羟基喜树碱诱导肝癌细胞凋亡前后线粒体蛋白质组表达差异的定量分析

目的 对羟基喜树碱诱导人肝癌细胞SMMC-7721凋亡前后的线粒体进行定量蛋白质组学研究.方法 用羟基喜树碱诱导肝癌细胞SMMC-7721凋亡,提取线粒体并鉴定其纯度;用可裂解的同位素标记的亲和标签技术标记线粒体蛋白质,利用二维液相色谱串联质谱分析鉴定蛋白质.结果 获得了羟基喜树碱诱导细胞凋亡前后的高纯度线粒体;分析鉴定了细胞凋亡前后,相对表达量差异有统计学意义的蛋白质74种,其中42种线粒体蛋白质在细胞凋亡后的表达量下调,32种蛋白质的表达量在凋亡细胞中上调.这些差异蛋白的分子功能主要表现为能量代谢和核酸的翻译、转录、复制以及细胞骨架等.结论 获得了羟基喜树碱诱导肝癌细胞凋亡前后的线粒体差异蛋白信息,将促进对癌细胞凋亡机制及羟基喜树碱药理作用的深入理解,同时,实验所采用的整合技术平台将有助于亚细胞定量蛋白质组学研究.     

羟基喜树碱诱导SMMC-7721细胞凋亡时线粒体凋亡诱导因子的转位研究

目的研究羟基喜树碱诱导肝癌细胞株SMMC-7721凋亡时线粒体凋亡相关蛋白凋亡诱导因子表达及从线粒体发生核转位的变化.方法用80 μg/ml羟基喜树碱作用于肝癌细胞株SMMC-7721后,用吖啶橙/溴化乙啶染色法观察细胞凋亡现象;用电子显微镜观察线粒体超微结构;分别用逆转录聚合酶链反应、Western blot检测凋亡诱导因子在mRNA与蛋白质水平表达的变化;用激光共聚焦显微镜观察凋亡诱导因子在细胞凋亡时从线粒体到核的迁移变化.结果 80μg/ml羟基喜树碱作用SMMC-7721细胞后,吖啶橙/溴化乙啶荧光双重染色可见细胞体积缩小、细胞皱缩、核碎裂等典型细胞凋亡形态学改变;超微结构观察发现线粒体肿胀;细胞凋亡时凋亡诱导因子在mRNA与蛋白质水平上的表达与对照组细胞相比没有明显变化,但凋亡诱导因子发生了从线粒体到核的迁移. 结论羟基喜树碱可以通过线粒体途径诱导人肝癌细胞发生凋亡;在线粒体凋亡途径中,线粒体凋亡相关蛋白凋亡诱导因子从线粒体释放并发生核转位可能与羟基喜树碱诱导细胞凋亡密切相关.     

人颗粒溶素对肝癌细胞SMMC-7721凋亡、线粒体跨膜电位及细胞色素C释放的影响

目的 构建携带人颗粒溶素(GLS)的真核表达质粒pBudCE4.1/GLS并研究其表达后对肝癌细胞SMMC-7721凋亡、线粒体跨膜电位与细胞色素C转位的影响. 方法 将RT PCR扩增出的人GLS编码基因克隆入pBudCE4.1载体中构建真核表达质粒pBudCE4.1/GLS并将其转染肝癌细胞株SMMC-7721,用RT-PCR、免疫细胞化学检测GLS的表达;用Hoechst法及电镜检测细胞的凋亡状况;用荧光染料MitocaptureTM检测线粒体跨膜电位,用Western blot法检测细胞色素C从线粒体的释放. 结果 成功构建了携带GLS的真核表达质粒pBudCE4.1/GLS,在转染的肝癌细胞株SMMC-7721中,从转录和翻译水半都检测到了目标基因GLS的表达产物;重组质粒转染SMMC-7721细胞后,细胞核染色质固缩,旱致密浓染的凋亡状态,线粒体膜跨电位下降并伴随有细胞色素C从线粒体至细胞质的释放. 结论携带人GLS的真核表达质粒在肝癌细胞SMMC-7721中表达后有致细胞凋亡作用,引起线粒体跨膜电位下降与细胞色素C的释放可能是其诱导肿瘤细胞凋亡的途径之一.     

科罗索酸对SMMC-7721细胞生长抑制作用的初步研究

目的研究中药猫人参中提取的三萜化合物科罗索酸（CRA）对人肝癌SMCC-7721细胞生长的影响。方法 MTT法检测不同浓度下细胞存活率,流式细胞仪检测细胞凋亡率,MitoCapture染色观察CRA作用后细胞线粒体膜电位的改变,并进一步用Western blot法检测线粒体对细胞色素C释放情况及Bax、Bcl-2表达情况的影响。结果 35μmol/L的CRA可明显抑制SMMC-7721细胞存活并具有凋亡诱导作用;CRA可使线粒体膜电位耗散,使细胞色素C由线粒体内释放入胞质;CRA可增加Bax表达而对Bcl-2表达无明显影响。结论猫人参提取物CRA可能经由线粒体途径及上调Bax表达、增加Bax/Bcl-2比率诱导肝癌SMMC-7721细胞凋亡。     

羟基喜树碱对人肝癌细胞增殖影响及凋亡诱导

目的 探讨羟基喜树碱对人肝癌细胞株SMMC-7721增殖的影响及其诱导凋亡的作用。方法 以不同浓度的羟基喜树碱在体外作用于人肝癌细胞株SMMC-7721,采用MTT法检测细胞增殖;化学荧光法检测Bcl-2的细胞表达;电镜观察、流式细胞仪与原位末端标记方法检测细胞凋亡情况。结果 与空白对照组比较,羟基喜树碱浓度在3.125μg/mL～100μg/mL组,对肿瘤细胞的增殖抑制率显著增高(P<0.01);在0.05mg/mL组出现细胞早期凋亡现象,Bcl-2表达明显减少;在0.1mg/mL组形成凋亡小体;细胞凋亡比例随羟基喜树碱浓度增加而增高。结论 羟基喜树碱在体外可抑制人肝癌细胞株SMMC-7721增殖,其作用机制可能系通过抑制Bcl-2表达诱导细胞凋亡。     

毛花苷C促进肝癌SMMC-7721细胞凋亡及抑制survivin的表达

目的:通过毛花苷C作用于人肝癌SMMC-7721细胞,研究其对SMMC-7721细胞增殖的影响初步探讨其作用机制.方法:使用不同浓度毛花苷C干预S M M C-7721细胞,通过细胞增殖实验及克隆形成实验,检测毛花苷C对SMMC-7721细胞增殖的作用;通过流式细胞仪检测毛花苷C对SMMC-7721细胞周期和凋亡的影响;采用Western blot技术分析细胞凋亡抑制基因survivin的表达.结果:毛花苷C对SMMC-7721细胞增殖有明显的抑制作用,各加药组与对照组相比差异有统计学意义(P0.01),并呈现剂量-效应相关关系;流式细胞术显示,毛花苷C将S M M C-7721细胞阻滞于S期,并诱导其凋亡;Western blot检测结果显示毛花苷C下调SMMC-7721细胞内survivin蛋白的表达.结论:毛花苷C明显抑制SMMC-7721细胞增殖,将细胞阻滞在S期并诱导其凋亡.该机制可能与下调survivin的蛋白表达有关.     

过氧化氢在乙醇抑制肝癌细胞增殖中的作用

目的探讨过氧化氢(H2O2)在乙醇抑制肝癌细胞增殖过程中的作用.方法 40mmol/L低浓度乙醇作用于人肝癌细胞株SMMC-7721,分别于12 h、24 h、48h后观测细胞增殖情况.流式细胞仪检测H2O2、线粒体膜电位和细胞亚二倍体凋亡峰情况,比较乙醇组与乙醇合用过氧化氢酶(CAT)组两组之间线粒体膜电位改变及细胞亚二倍体凋亡峰变化情况.结果乙醇能抑制SMMC-7721细胞增殖,在48h后细胞抑制率达85.44±2.97%.细胞内H2O2在乙醇作用30 min后增加不明显(6.32±0.93%),1 h后明显增加(25.68±1.67%),2 h后增加非常明显(98.78±3.65%).乙醇作用6 h后线粒体膜电位出现降低,24 h后检测到细胞亚二倍体凋亡峰出现.CAT能抑制上述两指标改变,差异均有显著性.结论乙醇能够抑制SMMC-7721细胞增殖,其作用机制和H2O2损伤SMMC7721细胞线粒体,诱导细胞凋亡有关.     

美洲大蠊提取物诱导人肝癌细胞SMMC-7721凋亡及作用机制

目的 探讨美洲大蠊提取物对人肝癌细胞SMMC-7721增殖、凋亡的影响并探讨其相关机制.方法 取对数生长期状态良好的SMMC-7721细胞分为三组,观察组常规培养24h后加入美洲大蠊提取物,使终浓度分别为300、100、33.3 μg/mL,顺铂组加入顺铂20 μg/mL作用细胞48 h,对照组不做任何处理.采用MTT比色法检测细胞增殖抑制率;采用流式细胞仪分析细胞凋亡率;JC-1染色法检测细胞线粒体膜电位变化;分光光度法检测Caspase-3活性变化.结果 观察组和顺铂组细胞抑制率明显高于对照组,IC50为100 μg/mL,并呈现时间一剂量依赖关系(P＜0.05);观察组和顺铂组细胞凋亡率明显高于对照组,呈现剂量依赖性(P＜0.05).凋亡过程中线粒体膜电位下降,Caspase-3活性升高(P＜0.05).结论 美洲大蠊提取物具有抑制人肝癌细胞SMMC-7721增殖并诱导其凋亡作用,线粒体途径可能是其诱导肝癌细胞凋亡的主要机制之一.     

羟基磷灰石纳米粒子诱导肝癌SMMC-7721细胞凋亡的研究

目的观察不同浓度的羟基磷灰石纳米粒子对肝癌SMMC-7721细胞作用的影响。方法将羟基磷灰石纳米粒子以不同浓度和时间作用于肝癌SMMC-7721细胞，采用MTT比色法观察细胞毒性；应用电镜技术及HE染色法观察凋亡细胞的形态；原位末端标记法（TUNEL法）检测细胞凋产率。结果羟基磷灰石纳米粒子以剂量依赖和时间依赖的方式抑制SMMC-7721细胞的生长，作用48h后的半数有效抑制浓度IC50值为179．8μg／ml。HE染色和透射电镜观察到凋亡特性的形态学改变。结论HAP抑制SMMC-7721细胞的增殖，诱导细胞凋亡，HAP也许会成为临床治疗肝癌自可有效抗肿瘤药物。     

NRF2/PI3K通路介导肝癌细胞SMMC-7721出现索拉非尼耐药的机制研究

目的探讨NRF2PI3K通路介导肝癌细胞SMMC-7721出现索拉非尼耐药的机制研究。方法建立肝癌细胞系SMMC-7721耐药细胞株SMMC-7721-SR,构建NRF2-siRNA转染肝癌细胞,并给与10μmol/L索拉非尼处理48 h。采用CCK-8法检测细胞活力,采用流式细胞仪检测细胞凋亡,Western blot检测NRF2、Keap1、ARE、p-PI3K和p-Akt蛋白表达水平。Real-Time PCR检测NRF2、Keap1、ARE、p-PI3K和p-Akt基因表达水平。结果索拉非尼明显抑制肝癌细胞SMMC-7721的存活率,促进肝癌细胞SMMC-7721凋亡发生(P0.05)。索拉非尼对SMMC-7721细胞促凋亡作用明显强于SMMC-7721-SR细胞(P0.05)。SMMC-7721-SR细胞中NRF2蛋白水平及mRNA表达明显高于SMMC-7721细胞,Keap1、ARE、PI3K和Akt蛋白水平及mRNA表达明显增加(P0.05)。索拉非尼明显上调SMMC-7721细胞中NRF2蛋白水平及mRNA表达(P0.05)。抑制NRF2 mRNA表达并给予索拉非尼处理后,SMMC-7721-SR细胞存活率明显降低,凋亡率显著升高,Keap1、ARE、p-PI3K和p-Akt蛋白水平及mRNA表达明显降低(P0.05)。结论索拉非尼激活NRF2后诱导肝癌细胞SMMC-7721出现耐药;抑制NRF2可逆转肝癌细胞SMMC-7721对索拉非尼的耐药情况。     

Protein profile of human hepatocarcinoma cell line SMMC-7721： Identification and functional analysis

AIM: To investigate the protein profile of human hepatocarcinoma cell line SMMC-7721, to analyze the specific functions of abundant expressed proteins in the processes of hepatocarcinoma genesis, growth and metastasis, to identify the hepatocarcinoma-specific biomarkers for the early prediction in diagnosis, and to explore the new drug targets for liver cancer therapy. METHODS: Total proteins from human hepatocarcinoma cell line SMMC-7721 were separated by two-dimensional electrophoresis (2DE). The silver-stained gel was analyzed by 2DE software Image Master 2D Elite. Interesting protein spots were identified by peptide mass fingerprinting based on matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database searching. RESULTS: We obtained protein profile of human hepatocarcinoma cell line SMMC-7721. Among the twenty-one successfully identified proteins, mitofilin, endoplasmic reticulum protein ERp29, ubiquinol- cytochrome C reductase complex core proteinⅠ, peroxisomal enoyl CoA hydratase, peroxiredoxin-4 and probable 3-oxoacid CoA transferase 1 precursor were the six novel proteins identified in human hepatocarcinoma cells or tissues. Specific functions of the identified heat-shock proteins were analyzed in detail, and the results suggested that these proteins might promote tumorigenesis via inhibiting cell death induced by several cancer-related stresses or via inhibiting apoptosis at multiple points in the apoptotic signal pathway. Other identified chaperones and cancer-related proteins were also analyzed.CONCLUSION: Based on the protein profile of SMMC-7721 cells, functional analysis suggests that the identified chaperones and cancer-related proteins have their own pathways to contribute to the tumorigenesis, tumor growth and metastasis of liver cancer. Furthermore, proteomic analysis is indicated to be feasible in the cancer study.     

Alreration of nuclear matrix-intermediate filament system and differential expression of nuclear matrix proteins during human hepatocarcinoma cell differentiation

AIM:To investigate the association between the configurational and compositional changes of nuclear matrix and the differentiation of carcinoma cells. METHODS: Cells cultured with or without 5 x 10"3 mmol/L of hexamethylene bisacetamide (HMBA) on Nickel grids were treated by selective extraction and prepared for whole mount observation under electron microscopy. The samples were examined under transmission electron microscope. Nuclear matrix proteins were selectively extracted and subjected to subcellular proteomics study. The protein expression patterns were analyzed by PDQuest software. Spots of differentially expressed nuclear matrix proteins were excised and subjected to in situ digestion with trypsin. The peptides were analyzed by matrix-assisted laser-desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). Data were submitted for database searching using Mascot tool (www.matrixscience.com). RESULTS: The nuclear matrix (NM) and intermediate filament (IF) in SMMC-7721 hepatocarcinoma cells were found relatively sparse and arranged irregularly. The nuclear lamina was non-uniform,and two kinds of filaments were not tightly connected. After induction for differentiation by HMBA,the NM-IF filaments were concentrated and distributed uniformly. The heterogeneous population of filaments,including highly branched utrathin filaments could also be seen in the regular meshwork. The connection between the two kinds of filaments and the relatively thin,condensed and sharply demarcated lamina composed of intermediate-sized filaments was relatively fastened. Meanwhile,21 NM proteins changed remarkably during SMMC-7721 cell differentiation. Four proteins,i.e. mutant Pyst1,hypothetical protein,nucleophosminl,and LBP were downregulated,whereas four other proteins,eIF6,p44 subunit,(3-tubulin,and SIN3B were upregulated with the last one,SR2/ASF found only in the differentiated SMMC-7721 cells. CONCLUSION: The induced differentiation of SMMC-7721 cells by HMBA is accompanied by the configurational changes of nuclear matrix-intermediate filament (NM-IF) system and the compositional changes of nuclear matrix protein expression. These changes may be important morphological or functional indications of the cancer cell reversion.     

Alteration of nuclear matrix-intermediate filament system and differential expression of nuclear matrix proteins during human hepatocarcinoma cell differentiation

AIM: To investigate the association between the configurational and compositional changes of nuclear matrix and the differentiation of carcinoma cells. METHODS: Cells cultured with or without 5 x 10(-3) mmol/L of hexamethylene bisacetamide (HMBA) on Nickel grids were treated by selective extraction and prepared for whole mount observation under electron microscopy. The samples were examined under transmission electron microscope. Nuclear matrix proteins were selectively extracted and subjected to subcellular proteomics study. The protein expression patterns were analyzed by PDQuest software. Spots of differentially expressed nuclear matrix proteins were excised and subjected to in situ digestion with trypsin. The peptides were analyzed by matrix-assisted laser-desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). Data were submitted for database searching using Mascot tool (www.matrixscience.com). RESULTS: The nuclear matrix (NM) and intermediate filament (IF) in SMMC-7721 hepatocarcinoma cells were found relatively sparse and arranged irregularly. The nuclear lamina was non-uniform, and two kinds of filaments were not tightly connected. After induction for differentiation by HMBA, the NM-IF filaments were concentrated and distributed uniformly. The heterogeneous population of filaments, including highly branched ultrathin filaments could also be seen in the regular meshwork. The connection between the two kinds of filaments and the relatively thin, condensed and sharply demarcated lamina composed of intermediate-sized filaments was relatively fastened. Meanwhile, 21 NM proteins changed remarkably during SMMC-7721 cell differentiation. Four proteins, i.e. mutant Pyst1, hypothetical protein, nucleophosmin 1, and LBP were downregulated, whereas four other proteins, eIF6, p44 subunit, beta-tubulin, and SIN3B were upregulated with the last one, SR2/ASF found only in the differentiated SMMC-7721 cells. CONCLUSION: The induced differentiation of SMMC-7721 cells by HMBA is accompanied by the configurational changes of nuclear matrix-intermediate filament (NM-IF) system and the compositional changes of nuclear matrix protein expression. These changes may be important morphological or functional indications of the cancer cell reversion.     

熊果酸诱导人肝癌SMMC-7721细胞凋亡的研究

目的：观察熊果酸（UA）对人肝癌SMMC-7721细胞的增殖抑制及诱导其凋亡作用。方法：MTT法检测5、10、20、30、40、50μmol/L UA对SMMC-7721细胞生长的抑制作用,吖啶橙（AO）荧光染色、电镜和流式细胞仪检测细胞凋亡。结果：UA能显著抑制SMMC-7721细胞的增殖,其作用呈剂量依赖性。35.2μmol/L UA作用SMMC-7721细胞48小时后AO染色,荧光显微镜下可见细胞出现体积缩小,核碎裂,染色质凝集等凋亡形态改变;电镜下SMMC-7721细胞出现明显的细胞凋亡的形态学改变,细胞核染色质出现边聚和中聚,细胞内部分线粒体肿胀;SMMC-7721细胞凋亡率为（67.91±5.24）%,与对照组（2.95±0.56）%比较差异有显著性意义（P〈0.05）。结论：UA通过诱导SMMC-7721细胞凋亡抑制其生长。     

双萘酰亚胺类化合物诱导SMMC-7721细胞凋亡的研究

目的 观察双萘酰亚胺类化合物(C8)对人肝癌细胞株SMMC-7721细胞的作用. 方法 四甲基偶氮唑盐法检测C8对SMMC 7721细胞的抑制情况;流式细胞术检测细胞周期和凋亡率;Western blot检测Bcl 2蛋白表达量;流式细胞术分析细胞内Bcl 2蛋白量;酶联免疫法检测Caspase9和Caspase 3表达量. 结果 C8抑制SMMC 7721细胞增殖,半数抑制浓度为15 umol/L.C8作用浓度在10,15、20 umol/L时,SMMC 7721细胞的凋亡比例分别为16.8%、29.4%和35.8%,对照组为2.1%,SMMC 7721细胞的凋亡率明显高于对照组,P<0.01.细胞内Bcl-2蛋白表达水平下降.酶联免疫检测结果表明Caspase 9和Caspase 3被活化.结论 C8可诱导人肝癌SMMC 7721细胞的凋亡,为抗肿瘤药物的研究提供新的化合物.     

低表达Smad4对肝癌细胞SMMC-7721上皮间质转化的影响

目的:探讨低表达Smad4调控上皮间质转化影响肝癌细胞(hepatocellular carcinoma cells,HCC)侵袭转移的相关机制.方法:采用Western blot法观察低表达Smad4对β-catenin和Vimentin总蛋白表达水平的影响;逆转录PCR法测定低表达Smad4后,β-catenin和VimentinmRNA表达的变化;细胞免疫荧光法检测Smad4、β-catenin和Vimentin在肝癌细胞SMMC-7721及其转染组中的定位及荧光表达强度.结果:低表达Smad4后,相较于CON组和RNAi-NC组,在转染组RNAi-Smad4-2和RNAi-Smad4-12细胞中,β-cateninmRNA和相应总蛋白的表达水平明显增加(P<0.05),并促使其发生了核转位的改变;另一方面,在RNAi-Smad4-2和RNAi-Smad4-12两转染组细胞中,Vimentin的蛋白表达水平和相应胞浆荧光的表达强度比对照组明显下调(P<0.05),相应mRNA的表达水平在肝癌SMMC-7721细胞及其转染组无显著差异.结论:低表达Smad4可调控上皮间质转化相关标志物β-catenin和Vimentin的表达,发挥抑制肝癌SMMC-7721细胞上皮间质转化的作用.     

The receptor for β2GP Ⅰon membrane of hepatocellular carcinoma cell line SMMC-7721 is annexin Ⅱ

AIM： To evaluate the receptor protein which can specifically bind to β2GP Ⅰ on the membrane of hepatocellular carcinoma （HCC） cell line SMMC-7721, and to study the biological function of the receptor.
METHODS： Through β2GP Ⅰ -affinity chromatography column, the peptid-polysome-mRNA complex, which can specially bind to β2GPⅠ, stayed with the column and was separated from the whole polysome of liver cells, and then eluted and collected. Using cDNA synthesis kit and cDNA PCR kit, the corresponding cDNA was obtained and sequenced. RT-PCR was used to amplify annexin Ⅱ, and flow cytometry was used to study the competitive binding of annexin Ⅱ with β2GPⅠ to SMMC-7721.
RESULTS： A total of 1.1 kb of the cDNA fragment of the specific binding protein of β2GPⅠ on liver cell membrane was obtained. The sequence of cDNA shared high homology with human annexin Ⅱ（98%）. Annexin Ⅱ was expressed on the membrane of SMMC-7721, and could compete with β2GP Ⅰ for combining with SMMC-7721.
CONCLUSION： The receptor for β2GP Ⅰ on membrane of SMMC-7721 cells is annexinⅡ, which might bridge HBV to infect hepatocytes.