在0～80?μmol/L时对细胞活力无明显影响;而在80～640?μmol/L时,细胞活力出现下降;在320和640?μmol/L时显著降低（P?<0.05）。40和80?μmol/L虫草素均能显著抑制细胞迁移和侵袭活动（P?< 0.05）。与空白对照组比较,虫草素（40和80?μmol/L）处理Bel-7402细胞48?h后,MMP-2和MMP-9 mRNA 及蛋白表达均下降（P?<0.05）。与空白对照组比较,虫草素（40和80?μmol/L）处理明显下调p-ERK和p-EGFR蛋白表达（P?<0.05）。结论 虫草素可能通过EGFR-ERK通路介导MMP-2和MMP-9表达下调,从而调控人肝癌细胞Bel-7402的迁移和侵袭活动。     

巨噬细胞移动抑制因子在原发性肝癌中的临床意义

【目的】探讨肝癌患者血清巨噬细胞移动抑制因子（macrophage migration inhibitory factor,MIF）水平与其临床特征及预后的关系。【方法】用酶联免疫吸附法检测2004年1月至2006年5月60例确诊初治的原发性肝癌患者的血清MIF水平,并与30例健康人相比较,分析其与临床特征及预后的关系。【结果】原发性肝癌患者血清MIF水平较健康对照组显著升高（中位值,34.1ng/mL与15.9ng/mL,P〈0.001）。血清MIF水平与血管侵犯（P=0.014）、进展的临床TMN分期（P=0.037）及转移（P=0.026）密切相关。血清MIF高（〉34.1ng/mL）的患者2年生存率较血清MIF低的患者（≤34.1ng/mL）明显降低（59%与28%,LogRank为6.02,P=0.014）。多因素分析表明MIF水平是影响患者生存的独立预后因素。【结论】MIF可能参与了原发性肝癌的疾病进展过程,提示MIF在原发性肝癌患者中可作为反应肿瘤侵袭及预后的一个有用的生物标记物。     

Clinical attachments: fond farewell or new beginning? A survey of the attitudes and practice of medical consultants and international medical graduates

Objectives

To analyse the experience of clinical attachment (CA) of international medical graduates (IMGs) and consultants.

Design

Analysis of questionnaires and CVs.

Setting and participants

573 IMGs applying for a house officer post and 102 consultant physicians working in North East England.

Results

IMGs had spent a mean of 16 months unemployed, of which 3.8 months was spent on CAs. The median number of CAs was two and the average number of applications sent before obtaining a CA was 73. 90% of IMGs found their CA helpful and 57% would not take up a post without a CA first. Criticisms related to lack of responsibility, isolation and poor job prospects. 90% would apply for honorary posts if advertised. 73% had received induction at the onset of placement, but only 32% had been assessed at the end. 50% of consultants took CAs and only 4% were thinking of stopping doing so. Those without CAs blamed work pressure (43%) and pressure from their employer (23%).

Conclusions

There are deficiencies in pastoral care, the application process and assessment, but CAs are valued by IMGs and offered by half the consultants surveyed. New immigration rules will mean fewer IMGs will come to the UK, but CAs will be needed by those that do, as well by refugees and European Economic Area (EEA) graduates. The tradition of CAs for international graduates could be used to accommodate those coming to the UK on exchanges and scholarships and form part of the recently announced Medical Training Initiative for IMGs.     

甘珀酸增强RSL3对耐顺铂睾丸癌细胞增殖、侵袭和迁移的抑制作用

目的 探讨铁死亡诱导剂RSL3对耐顺铂睾丸癌细胞（I-10/DDP）增殖、侵袭和迁移能力的影响以及甘珀酸对RSL3抗耐药睾丸癌活性的作用。方法 MTT法检测不同浓度RSL3（0、1、2、4、8、16、32 μmol/L）及合用甘珀酸（100 μmol/L）作用后I-10/DDP细胞的存活率、铁死亡抑制剂Fer-1（2 μmol/L）的作用下RSL3（4 μmol/L）及甘珀酸（100 μmol/L）合用RSL3（4 μmol/L）处理后I-10/DDP细胞的存活率。后续实验分为Control组、甘珀酸（100 μmol/L）组、RSL3（2 μmol/L）组、甘珀酸（100 μmol/L）合用RSL3（2 μmol/L）组,采用集落克隆实验检测细胞增殖能力、划痕实验和Transwell实验检测细胞侵袭与迁移能力。Western blot检测GPX4水平、C11 BODIPY 581/591荧光探针检测lipid 活性氧（ROS）水平、FerroOrange荧光探针检测Fe2+水平。结果 RSL3呈浓度依赖性降低I-10/DDP细胞存活率,且在RSL3浓度2、4、8 μmol/L 时,合用甘珀酸后细胞存活率显著降低（P<0.05）;与Control组相比,RSL3处理后I-10/DDP细胞的集落形成数减少、划痕愈合率减小（P=0.012）、侵袭和迁移细胞数减少（P<0.001）;与单用RSL3相比,甘珀酸合用RSL3处理后I-10/DDP细胞的集落形成数显著减少、划痕愈合率显著减小（P=0.005）、侵袭和迁移细胞数显著减少（P=0.001,P=0.002）。Fer-1降低单用RSL3、甘珀酸合用RSL3对I-10/DDP细胞增殖的抑制率（P<0.01）;与Control组相比,RSL3作用后细胞内GPX4水平降低（P=0.001）、lipid ROS 水平（P=0.001）和Fe2+水平升高;且与单用RSL3相比,甘珀酸合用RSL3处理后细胞内GPX4水平明显降低（P=0.01）、lipid ROS 水平（P=0.001）和Fe2+水平明显升高。结论 RSL3可诱导耐顺铂睾丸癌细胞发生铁死亡,并能抑制细胞增殖、侵袭和迁移能力;甘珀酸通过促进RSL3诱导的铁死亡从而增强RSL3的抑制作用。     

miR-29a促进人乳腺癌MCF-7细胞体外迁移和侵袭的机制

探讨微小核酸miRNA-29a对人乳腺癌细胞MCF-7体外迁移和侵袭的促进作用及其机制。采用miR-29a模拟物及miR-29a抑制剂分别上调和下调miR-29a的表达;采用细胞划痕法和Transwell小室法检测miR-29a对细胞迁移和侵袭能力的影响;采用Targetscan7.1数据库预测miR-29a的靶基因;荧光素酶报告法验证miR-29a的靶基因;Western blot和实时荧光定量PCR验证其表达结果。结果表明:miR-29a可显著促进MCF-7细胞的迁移和侵袭能力。Targetscan软件预测HBP1可能为miR-29a的靶基因,荧光素酶报告实验显示miR-29a靶向HBP1基因的3′-UTR区。Western blot和实时荧光定量PCR结果显示,miR-29a下调了HBP1蛋白水平的表达,而mRNA水平则无明显变化。研究结果揭示在乳腺癌中高表达的miR-29a通过下调HBP1,从而使乳腺癌细胞获得高的迁移和侵袭能力,促进乳腺癌的转移。     

南蛇藤素对ApoE基因敲除小鼠主动脉壁MIF及MMP-9表达的影响

目的观察南蛇藤素对ApoE基因敲除小鼠在动脉粥样硬化斑块形成的早期阶段主动脉壁中巨噬细胞移动抑制因子(macrophage migration inhibitory factor,MIF)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)表达的影响。方法8周龄雄性ApoE基因敲除小鼠12只,按随机数字表法分为南蛇藤素干预组和对照组,每组6只,均给予高脂饮食饲养8周,在高脂饲养的后4周,分别予以2mg.kg-1.d-1南蛇藤素和相当剂量的溶剂二甲基亚砜(DMSO)腹腔注射,每日1次,连续用药4周;小鼠处死后行主动脉连续石蜡切片,HE染色观察组织形态学改变,测定ApoE基因敲除小鼠主动脉根部粥样斑块面积,同时采用免疫组化方法观察主动脉壁MIF和MMP-9蛋白表达的强度。结果图像分析测量结果显示对照组形成了早期斑块;南蛇藤素干预组斑块面积较对照组明显减小(P<0.01),斑块面积/动脉壁横切面积也明显降低(P<0.01);南蛇藤素干预组与对照组比较,MIF、MMP-9的表达均明显降低(P<0.01)。结论南蛇藤素可能通过下调ApoE基因敲除小鼠主动脉壁MIF、MMP-9表达,发...     

熊果酸拮抗巨噬细胞促进肝癌细胞迁移和侵袭的作用及其机制

目的：研究熊果酸对巨噬细胞-肝癌细胞共培养体中肝癌细胞迁移和侵袭能力的影响,并初步探讨其作用 机制。方法：采用Transwell迁移和侵袭试验检测熊果酸处理与非处理的巨噬细胞-肝癌细胞共培养体中肝癌细胞的迁 移和侵袭能力的变化;Western印迹法检测共培养体中肝癌细胞上皮-间质转化蛋白E-cadherin,N-cadherin和vimentin的 表达情况。结果：共培养后的肝癌细胞的迁移和侵袭能力显著增强,并发生了上皮-间质样表型转变,上皮-间质转化 的标志蛋白E-cadherin的表达下调,而N-cadherin和vimentin的表达均上调;熊果酸处理的巨噬细胞-肝癌细胞共培养体 中,肝癌细胞的迁移和侵袭能力降低,E-cadherin表达上调,N-cadherin和vimentin的表达下调。结论：熊果酸能够显 著抑制共培养体中肝癌细胞的迁移和侵袭能力及上皮-间质转化能力。     

催乳素对外周血T细胞巨噬细胞移动抑制因子表达的影响

目的:观察催乳素(PRL)对人外周血T细胞分泌巨噬细胞移动抑制因子(macrophage migration inhibition factor, MIF)的调节作用.方法:采用Ficoll-Hypaque密度梯度离心法分离人外周血单个核细胞,再经尼龙棉柱过滤法纯化T细胞.采用植物凝集素(PHA,10 μg/ml)和乙酸豆寇佛波酯(PMA,5 μg/ml)刺激T细胞活化,再分别加入不同浓度的催乳素(20,300,1 000 ng/ml)进行干预.细胞培养24 h后收集细胞,RT-PCR法检测外周血T细胞MIF基因表达水平;ELISA法检测T细胞培养液上清中的MIF含量.同时将MIF荧光素酶报告基因(pGl3-Basic-MIF)转染各组T细胞,检测各转染组的荧光素酶相对活性.结果:各催乳素处理组的MIF基因的表达水平、细胞培养上清的MIF浓度和MIF-lucr报告基因的荧光素酶相对活性比对照组显著增高.结论:催乳素可增强外周血T细胞表达和分泌巨噬细胞移动抑制因子.     

Ethanol Extract of Lycopodium serratum Thunb. Attenuates Lipopolysaccharide-Induced C6 Glioma Cells Migration via Matrix Metalloproteinase-9 Expression

Objectives: To elucidate how ethanol extract of L. serratum (ELS) could exert anti-migratory effects on glioma with the suppression of nuclear factor kappa B (NF-κB) downstream pathway. Methods: Cell viability of ELS on C6 glioma was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Nitric oxide (NO) assay and 2'',7''-dichlorofluorescin diacetate (DCFH-DA) assay were applied to measure NO production and reactive oxygen species (ROS) generation on lipopolysaccharide (LPS)-induced C6 glioma cells. NF-κB, mitogen-activated protein kinase (MAPK), inducible nictric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein were determined by Western blot. Wound healing assay was used to investigate the inhibitory effect of ELS on fetal bovine serum (FBS)-induced migration and matrix metalloproteinase (MMP)-9 and -2 activity was examined by zymography. Results: ELS suppressed LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 through inhibiting the expression of chemokine CCL2 (or monocyte chemoattractant protein-1, MCP-1). In addition, ELS inhibited the expression of iNOS, COX-2, and the production of NO by LPS in C6 glioma cells. ELS also significantly decreased serum-induced migration of C6 glioma cells in scratch wound healing in a dose-dependent manner (P<0.01). The activity of MMP-9 and -2 were also significantly attenuated by ELS with LPS treatment (P<0.01). Conclusion: Our results suggest that downregulation of MMP-9 gene expression might be involved in the anti-migration effect of ELS against LPS-induced C6 glioma cells.