共查询到20条相似文献,搜索用时 11 毫秒
1.
目的 通过增强型绿色荧光蛋白(EGFP)与PTEN融合蛋白真核表达载体的构建和表达,观察PTEN基因对人脑胶质瘤细胞生长的影响。方法 (1)以RT—PCR方法扩增人的PTEN基因,经T—A亚克隆筛选后连入真核表达载体pEGFP—N1,构建融合蛋白表达载体。采用阳离子聚合物转染试剂,将重组质粒DNA瞬时转染至SHG-44细胞,检测融合蛋白的表达。(2)G418筛选出稳定转染的细胞(SHG-44-Z),并扩增培养,通过细胞形态学、生长曲线观察PTEN基因对细胞形态和增殖的影响,免疫组织化学法检测对胶质纤维酸性蛋白(GFAP)表达的影响。结果 (1)重组质粒阳性克隆的测序结果与GenBank报告序列一致。瞬时转染的SHG-44细胞于荧光显微镜下可见绿色荧光,流式细胞仪可检测到荧光表达量为17.8%,免疫细胞化学法检测到外源PTEN蛋白表达。证实pEGFP—PTEN融合蛋白表达载体构建成功,并在胶质瘤细胞得以正确表达。(2)转染组SHG-44-Z细胞株的生长增殖受到明显抑制,第7天细胞计数为未转染组细胞数的27.8%,且GFAP表达上调。结论携带绿色荧光蛋白的PTEN基因真核表达载体的构建,为进一步研究PTEN的作用机理及抑癌效应奠定了基础。 相似文献
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Ritz R Wein HT Dietz K Schenk M Roser F Tatagiba M Strauss WS 《International journal of oncology》2007,30(3):659-667
The poor prognosis of patients suffering from malignant glioma requires further efforts. Photodynamic therapy (PDT) might be a therapeutic option to increase surgical radicality. Hypericin (HY) exhibit high phototoxicity to malignant cells and accumulates to a higher extent in glioblastoma cells as compared to neurons. Therefore, the impact of various experimental parameters on cytotoxicity, intracellular accumulation and phototoxicity of HY was quantitatively assessed in the three human glioblastoma cell lines U373 MG, LN229 and T98G. Additionally, intracellular location of HY was studied with fluorescence microscopic techniques. For all three cell lines, no cytotoxicity was found for incubation concentrations up to 5 microM. For short-time incubation (2 h), maximum HY fluorescence was achieved at an incubation concentration of about 5 microM. However, uptake kinetics of HY was dependent on its incubation concentration. Moreover, increase in HY fluorescence was negligible at 4 degrees C, which strongly indicates that the compound is taken up by an energy-dependent process. HY exhibited high phototoxicity (at 595 nm) in all three cell lines with ID50-values ranging from 0.15 J/cm(2) to 0.22 J/cm(2), but sensitivity decreased in the order U373 MG > LN229 > T98G. However, assessment of phototoxicity at different wavelengths revealed that highest cell inactivation was achieved at 600 nm. Fluorescence microscopy showed that HY fluorescence arose predominantly from the perinuclear region and the nuclear membrane. Fluorescence pattern of HY was significantly different from those observed for organelle markers staining lysosomes or mitochondria. Location of HY in the plasma membrane was proven by total internal reflection fluorescence microscopy. Thus, the present study demonstrates that glioblastoma cells can be effectively inactivated by HY-PDT after short-time incubation and exposure to low light doses. These results obtained in cell culture are encouraging and justify further evaluation HY-PDT for the treatment of malignant glioma in animal experiments. 相似文献
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目的:研究温热作用在体外对人胆囊癌GBC-SD细胞增殖的影响.方法:体外培养的胆囊癌GBC-SD细胞,给予43℃热作用1h,以37℃正常培养温度为对照,分别收集作用0、6、12h后的细胞.应用MTT、免疫细胞化学和Western-blot等技术,检测GBC-SD细胞经温热作用后增殖活性和PCNA蛋白表达的改变.结果:43℃热作用1h对胆囊癌细胞具有较明显的抑制效应,可有效抑制PCNA的表达.结论:43℃温热作用1h是抑制胆囊癌GBC-SD细胞增殖活性的有效热剂量. 相似文献
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目的:观察逆转录酶抑制剂叠氮胸苷(AZT,3'-azido-3'-deoxythmidine)对人脑胶质瘤细胞U251放射性DNA单链损伤(singlestrand break,SSB)修复的影响,探讨其放射增敏的机制。方法:实验分为四组:1)空白组:未行AZT与γ射线处理;2)放射组:细胞接受2Gyγ射线单次照射;3)加药组:细胞培养液中加入终浓度为0·8mmol/L的AZT作用24h;4)药放组:细胞经过0·8mmol/L的AZT作用24h后再行2Gyγ射线单次照射。用碱性单细胞凝胶电泳方法检测辐射后DNA SSB的尾矩。结果:空白组与加药组细胞无慧尾,两组差异无统计学意义,F=0·238,P=0·628,表明AZT本身不会导致DNASSB;而放射组和药放组均出现明显的彗星图象,药放组与放射组的初始SSB相比差异无统计学意义,P=0·628,但前者的修复速度较慢(15min、30min、1h和2h时间点两组的SSB差异有统计学意义,F值分别为4·652、4·160、7·134和4·715,P值分别为0·038、0·049、0·011和0·037),照射后2h放射组的SSB基本修复完全(放射组与空白组比较,P=0·099),而药放组仍有显著残留(药放组与空白组比较,P<0·0001)。结论:端粒酶抑制剂AZT放射增敏可能与其抑制DNASSB的修复有关。肿瘤防治杂志,2005,12(20):1525-1529 相似文献
5.
目的:观察逆转录酶抑制剂叠氮胸苷(AZT,3'-azido-3'-deoxythmidine)对人脑胶质瘤细胞U251放射性IONA单链损伤(single strand break,SSB)修复的影响,探讨其放射增敏的机制。方法:实验分为四组:1)空白组:未行AZT与γ射线处理;2)放射组:细胞接受2Gyγ射线单次照射;3)加药组:细胞培养液中加入终浓度为0.8mmol/1,的AZT作用24h;4)药放组:细胞经过0.8mmol/L的AZT作用24h后再行2Gyγ射线单次照射。用碱性单细胞凝胶电泳方法检测辐射后DNA SSB的尾矩。结果:空白组与如药组细胞无慧尾,两组差异无统计学意义,F=0.238,P=0.628,表明AZT本身不会导致DNA SSB;而放射组和药放组均出现明显的彗星图象,药放组与放射组的初始SSB相比差异无统计学意义。P=0.628.但前者的修复速度较慢(15min、30min、1h和2h时间点两组的SSB差异有统计学意义,F值分别为4.652、4.160、7.134和4.715,P值分别为0.038、0.049、0.011和0.037),照射后2h放射组的SSB基本修复完全(放射组与空白组比较,P=0.099),而药放组仍有显著残留(药放组与空白组比较.P〈0.0001)。结论:端粒酶抑制剂AZT放射增敏可能与其抑制DNA SSB的修复有关。 相似文献
6.
Effect of synthetic matrix-metalloproteinase inhibitors on invasive capacity and proliferation of human malignant gliomas in vitro 总被引:9,自引:0,他引:9
Tonn JC Kerkau S Hanke A Bouterfa H Mueller JG Wagner S Vince GH Roosen K 《International journal of cancer. Journal international du cancer》1999,80(5):764-772
Glioma invasion into the surrounding brain tissue is still a major obstacle for any therapeutical approach. As in other solid tumors, matrix-metalloproteases (MMPs) have been suggested as being involved. The aim of this study was to evaluate whether the use of MMP inhibitors to target the protease-mediated invasion process could be a feasible approach. Two human cell lines (U251 and GaMG) and surgical specimens of 6 patients with malignant gliomas were grown as monolayers and spheroid cultures respectively. MMP- and u-PA-mRNA expression was investigated by semi-quantitative RT-PCR. Invasion was studied in Matrigel-coated Boyden chamber transwell assays for monolayers and in confrontation cultures of tumor spheroids with fetal rat brain aggregates in the presence of the synthetic MMP inhibitors batimastat (BB-94) and marimastat (BB-2516). Cytotoxicity/cytostatic effects of high concentrations of both compounds were assessed by growth curves, MTT assays and flow cytometry in human glioma cell lines. Batimastat and marimastat revealed a cytostatic effect at high concentrations (above 1 microM) without cytotoxicity. Both MMP inhibitors effectively reduced glioma invasion in Boyden-chamber assays at low concentrations of 0.3 microM. In confrontation cultures, concentrations of 10 microM and above were necessary to reduce invasion. This effect was observable with inter-individual heterogeneity in the patient's tumor material. MMP inhibitors effectively reduce glioma invasion, although high concentrations were required in 3-dimensional culture systems. At these concentrations, both compounds revealed a cytostatic, but no cytotoxic effect. Thus, high local concentrations of MMP inhibitors could offer a new therapeutic strategy for the treatment of gliomas. 相似文献
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目的:观察枸橼酸他莫昔芬(Tamoxifen Citrate)对体外培养的人卵巢癌细胞SKOV-3增殖的影响.方法:采用四甲基偶氮唑蓝(MTT)比色法检测不同浓度(0、1、5、10、12、14、15、16、18、20nmol/L)的枸橼酸他莫昔芬在不同的时间点(24、48、72h)对SKOV-3细胞增殖的影响;采用流式细胞技术(FCM)分析不同浓度的枸橼酸他莫昔芬处理细胞24h和48h后对细胞凋亡的影响.结果:枸橼酸他莫昔芬对SKOV-3细胞的增殖具有明显的抑制作用,与对照组相比具有显著性差异(P<0.05),并呈现剂量和时间依赖性.枸橼酸他莫昔芬能够诱导细胞凋亡,且凋亡率随着枸橼酸他莫昔芬浓度和处理时间的增加而升高(P<0.01).结论:枸橼酸他莫昔芬可显著抑制SKOV-3细胞的增殖,其作用可能与其诱导细胞凋亡有关. 相似文献
9.
R Godbout J Miyakoshi K D Dobler R Andison K Matsuo M J Allalunis-Turner H Takebe R S Day 《Oncogene》1992,7(9):1879-1884
Human malignant gliomas (glioblastomas and anaplastic astrocytomas) are the most frequent brain tumors and are associated with a variety of genetic alterations including retinoblastoma (RB) and p53 gene mutations, loss of interferon alpha and beta (IFNA, IFNB) genes and lack of O6-methylguanine-DNA methyltransferase (MGMT) expression. Yet, in the studies performed to date, the relationship between these alterations has not been addressed. In this report, we have studied gene expression in 29 malignant glioma cell lines and have determined that, although loss of the interferon genes and loss of RB, p53 and MGMT mRNAs are frequent events, combinations of genetic alterations involving these four proven or putative tumor-suppressor genes are relatively infrequent. The exception was loss of RB mRNA, which may be associated with lack of MGMT mRNA. 相似文献
10.
Chen Jingkao Dou Yunling Zheng Xiaoke Leng Tiandong Lu Xiaofang Ouyang Ying Sun Huawei Xing Fan Mai Jialuo Gu Jiayu Lu Bingzheng Yan Guangmei Lin Jun Zhu Wenbo 《Tumour biology》2016,37(11):14721-14731
Tumor Biology - The melastatin-like transient receptor potential 7 (TRPM7) has been implicated in proliferation or apoptosis of some cancers, indicating the potential of TRPM7 as an anti-anaplastic... 相似文献
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目的:探讨他莫昔芬(TAM)对人胰腺癌细胞增殖的影响及其机制。方法:采用钙离子荧光指示剂flour3/Am,流式细胞仪动态检测TAM作用后人胰腺癌细胞(CapanⅡ)内游离钙离子([Ca2+]i)水平的变化,同时用MTT比色法测定细胞增殖情况。结果:TAM使细胞内[Ca2+]i水平上升,与静息状态细胞内[Ca2+]i水平相比差异有统计学意义,P<005。高浓度的TAM对癌细胞的增殖有抑制作用。结论:TAM有抑制人胰腺癌细胞增殖的作用,其作用机制除通过竞争性结合雌激素受体来抑制雌激素的作用外,还可通过诱导细胞内[Ca2+]i水平升高,抑制Ca2+依赖蛋白激酶C和钙调蛋白,从而抑制癌细胞的生长。 相似文献
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Inhibition by selenium of DNA and RNA synthesis in normal and malignant human cells in vitro. 总被引:1,自引:0,他引:1
Several studies have demonstrated differences between normal and malignant cells in their sensitivity to various effects of selenite. We have compared the effect of selenite on DNA and RNA synthesis in two pairs of normal and malignant human cell lines. One pair of cells, CCL-210 (normal lung fibroblasts) and A549 (lung adenocarcinoma cells), exhibited a large difference in their sensitivity to selenite but no significant difference in their sensitivity to selenodiglutathione. They also had a large difference in the level of intracellular sulfhydryl (SH) compounds. In contrast the other pair of cells, WI-38 (normal fetal lung fibroblasts) and WI-38VA (SV-40 transformed WI-38 cells) both had low levels of intracellular SH compounds and exhibited similar (low) sensitivity to selenite. Our results indicate that differences between normal and malignant cells in their sensitivity to selenite could be due to a difference in the reaction of selenite with intracellular sulfhydryl compounds to form selenotrisulfides. 相似文献
15.
Valproic acid increases the in vitro effects of nitrosureas on human glioma cell lines 总被引:1,自引:0,他引:1
Ciusani E Balzarotti M Calatozzolo C de Grazia U Boiardi A Salmaggi A Croci D 《Oncology research》2007,16(10):453-463
Valproic acid (VPA) has been recently investigated for its anticancer properties in different tumors, including malignant gliomas. The aim of the present work was to evaluate the effects of VPA, alone or in combination with other chemotherapeutic drugs, on in vitro growth of human glioma cell lines. A172, U373, U138, U87, and SW1783 were treated with VPA alone or in combination with mitoxantrone, etoposide, or 1,3-bis(2-chloroethyl)-l-nitrosourea (BCNU). The effects of treatments on cell growth were assessed with crystal violet staining and analyzed using the combination index (CI). The percentage of apoptotic cells and the DNA content for cell cycle phases detection were also investigated by flow cytometry. Despite a certain variability, glioma cell lines were rather resistant to the drugs tested. Addition of VPA decreased the IC50 of the chemotherapeutic agents in all cell lines tested. This effect was more evident with BCNU. The synergic effect of the association of VPA and BCNU was related to an increased block of cell cycle with accumulation in S-G2/M phases of cell cycle rather than an increased programmed cell death. In our experimental model, VPA showed anticancer properties per se on human glioma cell lines and our data support the hypothesis that, if used in association with conventional chemotherapy, it might improve the effects of single chemotherapeutic agents. 相似文献
16.
目的 探讨WNT4在脑胶质瘤细胞系和组织中细胞系的表达与甲基化对脑胶质瘤细胞系U87增殖的作用和机制。方法 qRT-PCR和免疫蛋白印迹实验分析WNT4在脑胶质瘤组织中的表达和甲基化及WNT4在脑胶质瘤细胞系中的表达;以胶质瘤U87细胞为本实验研究对象,分别转染慢病毒载体pLVX-Gfp-WNT4(实验组)和pLVX-Gfp-NC(对照组);细胞增殖和克隆形成实验分析WNT4基因对细胞增殖的影响;免疫蛋白印迹法验证WNT4对Wnt/β-catenin信号通路的影响。结果 与正常人星形胶质细胞相比,WNT4 mRNA在脑胶质瘤细胞系中的表达下调(P<0.001),与正常脑组织相比,WNT4 mRNA和蛋白在脑胶质瘤组织中表达下调(P<0.001);脑胶质瘤分级越高WNT4 mRNA表达越低(P<0.001),高表达WNT4 mRNA患者的预后好(P<0.001);WNT4在脑胶质瘤中甲基化程度明显高于正常脑组织。过表达WNT4后细胞活性和增殖能力受到抑制(P<0.001);恢复WNT4表达后Wnt/β-catenin信号通路及其下游细胞因子明显受到抑制。结论 WNT4在人脑胶质瘤组织中表达甲基化下调,通过抑制Wnt/β-catenin信号通路参与脑胶质瘤的进展。 相似文献
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Laszlo Geder John W. Kreider Javad Towfighi Robert B. Page Roger L. Ladda Robert W. Brennan Fred Rapp 《Journal of neuro-oncology》1987,5(3):251-271
Summary The effect of dimethylsulfoxide (DMSO) and iododeoxyuridine (IUdR) on the growth characteristics of two established human glioblastoma cell lines (FG and HMCN-1) was studied. The FG cell line has been characterized. The HMCN-1 cell line, established in our laboratory, consisted of fibroblastoid and polygonal cells that grew without contact inhibition. Subcutaneous injection of these cells into weanling athymic nude mice induced slowly growing, solid tumors that were histologically spindly with areas that were similar to the original tumor. Chromosomal analyses revealed a human heteroploid pattern with a modal number of 69. The cells of the original human glioma contained S-100 protein and glial fibrillary acidic protein (GFA protein), whereas the established cells failed to express markers. Prolonged treatment of glioma cells with DMSO generated a more adherent, normal human fibroblastoid phenotype that grew with contact inhibition. The new phenotype and proliferative restriction of these cells was evident as late as 50 days after discontinuation of treatment. The chemical induction of cell differentiation resulted in decreased tumorigenic potential in athymic nude mice. 相似文献
18.
Zhang H Zhu W Su X Wu S Lin Y Li J Wang Y Chen J Zhou Y Qiu P Yan G Zhao S Hu J Zhang J 《Journal of neuro-oncology》2012,109(1):53-62
Malignant glioma is the most devastating and aggressive tumor in brain, characterized by rapid proliferation and diffuse invasion. Chemotherapy and radiotherapy are the pivotal strategies after surgery; however, high drug resistance of malignant glioma and the blood-brain barrier usually render chemotherapy drugs ineffective. Here, we find that triptolide, a small molecule with high lipid solubility, is capable of inhibiting proliferation and invasion of malignant glioma cells effectively. In both investigated malignant glioma cell lines, triptolide repressed cell proliferation via inducing cell cycle arrest in G0/G1 phase, associated with downregulation of G0/G1 cell cycle regulators cyclin D1, CDK4, and CDK6 followed by reduced phosphorylation of retinoblastoma protein (Rb). In addition, triptolide induced morphological change of C6 cells through downregulation of protein expression of MAP-2 and inhibition of activities of GTPases Cdc42 and Rac1/2/3, thus significantly suppressing migratory and invasive capacity. Moreover, in an in vivo tumor model, triptolide delayed growth of malignant glioma xenografts. These findings suggest an important inhibitory action of triptolide on proliferation and invasion of malignant glioma, and encourage triptolide as a candidate for glioma therapy. 相似文献
19.
Krause M Joiner M Baumann M 《International journal of cancer. Journal international du cancer》2003,107(2):333; author reply 334-333
20.
Manfred Westphal Eva Ackermann Jürgen Hoppe Hans-Dietrich Herrmann 《Journal of neuro-oncology》1991,11(3):207-213
Summary A panel of 11 established human glioma cell lines was used to evaluate PDGF receptor binding using radio-idinated biosynthetic PDGF-AA and PDGF-AB as primary ligands. It was found that PDGF-receptor-binding was qualitatively heterogeneous. The affinities for PDGF-AA as well as PDGF-AB binding were within a close range of 0.13–0.33 nM and 0.16–1.1 nM, respectively. The number of binding sites per cell ranged between 56.000 and 250.000 for PDGF-AA and 72.000 to 300.000 for PDGF-AB. Two lines had only background levels of PDGF-AA binding. PDGF-AB binding was the dominant binding component in all but one cell line. In seven cell lines there were two binding components upon saturation analysis consisiting of a high affinity component and a non-saturable low affinity component.PDGF and PDGF-receptors are suspected to be part of an autocrine loop in gliomas. Therefore, the effect of suramin on cell proliferation in serumfree cultures was tested in the same cell lines using doses of 25, 200 or 500 g/ml. It was found that the response to suramin was variable and that two cell lines still reached 2.8 fold and 4.5 fold their initial cell density even in the presence of 500 g/ml whereas all other cells were completely arrested. Analyzing the response to 200 g/ml it became evident, that the PD GF binding characteristics are of no reliable predictive value in respect to the efficacy of suramin. 相似文献