PHP14沉默对肺癌细胞凋亡的影响及其机制

目的:在肺癌细胞中沉默PHP14,并研究其对肺癌细胞凋亡的影响及其可能机制。方法:利用shRNA稳定沉默肺癌细胞株A549中PHP14的表达,并利用Annexin V、PI双染和流式细胞仪检测细胞在正常培养条件下和凋亡诱导条件下的凋亡情况;通过皮下接种裸鼠,探讨PHP14沉默对肺癌细胞体内成瘤的影响,并利用Realtime-PCR和Western blotting检测PHP14沉默后凋亡相关基因的表达情况。结果:成功获得了PHP14稳定沉默的肺癌细胞株,发现PHP14沉默可促进肺癌细胞诱导性凋亡,并抑制肺癌细胞的体内成瘤能力,并且发现PHP14沉默对肺癌细胞凋亡的影响可能是通过抑制Bcl-2表达实现的。结论:PHP14沉默可促进肺癌细胞诱导性凋亡,并可能通过抑制Bcl-2影响肺癌细胞凋亡。     

长链非编码RNA SNHG17通过抑制p57表达促进肺癌进展

目的:分析肺癌中长链非编码RNA(lncRNA)小核仁RNA宿主基因17(SNHG17)与p57的表达相关性及功能联系。方法:通过starBase数据库分析SNHG17和p57在肺癌组织和正常组织中的表达差异;采用人正常肺上皮细胞BEAS-2B和人肺癌细胞系A549、H1975进一步分析SNHG17和p57在肺癌细胞和正常肺细胞中的表达差异;采用qRT-PCR和Western印迹检测si-SNHG17在mRNA和蛋白表达方面对SNHG17和p57的影响;采用CCK-8法检测siSNHG17对A549细胞增殖的影响;采用Transwell法检测si-SNHG17对A549细胞迁移和侵袭能力的影响。结果:通过数据分析发现SNHG17在肺腺癌和肺鳞癌组织中显著高表达,而p57在肺腺癌和肺鳞癌组织中却显著低表达;与正常肺细胞相比,SNHG17和p57在肺癌细胞中的表达趋势与在肺癌组织中一致;SNHG17和p57的表达呈负相关;沉默SNHG17使p57的表达一定程度上调,A549细胞的增殖、迁移和侵袭能力受到抑制。结论:SNHG17在肺癌中高表达,促进肺癌细胞增殖,并通过调节p57的表达来抑制肺癌细胞的增殖和迁移。SNHG17和p57在肺癌中的具体作用机制仍有待进一步研究。     

hTERT启动子调控rVBMDMP基因表达载体的构建与功能研究

为了探讨端粒酶催化亚单位(hTERT)启动子调控重组血管基膜衍生多功能肽(rVBMDMP)基因表达抑制肺癌细胞生长的作用机制,采用PCR方法,克隆hTERT启动子核心区片段,并检测其功能活性.然后,构建pLNSX/hTERT/rVBMDMP逆病毒载体,获取逆病毒,感染肺癌A549细胞,检测hTERT启动子调控rVBMDMP基因表达对细胞形态、细胞生长、细胞凋亡以及Caspase-3表达的影响.另外,观察hTERT启动子调控rVBMDMP基因表达对裸鼠成瘤的抑制作用、瘤组织细胞的凋亡及Caspase-3表达情况.结果发现:a.hTERT启动子核心区能调控rVBMDMP基因的表达(n=3,P<0.05);b.hTERT启动子调控rVBMDMP基因的表达具有抑制肺癌A549细胞的生长和裸鼠成瘤作用(n=6,P<0.05);c.rVBMDMP基因表达能促进肺癌A549细胞凋亡和Caspase-3蛋白表达.以上结果说明,hTERT启动子调控rVBMDMP基因表达后,通过提高Caspase-3的表达水平,促进细胞凋亡而抑制肺癌A549细胞的生长.     

稳定高表达人ERP57基因A549细胞株的建立及其对CRT表达的影响

建立稳定高表达人ERP57蛋白的A549细胞株,并观察对CRT表达的影响。采用巢式RT-PCR从人非小细胞肺腺癌A549细胞总RNA中克隆人ERP57 cDNA,构建ERP57真核表达质粒(pcDNA3.1(+)/ERP57)脂质体转染A549细胞。经G418筛选,获得高表达人ERP57蛋白的A549细胞株。通过Western blotting检测细胞中ERP57及CRT蛋白表达情况。成功获得稳定高表达ERP57蛋白的人A549细胞株,CRT表达量无明显改变。成功获得稳定高表达ERP57蛋白的人A549细胞株,证实细胞中高表达ERP57对CRT表达量无明显影响。     

Ad-ING4-IL-24 双基因共表达对人肺腺癌化疗的增敏效应

研究ING4 (肿瘤生长抑制因子4) 和IL-24 (人白细胞介素24) 双基因共表达腺病毒载体 (Ad-ING4-IL-24) 对肺腺癌的化疗增敏效应及分子机制。将Ad-ING4-IL-24感染A549肺癌细胞及联合顺铂 (DDP) 化疗药物作用,RT-PCR和Western blotting检测ING4和IL-24基因在A549肺癌细胞中的转录和表达,MTT法、流式细胞仪 (FCM) 和 Hoechst 染色法检测Ad-ING4-IL-24联合DDP (联合组) 对A549肺癌细胞的生长抑制和凋亡效应。采用A549细胞株建立人肺腺癌裸鼠模型,然后瘤体局部注射干预用药,动态测量肿瘤体积,并计算瘤重抑瘤率,免疫组化检测ING4、IL-24、bax、bcl-2、VEGF等基因的表达。结果表明,Ad-ING4-IL-24感染A549肺癌细胞后可获得成功转录和表达,体外联合组能明显抑制A549肺癌细胞生长和诱导细胞凋亡,呈现出典型细胞凋亡形态学变化。体内联合组同样能显著抑制肿瘤生长,瘤重抑瘤率达52.81％,免疫组化结果显示联合组能上调bax基因表达,同时下调bcl-2、VEGF等基因的表达。以上结果表明Ad-ING4-IL-24具有化疗增敏的作用,该作用机制可能与促进肿瘤细胞凋亡和抑制血管形成有关。     

siRNA表达载体稳定沉默肺癌A549细胞MEKK3基因的细胞株建立

目的构建人MEKK3基因的小干扰RNA（siRNA）表达载体并建立稳定沉默MEKK3基因表达的肺癌A549细胞克隆株。方法设计并合成针对人MEKK3基因4个不同部位siRNA靶点的模板DNA序列,以BamHI及Hindm酶切位点分别克隆入pSilencer4．1-CMVhygro载体,测序鉴定后以脂质体分别转染入A549细胞,Western印迹检测它们对MEKK3表达的抑制,并选择抑制效率最高的表达载体转染入A549细胞,潮霉素筛选后获得含该载体的抗性细胞克隆株,荧光实时定量PCR检测该细胞克隆株中MEKK3表达抑制。结果测序鉴定表明4个MEKK3siRNA表达载体正确无误;Western印迹结果显示对MEKK3的表达有抑制作用,其中pSilencer4．1-MEKK3siRNA2的抑制率达84％;荧光实时定量PCR结果表明,pSilencer4．1-MEKK3siRNA2可稳定沉默MEKK3mRNA的表达,有效率达83％。结论成功地构建了针对人MEKK3基因的siRNA表达载体,并成功地建立了能高效且稳定地沉默MEKK3基因表达的肺癌A549细胞克隆株。     

抗癌药莪棱舌草Ⅱ号诱导人肺癌细胞凋亡的研究

通过运用流式细胞光度术检测细胞凋亡;运用细胞化学方法检测凋亡相关基因蛋白的表达以及Westernblotting分析等方法来研究抗癌药莪棱舌草Ⅱ号对人肺癌细胞(A549细胞)凋亡的诱导作用。结果表明药物能够诱导A549细胞发生凋亡,凋亡率近40%;药物作用可以使细胞中凋亡抑制基因bcl2表达减少,而凋亡促进基因Bax表达增加。提示诱导肿瘤细胞凋亡可能是莪棱舌草Ⅱ号抑杀肺癌细胞的机制之一。     

Nupr1调控非小细胞肺癌细胞迁移、凋亡机制的研究

目的:探讨核蛋白1(Nupr1)调控非小细胞肺癌细胞迁移、凋亡机制的研究。方法:肿瘤抑制剂盐酸素(salinomycin)不同时间处理非小细胞肺癌细胞A549后采用Western Blot法检测非小细胞肺癌细胞A549中Cleaved Caspase-3、Nupr1的蛋白表达;Transwell小室检测Nupr1基因沉默后非小细胞肺癌细胞A549细胞体外迁移、侵袭能力的变化;Western Blot法检测Nupr1沉默后非小细胞肺癌细胞A549 MMP-2、TIMP-1的蛋白表达;流式细胞仪检测Nupr1沉默后非小细胞肺癌细胞A549的凋亡情况。结果:与未经肿瘤抑制剂salinomycin处理对照组相比较,salinomycin处理后的非小细胞肺癌细胞A549中Nupr1蛋白表达量下降,Cleaved Caspase-3蛋白表达量升高,并且随着作用时间呈依赖关系。Nupr1-siRNA转染组的迁移能力相比对照组未转染组下降(64.4±7.2)%,Nupr1-siRNA转染组的侵袭能力相比对照组下降(58.7±7.3)%。与未转染Nupr1-siRNA对照组相比较,转染后TIMP-1的表达明显上调,而MMP-2的表达则明显下调。流式细胞仪检测结果显示Nupr1沉默后非小细胞肺癌细胞A549出现大量凋亡。结论:Nupr1基因沉默后通过上调TIMP-1的表达,下调MMP-2的表达降低肺癌A549细胞的侵袭和迁移能力,进而促进非小细胞肺癌细胞凋亡。     

TRPM7的表达水平与肺癌发生发展的关系

为了解TRPM7在肺癌中的表达及其与肺癌进展的关系,本研究检测了TRPM7在非小细胞肺癌患者肺癌组织样本和相邻正常肺泡组织样本中的表达,以及TRPM7在人肺腺癌A549细胞系和人支气管上皮细胞系16HBE中的表达。通过转染shRNA敲低肺癌细胞中的TRPM7,并应用TRPM7拮抗剂Waixenicin A处理细胞。免疫组化染色和Western blotting分析显示,与正常肺泡组织样本中的TRPM7表达相比,TRPM7在肺癌样本中显著高表达。TRPM7的表达水平与癌症分期有关,分期越高,TRPM7的表达水平越高。TRPM7在A549细胞中的表达强度显著高于16HBE细胞。细胞集落形成测定结果显示,沉默TRPM7会显著抑制细胞集落形成的能力。SRB细胞活力测定显示,沉默TRPM7会显著抑制细胞活力。沉默TRPM7显著降低了肺癌细胞的迁移(-68.94%)和侵袭(-68.84%)能力。沉默TRPM7显著抑制了热休克蛋白90α(HSP90α)、尿激酶型纤溶酶原激活剂(uPA)和基质金属蛋白酶2 (MMP2)的表达。Waixenicin A显著抑制了肺癌细胞的活力及Hsp90α/uPA/MMP2信号分子的表达。另外,Waixenicin A显著降低了肺癌细胞的迁移(-65.35%)和侵袭(-71.85%)能力。本研究表明,TRPM7的异常表达通过激活Hsp90α/uPA/MMP2信号通路来提高人肺癌细胞的活力和转移能力。研究结果表明,靶向TRPM7的抑制剂可能是治疗肺癌的有效药物。     

Prohibitin对非小细胞肺癌细胞增殖和凋亡的影响

目的:研究Prohibitin对非小细胞肺癌株A549和NCI-H460细胞增殖和凋亡的影响.方法:将针对Prohibitin的特异性的干扰片段瞬时转染非小细胞肺癌A549和NCI-H460细胞株,以瞬时转染与Prohibitin没有同源性的干扰片段的细胞作为阴性对照,通过免疫蛋白印迹检测各组细胞Prohibitin和Survivin蛋白的表达情况,通过MTT法检测各组细胞的增殖情况,通过流式仪检测各组细胞的凋亡率.结果:针对Prohibitin基因设计的siRNA片段特异性地沉默该基因的表达,与对照组相比较,干扰组的细胞的增殖活性明显增强.同时与凋亡密切相关的Survivin的表达在沉默掉prohibitin后,在A549和NCI-H460中分别降低了46.3%和54.5%.而干扰prohibitin后导致A549细胞的凋亡率上升了约2%.结论:Prohibitin能显著抑制非小细胞肺癌A549和NCI-H460细胞的增殖,而对凋亡的影响可能并不是通过survivin介导的.     

Effect of doxycycline-regulated ERp57 expression on specific thrombopoietin productivity of recombinant CHO cells

In an attempt to increase the specific thrombopoietin (TPO) productivity (q(TPO)) of recombinant Chinese hamster ovary (rCHO) cells (TPO-33), the effect of expression level of ERp57, an isoform of protein disulfide isomerase, on q(TPO) was investigated. To regulate ERp57 expression level, the Tet-Off system was first introduced in TPO-33 cells and stable Tet-Off cells (TPO-33-Tet-Off) were screened by the luciferase assay. The rCHO cells with a doxycycline-regulated ERp57 expression system (TPO-33-ERp57) were obtained by cotransfection of pTRE-ERp57 and pTK-Hyg expression vectors into TPO-33-Tet-Off cells and subsequent screening by Western blot analysis of ERp57 and an enzyme-linked immunosorbent assay of secreted TPO. Western blot analysis showed that ERp57 expression level in TPO-33-ERp57 cells could be regulated tightly by the addition of different concentrations of doxycycline to a culture medium. A doxycycline concentration of 1 microg/mL, which did not influence cell growth and TPO production of TPO-33-Tet-Off cells, was high enough to suppress the ERp57 expression to a basal level. Compared with the basal level, a 1.7-fold increase in ERp57 expression level was obtained in the absence of doxycycline. This increased expression level of ERp57 resulted in a 2.1-fold increase in q(TPO) without growth inhibition, probably as a result of the chaperone-like activity of ERp57 in CHO cells. Taken together, the results obtained here demonstrate that q(TPO) of rCHO cells can be increased by elevating the expression level of ERp57.     

The co-translocation of ERp57 and calreticulin determines the immunogenicity of cell death

The exposure of calreticulin (CRT) on the plasma membrane can precede anthracycline-induced apoptosis and is required for cell death to be perceived as immunogenic. Mass spectroscopy, immunofluorescence and immunoprecipitation experiments revealed that CRT co-translocates to the surface with another endoplasmic reticulum-sessile protein, the disulfide isomerase ERp57. The knockout and knockdown of CRT or ERp57 inhibited the anthracycline-induced translocation of ERp57 or CRT, respectively. CRT point mutants that fail to interact with ERp57 were unable to restore ERp57 translocation upon transfection into crt(-/-) cells, underscoring that a direct interaction between CRT and ERp57 is strictly required for their co-translocation to the surface. ERp57(low) tumor cells generated by retroviral introduction of an ERp57-specific shRNA exhibited a normal apoptotic response to anthracyclines in vitro, yet were resistant to anthracycline treatment in vivo. Moreover, ERp57(low) cancer cells (which failed to expose CRT) treated with anthracyclines were unable to elicit an anti-tumor response in conditions in which control cells were highly immunogenic. The failure of ERp57(low) cells to elicit immune responses and to respond to chemotherapy could be overcome by exogenous supply of recombinant CRT protein. These results indicate that tumors that possess an intrinsic defect in the CRT-translocating machinery become resistant to anthracycline chemotherapy due to their incapacity to elicit an anti-cancer immune response.     

Mechanisms of pre‐apoptotic calreticulin exposure in immunogenic cell death

Dying tumour cells can elicit a potent anticancer immune response by exposing the calreticulin (CRT)/ERp57 complex on the cell surface before the cells manifest any signs of apoptosis. Here, we enumerate elements of the pathway that mediates pre‐apoptotic CRT/ERp57 exposure in response to several immunogenic anticancer agents. Early activation of the endoplasmic reticulum (ER)‐sessile kinase PERK leads to phosphorylation of the translation initiation factor eIF2α, followed by partial activation of caspase‐8 (but not caspase‐3), caspase‐8‐mediated cleavage of the ER protein BAP31 and conformational activation of Bax and Bak. Finally, a pool of CRT that has transited the Golgi apparatus is secreted by SNARE‐dependent exocytosis. Knock‐in mutation of eIF2α (to make it non‐phosphorylatable) or BAP31 (to render it uncleavable), depletion of PERK, caspase‐8, BAP31, Bax, Bak or SNAREs abolished CRT/ERp57 exposure induced by anthracyclines, oxaliplatin and ultraviolet C light. Depletion of PERK, caspase‐8 or SNAREs had no effect on cell death induced by anthracyclines, yet abolished the immunogenicity of cell death, which could be restored by absorbing recombinant CRT to the cell surface.     

维甲酸对A549细胞增殖和凋亡及Skp2、p27^kip1蛋白表达的影响

目的探讨维甲酸对A549细胞增殖和凋亡及相关基因表达的影响。方法MTT法观察ATRA对A549细胞增殖的抑制作用;流式细胞仪、AO/EB荧光双染法检测细胞凋亡;免疫细胞化学检测ATRA处理前后A549细胞Skp2、p27^kip1蛋白表达的情况。结果ATRA处理后①MTT法结果显示ATRA对A549细胞具有增殖抑制作用,在一定范围内呈时间-剂量依赖性。②AO/EB荧光双染色法观察到ATRA 25μmol/L作用A549细胞48h后,即可发现典型的凋亡形态学改变。③流式细胞仪结果出现凋亡峰,与对照组细胞相比,实验组细胞周期延长,主要表现为G0/G1期细胞比例增加,同时S期细胞比例减少。④免疫细胞化学结果显示,ATRA 25μmol/L处理细胞48h后,维甲酸处理组Skp2有明显下调,p27^kip1则明显上调。结论ATRA具有抑制肺腺癌A549细胞增殖,诱导细胞凋亡的作用,其机制可能与下调Skp2,上调p27^kip1蛋白的表达水平有关。     

Interaction of ERp57 with calreticulin: Analysis of complex formation and effects of vancomycin

The protein ERp57 (also known as PDIA3) is a widely distributed protein, mainly localized in the endoplasmic reticulum, where it acts as disulfide isomerase, oxidoreductase and chaperone, in concert with the lectins calreticulin (CRT) and calnexin. The ERp57/CRT complex has been detected on the cell surface and previous studies have suggested its involvement in programmed cell death. Although the ERp57-CRT complex has been characterized, little is known about its role in different cellular compartments as well as inhibitors of this interaction.We focused on the kinetic, extent and stability of the ERp57-CRT complex, using the surface plasmon resonance spectroscopy, investigating the possible role as inhibitor of the antibiotic vancomycin. Equilibrium thermodynamic data suggested that vancomycin may hinder the interaction between the two proteins and could interfere with the ERp57 conformational changes that stabilize the complex. Furthermore, by means of confocal microscopy, we evaluated the effect of the in vivo administration of vancomycin on the ERp57/CRT complex on the surface of HeLa cells.The model presented here could be used for the search of other specific inhibitors/interactors of ERp57, which can be extremely helpful to understand the biological pathways where the protein is involved and to modulate its activity.     

香烟烟雾提取物抑制肺泡上皮细胞的增殖并诱导其凋亡

香烟烟雾提取物（cigarette smoke extract,CSE）中含有丰富的氧化剂和自由基,由它所引起的氧化应激可导致肺泡壁的损伤进而发展为肺气肿.近年来,围绕CSE损伤肺泡壁作用机制的研究较为活跃,但其结果却一直存在着分歧.本实验的目的是观察CSE对肺泡Ⅱ型上皮细胞的损伤作用并探讨与其相关的分子机制.MTT比色法的结果显示,CSE以时间和剂量依赖性的方式降低细胞的增殖活力,流式细胞术的分析结果表明细胞增殖周期被阻滞在G1/S期.Hoechst 33258染色以及透射电镜观察从形态上确认CSE诱导细胞凋亡的发生,DNA梯的出现和Annexin V-FITC/碘化丙啶双染色的结果从分子水平得到进一步的证实.同时,运用流式细胞术检测到CSE诱导的凋亡伴随着Fas受体的高表达和caspase-3的显著活化.另外,使用H2DCFDA染色,经激光共聚焦显微镜术测得细胞内氧自由基在细胞受到CSE刺激以后大量快速积累.结果表明CSE能够抑制肺泡Ⅱ型上皮细胞来源的A549细胞的生长和增殖,并诱导细胞凋亡,由Fas受体所介导的死亡受体途径参与此凋亡过程,而CSE所引起的氧化应激则可能是阻止肺泡上皮细胞生长增殖并诱导其凋亡的始动因素.     

Rose Bengal Acetate PhotoDynamic Therapy (RBAc-PDT) Induces Exposure and Release of Damage-Associated Molecular Patterns (DAMPs) in Human HeLa Cells

The new concept of Immunogenic Cell Death (ICD), associated with Damage Associated Molecular Patterns (DAMPs) exposure and/or release, is recently becoming very appealing in cancer treatment. In this context, PhotoDynamic Therapy (PDT) can give rise to ICD and to immune response upon dead cells removal. The list of PhotoSensitizers (PSs) able to induce ICD is still short and includes Photofrin, Hypericin, Foscan and 5-ALA. The goal of the present work was to investigate if Rose Bengal Acetate (RBAc), a powerful PS able to trigger apoptosis and autophagy, enables photosensitized HeLa cells to expose and/or release pivotal DAMPs, i.e. ATP, HSP70, HSP90, HMGB1, and calreticulin (CRT), that characterize ICD. We found that apoptotic HeLa cells after RBAc-PDT exposed and released, early after the treatment, high amount of ATP, HSP70, HSP90 and CRT; the latter was distributed on the cell surface as uneven patches and co-exposed with ERp57. Conversely, autophagic HeLa cells after RBAc-PDT exposed and released HSP70, HSP90 but not CRT and ATP. Exposure and release of HSP70 and HSP90 were always higher on apoptotic than on autophagic cells. HMGB1 was released concomitantly to secondary necrosis (24 h after RBAc-PDT). Phagocytosis assay suggests that CRT is involved in removal of RBAc-PDT generated apoptotic HeLa cells. Altogether, our data suggest that RBAc has all the prerequisites (i.e. exposure and/or release of ATP, CRT, HSP70 and HSP90), that must be verified in future vaccination experiments, to be considered a good PS candidate to ignite ICD. We also showed tha CRT is involved in the clearance of RBAc photokilled HeLa cells. Interestingly, RBAc-PDT is the first cancer PDT protocol able to induce the translocation of HSP90 and plasma membrane co-exposure of CRT with ERp57.     

RG108对肺腺癌A549细胞增殖、凋亡及RASSF1A基因表达的影响

目的探讨DNA甲基转移酶抑制剂RG108对人肺腺癌细胞株A549增殖、凋亡以及对RASSF1A（Ras as-sociation domain proteinfamily1）基因启动子区域甲基化状态、表达的影响。方法用20μmol/L的RG108对A549细胞进行化学干预72h,用MTT法检测细胞生长抑制率;流式细胞术检测细胞周期以及凋亡情况;RT-PCR观察RASSF1A基因mRNA水平变化;Western blot检测RASSF1A蛋白的表达;甲基化特异性PCR（MS-PCR）检测RASSF1A基因启动子区域甲基化状态的改变。结果经RG108干预72h后,A549细胞的抑制率为17.2±0.43%,细胞周期阻滞于G0/G1期,并引起细胞凋亡。RT-PCR和Western blot结果显示在干预组细胞中分别出现RASSF1A基因的DNA条带（329bp）和蛋白质条带（39kD）,而对照组中无相应条带出现。RASSF1A基因启动子区域由甲基化状态转变为非甲基化状态。结论RG108可使RASSF1A基因启动子区域去甲基化,并通过该机制诱导RASSF1A基因在人肺腺癌细胞株A549中表达。