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。     

去磷酸化RB蛋白表达状况对阿霉素诱导人乳腺癌细胞凋亡和抑制其增殖的关系

目的探讨去磷酸化RB蛋白表达状况对阿霉素(ADR)诱导人乳腺癌细胞(MCF-7/S)凋亡和抑制其增殖的影响。方法应用MTT比色法检测ADR对MCF-7/S细胞增殖抑制作用,同时应用末端标记(TUNEL)法测定ADR诱导MCF-7/S细胞凋亡程度。采用免疫细胞化学法检测去磷酸化RB蛋白的表达状况。结果ADR抑制MCF-7/S细胞增殖,呈剂量依赖性,半数抑制浓度(IC50)为0.128mg.L-1;ADR作用组MCF-7/S细胞的凋亡率及去磷酸化RB蛋白的表达量分别与对照组细胞相比明显增高。结论去磷酸化RB蛋白的表达量与ADR抑制MCF-7/S细胞增殖和诱导MCF-7/S细胞凋亡呈正相关。     

青蒿素对乳腺癌细胞血管内皮生长因子表达的影响

目的探讨青蒿素(artemisinin)对人乳腺癌细胞血管内皮生长因子(VEGF)表达的影响及作用机制。方法应用四甲基偶氮唑盐(MTT)法检测青蒿素对人乳腺癌细胞系MCF-7和MDA-MB-231细胞增殖的影响,应用酶联免疫吸附试验(ELISA)检测VGEF蛋白的分泌水平,采用半定量逆转录-聚合酶链反应(RT-PCR)技术检测VEGF mRNA表达水平。结果青蒿素对MCF-7和MDA-MB-231细胞均有明显增殖抑制效应。青蒿素降低了VEGF分泌水平和VEGFmRNA的表达水平,并呈剂量-时间效应关系。结论青蒿素能抑制人类乳腺癌细胞增殖和细胞VEGF mRNA的表达。     

BAG-1基因在Luminal型乳腺癌中的表达及其对他莫昔芬敏感性的影响

目的探讨Bcl-2结合抗凋亡基因(BAG-1)与Luminal型乳腺癌细胞株MCF-7对他莫昔芬(TMA)敏感性的关系以及可能的作用机制。方法 (1)采用免疫组织化学法检测Luminal型乳腺癌组织和癌旁组织中BAG-1的表达;(2)采用药物浓度梯度间歇诱导法体外建立MCF-7耐药细胞,采用MTT法测定TMA对MCF-7和MCF-7/TMAR细胞增殖活性的影响;(3)采用RNA干扰技术靶向沉默MCF-7/TAMR细胞BAG-1的表达;(4)采用RT-PCR法和Western blot法检测MCF-7细胞和MCF-7/TAMR细胞BAG-1、ER、p-AKT和p-ERK1/2 mRNA和蛋白的表达水平。结果 (1)乳腺癌组织中BAG-1的高表达率明显高于癌旁组织(P0. 05);(2)MCF-7/TAMR细胞中BAG-1、p-AKT和p-ERK1/2相对表达量明显高于MCF-7细胞(P0. 05);两组细胞ER表达情况差异无统计学意义(P0. 05); TMA对MCF-7/TAMR细胞增殖活性的抑制作用明显低于MCF-7细胞(P0. 05);(3)经siRNA BAG-1转染后,MCF-7/TAMR细胞增殖活性明显低于阴性对照组细胞(P0. 05); p-AKT和p-ERKmRNA和蛋白表达水平下调,与阴性对照组比较差异有统计学意义(P0. 05)。结论下调BAG-1可降低AKT和ERK磷酸化水平,从而提高Luminal型乳腺癌细胞对他莫昔芬的敏感性。     

Rb基因在染料木黄酮抑制人乳腺癌细胞生长中的作用

目的:研究Rb基因在染料木黄酮(genistein,Gen)抑制人乳腺癌细胞MCF-7细胞增殖中的作用。方法:采用MTT实验和集落形成实验观察Gen对人乳腺癌细胞增殖影响,Westernblotting检测Rb基因、细胞周期素cyclinE蛋白表达情况,RT-PCR检测Rb基因mRNA的表达。结果:Gen显著抑制MCF-7细胞生长,促进细胞Rb基因在蛋白及mRNA水平的表达,抑制cyclinE蛋白的表达。结论:Gen抑制人乳腺癌细胞增殖,其机制可能通过上调Rb基因表达,下调cyclinE蛋白表达。     

STAT3在双酚A促乳腺癌细胞增殖中的作用研究

目的:探讨STAT3在双酚A促乳腺癌MCF-7细胞增殖中的作用,为研究双酚A诱导乳腺癌的确切机制提供依据。方法:采用Western blot检测双酚A处理乳腺癌MCF-7细胞24 h和48 h后STAT3的表达情况,采用MTT法检测RNA干扰技术抑制STAT3后双酚A对乳腺癌细胞增殖的影响。结果:Western blot结果表明,STAT3在1μM双酚A作用48 h后其诱导表达最明显(P<0.05);通过对照研究筛选出有效的干扰片段,能显著抑制STAT3基因的表达,当干扰片段抑制了STAT3基因表达后,双酚A未能抑制STAT3的MCF-7细胞发生增殖效应(P>0.05)。结论:在双酚A诱导乳腺癌细胞的增殖作用中,STAT3的活化和活化后的信号传导是非常重要的一个环节。     

川芎嗪对乳腺癌MCF-7细胞AKT、Bcl-2蛋白活性表达的影响

目的:研究川芎嗪(TMP)对人乳腺癌MCF-7细胞增殖与凋亡的影响并探讨其可能的作用机制。方法:对乳腺癌MCF-7细胞分别施以0,0.5,1.0,2.0 mg/ml浓度TMP处理24、48、72 h,MTT法检测细胞的增殖抑制作用,Western Blot法检测AKT、Bcl-2蛋白的表达情况。所有数据均采用SPSS18.0,P0.05差异具有显著性,P0.01差异极具显著性。结果:与对照组相比,TMP对MCF-7细胞的增殖有抑制作用,且呈现一定的浓度、时间相关性(P0.01)。同时TMP可下调Bcl-2及AKT蛋白表达(P0.05,P0.01)。结论:TMP可能是通过调节Bcl-2、AKT蛋白的表达达到抑制MCF-7细胞增殖及诱导凋亡的效果。     

GPR30-EGFR信号通路在双酚A促乳腺癌细胞增殖中的作用

目的:探讨GPR30-EGFR信号传导通路在双酚A促乳腺癌MCF-7细胞增殖中的作用,为研究双酚A诱导乳腺癌的确切机制提供依据。方法:采用Western blot检测双酚A处理乳腺癌MCF-7细胞24 h和48 h后GPR30-EGFR的表达情况,采用MTT法检测AG1478抑制EGFR后双酚A对乳腺癌细胞增殖的影响。结果:EGFR在1μM双酚A作用48 h后其诱导表达最明显(P<0.05);GPR30在双酚A作用48 h后表达下调明显(P<0.05)。通过EGFR的高选择性抑制剂AG1478对乳腺癌细胞中的EGFR进行阻断,当AG1478和双酚A协同作用时,乳腺癌MCF-7细胞的增殖相对于双酚A单独作用组无明显区别(P>0.05)。结论:在双酚A所诱导的乳腺癌MCF-7细胞的增殖作用中,EGFR被有效地激活,GPR30蛋白在与双酚A作用后表达有所减弱;EGFR不是双酚A促细胞增殖的必经通路,双酚A可能通过其他通路发挥促细胞增殖作用。     

异汉防己碱增强阿霉素诱导乳腺癌细胞凋亡的实验研究

目的:探讨异汉防己碱增强阿霉素诱导耐阿霉素乳腺癌细胞系MCF-7/DOX凋亡的效应和机制。方法:采用MTT法检测异汉防己碱、阿霉素及两者联合对MCF-7/DOX细胞增殖的抑制作用,用流式细胞术定量分析MCF-7/DOX细胞的凋亡率,用Westem blot技术检测Bax及Bcl-2表达。结果:异汉防己碱可增强阿霉素对MCF-7/DOX细胞增殖的抑制作用,并可诱导细胞凋亡;异汉防己碱联合阿霉素可上调Bax表达,降低Bcl-2表达。结论:异汉防己碱联合阿霉素是通过上调Bax/Bcl-2比值而增强阿霉素诱导癌细胞凋亡的作用。     

Obesity and the Associated Mediators Leptin,Estrogen and IGF-I Enhance the Cell Proliferation and Early Tumorigenesis of Breast Cancer Cells

Breast cancer continues to be a major cause of cancer deaths in women. Estrogen, which is also produced by the adipose tissue, is held responsible for the elevated risk of breast cancer in obese women. However, the adipose tissue secrets hormones and adipokines such as leptin and IGF-I and these substances could also contribute to an increased breast cancer risk for obese women. In this study, the impact of obesity on cell proliferation was investigated. The carcinogen 7, 12, dimethylbenz[a]anthracene (DMBA) was administered to normal weight and diet-induced obese female Sprague-Dawley rats. Cell proliferation was evaluated by immunohistological staining of BrdU-incorporation. In the mammary glands and inguinal lymphatic nodes of the obese rats, cell proliferation was significantly increased, indicating a significant influence of obesity on breast cancer. Effects of leptin, estrogen, and IGF-I on the proliferation of MCF-7 cells in vitro were assessed using an MTT assay. Cell culture experiments demonstrated a mitogenic role of these three mediators on cell proliferation. Our data demonstrate a stimulative effect of substances produced by the adipose tissue on breast cancer. Body weight specific cell proliferation suggests that obesity-related adipokines and mediators enhance cell proliferation and increase the risk for breast cancer.     

三羟异黄酮对乳腺癌异种移植瘤血管生成影响

目的 探讨三羟异黄酮(genlstein)对原癌基因(HER-2／neu)高表达乳腺癌血管形成的影响及其与血管内皮生长因子(VEGF)的关系。方法 应用基因转染技术建立HER—2／neu高表达的乳腺癌细胞(MCF—7／HER—2)。免疫缺陷裸鼠(BALB／c)皮下接种乳腺癌(MCF—7和MCF—7／HER—2)细胞，其中接种MCF—7／HER—2细胞的裸鼠随机分为3组：对照组；genistein处理组：HER—2／neu抗体处理组。应用免疫组化法观察移植瘤内微血管密度(microvessel density，MVD)和VEGF的表达变化。结果 MCF—7／HER—2移植瘤与MCF—7移植瘤相比血管密度较大。VEGF表达增强；MCF—7／HER—2移植瘤经genistein和HER—2／neu抗体处理后。移植瘤的血管密度减少，VEGF表达降低。结论 HER—2／neu高表达能促进乳腺癌的血管生成，genistein可能通过下调VEGF的表达从而抑制HER—2／neu高表达乳腺癌的血管生成。     

VEGF对乳腺癌CXCR4表达及细胞增殖的影响

目的:探讨血管内皮生长因子(VEGF)对乳腺癌细胞CXCR4蛋白表达及癌细胞增殖的影响。方法:选用高表达CXCR4的乳腺癌细胞系MDA-MB-231作为研究对象。将该细胞系分为4组培养:阴性对照组、siRNA-CXCR4组、VEGF组和siRNA-CXCR4同时加入VEGF组。Western-blot方法检测各组CXCR4蛋白水平表达,并用体外增殖实验检测各组乳腺癌细胞增殖情况。结果:Western-blot结果显示,siRNA-CXCR4组CXCR4表达量较阴性对照组低;VEGF组CXCR4表达量较阴性对照组高;且siRNA-CXCR4同时加入VEGF组CXCR4表达量较siRNA-CXCR4组增加。体外细胞增殖实验显示,不同时间点各实验组细胞增殖速度与阴性对照组相比,siRNA-CXCR4组显著减低(P<0.05),VEGF组显著提高(P<0.05);并且siRNA-CXCR4同时加入VEGF组与siRNA-CXCR4组相比细胞增殖速度增加(P<0.05)。结论:siRNA沉默CXCR4基因可下调乳腺癌细胞CXCR4表达且体外细胞实验显示可有效抑制细胞增殖,提示CXCR4可能有促进乳腺癌细胞增殖的作用。在VEGF刺激下,乳腺癌细胞CXCR4表达增加,且癌细胞增殖速度明显增快,即使在沉默CXCR4条件下,VEGF仍能上调CXCR4表达,从而促进乳腺癌细胞增殖。因此说明在乳腺癌细胞增殖过程中VEGF和CXCR4有协同作用,针对CXCR4的单一靶点治疗可能难以有效抑制肿瘤生长,而作用于二者的联合用药也许能获得更佳的疗效,该结论尚需在临床实践中进一步验证。     

氯化汞雌激素样作用及其机制的实验研究

目的评价氯化汞(HgCl2)的雌激素样作用及其作用机制.方法从体内和体外两个水平,观察不同浓度的HgCl2对MCF-7人乳腺癌细胞增殖作用、去卵巢SD大鼠子宫的诱导增生作用、过氧化物活力的变化及对雌激素结合雌激素受体的影响.结果 10-6～10-9 mol/L的HgCl2均可引起MCF-7人乳腺癌细胞增殖,10-7 mol/L的HgCl2使MCF-7人乳腺癌细胞增殖达最大.每天0.04、0.20及1.00 mg/kg连续3 d腹腔注射HgCl2能刺激大鼠子宫增生和过氧化物酶活力增加;但HgCl2不影响雌二醇(E2)与雌激素受体结合.结论 HgCl2可能通过雌激素受体介导而表现出雌激素样作用,但不与E2竞争结合雌激素受体.     

Inhibitory effects of combination of lycopene and genistein on 7,12- dimethyl benz(a)anthracene-induced breast cancer in rats

Breast cancer is one of the most common cancers in women. Carotenoids and soy isoflavones have been postulated to have breast cancer preventive effects. We investigated the potential preventive effects of lycopene and genistein, alone and in combination, on breast cancer development in female Wistar rats treated with 7,12-dimethylbenz[a]anthracene (DMBA), a carcinogen known to induce breast tumors. Mammary carcinogenesis was initiated by a single, oral gavage of DMBA (80 mg/kg body weight) at 55 days of animal age. Fifty female Wistar rats were divided into 5 experimental groups having 10 animals per group: Group 1 (normal control), Group 2 (DMBA control), Group 3 (DMBA + lycopene), Group 4 (DMBA + genistein), and Group 5 (DMBA + lycopene and genistein). Rats were fed either lycopene (20 mg /kg bw) or genistein (2 mg /kg bw) by oral gavage (3 times per week) starting 2 wk prior to DMBA injection. Treatment was continued for 20 wk. Rats treated with DMBA developed mammary tumors with 100% tumor incidence during the 20-wk study. Inhibition of mammary cancer incidence by lycopene (70%), genistein (60%) and their combination (40%) was observed. Tumor weight decreased by 48%, 61%, and 67%, and mean tumor volume decreased by 18%, 35%, and 65% with lycopene, genistein, and lycopene + genistein, respectively (P < 0.01 for the combination). The proportions of adenocarcinoma masses decreased with lycopene and genistein combination (P < 0.05). Administration of lycopene and genistein combination suppressed breast cancer development and was associated with a decrease in MDA, 8-isoprostane, and 8-OhdG levels and with an increase in serum lycopene and genistein levels. Animals administered DMBA developed breast cancer, which was associated with increased expression of Bcl-2 and decreased expression of Bax, caspase 3, and caspase 9 in mammary tissues. Administration of genistein and lycopene in combination was more effective in inhibiting DMBA-induced breast tumors and modulating the expression of apoptosis associated proteins than the administration of each agent alone. Our results suggest that lycopene and genistein are potent antioxidants and, when given in combination, offer maximum protection against DMBA-induced mammary carcinogenesis.     

Inhibitory Effects of Combination of Lycopene and Genistein on 7,12- Dimethyl Benz(a)anthracene-Induced Breast Cancer in Rats

Breast cancer is one of the most common cancers in women. Carotenoids and soy isoflavones have been postulated to have breast cancer preventive effects. We investigated the potential preventive effects of lycopene and genistein, alone and in combination, on breast cancer development in female Wistar rats treated with 7,12-dimethylbenz[a]anthracene (DMBA), a carcinogen known to induce breast tumors. Mammary carcinogenesis was initiated by a single, oral gavage of DMBA (80 mg/kg body weight) at 55 days of animal age. Fifty female Wistar rats were divided into 5 experimental groups having 10 animals per group: Group 1 (normal control), Group 2 (DMBA control), Group 3 (DMBA + lycopene), Group 4 (DMBA + genistein), and Group 5 (DMBA + lycopene and genistein). Rats were fed either lycopene (20 mg /kg bw) or genistein (2 mg /kg bw) by oral gavage (3 times per week) starting 2 wk prior to DMBA injection. Treatment was continued for 20 wk. Rats treated with DMBA developed mammary tumors with 100% tumor incidence during the 20-wk study. Inhibition of mammary cancer incidence by lycopene (70%), genistein (60%) and their combination (40%) was observed. Tumor weight decreased by 48%, 61%, and 67%, and mean tumor volume decreased by 18%, 35%, and 65% with lycopene, genistein, and lycopene + genistein, respectively (P < 0.01 for the combination). The proportions of adenocarcinoma masses decreased with lycopene and genistein combination (P < 0.05). Administration of lycopene and genistein combination suppressed breast cancer development and was associated with a decrease in MDA, 8-isoprostane, and 8-OhdG levels and with an increase in serum lycopene and genistein levels. Animals administered DMBA developed breast cancer, which was associated with increased expression of Bcl-2 and decreased expression of Bax, caspase 3, and caspase 9 in mammary tissues. Administration of genistein and lycopene in combination was more effective in inhibiting DMBA-induced breast tumors and modulating the expression of apoptosis associated proteins than the administration of each agent alone. Our results suggest that lycopene and genistein are potent antioxidants and, when given in combination, offer maximum protection against DMBA-induced mammary carcinogenesis.     

桦褐孔菌提取物体外抗肿瘤活性及对细胞周期的影响

目的 研究桦褐孔菌提取物的抗肿瘤活性及对人乳腺癌MCF-7 细胞周期的影响及其可能机制。方法 使用细胞计数试剂盒(cell counting kit-8,CCK-8)检测桦褐孔菌提取物对HepG2、A549、SGC-7901、HeLa和MCF-7细胞增殖的抑制作用并计算半数抑制浓度(half maximal inhibitory concentration,IC₅₀);选择抑制效果最好的MCF-7细胞株,观察其作用后细胞的形态学改变、细胞凋亡率和细胞周期的变化;并通过Western Blot实验检测细胞周期相关蛋白Cyclin D1、CDK4、PCNA和NUSAP1的表达。结果 桦褐孔菌提取物可有效抑制HepG2、A549、SGC-7901、HeLa和MCF-7细胞增殖,作用48 h后的IC₅₀分别为2.34、3.71、2.24、2.27、0.59 mg/ml;桦褐孔菌提取物可引起MCF-7细胞显著的形态学改变;可诱导MCF-7细胞凋亡,与对照组相比,差异有统计学意义(P<0.05或P<0.01);并明显影响MCF-7细胞的细胞周期分布,使细胞阻滞于S期(P＜0.01);桦褐孔菌提取物可抑制MCF-7细胞中Cyclin D1、CDK4、PCNA、NUSAP1蛋白的表达,与对照组比较,差异均有统计学意义(P<0.05)。结论 桦褐孔菌提取物可抑制多种组织来源的肿瘤细胞增殖,其中对MCF-7细胞抑制效果最好,可以诱导细胞凋亡,阻滞细胞周期达到抗肿瘤作用,可能是通过下调Cyclin D1、CDK4、PCNA和NUSAP1的蛋白表达来调控细胞周期,从而抑制肿瘤细胞过度增殖。本实验为桦褐孔菌提取物的药用开发提供新的方法和思路。     

葡多酚对人乳腺癌细胞增殖的抑制作用研究

目的研究葡多酚(GPC)对人乳腺癌(MCF-7)细胞增殖活性的影响及雌激素受体(ER)的调节作用。方法将GPC与MCF-7细胞共同培养,共设肿瘤细胞对照组、高、中、低(200、100、10μg/ml)剂量GPC组、ER阻断剂对照组(ICI10-6mol/L)和ER阻断剂(ICI10-6mol/L)+GPC(200μg/ml)6个组。用MTT法测定各组乳腺癌细胞的增殖活性水平,用免疫组化方法检测乳腺癌细胞中增殖细胞核抗原(PCNA)和Bax蛋白的表达水平。结果与肿瘤细胞对照组比,高剂量GPC组乳腺癌细胞的增殖活性水平和PCNA阳性表达率降低,Bax蛋白阳性表达率升高(P<0.05);ER阻断剂+GPC组乳腺癌细胞的增殖活性水平、PCNA阳性表达率,均较高剂量GPC组升高,Bax蛋白阳性表达率降低,各项差别均有显著性意义(P<0.05)。结论GPC可有效抑制人乳腺癌细胞的增殖,并促进其凋亡;其作用与ER调节有密切关系。