TRAIL基因修饰联合阿霉素对大肠癌细胞株RKO作用的研究

目的:探讨肿瘤坏死因子(tumor necrsis factor,TNF)相关的凋亡诱导配体(TNF-related apoptosis-inducing ligand,TRAIL)基因联合阿霉索后,应用于人大肠癌细胞株RKO基因治疗的实验研究.方法:将重组腺病毒载体(Ad)介导的TRAIL基因作用于大肠癌细胞株RKO,并联合低剂量的阿霉素协同作用.通过MTF比色法与流式细胞仪研究分析其对RKO细胞的作用效果,并以RT-PCR检测联合应用阿霉素前后TRAIL基因的表达水平.结果:病毒载体对RKO细胞的生长有轻微的抑制作用,作用4 d抑制率为11.9%,但不增加RKO细胞的凋亡率.TRAIL对RKO细胞的生长抑制率及凋亡诱导率分别为50.1%和19.8%.联合阿霉素后,TRAIL对RKO细胞株的生长抑制率及凋亡率均有显著的增强作用,分别达60.3%及49.0%.RT-PCR结果提示联合应用阿霉素后,TRAIL基因的表达并未增强.结论:TRAIL能有效抑制RKO的生长,联合阿霉素后,其对RKO的生长抑制作用及凋亡诱导作用均明显增强.阿霉素不是通过增加TRAIL基因的表达来实现上述作用的.     

自噬相关WIPI1基因在结肠癌细胞中的表达及功能

目的:探讨细胞自噬相关WIPI1基因在结肠癌组织中的表达及其与结肠癌细胞功能之间的关系。方法:RT-PCR技术检测WIPI1基因在HCT116、SW60、RKO细胞中的表达。利用针对WIPI1基因的shRNA慢病毒感染人低分化结肠癌RKO细胞株，应用Celigo法检测WIPI1敲减对细胞增殖能力的影响；FACS检测WIPI1敲减对细胞周期阻滞能力的影响；Casepase3/7检测WIPI1基因敲减对细胞凋亡的影响；抗体芯片技术检测其可能影响的信号通路。结果:RT-PCR结果证实WIPI1基因在三株结肠癌细胞中表达丰度均为高表达。在基因沉默后，与对照组相比较，RKO细胞增殖受到显著抑制（P＜0.05)，且凋亡细胞数显著增加（P＜0.05)，细胞周期阻滞于S期；抗体芯片技术显示:细胞内信号通路中Stat3，Akt(Ser473)，mTOR，p38，GSK-3β等相关分子显著下调。结论:沉默细胞自噬相关WIPI1基因对结肠癌细胞起到一定的抑制作用。     

RNAi沉默GTPBP4基因对结肠癌RKO细胞增殖及凋亡的影响

 目的 探讨GTPBP4基因沉默后,RKO细胞增殖和凋亡等生物学行为的改变。方法 将慢病毒GTPBP4-siRNA及CON053阴性病毒转染结肠癌RKO细胞株,以Real-time PCR 和Western blot检测敲减效率。Cellomics细胞计数检测细胞生长,MTT法检测细胞增殖,FACS法进行细胞周期检测,并进行细胞克隆形成实验,AnnexinⅤ-APC单染法流式细胞仪检测细胞凋亡。 结果 慢病毒成功感染RKO细胞,mRNA和蛋白检测均显示GTPBP4基因敲减成功。GTPBP4基因敲减后,RKO细胞增殖速率受到显著抑制,MTT值比值（即增殖倍数）减小,G_0/1、G₂/M期细胞显著增多,S期明显减少,细胞克隆集落数目减少,凋亡峰值明显高于对照组,且峰值出现时间早于对照组。 结论 GTPBP4基因可能通过促进肿瘤细胞增殖、抑制凋亡而影响结肠癌的发生发展。     

RNA干扰介导的Adrml基因沉默对大肠癌细胞增殖的抑制作用

目的 探讨RNA干扰使Adrml基因沉默后对大肠癌细胞增殖的影响.方法 构建靶向Adrml基因的shRNA真核表达载体,转染大肠癌细胞RKO,筛选Adrml基因沉默的稳定克隆.实验细胞分为3组,即稳定转染Adrml-shRNA的实验组、仅含大肠癌RKO细胞的空白对照组和转染空载体的阴性对照组.采用Western blot法检测Adrml蛋白的表达水平.通过软琼脂细胞集落形成实验观察3组细胞的集落形成能力.采用四甲基偶氮唑蓝(MTT)法和原位末端标记(TUNEL)法检测细胞的增殖和凋亡水平.应用流式细胞仪检测细胞周期的变化情况.结果 实验组大肠癌RKO细胞中,Adrml蛋白的表达受到明显抑制.实验组细胞的非贴壁依赖生长能力明显下降,偶见个别集落形成.实验组细胞的凋亡百分率为(12.4±1.1)%,明显高于阴性对照组[(1.3±0.2)%,P＜0.05].实验组G_0/G_1期和S/G_2期细胞所占的比例分别为(41.2±1.1)%和(58.8±1.1)%,实验组细胞被阻滞在G_1期.Adrml基因沉默能明显增强5-氟尿嘧啶(5-Fu)对大肠癌RKO细胞的生长抑制作用,并引起大肠癌RKO细胞大量凋亡.结论 RNA干扰介导的Adrml基因沉默能诱导大肠癌细胞发生凋亡并出现细胞周期阻滞,从而抑制肿瘤细胞的增殖.对于Adrml基因高表达的大肠癌患者,RNA干扰Adrml基因的表达并结合传统化疗有望成为新的治疗手段.     

Selenomethionine induces p53 mediated cell cycle arrest and apoptosis in human colon cancer cells

While there is an increasing interest in selenium chemoprevention against human colon polyp recurrence and other cancers, the mechanism(s) by which these agents inhibit carcinogenesis are uncertain. Some of the proposed mechanisms include the inhibition of cytosine methyltransferases, carcinogen bioactivation, and inhibition of cyclooxygenase (COX). More recently, it has been suggested that selenium may exert growth inhibitory effects by activating p53. However, the molecular mechanisms of action of selenomethionine, an organoselenium compound present in selenized yeast and currently being investigated in human clinical trials for colon polyp prevention, are unclear. In the present study we tested the hypothesis that selenomethionine might affect colon cancer cell growth by p53 mediated apoptosis and/or cell cycle regulation. Four human colon cancer cell lines including HCT116 and RKO (wild type p53), HCT116-p53KO (isogenic control of HCT116 cells with p53 knocked out) and Caco-2 (mutant p53) were treated with 0-100 microM of selenomethionine for 24, 48 and 72 h. Cell viability rates were determined by the MTT assay. Cell cycle analysis was performed by flow cytometry and apoptosis measured by Annexin V-Cy5 staining. Expression of p53 protein was determined by Western blotting and immunofluorescence assays. All cell lines showed concentration and time dependent growth inhibition with selenomethionine, although HCT116 and RKO cells were the most sensitive to such treatments. Interestingly, although HCT116 and HCT116-p53KO are isogenic cell lines, selenomethionine caused a G2/M cell cycle arrest in HCT116 and RKO cells, but not in HCT116-p53KO cells. Similarly, both HCT116 and RKO demonstrated a significant increase in apoptosis (100-170%; p < 0.01) with 50-100 microM selenomethionine. Cell cycle arrest and apoptosis observed in HCT116 and RKO cell lines were accompanied by a marked increase in p53 protein expression following selenium treatment. These results clearly suggest that selenomethionine exerts p53 dependent growth inhibitory effects in colon cancer cells by inducing G2/M cell cycle arrest as well as apoptosis.     

Decreased 13-S-hydroxyoctadecadienoic acid levels and 15-lipoxygenase-1 expression in human colon cancers.

13-S-Hydroxyoctadecadienoic acid (13-S-HODE), the product of 15-lipoxygenase (15-LOX) metabolism of linoleic acid, enhances cellular mitogenic responses to certain growth factors. Other observations have questioned whether 13-S-HODE has tumorigenic effects. Our study evaluated the hypothesis that 15-LOX-1 is overexpressed in colon cancers resulting in an increase in intracellular 13-S-HODE. 15-LOX-1 and 13-S-HODE were quantified using western blots, ELISA and immunohistochemistry in 18 human colon cancers with paired normal colonic mucosa. Additionally, 15-LOX-1 expression was measured by western blots in three transformed colonic cell lines and in a human umbilical vein endothelial cell line. Next, we evaluated 13-S-HODE effects on cellular proliferation, cell cycle distribution and apoptosis in a transformed colonic cell line (RKO). Cell cycle distributions were measured by flow cytometry and apoptosis was assessed by phase contrast microscopy, electron microscopy, flow cytometry and DNA fragmentation assay. 15-LOX-1 immunohistochemistry staining scores were reduced in tumor tissues (P 相似文献   

叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的机制

目的 探究叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的作用机制,为前列腺癌预防及治疗提供新的理论依据。方法 不同浓度叶黄素作用于PC3细胞,CCK8法检测细胞增殖情况;流式细胞仪检测细胞周期分布和凋亡变化;细胞划痕和Transwell实验观察细胞迁移和侵袭能力;RT-PCR和Western blot技术检测细胞中Bax、Bcl-2的mRNA水平和蛋白表达。结果 叶黄素显著抑制PC3细胞的增殖,并呈时间和浓度依赖性。叶黄素可以将细胞生长阻滞在G0/G1期,抑制细胞迁移和侵袭;还可促进细胞凋亡,使Bcl-2表达下降,Bax表达上升。叶黄素可在转录水平上下调Bcl-2 mRNA和上调BaxmRNA。结论 叶黄素抑制PC3细胞增殖并促进其凋亡,其机制可能与阻滞细胞周期、抑制细胞迁移、侵袭以及调节凋亡相关基因和蛋白表达有关。     

Cdc42 小干扰RNA对结肠癌细胞恶性表型的影响

 目的 研究细胞周期分裂蛋白Cell division cycle 42(Cdc42)小干扰RNA(siRNA)对人结肠癌细胞恶性表型的影响. 方法 Western blot 检测五种结肠癌细胞系中Cdc42的表达。设计并合成靶向Cdc42编码区的三对siRNA及阴性对照RNA,应用Lipofectamine^TM2000分别转染结肠癌细胞系中高表达Cdc42的Lovo和SW620细胞,RT-PCR和Western blot分别检测48h后Cdc42 mRNA及蛋白的表达。Cell Counting Kit-8检测细胞的增殖能力,损伤刮擦实验和Transwell小室法分别检测细胞迁移与侵袭能力的变化。 结果 RT-PCR和 Western blot检测显示,Cdc42-siRNA能显著下调Cdc42 mRNA和蛋白水平,尤其Cdc42-siRNA1;siRNA处理后的肿瘤细胞增殖受到抑制,细胞迁移、侵袭能力也显著降低。 结论 Cdc42-siRNA可有效抑制结肠癌细胞的增殖、迁移和侵袭。提示Cdc42可能成为抑制结肠癌细胞增殖和转移新的分子靶点。     

Anti Cancer Effects of Cnidium officinale Makino Extract Mediated through Apoptosis and Cell Cycle Arrest in the HT-29 Human Colorectal Cancer Cell Line

The anti cancer properties and underlying cell death mechanism induced by the extract of the roots of Cnidium officinale Makino(COM) were investigated. The ethanolic extract of COM inhibited the proliferation of human colon cancer cells (HT-29) in both dose-dependent and time-dependent manners. Analysis of the cell cycle after treatment of HT-29 cells with various concentrations of COM showed that COM extract inhibited the cellular proliferation of HT-29 cells via G1 phase arrest of the cell cycle. The apoptotic effect of COM on HT-29 cells was confirmed by Annexin V- propidium iodide apoptosis test. RT-PCR and Western blot analysis both revealed that COM extract dose-dependently increased the expressions of p53, p21, Bax and Caspase-3. Anti-apoptotic factor Bcl-2 expression was down regulated as well as cyclin D1 and CDK4. These data suggest that COM has anti cancer properties by inducing apoptosis and cell cycle arrest in HT-29 cells and could have possible therapeutic potential against human colon adenocarcinoma.     

Protein phosphatase 1H, overexpressed in colon adenocarcinoma, is associated with CSE1L

In search for a new anticancer drug target, we explored genes involved in colon adenocarcinoma development through dysregulation of a signal transduction pathway. By using the gene expression profile database, we found protein phosphatase 1H (PPM1H), belonging to the protein phosphatase 2C (PP2C) family, upregulated in colon adenocarcinomas compared with normal colon tissues. RT-PCR analysis verified the elevated level of PPM1H expression in colon cancer cell lines relative to a normal colon cell line. PPM1H encodes a protein with a molecular mass of approximately 50 kDa that resides in the cytoplasm. PPM1H fused with maltose-binding protein expressed in E. coli exhibited phosphatase activity characteristic of the PP2C family. Co-immunoprecipitation coupled with mass spectrometry analysis identified CSE1L, a proliferation and apoptosis-related protein, as a PPM1H-interacting protein. Native, but not inactive, PPM1H expressed in HeLa cells increased the mobility of CSE1L on SDS gels and a similar mobility shift was observed for purified CSE1L after treatment with PPM1H in vitro, supporting the notion that CSE1L is a substrate of PPM1H. Dominant negative PPM1H protected HeLa cells from cell death triggered by staurosporine or taxol. Additionally, knockdown of PPM1H expression with small interfering RNAs suppressed the growth of MCF-7 cells weakly but consistently. PPM1H controls cell cycle and proliferation of cancer cells potentially through dephosphorylation of CSE1L and might be a new target of anticancer drugs.     

姜黄素对人黑色素瘤细胞凋亡机制探讨

目的：观察姜黄素对人恶性黑色素瘤细胞系A375凋亡的影响作用,探讨姜黄素抗癌的作用机制。方法：将人恶性黑色素瘤细胞系A375等分为4组,分别用0、5、10和20μmol/L的不同浓度姜黄素对该细胞株作用48h后,通过MTT法测定细胞增殖能力;利用流式细胞仪检测细胞凋亡;采用RT-PCR方法检测细胞BIRC mRNA的表达;蛋白质印迹法检测细胞BIRC7蛋白及Caspase-3蛋白的表达。结果：5μmol/L姜黄素对A375细胞增殖抑制率为（13.28±5.28）%,10μmol/L为（19.24±4.15）%,20μmol/L为（36.93±4.78）%,各组间差异有统计学意义,F=65.68,P〈0.01。5μmol/L姜黄素作用于A375细胞48h后凋亡率为（15.88±7.21）%,10μmol/L为（22.31±5.63）%,20μmol/L为（31.61±4.82）%,对照组为（3.36±1.54）%,各组间差异有统计学意义,F=25.78,P〈0.01。0μmol/L姜黄素作用A375细胞48h后BIRC7基因mRNA表达相对倍率为6.15±1.11,5μmol/L为4.54±1.23,10μmol/L为3.36±0.66,20μmol/L为2.54±0.65,各组间差异有统计学意义,F=4.743,P=0.015。0μmol/L姜黄素分别作用A375细胞48h后细胞BIRC7蛋白表达相对比值为0.88±0.36,5μmol/L为0.71±0.28,10μmol/L为0.56±0.14,20μmol/L为0.43±0.15,各组之间差异均有统计学意义,F=3.36,P=0.037。伴随姜黄素作用浓度的升高,A375细胞的生长呈显著抑制状态,呈剂量依赖性。肿瘤细胞生长、BIRC7mRNA和BIRC7蛋白表达水平均显著下调,呈剂量依赖性。结论：姜黄素可以抑制人恶性黑色素瘤细胞系A375的增殖,也可以促进其凋亡,具有抗癌作用,其作用机制之一可能通过下调BIRC7基因的表达促使黑色素瘤细胞凋亡。     

Cdc42小干扰RNA对结肠癌细胞恶性表型的影响

目的 研究细胞周期分裂蛋白 Cell division cycle 42(Cdc42)小干扰RNA(siRNA)对人结肠癌细胞恶性表型的影响.方法 Western blot检测五种结肠癌细胞系中Cdc42的表达.设计并合成靶向CAc42编码区的三对siRNA及阴性对照RNA,应用Lipofectamine~(TM)2000分别转染结肠癌细胞系中高表达Cdc42的Lovo和SW620细胞,RT-PCR和Western-blot分别检测48 h后Cdc42 mRNA及蛋白的表达.Cell Counting Kit-8检测细胞的增殖能力,损伤刮擦实验和Transwell小室法分别检测细胞迁移与侵袭能力的变化.结果 RT-PCR和 Western blot检测显示,CAc42-siRNA能显著下调CAc42 mR-NA和蛋白水平,尤其Cdc42-siRNAl;siRNA处理后的肿瘤细胞增殖受到抑制,细胞迁移、侵袭能力也显著降低.结论 Cdc42-siRNA可有效抑制结肠癌细胞的增殖、迁移和侵袭.提示Cdc42可能成为抑制结肠癌细胞增殖和转移新的分子靶点.     

Molecular mechanisms of celery seed extract induced apoptosis via s phase cell cycle arrest in the BGC-823 human stomach cancer cell line

Background: Mechanisms of apoptosis in tumor cells is an important field of tumor therapy and cancer molecular biology. Loss of cell cycle control, leading to uncontrolled proliferation, is common in cancer. Therefore, the identification of potent and selective cyclin dependent kinase inhibitors is a priority for anti-cancer drug discovery. There are at least two major apoptotic pathways, initiated by caspase-8 and caspase-9, respectively, which can activate caspase cascades. Apoptosis triggered by activation of the mitochondrial-dependent caspase pathway represents the main programmed cell death mechanism. This is activated by various intracellular stresses that induce permeabilization of the mitochondrial membrane. Anti-tumor effects of celery seed extract (CSE) and related mechanisms regarding apoptosis were here investigated in human gastric cancer BGC-823 cells. Methods: CSE was produced by supercritical fluid extraction. Cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay and apoptosis by flow cytometry using Annexin/PI staining and DAPI staining and a laser scanning confocal microscope (LSCM). Cell cycling was evaluated using PI staining with flow cytometry and expression of cell cycle and apoptosis-related proteins cyclin A, CDK2, bcl-2 and bax was assessed by immunohistochemical staining. Results: CSE had an anti-proliferation effect on human gastric cancer BGC-823 cells in a dose- and time-dependent manner. After treatment, the apoptotic rate significantly increased, with morphological changes typical of apoptosis observed with LSCM by DAPI staining. Cell cycle and apoptosis related proteins, such as cyclin A, CDK2 and bcl-2 were all down-regulated, whereas bax was up-regulated. Conclusions: The molecular determinants of inhibition of cell proliferation as well as apoptosis of CSE may be associated with cycle arrest in the S phase.     

番茄红素对肺癌A549细胞增殖和凋亡的影响及其机制研究

目的:研究番茄红素(lycopene,LP)对人非小细胞肺癌A549细胞增殖和凋亡的影响并探讨其机制.方法:体外培养并取对数生长期人非小细胞肺癌A549细胞,分别给予不同浓度的LP(2.5、5、10、20 μg/ml)和顺铂(40 μg/ml)进行干预,48 h后采用四甲基偶氮唑盐(MTT)比色法测定吸光度值并计算细胞增殖抑制率,流式细胞术(FCM)检测细胞周期和细胞凋亡状况,逆转录PCR法(RT-PCR)检测细胞中凋亡相关基因(BaxmRNA、bcl-2 mRNA)表达,免疫印迹法(Western blot)检测凋亡相关蛋白(caspase-3)表达.结果:与空白对照组比较,LP能够剂量依赖性地提高人非小细胞肺癌A549细胞增殖抑制率,延长细胞周期中G0/G1期并缩短G2/M期,提高A549细胞凋亡率(AI),上调Bax mRNA表达、下调bcl-2 mRNA表达,提高Bax/bcl-2比值,上调caspase-3蛋白表达.结论:LP具有抑制人非小细胞肺癌A549细胞增殖并促进其凋亡的作用,其机制可能与LP能够阻滞细胞周期并调节凋亡相关基因蛋白表达有关.     

Induction of Apoptosis in RKO Colon Cancer Cell Line by an Aqueous Extract of Millingtonia hortensis

Millingtonia hortensis is an important medicinal plant in Southeast Asia, used for the treatment of asthma, sinusitisand as a cholagogue and tonic. The aim of this study was to compare the effects of aqueous and ethanol extracts ofMillingtonia hortensis on the induction of apoptosis in an RKO human colon cancer cell line. Viability of RKO cellswas assessed by MTT reduction assay. The aqueous extract, but not the ethanol extract of M. hortensis inhibited cellgrowth and proliferation in a dose- and time-dependent manner. Apoptotic cells were determined by flow cytometryand DNA fragmentation assay. Apoptotic cell numbers increased in a dose-dependent manner after treatment withaqueous extract. DNA ladders were clearly observed in RKO cells treated with 200, 300 and 400 μg/ml of the aqueousextract of M. hortensis for 48 h. These results indicate that the aqueous extract of M. hortensis inhibited cellproliferation in an RKO colon cancer cell line via the apoptosis pathway.     

特异性核酶诱导宫颈癌细胞凋亡的研究

目的：研究特异性抗HPV16E6核酶对宫颈癌细胞凋亡的影响。方法：设计特异性切割HPV16E6基因的核酶,构建抗HPV16E6核酶的真核表达质粒。以脂质体法将抗HPV16E6核酶、空载体质粒分别导入CaSKi细胞,命名为CaSKi-R,CaSKi-P细胞。Northern杂交细胞3种细胞中E6基因的表达。流式细胞仪检测3种细胞的凋亡率,并测定HPV16E6,c-myc,bal-2,p53,fas等蛋白的表达。将3种细胞在相差显微镜和荧光显微镜下观察,采用荧光（Hoechst33342）染色和TUNEL（TDT-mediated dUTP nick end labelling）2种方法测定细胞凋亡。结果：Northern杂交证实CaSKi-P中表达E6较CaSKi-P,CaS-Ki明显降低。与CaSKi-R细胞表达HPV16E6,c-myc,bcl-2蛋白明显减少,而表达p53明显增高;两者中fas蛋白的表达相近。CaSKi-P细胞中各基因的表达与CaSKi细胞无显著差异。结论：抗HPV16E6-Ribozyme的导入能诱导宫颈癌细胞凋亡,其原因可能在于病毒癌基因E6表达的降低,以及由此而引起的细胞内一系列基因表达的改变。     

Survivin基因的shRNA 干扰对结肠癌SW480 细胞增殖和凋亡的影响*

目的:以携带shRNA 片段的腺病毒为载体,对结肠癌细胞SW480 中Survivin基因的表达进行干扰,研究其对肿瘤细胞中Survivin基因沉默效果及对细胞周期、凋亡和增殖的影响。方法:将构建好的携带Survivin-shRNA 片段腺病毒,体外转染结肠癌细胞株SW480。以EGFP为报告基因,采用流式细胞计数测定不同感染复数（MOI）下的转染效率,选取适当病毒浓度进行下一步实验。通过RT-PCR 和Western blot检测基因沉默后结肠癌细胞内Survivin mRNA和蛋白的表达水平;在Annexin V-FITC 和PI染色后通过流式细胞术检测并分析Survivin基因沉默后细胞周期和凋亡的变化;同时采用噻唑蓝（MTT）法、克隆增殖实验对细胞不同时期增殖活性进行观察,明确对细胞增殖的抑制时效性。结果:腺病毒转染后MOI 值在0～50时,剂量与转染效率成正比,确定最佳MOI 值为50并进行后续实验;shRNA 干扰后细胞内Survivin mRNA和蛋白表达水平降低,较对照细胞组差异有统计学意义（P<0.01）。 流式细胞仪检测结果显示基因沉默后细胞凋亡率升高,与对照组相比差异有统计学意义（P<0.01）。 同时基因沉默后,细胞周期也有明显变化,表现为G1/S 期细胞增多和G2/M期细胞减少,与对照细胞组相比差异有统计学意义（P<0.05）。 MTT 和单克隆平板实验均显示Survivin基因的沉默,对细胞的增殖和生长均具有明显抑制作用（P<0.05）。 结论:采用腺病毒对结肠癌进行靶向Survivin基因的shRNA 干扰,能有效降低目的基因的表达。其介导的Survivin基因的沉默,可以有效的诱导结肠癌细胞凋亡,同时Survivin基因可以通过抑制细胞G1/S 期转化来阻止细胞分裂,抑制细胞生长。      

VES对Her-2、p53共表达乳腺癌细胞的抑制作用及机制

目的:研究VES对Her-2、p53共表达乳腺癌细胞株MDA-MB-453细胞的增殖、凋亡的影响、通过检测Her-2、p53探讨VES抑制乳腺癌细胞生长的机制。方法:应用MTT法检测VES对MDA-MB-453细胞增殖的影响;流式细胞仪检测细胞周期变化及细胞凋亡;RT-PCR和免疫细胞化学法分别检测Her-2基因mRNA和Her-2、p53蛋白表达水平。结果:VES能抑制乳腺癌MDA-MB-453细胞增殖,随VES剂量的增加,抑制作用增强。其中20μg/ml VES处理组在48h后受到明显抑制,抑制率达52.25%;经VES处理后细胞出现凋亡,5μg/ml处理48h后,凋亡率为39.52%;药物干预组使肿瘤细胞大量阻滞于G1期(P<0.01);RT-PCR和免疫细胞化学法结果表明,VES能抑制Her-2基因mRNA的转录水平,从而抑制其蛋白的表达,也能降低p53蛋白的表达。结论:VES可诱导Her-2、p53共表达乳腺癌MDA-MB-53细胞凋亡,抑制增殖。其机制可能是通过抑制Her-2基因mRNA及蛋白的表达和通过抑制突变型p53蛋白的表达使细胞停滞于G1有关。     

siRNA沉默HYAL1基因表达对人乳腺癌细胞生长和增殖的影响

背景与目的：有研究证实透明质酸酶（hyaluronidase,Hyase）与人乳腺癌的恶性潜能相关。本研究拟探讨RNA干扰是否能有效抑制Hyde基因HYAL1的表达以及人乳腺癌细胞的生长和增殖。方法：体外化学合成HYAL1序列特异性双链RNA（dsRNA）,在脂质体（SiPORT Lipid）的介导下转染人乳腺癌细胞株MDA-MB-231、MDA-MB-453S、ZR-75和ZR-75-30。荧光共聚焦显微镜下观察转染效率,RT-PCR分析HYAL1 mRNA的表达,MTT测定细胞的增殖,流式细胞仪测定细胞周期。结果：（1）HYAL1-siRNA能有效地封闭HYALl基因的表达．使HYAL1 mRNA相对水平明显降低（P〈0．05）;（2）HYAL1-siRNA能明显抑制细胞增殖（P〈0．05）;（3）HYAL1-siRNA使细胞周期G0／G1期细胞百分比明显增加,S期的细胞百分比显著减少（P〈0．05）。结论：siRNA-HYAL1能有效抑制人乳腺癌细胞株HYAL1基因的表达,抑制细胞增殖,将更多的细胞阻滞在G0／G1期。