人乳腺癌MCF-7细胞的TRF2 siRNA表达载体的构建和鉴定

目的:构建表达端粒重复序列结合因子2(TRF2)基因小干扰RNA(siRNA-TRF2)的腺病毒表达载体(rAd-shRNA-TRF2),并检测该载体对人乳腺癌(MCF-7)细胞TRF2基因表达的沉默效应。方法:采用同源重组法构建重组腺病毒rAd-shRNA-TRF2表达载体,鉴定正确后转染MCF-7细胞,用FQ-RT-PCR和Western blot检测转染后48 h TRF2基因的表达,MTT法和克隆形成实验检测细胞生长状况。结果:重组腺病毒rAd-shRNA-TRF2包装成功,转染MCF-7细胞后,TRF2基因的表达明显被抑制,细胞生长显著抑制,细胞克隆形成能力显著下降。结论:腺病毒介导的TRF2 RNAi表达载体rAd-shRNA-TRF2构建成功,可有效抑制人乳腺癌MCF-7细胞TRF2基因的表达,抑制细胞生长。     

Conjugated linoleic acid alters caveolae phospholipid fatty acid composition and decreases caveolin-1 expression in MCF-7 breast cancer cells

Conjugated linoleic acid (CLA) refers to a group of biologically active fatty acids that exhibit anticarcinogenic properties; however, the mechanism of action remains poorly understood. Caveolae are specialized plasma membrane structures that affect many facets of cancer cell function, including growth, cell signaling, and apoptosis. Therefore, one potential mechanism could be alteration of caveolae lipid composition and function. We hypothesized that CLA can alter the lipid microenvironment of caveolae and alter expression of the major caveolae-resident protein, caveolin-1. MCF-7 human breast cancer cells were treated with a vehicle control, linoleic acid (LA), or CLA for 3 days after which total cell lysate, plasma membrane, and caveolae membrane fractions were isolated. Our findings indicate that CLA readily incorporates into caveolae (Δ9cis,11trans-18:2 being the major isomer) and maybe preferentially enriched in specific phospholipid species. Furthermore, caveolin-1 localization to caveolae after treatment with CLA was decreased relative to either control- or LA-treated cells, without changes in total cellular levels of protein relative to vehicle-control treated cells. Taken together, our results suggest that further investigation of a potential therapeutic role for CLA in modulating caveolae function in breast cancer is merited.     

Tetrahydrofurandiol stimulation of phospholipase A2, lipoxygenase, and cyclooxygenase gene expression and MCF-7 human breast cancer cell proliferation

BACKGROUND: We characterized an endocrine disruptor from ground corncob bedding material that interferes with male and female sexual behavior and ovarian cyclicity in rats and stimulates estrogen receptor (ER)-positive and ER-negative breast cancer cell proliferation. The agents were identified as an isomeric mixture of tetrahydrofurandiols (THF-diols; 9,12-oxy-10,13-dihydroxy-octadecanoic acid and 10,13-oxy-9,12-dihydroxyoctadecanoic acid). Synthetic THF-diols inhibited rat male and female sexual behavior at oral concentrations of 0.5-1 ppm, and stimulated MCF-7 human breast cancer cell proliferation in vitro. OBJECTIVES: Because THF-diols are derived from lipoxygenase and cyclooxygenase pathways, we suspected that these compounds may regulate cell proliferation by modulating specific enzymatic sites involved in linoleic acid metabolism including phospholipase A(2) (PLA2), lipoxygenases (LOX-5 and LOX-12), cyclooxygenases (COX-1 and COX-2), and closely coupled enzymes including aromatase (AROM). METHODS: MCF-7 human breast cancer cells were treated with inhibitors for PLA2 (quinacrine), lipoxygenases (LOX-5 and LOX-12; baicalein, REV-5091, nordihydroguaiaretic acid), cyclooxygenases (COX-1, COX-2, indomethacin), and AROM (formestane). The effects of these enzyme inhibitors on cell proliferation in response to THF-diols or estradiol (E(2)) were assessed. THF-diol modulation of the expression (RNA and protein) of these enzymes was also evaluated by quantitative real-time PCR (QPCR) and Western blot analyses. RESULTS: The enzyme inhibition and gene expression (RNA and protein) studies identified PLA2, LOX-5, LOX-12, COX-2, and perhaps AROM as likely sites of THF-diol regulation in MCF-7 cells. COX-1 was not affected by THF-diol treatment. DISCUSSION: THF-diol stimulation of MCF-7 cell proliferation is mediated through effects on the expression of the PLA2, COX-2, LOX-5, and LOX-12 genes and/or their respective enzyme activities. The products of these enzymes, including prostaglandins, hydroxyeicosatetraenoic acids (HETEs) and hydroxyoctadecenoic acids (HODEs), are well-established mitogens in normal and malignant cells. Therefore, it is likely that these compounds are involved in the mechanism of action of THF-diols in breast cancer cells. Although the formestane inhibition studies suggested that AROM activity might be modulated by THF-diols, this was not confirmed by the gene expression studies.     

FTY720对人乳腺癌MCF-7细胞、喉癌Hep-2细胞增殖的影响

目的:探讨FTY720抑制人乳腺癌MCF-7细胞和喉癌Hep-2细胞增殖作用。方法:将人乳腺癌MCF-7细胞和喉癌Hep-2细胞用不同浓度FTY720作用48 h,MTT法检测细胞活性,流式细胞术检测其对细胞周期及凋亡率的影响。结果:MTT结果显示,FTY720对乳腺癌MCF-7细胞和喉癌Hep-2细胞增殖均有抑制作用,而且对喉癌Hep-2细胞抑制作用的浓度依赖性高于对乳腺癌细胞的作用;流式细胞术检测结果显示,FTY720可将乳腺癌MCF-7细胞阻滞于G1期,将喉癌Hep-2细胞阻滞于G2/M期,并明显促进乳腺癌MCF-7细胞凋亡。结论:一定浓度的FTY720能明显抑制体外培养的乳腺癌和喉癌细胞增殖,调节其细胞周期,诱导乳腺癌MCF-7细胞凋亡。     

用MCF-7细胞检测有机磷农药拟雌激素样活性

目的 观察常用有机磷农药对MCF-7细胞增殖以及对雌激素受体基因和pS2基因表达的影响。方法 选用乐果、乙酰甲胺磷、久效磷、马拉硫磷、对硫磷、对氧磷6种有机磷农药进行MCF-7人乳腺癌细胞增殖实验和转录活化实验。结果 6种有机磷农药不能诱导MCF-7人乳腺癌细胞增殖,但乐果却能使pS2基因表达上调。结论 乐果可能具有拟雌激素样活性,且引起pS2基因表达上调不通过雌激素受体介导。     

槲皮素逆转人乳腺癌MCF - 7细胞阿霉素耐药及其相关机制的研究

目的 探讨槲皮素（quercetin,Que）逆转人乳腺癌MCF - 7细胞阿霉素（doxorubicin,Dox）耐药及其相关机制。方法 用不同浓度的槲皮素处理MCF - 7细胞及其阿霉素耐药的MCF - 7/dox细胞,MTT法筛选无毒剂量的槲皮素用于实验。用无毒剂量的槲皮素联合不同浓度的阿霉素处理MCF - 7和MCF - 7 /dox细胞,MTT法检测细胞增殖率,Transwell法检测细胞侵袭能力,流式细胞法检测细胞凋亡率和人乳腺癌干细胞表面标志物CD44+/CD24 - /low的表达, Western - blot检测人第10号染色体缺失的磷酸酶及张力蛋白同源的基因（Phosphatase and tensin homologue deleted on chromosome 10 ,PTEN）及磷酸化的丝氨酸/苏氨酸激酶（Phosphorylated serine/threonine kinases,p - AKT）的表达。结果 与MCF - 7细胞组相比较,MCF - 7/dox细胞组的乳腺癌干细胞表面标志物CD44+/CD24 - /low表达增高(P＜0.01),且PTEN的表达降低、p - AKT的表达升高(P＜0.05);与单用阿霉素组相比较,阿霉素与槲皮素联合应用能抑制细胞增殖和侵袭、诱导细胞凋亡、杀死肿瘤干细胞,并能上调PTEN、下调p - AKT的表达。结论 槲皮素能有效逆转人乳腺癌MCF - 7细胞阿霉素耐药,其机制可能与槲皮素协同阿霉素杀死人乳腺癌干细胞,调控PTEN/AKT信号通路有关。     

枸橼酸芬太尼对人乳腺癌MCF-7细胞MMP-2及MMP-9表达的影响

目的:探讨枸橼酸芬太尼对人乳腺癌MCF-7细胞MMP-2和MMP-9表达的影响。方法:以MCF-7细胞为对象,分别加入0、0.000 1、0.01、1μmol/L的枸橼酸芬太尼干预48 h,RT-PCR检测MMP-2和MMP-9 mRNA的表达,Western blot检测MMP-2和MMP-9蛋白的表达。结果:MCF-7细胞MMP-2和MMP-9 mRNA的表达随着枸橼酸芬太尼浓度的增加而减少,0.01及1μmol/L枸橼酸芬太尼组与对照组差异有统计学意义(P<0.05)。枸橼酸芬太尼呈浓度依赖性抑制MCF-7细胞MMP-2、MMP-9蛋白的表达,各浓度实验组与对照组差异有统计学意义(P<0.01)。结论:芬太尼可抑制MCF-7细胞MMP-2及MMP-9的表达,该作用可能是芬太尼降低人乳腺癌MCF-7细胞侵袭能力的分子机制之一。     

金雀异黄素对人乳腺癌细胞MCF-7生长影响

目的 观察金雀异黄素在低雌激素水平情况下对雌激素依赖阳性人乳腺癌细胞MCF-7的生长影响.方法 采用四甲基偶氮噻唑蓝(MTT)法检测细胞增殖,流式细胞术分析细胞周期分布情况,磷脂结合蛋白V/碘化丙啶(AnnexinV/PI)联合双染法检测细胞凋亡,间接免疫荧光法测定雌激素调节蛋白(prcsenilin2,PS2>)的表达.结果 当MCF-7细胞经过去雌激素处理以后,与对照组相比,金雀异黄素在5×10-7～10-5mol/L时可以促进细胞增殖,G0>/G1>期细胞向S期推进,PS2>蛋白表达增加,但是抑制细胞凋亡作用并不明显.结论 金雀异黄素在低雌激素水平情况下可以促进人乳腺癌细胞MCF-7的细胞增殖、DNA合成以及PS2>蛋白的表达,具有一定的雌激素样作用.     

雌二醇与不同孕激素联合对人乳腺癌细胞增殖的影响

目的探讨雌二醇/孕激素联合方案对人乳腺癌细胞MCF-7和MCF-7/PGRMC1(WT-12)增殖的影响。方法 MCF-7细胞,用表达PGRMC1的质粒稳定转染到MCF-7细胞,使其成为MCF-7/WT-12乳腺癌细胞。雌二醇浓度(10-10M,10-12M,10-14M)与孕酮、合成孕激素安宫黄体酮、炔诺酮序贯联合加入上述两种人乳腺癌细胞进行培养6天,MTT法分别测定MCF-7、MCF-7/WT-12肿瘤细胞的生长增殖情况。结果单纯雌二醇在高浓度10-10M下,明显刺激细胞生长,这种生长不受加入各种孕激素的影响。单纯雌二醇在低浓度下10-12M、10-14M下对MCF-7及MCF-7/WT-12细胞刺激增殖作用轻微或没有明显刺激细胞增殖的作用,然而,加用炔诺酮则可激发细胞明显的增殖反应,而增加安宫黄体酮和孕酮则显示中性作用,无激发反应。MCF-7/WT-12细胞的增殖反应更明显。结论雌二醇在表达孕激素受体膜组分1(progesterone receptor membrane component 1,PGRMC1)的MCF-7细胞中能明显诱发细胞增殖的增加,且表现为剂量依赖性。在低的雌二醇浓度下,某些孕激素可能启动了一种强增殖信号。关于HRT低剂量雌二醇致乳腺癌风险增加的可能性,可能与用某些特殊的孕激素有关。     

RNA沉默Slug基因对人乳腺癌细胞株MCF-7侵袭及血管生成的影响

目的:研究Slug-shRNA-1干扰Slug基因对MCF-7侵袭潜力及诱导血管内皮细胞形成管腔能力的影响。方法:通过体外侵袭模型,测定MCF-7通过Slug-shRNA-1作用于Slug基因后穿透Matrigel的潜力;应用MCF-7与人脐静脉内皮细胞(HUVEC)双室联合培养技术,观察MCF-7通过Slug-shRNA-1作用于Slug基因后诱导HUVEC形成管腔能力的影响。结果:siRNA-Slug作用于Slug基因后能明显降低MCF-7穿透Matrigel的能力(P<0.05),抑制MCF-7诱导HUVEC形成管腔样结构的能力(P<0.05)。结论:Slug-shRNA-1作用于Slug基因后能明显降低MCF-7的侵袭潜力,抑制MCF-7诱导管腔形成能力。     

1800 MHz射频电磁场对人乳腺癌细胞蛋白质表达的影响

目的采用高通量的蛋白质组学技术研究人乳腺癌细胞株MCF-7细胞受GSM 1800MHz射频电磁场辐照后,其蛋白质表达谱的变化,以探索移动电话信号对细胞正常生理功能的可能影响。方法比吸收率为3．5W／kg时,采用不同时间（1、3、6、12和24h）和辐照模式（间断辐射和连续辐射）的GSM 1800MHz射频电磁场处理MCF-7细胞后,直接抽提蛋白质,然后进行双向凝胶电泳。凝胶经银染后,使用PDQuest软件分析假辐照组与电磁场辐照组间的差异表达蛋白质斑点。每个实验重复3次。结果凝胶上平均可检测到1100个蛋白斑点。3．5W／kg连续辐射6h未发现差异点,其他暴露情况下均可检测到不同数量的差异蛋白,以3．5W／kg间断辐射3h和连续辐照12h检测的差异蛋白点较多,分别为18个和7个。通过搜索SWISS-PROT蛋白数据库,对差异蛋白的类别和功能进行了初步推测,结果表明差异蛋白主要与生物分子的合成和调控、信号转导、DNA损伤修复等功能相关。结论GSM 1800MHz射频电磁场对MCF-7细胞蛋白质表达谱具有一定程度的影响,且依赖于暴露的强度、时间和模式,影响环节可能涉及多个生物学过程。     

E-钙黏蛋白与miR-200c在MCF-7/ADR及乳腺癌组织的表达研究

目的探讨乳腺癌耐药株中E-钙黏蛋白（E-cadherin）和miR-200c的表达,以及E-cadherin表达与新辅助化疗疗效的关系。方法应用定量RT-PCR方法检测人乳腺癌细胞株MCF-7和阿霉素耐药株MCF-7/ADR中E-cadherin、Twist1以及miR-200c表达,采用免疫组化法检测82例乳腺癌患者新辅助化疗前组织E-cadherin表达。结果与MCF-7相比,E-cadherin在MCF-7/ADR中表达明显降低（P=0.01）,Twist1在MCF-7/ADR中表达明显升高（P〈0.01）,miR-200c在MCF-7/ADR表达较MCF-7显著下降（P〈0.01）。结论 E-cadherin和miR-200c表达下调参与乳腺癌阿霉素耐药,可能是逆转乳腺癌耐药的潜在治疗靶点。     

Eicosapentaenoic acid suppresses cell proliferation in MCF-7 human breast cancer xenografts in nude rats via a pertussis toxin-sensitive signal transduction pathway

The type and content of dietary PUFAs have profound influences on the growth rate of transplantable human breast cancers in immunodeficient rodents. Diets enriched in linoleic acid (LA), an (n-6) fatty acid, stimulate tumor growth, whereas dietary fats containing (n-3) fatty acids slow such growth. Interactions between LA and (n-3) fatty acids capable of regulating cell proliferation in solid tumors in vivo are not yet well defined. Here we tested the hypothesis that plasma eicosapentaenoic acid (EPA), an (n-3) fatty acid, suppresses cell proliferation in MCF-7 human breast cancer xenografts via a pertussis toxin-sensitive reduction of intratumor cAMP, LA uptake, and formation of the mitogen 13-hydroxyoctadecadienoic acid (13-HODE) from LA. Plasma fatty acid uptake and 13-HODE release were determined in control and EPA-treated xenografts from arteriovenous differences measured during perfusion in situ. Intratumor cAMP, extracellular signal-regulated kinase p44/p42 (ERK1/2) phosphorylation, and [3H]thymidine incorporation (TTI) were measured in tumors freeze-clamped at the end of the perfusions. Arterial blood containing EPA caused significant decreases (P < 0.05) in cAMP, uptake of SFA, monounsaturated fatty acids, and (n-6) PUFA, 13-HODE formation, ERK1/2 phosphorylation, and TTI in MCF-7 xenografts. These effects of EPA were reversed by the addition of either pertussis toxin or 8-bromoadenosine-cAMP to the EPA-containing arterial blood. Addition of 13-HODE to the EPA-containing arterial blood restored phosphorylated ERK1/2 and TTI but not FA uptake. The results suggest that EPA regulates cell proliferation in MCF-7 xenografts via a novel inhibitory G protein-coupled, (n-3) FFA receptor-mediated signal transduction pathway.     

Growth inhibition and induction of apoptosis in MCF-7 breast cancer cells by fermented soy milk

The effect of a fermented soy milk product (FSP) on various human breast carcinoma cell lines was investigated, and it was shown to have a growth-inhibitory effect, especially on MCF-7 cells. Thus the MCF-7 cell line was used to study the mechanism of action. In female severe combined immune deficiency mice implanted with MCF-7 cells, pretreatment with FSP significantly inhibited tumor growth. The inhibitory effect of FSP on MCF-7 cells seemed to be caused by the additive effects of a wide variety of constituents. The active components of FSP are mainly in the water phase, and the lipid-soluble fraction, which includes the soy isoflavones such as genistein and daidzein, is relatively ineffective. A variety of methods were used to demonstrate that FSP caused apoptotic cell death in MCF-7 cells. FSP induced generation of reactive oxygen species (ROS). Growth inhibition and ROS generation induced by FSP could be inhibited by catalase and deferoxamine, indicating that the ROS production probably was the cause of this apoptotic cell death. This study suggests that FSP retards tumor growth in vivo and can trigger apoptosis in vitro. It may, therefore, be a potential nutritional supplement in chemotherapy.     

大豆异黄酮抑制人乳腺癌细胞生长及作用机制研究

采用体外细胞培养的方法 ,探讨大豆异黄酮对体外培养的人乳腺癌MCF - 7细胞生长的作用及作用机制。结果表明 ,大豆异黄酮抑制MCF - 7细胞生长 ,诱导MCF - 7细胞凋亡。蛋白水平检测表明大豆异黄酮可使MCF - 7细胞iNOS表达升高。结果提示大豆异黄酮抑制MCF - 7细胞生长 ,诱导细胞凋亡 ,并主要是通过调节iNOS基因表达实现的     

-紫罗兰酮诱导人乳腺癌细胞(ER+)凋亡作用

目的 为了研究β-紫罗兰酮对雌激素阳性的人乳腺癌细胞(MCF-7)凋亡诱导作用的影响。方法 采用细胞生长曲线,凋亡细胞的荧光显微镜和电镜观察,TUNEL方法及流式细胞光度术以及Western blot的检测方法,观察了用不同浓度β-紫罗兰酮(25、50、100 和200 μmol/L)对MCF-7细胞的抑制作用及诱导该细胞产生凋亡情况。结果 β-紫罗兰酮可明显抑制MCF-7细胞生长,抑制率分别为6.57%、34.58%、65.22%和81.87%。通过荧光显微镜和电镜技术观察到了MCF-7细胞有凋亡的形态特征;TUNEL(末端脱氧核苷酸转移酶缺口末端标记)方法和流式细胞光度术均检测到β-紫罗兰酮可诱导MCF-7细胞产生凋亡,并随着β-紫罗兰酮浓度的增加,细胞凋亡率逐渐增加。TUNEL凋亡指数(AI)分别为20.74%(24h)和33.15%(48h);流式细胞光度术的凋亡指数(AI)分别为27.96%(24h)和38.59%(48h)。通过Western blotting方法观察到β-紫罗兰酮可对MCF-7的细胞增殖相关蛋白PCNA及bcl-2蛋白表达有明显地抑制作用,呈现明显地剂量-反应关系。结论 β-紫罗兰酮可明显地抑制雌激素阳性(ER⁺)人乳腺癌MCF-7细胞的增殖,并诱导该细胞产生凋亡,其作用机制需要进一步探讨。     

黑升麻的雌激素活性及其对人类乳腺癌MCF-7细胞雌激素受体水平的影响

为了检测黑升麻 (CR)的雌激素活性及其对人类乳腺癌 MCF- 7细胞雌激素受体 (ERs)水平的影响 ,未成年雌性小鼠按体重以 75、15 0和 30 0 m g/ kg的 CR灌胃 14d,观察处于动情期的时间 ,第 15天处死后取子宫和卵巢称重。以 MTT实验筛选 CR的最佳细胞作用剂量 ,观察对照组、CR组 (4.75μg/ L )和 17β-雌二醇组 (0 .3nmol/ L)的细胞生长曲线 ,并在流式细胞仪上用间接免疫荧光法测定各组 ERs水平。结果发现子宫重量随 CR剂量增加而增加 ,30 0 mg/ kg的 CR可显著增加动情天数 (P<0 .0 5 )。 4.75 μg/ L CR对 MCF- 7细胞的促增殖作用最强 ,达 6 4.7% ;CR组和 17β-雌二醇组的细胞群体倍增时间 (TD)分别为 32 .1h和31.7h,明显低于对照组 (TD=35 .3h) ;4.75 μg/ L 的 CR可显著增加细胞的 ERs水平 (P<0 .0 1)。结果表明CR具有雌激素活性 ,其升高 ERs水平的作用可能是该物质可治疗更年期综合征的机制之一。