P,P’-DDD对人乳腺癌细胞的增殖作用

[目的]观察对,对-二氯二苯基二氯乙烷（P,P’-DDD）对人乳腺癌（MCF-7）细胞增殖的影响。[方法]采用体外培养MCF-7细胞增殖试验检测DDD的类雌激素活性,并用生长曲线对其作用机制进行初步探讨。[结果]DDD染毒剂量在3×10^-7mol／L、3×10^-6mol／L时,存在刺激MCF-7细胞增殖的类雌激素活性（P〈0．05）,在3×10^-6mol／L剂量时其增殖效应最大。细胞生长曲线方面,DDD组在第3、5、7天各时间段细胞数均明显高于溶剂对照组（P〈0．05）。[结论]DDD在3×10^-7mol／L、3×10^-6mol／L具有刺激MCF．7细胞增殖的类雌激素活性。     

二氯二苯二氯乙烯的类雌激素活性的实验研究

目的研究二氯二苯二氯乙烯(DDE)的类雌激素活性对人乳腺癌细胞株MCF-7增殖的影响。方法采用了体外MCF-7细胞增殖试验检测了DDE(3×10-5、3×10-6、3×10-7、3×10-8、3×10-9 mol/L)的类雌激素活性,并用生长曲线分析对其作用机制进行了初步探讨。结果3×10-6 mol/LDDE染毒组吸光度值高于溶剂对照组且MST-7细胞增殖的生长曲线与10-9 mol/L17β-雌二醇染毒组相似。结论DDE具有刺激MCF-7细胞增殖的类雌激素活性,其机制可能与17β-雌二醇相同。     

杀螟硫磷体外环境雌激素活性及机制研究

目的 检测杀螟硫磷的环境雌激素活性，并探讨其作用机制。方法 人乳腺癌细胞株（MCF-7）细胞在含10％小牛血清的RPMI1640培养基中进行半开放式贴壁培养，加受试物前2周，改在含10％去激素小牛血清的无酚红RPMI1640培养基中培养。试验设溶剂对照组、阳性对照组及杀螟硫磷5个不同浓度实验组，采用MCF-7细胞增殖试验、四甲基偶氮噻唑蓝（MTT）试验和生长曲线观察杀螟硫磷对MCF-7细胞增殖的影响，并通过雌激素受体（ER）结合试验分析杀螟硫磷与ER的结合情况。结果 杀螟硫磷在10^-9～10^-6mol／L剂量范围内可诱导MCF-7细胞增殖，差异有统计学意义（P〈0．05），且存在剂量-效应关系。杀螟硫磷能与ER结合，抑制^125I-E2与ER结合。结论 杀螟硫磷具有环境雌激素活性，其拟雌激素作用由ER介导而产生。     

五氯酚的类雌激素效应初探

目的 研究五氯酚(PCP)的类雌激素活力对MCF-7细胞增殖的影响.方法 采用离体MCF-7细胞增殖试验检测PCP的类雌激素活力,并用生长曲线对其作用机制进行初步探讨.结果 PCP在7.5×10-7～7.5×10-5 mol/L有明显刺激MCF-7细胞增殖的类雌激素活力,在7.5×10-6 mol/L增殖效应最大.细胞周期分析PCP组细胞增殖指教均明显高于溶剂对照组.结论 PCP在7.5×10-7 ～7.5×10-5 mol/L具有刺激MCF-7细胞增殖的类雌激素活力.     

邻苯二甲酸二丁酯的拟雌激素活性研究

目的探讨邻苯二甲酸二丁酯(DBP)的拟雌激素活性。方法对雌激素敏感的人乳腺癌MCF-7细胞在RPMI 1640培养基中采用开放式单层贴壁培养,开始实验前将细胞用PBS洗涤后改为在无酚红RPMI 1640培养基中培养5d,实验设溶剂对照、雌激素阳性对照和邻苯二甲酸二丁酯各剂量组(10^-7-10^-3mol／L),采用四唑盐(MTT)法、生长曲线、有丝分裂指数和细胞克隆形成试验对MCF-7细胞增殖情况进行分析。结果与溶剂对照组相比,10^-5mol／LDBP处理24h就可促进MCF-7细胞增殖,提高增殖指数;随着培养时间延长至96h,其他浓度DBP也表现出促进细胞增殖的效果,且浓度在10^-5mol／L时,细胞增殖活性达到最大;在对数生长期,DBP可提高MCF-7细胞的有丝分裂指数;10^-5mol／LDBP处理48h就可增强MCF-7细胞形成细胞克隆的能力。结论邻苯二甲酸二丁酯可促进雌激素依赖性乳腺癌MCF-7细胞的增殖,可能具有拟雌激素作用。     

农药咪鲜安雌激素样作用机制体外研究

目的用体外试验检测农药咪鲜安的雌激素样作用,并对其可能的作用机制进行探讨。方法将人乳腺癌细胞株（MCF-7）细胞在含10%小牛血清的RPM11640培养基中进行半开放式贴壁培养,加受试物前2周,改在含10%去激素小牛血清的无酚红RPMI 1640培养基中培养。设溶剂对照组、阳性对照组及5个不同浓度的咪鲜安样品组,采用MCF-7细胞增殖试验、四甲基偶氮噻唑蓝（MTT）试验和生长曲线观察咪鲜安对MCF-7细胞增殖的影响,并通过雌激素受体（ER）结合试验分析咪鲜安与ER的结合情况,探讨可能的作用机制。结果咪鲜安在10-7~10-5mol/L剂量范围内可诱导MCF-7细胞增殖,差异有统计学意义（P〈0.05或P〈0.01）,且存在剂量-效应关系;咪鲜安能竞争性地与ER结合,从而抑制125I-E2与ER结合。结论咪鲜安具有雌激素样作用,其作用机制在于其竞争性地与ER的结合。     

开环异落叶松树脂酚对乳腺癌MOF-7细胞增殖的影响

目的研究开环异落叶松树脂酚（SECO）及其代谢产物肠内酯（ENL）、肠二醇（END）对人乳腺癌MCF-7细胞株增殖的影响，揭示其可能的作用机制。方法采用四甲基偶氮唑盐（MTT）比色法测定SECO、END与ENL对MCF-7细胞增殖的影响，并与染料木黄酮（GEN）进行对比。采用光学显微镜与流式细胞仪（FCM）检测了MCF-7细胞生长过程中受到的影响，分析了SECO抗乳腺癌的作用机制。结果低浓度SECO对MCF-7细胞增殖起促进作用，高浓度SECO对MCF-7细胞增殖起明显的抑制作用；呈现G2／M期阻滞。光学显微镜观察到细胞凋亡的形态。ENL与END则在不同浓度下均表现出抑制作用。结论SECO对MCF-7细胞的增殖具有浓度依赖效应，其抑制MCF-7细胞增殖作用可能与其代谢产物有关。     

玉米赤霉烯酮对乳腺癌细胞MCF-7增殖和凋亡的影响

目的 观察真菌雌激素玉米赤霉烯酮（ZEA）对人乳腺癌细胞MCF-7增殖和凋亡的影响,并初步探讨其分子生物学作用机制。方法 用噻唑蓝比色法观察ZEA对MCF-7细胞增殖活力流式细胞术观察ZEA对MCF-7细胞增殖活力和细胞周期分布的影响;用凋亡DNA片段检测试剂盒和流式细胞术从不同方面检测ZEA对细胞凋亡的影响;逆转录聚合酶链反应（RT-PCR）和蛋白印迹技术检测ZEA对bcl-2和bax mRNA和蛋白质表达的影响。结果 MCF-7细胞生长为雌激素依赖性：溶剂对照组（外源性雌激素缺乏且内源性雌激素耗尽的条件下）细胞增殖活力为100％,10nmol／L雌二醇组细胞增殖活力为257．6％;另外,以溶剂对照组发生凋亡率为100％来计,10nmol／L雌二醇组细胞凋亡率只有为10．8％。ZEA对MCF-7细胞生物学效应的影响同雌二醇类似：在2～96nmol／L浓度范围内,ZEA可快速恢复MCF-7细胞增殖活力（96nmol／L组细胞增殖活力为对照组的2．4倍）,提高S期细胞分布比例（96nmol／L组S期细胞分布比例为对照组的2．3倍）,降低凋亡百分率（96nmol／L组细胞细胞凋亡率为对照组的23．7％）,并呈现出良好的剂量-效应关系。RT-PCR和蛋白印迹结果分析显示,ZEA能够促进bcl-2 mRNA和蛋白质表达,对bax的表达则表现出抑制作用。结论 同雌激素类似,ZEA可提高MCF-7细胞增殖活力并促进有丝分裂指数;通过对bcl-2和bax表达的调节作用,ZEA可抑制雌激素耗尽所诱导的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。     

镉对MCF-7细胞生长和雌激素受体表达影响

目的 观察镉对MCF-7人乳腺癌细胞生长和雌激素受体表达的影响.方法 四甲基偶氮噻唑蓝(MTT)法筛选镉促进MCF-7细胞增殖的最佳作用时间和剂量,用流式细胞术观察细胞死亡情况,划痕实验评价细胞迁移能力,western-blot检测雌激素受体α、雌激素受体β蛋白表达,同时加入雌激素受体阻断剂氟维司群观察细胞增殖和2种雌激素受体表达的变化情况.结果 1μmol/L镉处理24 h和1nmol/L镉处理72 h对MCF-7细胞的促增殖效应最明显,增殖率(PR)分别为133％、138％;l nmol/L镉处理72 h能明显抑制MCF-7细胞死亡,死亡细胞比例为28.5％,低于对照组的44.5％(t=4.557,P ＜0.05);增强细胞迁移能力,划痕伤口愈合率为25.7％,与对照组比较差异有统计学意义(t =5.696,P＜0.05);增加雌激素受体α蛋白的表达;雌激素受体阻断剂能够抑制镉对MCF-7细胞的促增殖作用和拮抗镉对雌激素受体α蛋白表达增加的效应.结论 长时间低剂量处理镉对MCF-7乳腺癌细胞生长有促进作用并可能与激活雌激素受体α表达有关.     

镉雌激素样作用的实验研究

目的 评价镉的雌激素样效应。方法 从体外和体内两个水平,观察不同浓度的氯化镉对MCF－7人乳腺癌细胞生长和去卵巢SD大鼠子宫的诱导增生作用。结果 10^-6mol/L的氯化镉使MCF－7细胞增殖达最大,为对照的3．92倍,并且其诱导增殖作用被纯抗雌激素ICI 182,780完全阻断。镉的相对增殖效率为雌二醇的65％,相对增殖能力为雌二醇的1／1000。每天0．1、0．5及2．5mg/kg连续3d腹腔注射氯化镉能明显促进去卵巢大鼠子宫的增生,并且具有剂量－效应关系。结论 镉能够模拟雌二醇诱导MCF－7细胞增殖及大鼠子宫增重。镉具有雌激素样效应。     

The E-screen assay: a comparison of different MCF7 cell stocks.

MCF7 human breast cancer cells have been studied extensively as a model for hormonal effects on breast cancer cell growth and specific protein synthesis. Because the proliferative effect of natural estrogen is considered the hallmark of estrogen action, it was proposed that this property be used to determine whether a substance is an estrogen. The E-screen assay, developed for this purpose, is based on the ability of MCF7 cells to proliferate in the presence of estrogens. The aim of our study was to characterize the response of four MCF7 cell stocks (BUS, ATCC, BB, and BB104) and determine which of them performed best in the E-screen test. The four stocks assayed were distinguishable by their biological behavior. In the absence of estrogen, MCF7 BUS cells stopped proliferating and accumulated in the G0/G1 phase of the cell cycle; estrogen receptors increased, progesterone receptors decreased, and small amounts of pS2 protein were secreted. Of all the MCF7 stocks tested, MCF7 BUS cells showed the highest proliferative response to estradiol-17 beta: cell yields increased up to sixfold over those of nontreated cells in a 144-hr period. The differences between estrogen-supplemented and nonsupplemented MCF7 BUS cells were due mostly to G0/G1 proliferative arrest mediated by charcoal dextran-stripped serum. MCF7 BUS cell stocks and others showing a similar proliferative pattern should be chosen for use in the E-screen test, or whenever a proliferative effect of estrogen is to be demonstrated.     

Effect of soy‐derived isoflavonoids on the induced growth of MCF‐7 cells by estrogenic environmental chemicals

Isoflavonoids are natural plant compounds and possess antitumorigenic properties. Many environmental chemicals have been found to be estrogenic and can enhance tumor growth in estrogen receptor‐positive cells. In the present study, the effects of genistein, daidzein, biochanin A, formononetin, and equol on the proliferation of estrogen receptor‐positive MCF‐7 cells induced by synthetic chemicals 1‐(o‐chlorophenyl)‐1‐(p‐chlorophenyl)‐2,2,2‐trichloroethane (o,p'‐DDT), 4‐nonylphenol (4‐NP), and 5‐octylphenol (5‐OP) found in the environment were investigated. Genistein, biochanin A, equol, and to some extent daidzein, but not formononetin, at <10 μM can enhance the growth of MCF‐7 cells in the absence of environmental chemicals. Formononetin was toxic to MCF‐7 cells at the tested concentrations. The environmental chemicals 4‐NP, 5‐OP, and o,p'‐DDT and the natural estrogen 17β‐estradiol at 5, 5, and 10 μM and 5 nM, respectively, induced proliferation of MCF‐7 cells. In the presence of isoflavonoids (>25 μM), the environmental chemical‐induced cell proliferation was inhibited. Individually, genistein (IC50 = 25–33 μM) was the most potent inhibitor against the induced proliferation of MCF‐7 cells of the isoflavonoids needed for a 50% suppression of growth induced by 4‐NP, 5‐OP, and o,p'‐DDT. A mixture of isoflavonoids was the most potent inhibitor against the induced proliferation. Estrogen receptor‐dependent and ‐independent pathways could be involved in the inhibitory actions of isoflavonoids. Because it is impossible to have a chemical‐free environment, the in vitro data presented here are of practical importance to develop evolving dietary strategies and tactics against the adverse health effects of environmental chemicals.     

雌激素对前列腺基质细胞生长的影响

目的探讨雌激素对前列腺基质细胞生长的影响。方法体外分离和培养前列腺基质细胞，细胞计数法及MTT法检测细胞生长情况。结果雌激素在一定浓度范围内促进前列腺基质细胞生长，但浓度继续增加时，前列腺基质细胞生长受抑制。结论雌激素的浓度与前列腺基质细胞生长呈倒U形关系，在一定浓度范围，雌激素刺激基质细胞增殖，否则表现为抑制作用。     

共轭亚油酸异构体的抗乳腺癌活性研究

目的 :　研究共轭亚油酸 (CLA)两种主要异构体 (9,1 1 - CLA和 1 0 ,1 2 - CLA)对两种人乳腺癌细胞 (MCF- 7,MDA- MB- 2 31 )和大鼠扩散乳腺癌细胞 (F3 )活性的异同。方法 :　采用MTT方法研究两种主要 CLA异构体在不同浓度、不同作用时间及不同给药方式下 ,抑制上述几种癌细胞增殖的能力。结果 :　 1 0 ,1 2 - CLA对所有的试验癌细胞均呈现较强的抑制活性 ,而 9,1 1 -CLA仅对 MCF- 7呈现抑制活性 ,对 MDA- MB- 2 31和 F3 基本无活性 ;1 0 ,1 2 - CLA对 F3 的抑制活性与处理时间和给药方式密切相关 ,加药后不更换培养液处理 72 h可使其抑制能力达到最大值 ;细胞周期研究显示 1 0 ,1 2 - CLA对 MCF- 7呈微弱的 G0 / G1期抑制 ,而对 F3 细胞周期则无影响。结论 :　 CLA的两种主要异构体在该实验条件下对上述三种癌细胞增殖抑制能力和作用机制有着明显的差异 ,其中 1 0 ,1 2 - CLA活性明显强于 9,1 1 - CLA。 1 0 ,1 2 - CLA是通过其代谢物对 F3 的增殖起抑制作用     

Effects of Phytoestrogen Extracts Isolated from Pumpkin Seeds on Estradiol Production and ER/PR Expression in Breast Cancer and Trophoblast Tumor Cells

Phytoestrogens have a controversial effect on hormone-dependent tumours. Herein, we investigated the effect of the pumpkin seed extract (PSE) on estradiol production and estrogen receptor (ER)-α/ER-β/progesterone receptor (PR) status on MCF7, Jeg3, and BeWo cells. The PSE was prepared and analyzed by mass spectrometry. MCF7, Jeg3, and BeWo cells were incubated with various concentrations of PSE. Untreated cells served as controls. Supernatants were tested for estradiol production with an ELISA method. Furthermore, the effect of the PSE on ER-α/ER-β/PR expression was assessed by immunocytochemistry. The PSE was found to contain both lignans and flavones. Estradiol production was elevated in MCF7, BeWo, and Jeg3 cells in a concentration-dependent manner. In MCF7 cells, a significant ER-α downregulation and a significant PR upregulation were observed. The above results after properly designed animal studies could highlight a potential role of pumpkin seed's lignans in breast cancer prevention and/or treatment.     

Phytoestrogen concentration determines effects on DNA synthesis in human breast cancer cells

Thirteen isoflavonoids, flavonoids, and lignans, including some known phytoestrogens, were evaluated for their effects on DNA synthesis in estrogen‐dependent (MCF‐7) and ‐independent (MDA‐MB‐231) human breast cancer cells. Treatment for 24 hours with most of the compounds at 20–80 μM sharply inhibited DNA synthesis in MDA‐MB‐231 cells. In MCF‐7 cells, on the other hand, biphasic effects were seen. At 0.1–10 μM, coumestrol, genistein, biochanin A, apigenin, luteolin, kaempferol, and enterolactone induced DNA synthesis 150–235% and, at 20–90 pM, inhibited DNA synthesis by 50%. Treatment of MCF‐7 cells for 10 days with genistein or coumestrol showed continuous stimulation of DNA synthesis at low concentrations. Time‐course experiments with genistein in MCF‐7 cells showed effects to be reversed by 48‐hour withdrawal of genistein at most concentrations. Induction of DNA synthesis in MCF‐7 cells, but not in MDA‐MB‐231 cells, is consistent with an estrogenic effect of these compounds. Inhibition of estrogen‐dependent and ‐independent breast cancer cells at high concentrations suggests additional mechanisms independent of the estrogen receptor. The current focus on the role of phytoestrogens in cancer prevention must take into account the biphasic effects observed in this study, showing inhibition of DNA synthesis at high concentrations but induction at concentrations close to probable levels in humans.