拓扑替康对HeLa细胞增殖与凋亡的影响

目的:观察拓扑替康(TPT)对宫颈癌Hele细胞增殖与凋亡的影响.方法:在相同放疗条件下,采用MTT法检测不同浓度TPT对HeLa细胞增殖的抑制作用;采用流式细胞仪检测细胞周期,TUNEL法检测TPT对HeLa细胞凋亡的影响.结果:随着TPT浓度升高(0.05 mg/L、0.1 mg/L、0.2 mg/L、升至0.4 mg/L),HeLa细胞的增殖抑制率逐渐升高,细胞的凋亡率依次增加.结论:TPT能抑制宫颈癌HeLa细胞的增殖并促进其凋亡.     

增殖细胞核抗原突变体的稳定高表达对HeLa细胞顺铂敏感性的影响

目的 建立稳定高表达增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)或突变体PC-NA(mutant PCNA,mPCNA)目的蛋白的宫颈癌细胞系HeLa细胞,观察PCNA在顺铂诱导的DNA损伤修复中的作用.方法 采用显性负突变策略,通过构建重组人PCNA或mPCNA的真核表达质粒pCDNA3.1/V5-His A-PCNA(His-PCNA)和pCDNA31/V5-His A-mPCNA(His-mPCNA),稳定转染到HeLa细胞中,G418筛选建立稳定高表达目的蛋白的HeLa细胞系;Western印迹法检测蛋白的表达情况;MTT法测定顺铂损伤后不同细胞系的细胞存活率.结果 真核表达质粒经酶切、测序分析与实验设计完全一致;稳定建系后,Western印迹结果显示在相应位置可见清楚的目的条带;MTT结果显示稳定高表达突变体PCNA的细胞系与对照组相比,其细胞存活率呈明显下降趋势.结论 成功构建了真核表达质粒His-PCNA和His-mPC-NA;建立了稳定高表达该质粒的HeLa细胞系;稳定高表达突变体PCNA的细胞系对顺铂损伤更敏感.     

Caveolin-1对MGC803细胞增殖、分化的影响及其机制

为了研究caveolin-1对胃癌细胞生物学行为的影响，探讨caveolin-1作为基因治疗的候选基因的可能性，用Lipofectin将caveolin-1基因稳定转染胃癌细胞系建立稳定表达caveolin-1的胃癌细胞系MGCS03／Cav-1，并将空载体转染MGC803作为对照(MGC803／pcl-neo)。采用免疫细胞化学及western blot检测转染及未转染的MGC803细胞中caveolin-1的表达情况。     

膜联蛋白A5低表达对人宫颈癌细胞系HeLa细胞增殖与凋亡的影响

目的 观察宫颈癌细胞系HeLa细胞在膜联蛋白A5表达降低后,细胞增殖和凋亡的情况. 方法 采用BNA干扰的方法,通过免疫印迹法筛选出对HeLa细胞中膜联蛋白A5的表达抑制效率最高的siRNA,脂质体法将siRNA转染入细胞48h后,用MTT法检测细胞增殖的改变情况,用细胞凋亡光学检测试剂盒检测细胞的凋亡.结果 Helm细胞中膜联蛋白A5的表达被显著抑制,其增殖速度与未转染siRNA的普通HeLa细胞相比,无显著性差异;细胞凋亡显著减少,与未转染siRNA的普通HeLa细胞相比,有显著性差异. 结论 膜联蛋白A5低表达对宫颈癌细胞系HeLa细胞的增殖未见显著影响,但可能影响了细胞的凋亡.     

hPOT1基因过表达对HeLa细胞细胞周期和凋亡的影响

目的观察人POT1(protection of telomeres1)基因过表达对HeLa细胞细胞周期和细胞凋亡的影响。方法利用本课题组构建的hPOTl基因真核表达重组质粒pcDNA3-hPOT1,经脂质体介导瞬时转染HeLa细胞;通过RT-PCR和EMSA法(电泳迁移率改变分析)检测外源基因的表达效果,流式细胞术分析细胞周期,Hoechst33342荧光染色检测细胞凋亡。结果pcDNA3-hPOT1重组质粒转染HeLa细胞48h后,mRNA和蛋白质分析表明,外源性hPOT1基因能在HeLa细胞中有效表达,HeLa细胞阻滞于细胞周期s期,而对凋亡无明显影响。结论hPOT1基因可能参与了高等真核细胞细胞周期调控过程,但与细胞凋亡无密切关系。     

Nucleostemin特异性RNA干扰对HeLa细胞体内外增殖能力的影响

目的：检测肿瘤细胞Nucleostemin（NS）的表达，研究NS特异性RNA干扰对HeLa细胞体内外增殖的影响。方法：提取6种肿瘤细胞总RNA，用 RT-PCR和Northern blot方法检测NS的表达。用NS特异性siRNA表达载体转染HeLa细胞，观察转染的HeLa细胞（简称NS-siRNA-HeLa细胞）体内外增殖的变化。结果：6种肿瘤细胞中NS明显高表达。体外培养的NS-siRNA-HeLa细胞中NS表达显著低于对照组，G0/G1期细胞百分率显著升高。体内致瘤实验显示，NS-siRNA-HeLa细胞在裸鼠体内增殖显著低于对照组。结论： NS在肿瘤细胞中高表达具有普遍性。NS特异性RNA干扰使HeLa细胞进入S期受阻，并可明显降低HeLa细胞体内外的增殖能力。     

截短型人凋亡诱导因子AIF1-400对HeLa细胞的促凋亡作用

目的:观察人截短型AIF(AIF△1-400)对HeLa细胞的促凋亡作用。方法:在AIF△1-120基因克隆成功的基础上进一步改造,构建截去AIF基因线粒体定位信号、FAD结合结构域和NADH结合结构域(1～400位氨基酸)编码序列的AIF△1-400基因,将其克隆入pcDNA3真核表达载体,用脂质体法转染HeLa细胞,通过Western blot检测该基因在转染细胞中的表达通过电镜观察截短型分子对肿瘤细胞的具有促凋亡活性。结果:经酶切鉴定与测序证实,AIF△1-400的真核表达载体构建成功。通过Western blot证实截短型基因在HeLa细胞中表达,电镜观察可见转染细胞骨架的破坏和细胞核固缩等凋亡特征。结论:人截短型AIF(AIF△1-400)基因的表达可诱导HeLa细胞凋亡。     

短发夹状RNA特异性抑制HeLa细胞的Hax-1基因表达

目的:构建靶向Hax-1基因的短发夹状干扰RNA(short hairpin RNA,shRNA)表达载体pGenesil-Hax-1,并探讨siRNA靶向抑制Hax-1基因表达的作用。方法:根据shRNA设计的原则,在Hax-1全长序列中选取含19个核苷酸靶序列,设计形成siRNA的DNA模板并克隆到shRNA表达载体pGenesil-1中,获得可靶向抑制Hax-1基因的重组shRNA表达载体。采用LipofectamineTM2000转染试剂将pGenesil-Hax-1导入HeLa细胞中;分别采用RT-PCR以及Western blot从mRNA和蛋白水平上检测干扰效果。结果:半定量PCR及Western blot结果表明,siRNA可使Hax-1mRNA的转录水平得到显著抑制(P<0.01),Hax-1蛋白的表达较对照组减少约70%。结论:靶向Hax-1基因的重组shRNA表达载体pGene-sil-Hax-1介导的siRNA可显著抑制Hax-1基因在人宫颈癌HeLa细胞中的表达。     

截短型人凋亡诱导因子AIF△1-400对HeLa细胞的促凋亡作用

目的：观察人截短型AIF（AIF△l-400）对HeLa细胞的促凋亡作用。方法：在AIF△l-120基因克隆成功的基础上进一步改造，构建截去AIF基因线粒体定位信号、FAD结合结构域和NADH结合结构域（1～400位氨基酸）编码序列的AIF△l-400基因，将其克隆人pcDNA3真核表达载体，用脂质体法转染HeLa细胞，通过Western blot检测该基因在转染细胞中的表达通过电镜观察截短型分子对肿瘤细胞的具有促凋亡活性。结果：经酶切鉴定与测序证实，AIFAl-400的真核表达载体构建成功。通过Western blot证实截短型基因在HeLa细胞中表达，电镜观察可见转染细胞骨架的破坏和细胞核固缩等凋亡特征。结论：人截短型AIF（AIF△l-400）基因的表达可诱导HeLa细胞凋亡。     

人NSPc1基因慢病毒过表达系统的建立与鉴定

 目的 建立并鉴定人NSPc1慢病毒过表达系统,以便应用过表达技术进一步研究NSPc1功能。方法 设计针对人NSPc1基因cDNA序列的带酶切位点引物,PCR扩增获得双链DNA后,与酶切后的pLenti6-TO-EGFP-TRIP载体片段进行连接、转化,酶切及DNA测序鉴定重组克隆。提取阳性克隆质粒, 转染293T细胞并用Western blot检测质粒过表达效果。用293T细胞制备慢病毒颗粒,感染293T细胞后收集细胞全蛋白用Western blot检测慢病毒系统过表达效果。 结果 证实人NSPc1基因正确插入慢病毒载体,人NSPc1慢病毒过表达质粒及相应病毒颗粒能有效过表达NSPc1基因。结论 人NSPc1慢病毒表达系统的成功建立,为应用过表达技术研究人NSPc1功能打下了基础。     

Hypoxia-inducible factor 1 alpha is essential for hypoxic p27 induction in endometrioid endometrial carcinoma

Hypoxia-inducible factor 1alpha (HIF-1alpha) plays an essential role in the adaptive response of cells to hypoxia. The cyclin-dependent kinase inhibitor p27(Kip1) is highly expressed in the normal endometrium but is lost during endometrial carcinogenesis. However, in high-grade cancers, p27 re-expression is observed. We analysed the role of HIF-1alpha in hypoxia-induced expression of p27 in vitro and in vivo in endometrial cancer. Paraffin-embedded specimens from endometrioid endometrial carcinoma (n = 39) were stained immunohistochemically for HIF-1alpha, p27, and Ki67. HEC1B, an endometrial carcinoma cell line, was cultured under normoxic or hypoxic conditions in the presence or absence of transiently expressed short hairpin RNAs targeting HIF-1alpha. Protein expression of p27 and HIF-1alpha was assessed by western blotting. Immunohistochemical staining revealed perinecrotic HIF-1alpha expression in 67% of the cases and p27 staining centrally in the tumour islands, mostly around necrosis, in 46% of the cases. In 50% of the tumours with perinecrotic HIF-1alpha expression, p27 and HIF-1alpha perinecrotic/central co-localization was observed. In these tumour sections, hypoxia-associated p27 expression showed less proliferation around necrosis. Analysis of cultured endometrial carcinoma cells demonstrated that p27 protein expression is induced by hypoxia. This induction was abrogated by transient knockdown of HIF-1alpha using RNAi. Furthermore, hypoxia induced cell cycle arrest in HEC1B cells. We conclude that, in endometrioid endometrial carcinoma, p27 re-expression by hypoxia is HIF-1alpha-dependent and leads to cell cycle arrest. This may contribute to the survival of cancer cells in hypoxic parts of the tumour.     

LKB1 is essential for the proliferation of T‐cell progenitors and mature peripheral T cells

The serine/threonine kinase LKB1 has a conserved role in Drosophila and nematodes to co‐ordinate cell metabolism. During T lymphocyte development in the thymus, progenitors need to synchronize increased metabolism with the onset of proliferation and differentiation to ensure that they can meet the energy requirements for development. The present study explores the role of LKB1 in this process and shows that loss of LKB1 prevents thymocyte differentiation and the production of peripheral T lymphocytes. We find that LKB1 is required for several key metabolic processes in T‐cell progenitors. For example, LKB1 controls expression of CD98, a key subunit of the L ‐system aa transporter and is also required for the pre‐TCR to induce and sustain the regulated phosphorylation of the ribosomal S6 subunit, a key regulator of protein synthesis. In the absence of LKB1 TCR‐β‐selected thymocytes failed to proliferate and did not survive. LBK1 was also required for survival and proliferation of peripheral T cells. These data thus reveal a conserved and essential role for LKB1 in the proliferative responses of both thymocytes and mature T cells.     

BRCA1 is an essential mediator of vinorelbine-induced apoptosis in mesothelioma

Therapeutic options for malignant pleural mesothelioma (MPM) are limited despite the increasing incidence globally. The vinca alkaloid vinorelbine exhibits clinical activity; however, to date, treatment optimization has not been achieved using biomarkers. BRCA1 regulates sensitivity to microtubule poisons; however, its role in regulating vinorelbine-induced apoptosis in mesothelioma is unknown. Here we demonstrate that BRCA1 plays an essential role in mediating vinorelbine-induced apoptosis, as evidenced by (1) the strong correlation between vinorelbine sensitivity and BRCA1 expression level; (2) induction of resistance to vinorelbine by BRCA1 using siRNA oligonucleotides; (3) dramatic down-regulation of BRCA1 following selection for vinorelbine resistance; and (4) the re-activation of vinorelbine-induced apoptosis following re-expression of BRCA1 in resistant cells. To determine whether loss of BRCA1 expression in mesothelioma was potentially relevant in vivo, BRCA1 immunohistochemistry was subsequently performed on 144 primary mesothelioma specimens. Loss of BRCA1 protein expression was identified in 38.9% of samples. Together, these data suggest that BRCA1 plays a critical role in mediating apoptosis by vinorelbine in mesothelioma, warranting its clinical evaluation as a predictive biomarker.     

肺癌细胞中PAK1的表达下调抑制肺癌细胞的增殖和侵袭能力

目的探讨P21激活激酶1(PAK1)在非小细胞肺癌(NSCLC)组织中的表达及其对NSCLC细胞增殖和侵袭能力的影响。方法采用免疫组化和Western blot(WB)方法检测正常肺组织及NSCLC组织中PAK1的蛋白表达水平。利用PAK1-siRNA下调肺癌细胞系A549和LK-2中PAK1的表达后,通过MTT和Transwell等实验方法,明确PAK1对NSCLC细胞增殖和侵袭能力的影响。结果与正常肺组织相比,PAK1在肺癌组织中呈现明显的胞浆强表达,并且其异常表达与肺癌组织的TNM分期(P=0.020)、组织类型(P=0.007)和淋巴结转移相关(P=0.040)。肺癌细胞系中,PAK1的表达下调能够明显抑制肺癌细胞的侵袭和增殖能力(P0.05)。结论 PAK1促进肺癌细胞的增殖及侵袭能力,发挥着重要的促癌基因功能。     

Liver receptor homolog 1 is essential for ovulation

Female fertility requires normal ovarian follicular growth and ovulation. The nuclear receptor liver receptor homolog 1 has been implicated in processes as diverse as bile acid metabolism, steroidogenesis, and cell proliferation. In the ovary, Lrh1 is expressed exclusively in granulosa and luteal cells. Using somatic targeted mutagenesis, we show that mice lacking Lrh1 in granulosa cells are sterile, due to anovulation. The preovulatory stimulus fails to elicit cumulus expansion, luteinization, and follicular rupture in these mice. Multiple defects, including severely reduced transactivation of the Lrh1 target gene, nitric oxide synthase 3, leads to increased intrafollicular estradiol levels in the absence of Lrh1. This further causes dysfunction of prostaglandin and hyaluronic acid cascades and interrupts cumulus expansion. Lack of Lrh1 also interferes with progesterone synthesis because of failure of normal expression of the Lrh1 targets, steroidogenic acute regulatory protein and cytochrome P450 side-chain cleavage. In addition, expression of extracellular matrix proteases essential for ovulation is compromised. These results demonstrate that Lrh1 is a regulator of multiple mechanisms essential for maturation of ovarian follicles and for ovulation. Lrh1 is therefore a key modulator of female fertility and a potential target for contraception.     

NSPc1相互作用蛋白的筛查及其与组蛋白乙酰化酶HBO1相互作用的验证

目的 寻找多梳家族(polycomb group)蛋白NSPc1的体内可能的相互作用蛋白.方法 通过酵母双杂交实验筛选与NSPc1相互作用的蛋白.使用Pull-down实验,Co-IP实验以及细胞内荧光共定位实验进一步证实双杂交中发现的相互作用.结果 分别以NSPc1蛋白的全长、N端和C端作为诱饵筛查人3月胎脑cDNA文库,发现N端诱饵可以与组蛋白乙酰化转移酶HBO1相互作用,该相互作用在体内外实验中都得到了验证.结论 组蛋白乙酰化酶HBO1是NSPc1的相互作用蛋白之一,该相互作用可能参与NSPc1对靶基因转录的表观抑制活性的发挥.