应用mRNA差异显示方法克隆维甲酸诱导的人肺腺癌GLC-82细胞分化相关基因

目的克隆维甲酸诱导的人肺腺癌ＧＬＣ８２细胞分化相关基因。方法在全反式维甲酸诱导人肺腺癌ＧＬＣ８２细胞系分化的基础上,采用ｍＲＮＡ差异显示技术,对这个细胞系以全反式维甲酸诱导前及诱导后８小时、２４小时和４天的细胞基因表达差异情况进行分析。结果在全反式维甲酸诱导前后的细胞之间存在明显的基因表达差异。有些基因经维甲酸（ＲＡ）诱导后持续表达或瞬时表达,而有些基因经ＲＡ作用后表达水平降低或完全被抑制。经克隆筛选,获得了一些经全反式维甲酸诱导激活或抑制的差异表达基因片段,对其中的３个片段进行了序列分析和同源性比较。结论全反式维甲酸具有调控分化相关基因表达与否的重要作用,由ＲＡ诱导的肿瘤细胞再分化是一个多基因参与的过程     

全反式维甲酸激活的人肺腺癌细胞基因的筛选

筛选人肺腺癌细胞中全反式维甲酸（ａｌｌｔｒａｎｓ－ｒｅｔｉｎｏｃｉａｃｉｄ,ＡＴＲＡ）激活表达的基因。方法以我室构建的ＡＴＲＡ诱导前后人肺腺癌细胞系ＧＬＣ－８２的ｃＤＮＡ文库Ｌｉｂ．ＧＬＣ－８２,Ｌｉｂ,ＧＬＣ－８２．ＲＡ１,Ｌｉｂ,ＧＬＣ－８２．ｒａ４ＦＪＴＦ     

克隆肺腺癌亲代细胞A549与耐顺铂细胞A549^DDP耐药相关基因的差异表达片段

目的：克隆肺腺癌耐药相关基因。方法以mRNA差异显示法技术检测耐顺铂肺腺癌细胞A549^DDP及其亲代细胞A549基因表达的差异。差异表达基因片段段被克隆并经Northern blot证实。结果获得4个基因表达的差异cDNA片段,经测序,同源性分析,其中2个片段（A1、D1）在GeneBank中未发现同源序列,一个片段（A2）与白介素－1β转化酶（Interleukin 1 β怀脲,ICE）89％同源性,一个片段（D2）与MM45s rRNA(Mouse musculus 45s pre-rRNA)基因100％同源。A1、A2cDNA片段仅表达于A549细胞,D1、D2cDNA片段仅表达于A549^DDP细胞。结论应用mRNA差异显示技术获得4个肺腺癌A549与A549^DDP间的基因差异3表达片段。2个新的差异表达片段以及与ICE、、MM45sRNA高度同源的基因片段是否与耐药相关尚需进一步研究。     

mRNA差异显示技术与肿瘤分子生物学研究

信使ＲＮＡ差异显示技术可通过分离、克隆直核细胞的ｍＲＮＡ，比较正常细胞和肿瘤细胞中不同表达的基因。因该方法简便、特异、敏感、可复性强等特点，将成为研究肿瘤分子生物学基础的良好工具。本文综述了ｍＲＮＡ差异显示技术的基因原理、主要操作方法及其在肿瘤研究中的应用。     

mRNA差异显示技术的改进及在肿瘤中的应用

在真核生物中,从个体的发育、生长、衰老、死亡,到组织、细胞的分化、凋亡以及细胞对各种生物、理化因子的应答,本质上都涉及基因在时间上或空间上选择性表达,即基因的差异表达,因而获取差异表达的基因将有助于了解正常生理变化和病理改变的分子机制,为基因诊断、基...     

mRNA差异显示方法筛选卵巢癌相关基因

人和动物肿瘤的发生发展就细胞而言,是由于原癌基因的激活和抑癌基因的失活而造成的,所以癌基因与抑癌基因的研究对探索肿瘤发病机理,寻找预防和治疗肿瘤的新措施都具有重要意义.卵巢癌在妇科恶性肿瘤中以难治著称,不易早期发现,且存活率低.目前人类对卵巢癌的遗传基础认识仍然不很清楚,许多研究表明卵巢癌的发生涉及一系列基因的变化,包括显性癌基因、错配修复基因和众多的肿瘤抑制基因.mRNA差异显示方法因其简单、敏感、高效、快速等     

mRNA差异显示技术及其在肿瘤研究中的应用

mRNA差异显示技术是目前用于分析基因表达差异的方法,近年来发展迅速,广泛应用于肿瘤等生物学各领域.现综述mRNA差异显示技术的新发展及其在肿瘤研究中的应用.     

mRNA差异显示技术及其在肿瘤研究中的应用

mRNA差异显示技术是目前用于分析基因表达差异的方法，近年来发展迅速，广泛应用于肿瘤等生物学各领域。现综述mRNA差异显示技术的新发展及其在肿瘤研究中的应用。     

全反式维甲酸激活人肺腺癌细胞系GLC-82中-PIG-B高度同源基因-PIGB1

目的：探讨全反式维甲酸（all-trans retinlic acid,ＡＴＲＡ）诱导肿瘤细胞分化的分子机制。方法：采用Ｓouthern和Ｎorthern杂交方法对本室用ＡＴＲＡ诱导人肺腺癌细胞ＧＬＣ－８２,经消减杂交所构建的cＤＮＡ消减文库ＰＩＧＢ１,该基因与人ＰＩＧ－Ｂ（phosphaidylinlsitol glycan of clmplementaion class Ｂ）基因高度同源,在多种胎儿组织中均有表达。结论：ＰＩＧＢ１基因可能参与ＡＴＲＡ诱导肿瘤细胞分化过程。     

mRNA差异显示技术中差异条带的回收与再扩增

目的：对来泊于两种或两种以上组织的ＲＮＡ经反转录和ＰＣＲ后进行比较。方法;采用ｍＲＮＡ差异显示过程中差异条带的回收与再扩增的方法。结果：直接将切下的弟胶条简单洗涤和碾碎后制备的再扩增模板比诉糖原沉淀法简单有效。结论：再扩增过程中将３０循环的低退火温度的ＤＤＰＣＲ和２０循环的严格条件的ＰＣＲ结合,能获得较高的再扩增效率。     

高能电磁脉冲诱导肺癌细胞株GLC-82凋亡的研究

背景与目的:电磁脉冲(electromagneticpulse,EMP)辐射已用于饮食行业的灭菌,且较2450MHz连续微波辐射消毒更加有效。本研究探讨高能电磁脉冲对肺癌细胞GLC-82凋亡的影响,以发现治疗肿瘤的新手段。方法:以场强为6×104V/m的EMP2min内辐照5次,然后采用细胞计数、MTT、流式细胞术及SP免疫组化法检测bcl-2和p53蛋白的表达,并对表达强度用CMIAS-Ⅱ图像分析仪在放大400倍条件下进行分析,通过上述方法观察EMP对肺癌细胞GLC-82的损伤作用,所有数据经SPSS8.0软件进行分析。结果:EMP可明显抑制肺癌细胞GLC-82的增殖与活力。照射后细胞的MTT光吸收值(A570)与对照组相比,在辐照后0h,1h和6h明显降低。流式细胞术证明,GLC-82细胞在辐照后6h发生明显的凋亡,凋亡率达13.38%。免疫组化的图像分析表明,照射后GLC-82细胞有不同程度的bcl-2蛋白表达的下调及p53蛋白表达的上调。结论:EMP可诱导肺癌细胞GLC-82的凋亡。bcl-2及p53蛋白参与了GLC-82细胞的凋亡过程。     

Effects of all-trans retinoic acid (ATRA) on human myeloma cells

All-trans retinoic acid (ATRA) is a natural oxidative metabolite of Vitamin A (retinol) and is known to be a regulator of cell proliferation differentiation, especially in various malignant cells. The cyto-differentiating action of ATRA has led to its usage in the treatment of several malignancies, particularly acute promyelocytic leukemia (APL). There have been many reports regarding the cell biological effects of ATRA on human myeloma cells and a few clinical trials. Most of these reports have revealed growth inhibition by ATRA mediated by down-regulation of the IL-6/IL-6R auto/paracrine loop, and upregulation of p21/Cip1. Here, we review previous reports and introduce experimental results obtained using various myeloma cell lines established in our laboratory.     

EMP INDUCES APOPTOSIS IN HUMAN LUNG CARCINOMA CELL LINE GLC-82

The possibility of health risks resulting from exposure to electric and magnetic fields provides a strong motivation to determine how such fields interact with cells. The short, intense electromagnetic pulse (EMP) produced by high-altitude nuclear explosions may radiate over many hundreds of miles. Basically, EMP consists of a pulse of radio-frequency waves with a nearly instantaneous rise in the electric and magnetic fields and a subsequent decline in the fields. EMP radiation may be repre…     

Her2/neu induces all-trans retinoic acid (ATRA) resistance in breast cancer cells

We observed that all-trans retinoic acid (ATRA) inhibited the growth of MCF-7 breast cancer cells, but not those transfected with HER2/NEU or its transactivating ligand HEREGULIN. This suggests that Her2/neu causes breast cancer cells to be resistant to the growth inhibitory effects of ATRA. To confirm this observation, MDA-MB-453 and BT-474 cells, which have high levels of Her2/neu and are resistant to ATRA, were incubated with the trastuzumab (Herceptin) antibody so that we could determine whether inhibition of the expression and function of Her2/neu would resensitize these cells to ATRA. Indeed, we found that MDA-MB-453 and BT-474 cells treated with trastuzumab were growth inhibitory by ATRA. We then determined whether Her2/neu uses Grb2 and Akt proteins to induce ATRA resistance. Liposome-incorporated Grb2 antisense oligonucleotides (L-Grb2) and a dominant negative (DN) AKT mutant were used to down-regulate Grb2 expression and inhibit Akt activity, respectively. When incubated with L-Grb2 or transfected with the DN AKT mutant, ATRA-resistant, Her2/neu-overexpressing cells became sensitive to ATRA. Our results indicate that Her2/neu utilizes Grb2 and Akt proteins to induce ATRA resistance in breast cancer cells. ATRA sensitivity was also correlated with RARalpha protein levels since higher RARalpha protein levels were observed in cells in which the Her2/neu pathway was inhibited.     

全反式维甲酸对人食管癌细胞增殖及DNA聚合酶β表达的影响

目的研究全反式维甲酸对人食管癌细胞诱导分化作用.方法在体外细胞培养的基础上,观察细胞形态学的变化,细胞增殖动力学的变化.采用MTT比色法测定细胞增殖抑制率,免疫组化和western blot 方法检测DNA聚合酶β(polβ)蛋白表达.结果经全反式维甲酸处理后,人食管癌Eca109细胞的细胞形态趋向良性分化,细胞增殖指数明显降低.polβ表达降低.结论全反式维甲酸对人食管癌Eca109细胞有诱导分化作用,其机理可能是抑制polβ的表达,改变细胞的形态结构和生物学特性,促进癌细胞的分化趋向正常.     

Multifactorial mechanism for the potentiation of cisplatin (CDDP) cytotoxicity by all-trans retinoic acid (ATRA) in human ovarian carcinoma cell lines.

All-trans retinoic acid (ATRA) has been previously shown to inhibit the proliferation of some human ovarian carcinoma cell lines, and this inhibition was accompanied by cellular changes that were indicative of differentiation (Caliaro et al, 1994). In this work, a pretreatment of these adenocarcinoma cells with ATRA, for their respective doubling time, enhanced cisplatin (CDDP) cytotoxicity in the cell ines that were sensitive to its antiproliferative effect, but not in the ATRA-resistant ones. Results were assessed using median effect analysis in two ATRA-sensitive cell lines (OVCCR1 and NIHOVCAR3 cells) and in one ATRA-insensitive cell line (IGROV1 cells). Synergy between these two agents was observed only in cells sensitive to ATRA, regardless of their relative sensitivity to CDDP. Potential mechanisms for this synergy were investigated. ATRA did not increase the cellular platinum content, did not decrease the cellular glutathione and had no influence on the metallothionein IIA mRNA levels in NIHOVCAR3 cells. Moreover, the protein kinase C (PKC) activity was modulated by this differentiating agent in all cell lines tested, indicating that this activity was not directly involved in this potentiation. However, an ATRA inhibition of glutathione-S-transferase activity associated with an increase in the total DNA adducts formation could explain the potentiation of the CDDP cytotoxicity observed in NIHOVCAR3 cells. Finally, the ATRA modulation of the epidermal growth factor (EGF) receptor mRNA level could also be implicated in this synergy.     

全反式维甲酸诱导食管癌细胞凋亡的实验研究

目的探讨全反式维甲酸(ATRA)诱导食管癌EC9706细胞凋亡的作用及其机制。方法用不同浓度的ATRA处理EC9706细胞,采用四甲基偶氮唑盐(MTT)法检测ATRA对EC9706细胞的增殖抑制效应;采用流式细胞仪和原位末端标记(TUNEL)法检测细胞周期的变化和凋亡率;采用免疫组化S-P法,检测凋亡相关基因caspase-3和bcl-2的蛋白表达,并用病理图像分析软件进行半定量分析。结果ATRA对EC9706细胞有增殖抑制和诱导凋亡的作用;流式细胞仪检测显示,在G1期之前可出现Sub-G1峰,凋亡率最高为(32.6±0.4)%,并有浓度和时间依赖性;TUNEL法显示凋亡小体形成;EC9706细胞在凋亡过程中,凋亡相关基因caspase-3的蛋白表达增强,bcl-2的蛋白表达减弱。结论ATRA作用于食管癌EC9706细胞后将引起细胞凋亡的增加,这主要与ATRA能促进caspase-3的活化,并下调bcl-2的蛋白表达有关。     

全反式维甲酸对人肺癌细胞诱导凋亡的作用

目的:研究全反式维甲酸(ATRA)对肺癌细胞生长的影响及其凋亡作用.方法:应用MTT法检测ATRA对体外培养人肺癌细胞株细胞A549的抑制率,光镜及透射电镜、流式细胞仪等检测ATRA对A549细胞诱导凋亡的作用.结果: 不同浓度的ATRA对A549细胞的增殖均有抑制作用,且量效关系明显.但大剂量主要导致细胞死亡,以10-5mol*L-1的ATRA作用效果最好,经10-5mol*L-1 ATRA作用7d后,A549细胞增殖抑制率达到60%.光镜及透射电镜下可见细胞恶性表型向正常表型发生逆转,并可观察到凋亡小体.流式细胞仪分析结果显示,ATRA处理组细胞周期延迟,G1期比例明显升高,S、G2期比例下降.结论:ATRA可抑制肺癌细胞的增殖,并诱导癌细胞凋亡.