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EB病毒转化人类外周血B-淋巴细胞建立永生细胞系
EB病毒(epstein-barr virus)转化外周血B淋巴细胞(B-LC),使其成为一种能连续分裂永久生存的类淋巴母细胞(lymphoblastoid),由此建立的类淋巴母细胞株即为永生细胞株(immortalized cell lines),它可永远传代,并且每一种永生细胞株保存了原来提供血样个体的完整基因组,而且它的生化和分子生物学特性不发生变化[1,2],可作为生物标本库建立的首选方法.
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阿司匹林促进宫颈癌HeLa细胞凋亡
阿司匹林(acetysalicylicacid,ASA)是非类固醇抗炎药(nonsteroidal antiinflammatory drugs,NSAIDs)的代表药物.近研究证实,阿司匹林具有高效降低直肠结肠肿瘤发病率的作用~([1]);文献报道普通阿司匹林应用在半年以上,可有效降低宫颈癌的发病率~([2]).本研究对阿司匹林抑制宫颈癌HeLa细胞增殖作用及相关机制进行研究,为宫颈癌的预防与治疗提供有益的探索.
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干细胞分化抗原和细胞增殖抗原在人胶质瘤细胞株中的表达
研究表明肿瘤组织中存在肿瘤干细胞(tumor stem cells,TSC).TSC具有自我更新、无限增殖和多向分化等干细胞的生物学特性,并且表达多种干细胞分化抗原[1].这些干细胞抗原在胶质瘤组织中也大量表达[2].通过建立在干细胞分化抗原基础上的肿瘤细胞亚群分离技术,已经在胶质瘤组织和胶质瘤细胞株中分离和鉴定出TSC[3-4],但各种干细胞分化抗原在胶质瘤细胞株中的表达状况尚不清楚.我们在本研究中检测人胶质母细胞瘤细胞株中干细胞分化抗原和细胞增殖抗原的表达,为进一步研究TSC打下基础.
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乳腺癌发生模型MCF10 抑癌基因NOEY2启动子区甲基化及mRNA表达
DNA甲基化是常见的表观遗传学变化[1].越来越多的证据表明,抑癌基因启动子区CpG岛甲基化可使其转录沉默,从而解除其抑癌作用,导致肿瘤的发生和发展.NOEY2是近年来发现的抑癌基因,表达于正常乳腺导管上皮细胞和卵巢生发上皮细胞,但在乳腺癌和卵巢癌细胞中表达显著减少或不表达[2, 3].在本实验中检测乳腺癌发生模型MCF10[4]中不同阶段的细胞系NOEY2基因启动子区CpG岛Ⅰ甲基化状态,并与mRNA表达水平进行比较,以研究乳腺癌的发生机制和早期诊断.
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EB病毒在人单克隆抗-D研制中的应用
EB病毒(EBV)可感染灵长类B细胞,使其获得持续生长的特性,即永生性.我们利用EBV的这一特性,在体外感染一能分泌抗-D的人B淋巴细胞,建立了能分泌抗-D的人淋巴细胞株(lymphocyte cell lines,LCL),为单克隆抗-D的研制奠定了基础.
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抑癌基因p27Kip1及其Ser10突变体对HepG2细胞周期和增生的影响
目的:p27kip1氨基端第10号位置的丝氨酸(Ser10)磷酸化位点是该蛋白分子中重要的磷酸化位点,探讨人工诱变该位点丝氨酸为丙氨酸(S10A)后对肝癌细胞株HepG2细胞周期以及细胞增生的影响.同时比较野生型p27kip1和Ser10突变型p27kip1基因转染对肝癌细胞株HepG2细胞周期和增生的影响.方法:应用脂质体转染法将含人野生型和突变型p27kip1质粒DNA瞬时转染HepG2细胞,免疫细胞化学检测p27kip1蛋白的表达和细胞内分布,流式细胞计数仪分析细胞周期变化.结果:野生型和突变p27kip1蛋白转基因后HepG2细胞均可以G0期阻滞,且突变型的阻滞作用强于野生型(P<0.05),细胞生长受到抑制.无血清培养96 h同步化于G0期,野生型和突变型p27kip1均分布于细胞核;而在20 mL/L血清继续培养8 h后野生型向细胞质转运而主要分布于细胞质,突变型仍然滞留于细胞核.结论:p27kip1的过度表达可明显抑制HepG2细胞的增生,p27kip1 Ser10酸化可能介导其细胞核外转运的重要分子机制.
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CD95配体分子诱导人肝癌细胞凋亡的作用
目的:探讨CD95 L在肝癌细胞凋亡过程中的作用.方法:ELISA法对慢性乙型肝炎、肝炎肝硬化与肝癌患者血清可溶性CD95 L(sCD95L)水平进行了初步检测,构建了人CD95 L的重组真核表达体pcDNA3.1hisB-CD95 L,将pcDNA3.1hisB-CD95 L转染至人肝癌细胞株HepG2细胞,采用Annexin V/PI双染后双变量流式细胞仪检测细胞凋亡率.结果:sCD95L在肝癌患者明显低于肝炎及肝硬患者,构建的表达重组体pcDNA3.1hisB-CD95 L经菌落PCR和限制性酶切消化有预期的目的片段出现,DNA序列分析证实CD95 L完整、正确插入,转染后的HepG2细胞细胞凋亡率为36.30%;未转染CD95L的对照组细胞凋亡率11.53%.结论:CD95L可使肝癌细胞凋亡.
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十一丙酸睾酮对胃上皮细胞株生物学特性的影响
目的:观察十一丙酸睾酮对胃癌细胞株SGC-7901以及正常胃上皮细胞株HFI-145生长的影响方法:用不同浓度的十一丙酸睾酮作用细胞,MTT方法研究生长状况,FCM观察细胞周期分布,TUNEL法检测细胞凋亡.比较不同浓度作用组间差异以及与对照组的差异.结果:0.0 004-0.4μmol/L十一丙酸睾酮对SGC-7901细胞生长有促进作用,对HFI-145细胞作用不明显;4μmol/L浓度对两种细胞均产生抑制,有时间依赖性,作用3 d抑制率分别达到17%和27%,4 pmol/L用药组细胞的G0/G1期细胞较对照组增多,FCM以及TUNEL未发现凋亡百分比的改变.结论:高浓度十一丙酸睾酮通过阻滞细胞于G0/G1期抑制胃上皮细胞生长,低浓度促进胃癌上皮细胞生长可能对胃癌的发展及预后产生影响.
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CD/5-FC系统对结肠癌细胞的杀伤作用
目的:探讨组织特异性胞嘧啶脱氨基酶(cytosine deaminase,CD)/5-氟胞嘧啶(5-fluorocytosine,5-FC)系统对不同分泌癌胚抗原(carcinoembryonic antigen,CEA)的大肠癌细胞LoVo和SW480的靶向杀伤作用.方法:脂质体法将CEA基因顺式转录调控序列(TRS)驱动CD基因的组织特异性逆转录病毒载体GICEACDNa及非组织特异性逆转录病毒载体pCD2分别转导入大肠癌细胞LoVo和SW480,以G418筛选阳性克隆扩增后给予前药5-FC进行敏感试验.结果:LoVo-CEACD及LoVo-CD比LoVo对5-FC的敏感性明显提高(P<0.01,t=5.688,n=9;P<0.01,t=3.136,n=9),SW480-CEACD及SW480-CD比SW480对5-FC的敏感性明显提高(P<0.01,t=3.437,n=9;P<0.01,t=3.516,n=9),LoVo-CEACD比LoVo-CD对5-FC的敏感性明显增强(P<0.05,t=2.183,n=9),而SW480-CEACD对5-FC的敏感性小于SW480-CD,SW480-CEACD对前药5-FC的敏感性低于LoVo-CEACD(P<0.05,t=2.504,n=9),转CD基因之LoVo和SW480细胞体外实验均可观察到明显的旁观者效应.结论:组织特异性CD/5-FC系统对LoVo和SW480细胞均有明显的靶向杀伤效果,但对SW480细胞的杀伤作用小于LoVo细胞.
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肠癌细胞株dynamin Ⅱ的差异表达
目的:应用半定量RT-PCR方法检测dynaminⅡ基因在大肠侧向发育型肿瘤细胞株同SW480细胞株及Lovo细胞株之间的差异表达.方法:以三种肠癌细胞株为标本,分别提取总RNA,逆转录合成cDNA,选择加入的模板量及循环数,优化PCR反应条件,确定适宜的反应体系,凝胶图像分析结果.结果:在大肠侧向发育型肿瘤细胞株同普通隆起型肠癌细胞株之间存在着dynaminⅡ基因的差异表达.结论:半定量RT-PCR方法具有简单,方便,经济的特点,通过该方法,我们发现在大肠侧向发育型肿瘤癌细胞株同SW480细胞株及Lovo细胞株之间存在dynaminⅡ基因的差异表达,此结果同我们基因芯片的筛选结果一致,结合dynaminⅡ基因的功能,我们推测该基因可能在LST的形态学或癌变机制中发挥一定作用.
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Objective: To screen novel genes related to adriamycin (Adr) resistance from human ovarian cancer resistance cell line OC3/Adr. Methods: Multidrug resistant ovarian cancer cell line OC3/Adr was induced by intermittent treatment of the human parent cell line OC3 with high concentration Adr. The difference of gene expression was screened by using different display analysis to the acquired Adr-resistance subline OC3/Adr and its parent cell line OC3. Results: OC3/Adr cell line was obtained which was more resistance to Adr than the parent cell line OC3 with the resistance index (RI) of 15.4. The OC3/Adr cell line also showed cross-resistance to other anti-cancer drugs (VP16, CDDP,5FU ). It grew slowly and exhibited changes of cell cycle. A number of differentially expressed ESTs (Expressed Sequence Tags, ESTs) were identified at mRNA level between the OC3/Adr and OC3. Four of 18 different ESTs were sequenced. The 431/432 base pair S1 was homologous to human sperm zona pellucida binding protein, while the other two ESTs, S3 and S4, were new gene segments, which were registered to GenBank with the number of AF 117656 and AF 126507 respectively. Particularly, the expression of S2 sequence increased in all the drug-resistance cell lines and S3 sequence overexpressed in human ovarian cancer tissues as compared with benign ovarian tumors. Adr in ovarian cancer OC3/Adr is involved with changes of multiple gene expressions.
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Objective: To establish a fluoregenic probe quantitative RT-PCR (FQ-RT-PCR) method for detection of the expression of MDR1 gene in tumor cells and to investigate the expression of MDR1 gene in patients with lung cancer. Methods: The fluorogenic quantitative RT-PCR method for detection of the expression of MDR1 gene was established. K562/ADM and K562 cell lines or 45 tumor tissues from patients with lung cancer were examined on PE Applied Biosystems 7700 Sequence Detection machine. Results: the average levels of MDR1 gene expression in K562/ADM cells and K562 cells were (6.86±0.65)× 107copies/mg RNA and (8.49±0.67)×105 copies/mg RNA, respectively. The former was 80.8 times greater than the latter. Each sample was measured 10 times and the coefficient variation (CV) was 9.5% and 7.9%, respectively. Various levels of MDR1 gene expression were detected in 12 of 45 patients with lung cancer. Conclusion: Quantitative detection of MDR1 gene expression in tumor cells was achieved by using FQ-RT-PCR. FQ-RT-PCR is an accurate, and sensitive method and easy to perform. Using this method, low levels of MDR1 gene expression could be detected in 24% of the patients with lung cancer.
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Objective: To understand whether verapamil (VER) resistance development in the multidrug-resistant cell line and its mechanism. Methods: K562/ADM/VER cell subline resistant to verapamil was established through a gradual increase of VER concentration in the media. MTT method was used to assay resistance to VER, cross resistance to dipyriamole (DPM), cyclosporin A (CsA) in the cells, and HPLC and spectrofluorometer to detect intracellular accumulation of VER or ADM respectively, as well as S-P immunocytochemical technique for detection of genes expression. Results: It were observed that 7.9-fold increase in VER resistance, significantly reduced intracellular accumulation of VER or ADM and also develop across resistance to DPM and CsA in K562/ADM/VER cells, compared with its parent cell, K562/ADM. High-level of p-glycoprotein(pgp), middle-level of p53, p16, was present in two cell lines without expression of GSTPI, C-myc, C-myc, C-fos and C-erbB-2. Bc1-2 protein expression was found only in K562/ADM cells. Conclusion: K562/ADM cells were capable of being induced to develop resistance to VER.
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Objective: To clone multidrug resistance (MDR) related genes in lung adenocarcinoma cell lines. Methods: The differentially expressed cDNA fragments between A549 and A549DDP cells were analyzed by mRNA differential display PCR(DD RT-PCR). The fragments thus obtained were further analyzed by DNA sequencing and Northern blotting. Results: Three differentially expressed cDNA fragments were obtained and confirmed by Northern blot. Sequence analysis revealed that two of them were novel and one was 100% identical with ICE gene. Conclusion: Analyzing differentially expressed fragment between A549 and A549DDP cells may be helpful for finding new MDR related genes. The drug resistance of A549DDP cells may be related to the inhibition or down-regulation of ICE gene.
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Objective: To clone multidrug resistance (MDR) related genes in lung adenocarcinoma cell lines. Methods: The differentially expressed cDNA fragments between A549 and A549DDP cells were analyzed by mRNA differential display PCR(DD RT-PCR). The fragments thus obtained were further analyzed by DNA sequencing and Northern blotting. Results: Three differentially expressed cDNA fragments were obtained and confirmed by Northern blot. Sequence analysis revealed that two of them were novel and one was 100% identical with ICE gene. Conclusion: Analyzing differentially expressed fragment between A549 and A549DDP cells may be helpful for finding new MDR related genes. The drug resistance of A549DDP cells may be related to the inhibition or down-regulation of ICE gene.
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Objective: To investigate the effects of anti-PML (promyelocytic leukemia) or anti-PML/RARa (promyelocytic leukemia/retionic acid receptora) antisense oligonucleotides on cell growth, expression of PML-RARa mRNA and PML-RARa/PML protein location of NB4 cell lines. Methods: RT-PCR was used for detecting PML-RARa mRNA expression, trypan blue exclusion for cell count, methylcellose assay for leukemic colony forming unit detection, immuno- fluorescence for PML-RARa/PML protein location. Results: Both anti-PML start codon region antisence (STAS) and anti-PML-RARa fusion region antisence (FUAS) could inhibit cell growth and the formation of acute myelocytic colony forming unit of cells(AML-CFU). Cells become partial differentiated at days 5, being more obvious in FUAS-treated cells than in STAS ones. Down regulation of PML-RARa mRNA expression occurred at 24 hours in STAS and FUAS-treated cells and maintained for up to 72 hours. Immuno-fluorescence analysis with anti-PML monoclonal antibody showed a remarkable decrease even complete disappearance of microgranules. The residual granules became enlarged as discrete dots (<10 per cell), similar to normal POD structure in some STAS-treated cells at 24 hours. At 72 hours, nearly all the granules disappeared. Similar changes were observed in FUAS-treated cells. Conclusion: Both PML and PML-RARa antisence oligonucleotides can specially block the expression of PML-RARa at mRNA and protein levels. PML protein is implicated in the regulations of cell differentiation.
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美国ASCO年会拾贝:组蛋白脱乙酰基酶抑制剂SNDX-275可能逆转乳腺癌细胞系对拉帕替尼或埃罗替尼耐药
在2009年的美国ASCO年会上,Witta等报道了题名为"Synergistic effect of SNDX-275 with lapatinib or erlotinib in breast, lung, or head and neck cancer cell lines expressing HER- 2"的研究.作者以两种表达HER-2(SK BR3、MCF-7)及一种不表达HER-2的乳腺癌细胞系(MDA-MB231)为实验对象,将细胞以不同浓度(0.16、1、6 μmol/L)的SNDX-275、拉帕替尼及埃罗替尼单药或联合培养5 d.
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Genistein对人鼻咽癌细胞系CNE抑制增殖和促进凋亡的研究
鼻咽癌是头颈肿瘤中具有鲜明流行病学、组织病理学、临床和治疗学特征的一种肿瘤.研究表明癌细胞的增殖活性是影响鼻咽癌生长进展的主导因素,肿瘤细胞的增殖活性与肿瘤的生物学行为与预后密切相关.
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中国人群出生缺陷核心家庭永生细胞株的建立
EB病毒(Epstein-Barr virus)转化人外周血B淋巴细胞,使其成为能连续分裂永久生存的类淋巴母细胞(lymphoblastoid),利用这一特点建立各种疾病人群永生细胞株(immortalized cell lines),可永远传代,并且保存了每个个体的完整基因组,其生化和分子生物学特性不发生变化,可作为建立生物标本库的首选方法.