原花青素对脂多糖诱导BV2小胶质细胞炎症介质分泌的影响

目的:探讨原花青素对脂多糖(LPS)激活小鼠小胶质细胞(BV2)炎症介质分泌的影响。方法:以LPS激活BV2细胞构建神经炎症模型。分别采用0.1、0.5、1.0、5.0 μg/mL原花青素预处理后,1.0 μg/mL的LPS刺激BV2细胞24 h。采用MTT法检测细胞存活率;Griess法检测BV2细胞培养液上清中一氧化氮(NO)水平;ELISA法检测肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6)的分泌水平。结果:在实验剂量范围内,原花青素及LPS对BV2细胞活性均无显著影响(P>0.05)。但1.0 μg/mL LPS可引起BV2细胞各炎症因子NO、TNF-α、IL-1β和IL-6水平明显升高(P<0.05)。与LPS组相比,原花青素(0.1、0.5、1.0、5.0 μg/mL)预处理能使激活的BV2细胞培养液上清中NO释放量减少(P<0.05),TNF-α、IL-1β和IL-6含量降低(P<0.05),抑制作用呈剂量-效应关系。结论:在体外实验中,原花青素对LPS诱导小胶质细胞所致的炎症反应具有保护作用。     

黏蛋白1基因转染DC对乳腺癌细胞MCF-7裸鼠移植瘤的免疫抑制作用

目的:探讨黏蛋白1 (mucin 1,MUC1基因转染DC对人乳腺癌MCF-7细胞裸鼠移植瘤的抑制作用.方法:体外诱导培养健康成人DC,应用脂质体转染法将pcDNA3.1-MUC1转染DC,ELISA法检测转染后DC分泌细胞因子IL-12和YNF-α的能力,LDH释放法检测基因转染后DC诱导特异性CTL对乳腺癌MCF-7细胞的杀伤活性.应用MU C1基因转染DC、空质粒转染DC、及生理盐水皮下注射治疗人乳腺癌MCF-7细胞裸鼠移植瘤,观测其对肿瘤生长的抑制作用.结果:转染pcDNA3.1-MUC1的DC分泌IL-12、TNF-α的能力较转染空质粒DC明显增强[IL-12:(202.52±29.61)vs(10.83±1.02)pg/ml;TNF-α:(349.07±79.42)vs(9.26±1.52)pg/ml,均P＜0.01];转染pcDNA3.1-MUC1的DC诱导产生特异性CTL,对人乳腺癌MCF-7细胞具有更明显的杀伤活性,效靶比为10∶1、5∶1和2.5∶1时的杀伤率分别达到56.2％、38.9％和25.8％,显著高于对照组CTL(均P＜0.01).MUC1基因转染DC对乳腺癌MCF-7裸鼠移植瘤生长抑制作用明显强于空质粒转染DC组(P＜0.05).结论:MUC1基因转染DC可以诱导特异性CTL,对乳腺癌MCF-7细胞具有更强的抗肿瘤免疫效应.     

人乳腺癌细胞过量产生NO对ADM和5-FU敏感性的调节作用

目的:研究内源性一氧化氮(NO)对于调节肿瘤细胞对化疗药物敏感性的影响.方法:应用IL-1β处理培养的MCF-7细胞检测NO的产生情况,并用蛋白质印迹法检测诱导型一氧化氮合酶(iNOS)蛋白的表达.设立实验组和对照组,采用MTT法检测MCF-7细胞在一氧化氮合酶(NOS)抑制剂NG甲基-L-精氨酸(L-NMMA)和NO合成原料L-精氨酸(L-Arg)作用下,对多柔比星(ADM)和氟尿嘧啶(5-FU)的药物敏感性.结果:内源性NO的产生量与IL-1β间存在着剂量依赖关系.蛋白质印迹法分析结果显示,在IL-1β诱导作用下,细胞大量表达iNOS蛋白.同时无论L-Arg和L-NMMA存在与否,iNOS蛋白都无差异.当ADM浓度为0.5和1μmol/L时,实验组细胞生存率有较明显的下降,P<0.05.L-NMMA的加入显著提高了实验组细胞的生存率,P<0..5;L-Arg的加入,在一定程度上提高了化疗药的敏感性,P<0.05.当L-Arg和L_NMMA与IL-1β同时存在,肿瘤细胞的生存率不会有明显下降,P<0.05.结论:在细胞因子IL-1β诱导下,MCF-7产生的内源性NO能提高肿瘤细胞的化学敏感性.     

弗林蛋白酶抑制剂对乳腺癌MCF-7细胞生长和迁移的影响

目的 探讨乳腺癌转移的机制,为深入研究乳腺癌发生、发展机制提供理论基础.方法 应用不同浓度的弗林蛋白酶（Furin）抑制剂α1-PDX处理乳腺癌MCF-7细胞.用四甲基偶氮唑蓝（MTT）和克隆形成实验检测Furin抑制剂对MCF-7细胞增殖和克隆形成的影响.单层细胞迁移实验和Transwell实验检测MCF-7细胞迁移和浸润能力.Hoechst 33342/PI双染法检测细胞凋亡.酶联免疫吸附法检测细胞培养液中基质金属蛋白酶2（MMP-2）和MMP-9蛋白水平.Western blot检测细胞迁移相关蛋白MT1-MMP、血管内皮生长因子（VEGF）-C和VEGF-D水平.结果 不同浓度α1-PDX作用MCF-7细胞48 h以上时,细胞的生长受到抑制,集落形成降低,细胞凋亡率升高.但在低浓度情况下对细胞迁移和侵袭起抑制作用.α1-PDX降低了细胞内MT1-MMP、VEGF-C、VEGF-D的表达,同时细胞培养液上清中MMP-2和MMP-9浓度也低于对照组.结论 Furin抑制剂通过抑制乳腺癌MCF-7细胞MMP及VEGF表达抑制肿瘤的迁移能力.     

雌激素对人乳腺癌细胞系基质细胞衍化因子-1影响的观察

目的:探讨雌激素对基质细胞衍化因子-1(SDF-1)的影响.方法:选取乳腺癌细胞系MCF-7和MDA-MB-231为研究对象,分成对照组、雌激素组和雌激素+雌激素受体阻断组,分别加入不同生理浓度的17-β雌二醇作用一定时间以及同一浓度17-β雌二醇作用不同时间点,用酶联免疫吸附实验(ELISA)方法测定培养液中SDF-1的浓度,半定量逆转录聚合酶链反应(RT-PCR)法检测细胞SDF-1 mRNA的表达.结果:MDA-MB-231细胞系加与未加雌激素,均未检测到SDF-1的分泌.而MCF-7细胞基础培养液中可检测到SDF-1分泌.不同生理浓度的17-β雌二醇均可增加MCF-7细胞SDF-1的分泌水平.当加入1×10-7 mol/L的生理高浓度17-β雌二醇时,细胞分泌SDF-1水平在2 h达到高峰,是对照组的6倍[(1 823.17±325.18)ρg/mL vs (307.23±5.42)ρg/mL,F=201.02,P<0.01],该作用可被雌激素受体拮抗剂(ICI182,780)消除.此外,SDF-1mRNA的表达水平与测得的SDF-1蛋白水平相一致.结论:在某些乳腺癌细胞系,生理浓度的雌激素可促进SDF-1的分泌,而这种作用主要是通过雌激素受体来实现.雌激素可通过SDF-1来影响乳腺癌的生物学特性.     

肿瘤相关巨噬细胞对乳腺癌MCF-7细胞侵袭迁移能力的影响

目的观察肿瘤相关巨噬细胞(tumor-associated macrophages,TAMs)对乳腺癌MCF-7细胞侵袭迁移能力的影响,并初步探索其机制。方法选取人单核细胞系THP-1,体外经佛波酯(PMA)、人白细胞介素-4(IL-4)诱导获得TAMs细胞模型;通过流式细胞术(FCM)检测TAMs表面标记分子CD206表达水平;MCF-7细胞与TAMs共培养后,光学倒置显微镜观察细胞形态;利用Transwell小室分别检测MCF-7细胞的侵袭和迁移能力;蛋白印记法(Western blotting)检测E-钙黏蛋白(E-cadherin)、N-钙黏蛋白(N-cadherin)、闭合蛋白(Occludin)及波形纤维蛋白(Vimentin)的表达;采用酶联免疫吸附法(ELISA)测定细胞培养上清中转化生长因子-β(TGF-β)、肿瘤坏死因子-α(TNF-α)和血管内皮生长因子(VEGF)的浓度。结果与TAMs共培养后的MCF-7细胞伪足增多,细胞排列更松散。通过FCM检测到TAMs表面标记物CD206显著表达。Transwell实验结果显示,与TAMs共培养后的MCF-7细胞迁移能力增强,对照组穿过Transwell小室细胞数为(54±2)个,实验组为(110±6)个,差异有统计学意义(P<0.001);其侵袭能力显著增强,对照组穿透基质膜的细胞数为(41±1)个,实验组为(77±4)个,差异亦有统计学意义(P<0.001)。Western blotting检测结果显示,MCF-7细胞与TAMs共培养后,E-cadherin、Occludin蛋白表达较对照组显著降低,而N-cadherin和Vimentin蛋白表达量显著升高(P均<0.05)。ELISA法检测TAMs与MCF-7细胞共培养上清中的TGF-β、TNF-α、VEGF浓度均较对照组升高(P均<0.05)。结论TAMs与乳腺癌MCF-7细胞的浸润转移过程密切相关,TAMs可通过促进MCF-7细胞发生上皮间质转化(EMT)进而促进乳腺癌的浸润转移。     

细胞因子对乳腺癌细胞钠碘转运体基因表达的调控

目的本实验通过三种细胞因子(肿瘤坏死因子-α,干扰素-γ和白细胞介素-6)对乳腺细胞钠碘转运体(NIS)基因表达的影响,探讨乳腺肿瘤组织NIS的表达特点和调控因素.方法采用乳腺癌细胞MCF-7和MB453进行培养,分别给予不同浓度的肿瘤坏死因子-α,干扰素-γ或白细胞介素-6刺激72 h.采用RT-PCR方法检测细胞中NIS mRNA表达情况.结果乳腺癌细胞在经过肿瘤坏死因子-α,干扰素-γ或白细胞介素-6刺激后,细胞中NIS的mRNA表达比对照组明显降低,并且与细胞因子浓度呈负相关.结论肿瘤坏死因子-α,干扰素-γ和白细胞介素-6对乳腺癌细胞MCF-7和MB453的NIS基因mRNA表达有抑制作用,这提示细胞因子可能通过调节乳腺癌NIS基因mRNA的表达,从而影响乳腺癌细胞对放射性碘治疗的敏感性.     

Apatinib联合5-Fu协同抑制乳腺癌MCF-7细胞的体外研究

目的 探讨阿帕替尼(Apatinib)联合5-氟尿嘧啶(5-Fu)对乳腺癌MCF-7细胞的抑制作用.方法 采用人乳腺癌细胞株MCF-7,首先采用MTr法及应用流式细胞仪测定不同浓度apatinib作用后对其细胞增殖和周期的影响,其次将MCF-7细胞分为4组,即对照组、Apatinib单药组、5-Fu单药组、Apanitib+ 5-Fu联合组.对各组细胞给予相应药物处理,48 h后分别应用流式细胞仪检测各组药物对MCF-7细胞株凋亡的作用.结果 Apatinib单药对MCF-7细胞有增殖抑制作用,且存在时间剂量依赖关系,而对其细胞周期影响不大.与对照组相比,Apatinib联合5-Fu作用后有协同诱导凋亡作用,经流式细胞仪检测,Apatinib组诱导的细胞凋亡率为12.05％,5-Fu组为25.76％.与单药组比,Apatinib+5-Fu联合组凋亡率升高更为明显,达34.90％ (P＜ 0.05).结论 Apatinib和5-Fu的联合应用在体外协同抑制乳腺癌MCF-7细胞并诱导凋亡,使抗肿瘤活性显著增强.     

没食子儿茶素没食子酸酯对乳腺癌MCF-7细胞HIF-1α和VEGF表达的影响

[目的]研究没食子儿茶素没食子酸酯(EGCG)对乳腺癌MCF-7细胞生长及其HIF-1α和VEGF表达的影响.[方法]分别用浓度为25、50、100mg/L的EGCG处理人乳腺癌细胞株MCF-7 48h后,采用台盼蓝染色法检测各组细胞生长增殖情况;RT-PCR法检测各组细胞中HIF-1α和VEGF mRNA的表达;Western Blot检测各组细胞中HIF-1α蛋白的表达;E LISA法检测各条件培养液中VEGF蛋白的分泌水平.[结果]经不同浓度EGCG处理的乳腺癌细胞,其细胞生长速度明显变缓,且随着药物浓度的增加,生长变缓更明显( P=0.007);不同浓度的EGCG处理MCF-7细胞后,细胞中VEGF mRNA或蛋白表达量均有明显下降(P＜0.05);不同浓度的EGCG处理MCF-7细胞后,细胞中HIF-1α蛋白的相对表达量下降(P＜0.05).[结论]EGCG可抑制乳腺癌细胞的生长增殖,可能与抑制HIF-1α和VEGF蛋白的表达有关.     

SDF-1α促进乳腺癌细胞CerbB-2蛋白的表达

目的:探讨SDF-1α对乳腺癌细胞CerbB-2表达的影响.方法:SDF-1α与乳腺癌细胞MCF-7共培养,Western印迹法检测CerbB-2的表达差异;裸鼠成瘤实验联合免疫组织化学法检测SDF-1α在体内对乳腺癌细胞CerbB-2表达的影响;细胞迁徙及失巢凋亡实验对比分析SDF-1α对乳腺癌MCF-7细胞体外迁徙及抗失巢凋亡能力的影响. 结果:Western印迹及裸鼠成瘤免疫组织化学检测结果显示,在体内体外SDF-1均能显著提高CerbB-2的表达,3组经不同浓度SDF-1α刺激的MCF-7细胞CerbB-2蛋白表达量均较空白对照组明显增高,其中400 ng/mL 组升高最为明显.侵袭小室实验发现,SDF-1α可明显增强乳腺癌MCF-7细胞株的细胞变形迁徙和侵袭破坏能力,培养6 h后迁徙进入微孔膜的细胞数比阴性对照组显著增多[(172.27±9.72) vs (128.63±13.72),P<0.01];SDF-1α+MCF-7细胞发挥破坏Matrigel基质胶作用,进入微孔膜内的细胞数也高于MCF-7细胞[(52.28±9.24) vs (17.21±2.89),P<0.01].悬浮培养的SDF-1α+ MCF-7细胞比MCF-7细胞更容易聚集,形成相对致密的细胞团;200、400、800 ng/mL SDF-1α作用24 h后,MCF-7细胞的凋亡率分别为(9.72±1.11)%、(8.64±1.22)% 和(10.36±1.31)%,与阴性对照组(18.41±1.71)%的差异有统计学意义(P＜0.01).结论:SDF-1α可显著提高乳腺癌细胞MCF-7的CerbB-2表达,拓宽了靶向药物Herceptin的应用范围.     

CD4+CD25+调节性T 细胞对乳腺癌细胞上皮间质转化和ALDH1+干样细胞的影响*

目的:研究CD4+CD25+调节性T 细胞（regulatory T cells ,Tregs）对乳腺癌细胞上皮间质转化（epithelial-mesenchymal transition ,EMT ）、细胞迁移侵袭能力,及ALDH1+干样细胞比例的影响。方法:采用免疫磁珠法分离乳腺癌患者外周血中CD4+CD25+Tregs,CD4+CD25+Tregs与乳腺癌BT474、MCF-7 细胞系共培养（共培养组）,BT474、MCF-7 单独培养（对照组）。 检测共培养组和对照组乳腺癌细胞EMT 相关标志物表达的变化,及细胞迁移和侵袭能力的变化。此外,检测BT474 细胞中ALDH1+干样细胞、微球形成能力和自我更新能力的变化。结果:CD4+CD25+Tregs诱导BT474 和MCF-7 细胞间质性标志物表达增高,诱导MCF-7 细胞上皮性标志物E-cadherin 表达降低。CD4+CD25+Tregs诱导BT474 和MCF-7 细胞迁移和侵袭能力上调。共培养组BT474 细胞中ALDH1+干样细胞比例、微球体形成能力、自我更新能力较对照组增强。结论:CD4+CD25+Tregs可诱导乳腺癌细胞发生EMT ,增强细胞体外迁移和侵袭能力,同时促进ALDH1+干样细胞增加。      

二甲双胍通过巨噬细胞抑制食管癌TE-1细胞的侵袭和迁移

目的:探究二甲双胍是否通过巨噬细胞抑制食管癌TE-1细胞的侵袭迁移及其可能的分子机制。方法:100 ng/mL PMA诱导THP-1巨噬细胞。取对数生长期TE-1细胞和巨噬细胞,分别用最终浓度为0.5 mmol/L、1 mmol/L和2 mmol/L二甲双胍处理,Western blot检测MMP9、VEGF蛋白表达水平,ELISA检测细胞TNF-α和IL-8浓度,筛选二甲双胍最佳作用浓度（2 mmol/L）。分别用100 ng/mL LPS、2 mmol/L二甲双胍、100 ng/mL LPS+2 mmol/L二甲双胍处理巨噬细胞制备条件培养基。将TE-1细胞分为4组:对照组、LPS-条件培养基组（LPS组）、二甲双胍-条件培养基组（Met组）和LPS+二甲双胍-条件培养基组（LPS+Met组）。划痕实验观察各组细胞迁移能力。Transwell小室检测细胞侵袭能力。Western blot检测各组细胞VEGF、E-cad、Vimentin和NEDD9的表达。ELISA检测各组细胞TNF-α和IL-8浓度。结果:与对照组相比,二甲双胍可显著降低TE-1细胞和巨噬细胞中MMP9、VEGF、TNF-α和IL-8水平（P＜0.05）,且呈剂量依赖性。二甲双胍可显著抑制TE-1细胞迁移和侵袭（P＜0.05）,显著抑制VEGF、Vimentin和NEDD9蛋白表达（P＜0.05）,促进E-cad蛋白表达（P＜0.05）;显著降低TE-1细胞中TNF-α和IL-8水平（P＜0.05）。结论:二甲双胍可通过巨噬细胞降低食管癌TE-1细胞NEDD9的表达,抑制食管癌细胞侵袭迁移。     

Protein array technology to detect HER2 (erbB-2)-induced 'cytokine signature' in breast cancer

Identification of genes/proteins that are differentially expressed in HER2 (erbB-2) oncogene-dependent breast carcinomas is essential in elucidating the mechanistic basis of their increased metastastic potential and resistance to several anti-cancer therapies. We here applied human cytokine antibody arrays with the goal of identifying a unique HER2-induced 'cytokine signature' in breast cancer. Human Cytokine Array III (RayBiotech, Inc.), which simultaneously detects 42 cytokines and growth factors on one membrane, was used to determine the profile of cytokines in conditioned media obtained from MCF-7/Her2-18 cells, a MCF-7-derived clone engineered to stably express the full-length human HER2 cDNA controlled by a SV40 viral promoter, and from the MCF-7/neo control sub-line. We identified two inflammatory and pro-angiogenic CXC chemokines with at least a 10-fold increased expression in HER2-overexpressing MCF-7/Her2-18 transfectants when compared to matched control MCF-7/neo cells: CXCL8 (IL-8; Interleukin-8) and CXCL1 and (GRO; Growth-related oncogene). HER2-induced differential overexpression of IL-8 and GRO was validated by ELISA and further confirmed by switching off the HER2 signalling. Treatment with the tyrosine kinase inhibitor gefitinib (Iressa) returned the expression levels of IL-8 and GRO back to the baseline observed in MCF-7 breast cancer cells, which express physiological levels of HER2. To evaluate the diagnostic utility of these findings, cytokine-specific antibody arrays were incubated with sera retrospectively collected from metastatic breast cancer patients. This approach revealed a high similarity between the 'cytokine signature' observed in serum samples and that obtained in media conditioned by breast cancer-derived cell lines. Thus, IL-8 and GRO circulating levels were significantly higher in HER2-positive breast cancer patients compared with HER2-negative patients. These findings reveal for the first time that: a) Enhanced synthesis and secretion of members of the IL-8/GRO chemokine family, which have recently been linked to oestrogen receptor (ER) inaction, increased cell invasion and angiogenesis, may represent a new pathway involved in the metastatic progression and endocrine resistance of HER2-overexpressing breast carcinomas, and b) Circulating levels of IL-8 and GRO cytokines may represent novel biomarkers monitoring breast cancer responses to endocrine treatments and/or HER2-targeted therapies.     

苏林酸在NF-κB对人乳腺癌TNF-α诱导细胞凋亡增敏中的相关作用

目的 探讨苏林酸在NF-κB对人乳腺癌TNF-α诱导细胞凋亡增敏中的相关作用。方法 取对数生长期的人乳腺癌细胞系MCF-7,加入苏林酸,使其终浓度分别为0.5mmol/L和1.0mmol/L,并设不加苏林酸的对照组进行培养;苏林酸处理48h后进行MTT、流式细胞实验和Western blot法检测,分析苏林酸对肿瘤细胞生长的作用与相关机制。结果 0.5mmol/L和1.0mmol/L苏林酸分别刺激MCF-7细胞48h后,对应的MCF-7细胞的增殖抑制率为(29.17±1.23)%、(38.15±1.51)%,对照组为(1.15±0.02)%(P＜0.05)。与对照组相比,0.5mmol/L和1.0mmol/L苏林酸作用后均可导致滞留在G₀~G₁期的MCF-7细胞显著增加(P＜0.05);0.5mmol/L和1.0mmol/L苏林酸作用后MCF-7细胞的凋亡率明显增加(P＜0.05);0.5mmol/L和1.0mmol/L苏林酸作用后TNF-α的相对表达量分别为2.09±0.67、1.18±0.09,明显低于对照组的7.42±0.56(P＜0.05)。结论 苏林酸具有一定抗人乳腺癌细胞生长的作用,能促使细胞周期G₀~G₁期延长,提高细胞凋亡增敏作用,其作用机制可能与抑制TNF-α活性有关。     

乳腺癌MMP-2、MMP-9的体外阻断研究

目的:探讨乳腺癌MMP-2、MMP-9表达的临床病理联系及直接阻断MMP-2、MMP-9对乳腺癌细胞增殖、侵袭及细胞周期的影响。方法:应用免疫组织化学方法检测48例乳腺癌MMP-2、MMP-9的表达。明胶酶谱法检测乳腺癌MCF-7细胞MMP-2、MMP-9的表达。MCF-7细胞接种于预铺BME的Tran-swell小室上室,与MMP-2、MMP-9的阻断剂CTT共孵育16h,观察阻断MMP-2、MMP-9对MCF-7细胞侵袭能力的影响。MCF-7细胞与CTT共孵育12h后,MTT法检测阻断MMP-2、MMP-9对细胞增殖能力的影响。MCF-7细胞与CTT共孵育24h后,PI染色流式法检测阻断MMP-2、MMP-9对细胞凋亡和细胞周期的影响。结果:48例乳腺癌组织有MMP-2表达者45例(93.75%),MMP-9表达者38例(79.17%),MMP-2和MMP-9在发生淋巴结转移组明显高表达(P<0.05);组织学分级越高,MMP-2和MMP-9的表达越显著(P<0.05)。明胶酶谱法检测:在MCF-7培养上清中检测到MMP-2、MMP-9的表达。在浓度为100μg/ml和200μg/ml时CTT对MCF-7细胞的侵袭抑制率达到39.5%和61.9%。在终浓度为50、100、200μg/ml时,CTT对MCF-7细胞的增殖率均无明显下降(P>0.05)。CTT处理组MCF-7细胞经流式法检测未见凋亡峰,细胞周期各期未见明显阻滞(P>0.05)。结论:MMP-2、MMP-9与乳腺癌的淋巴结转移密切相关,阻断MMP-2、MMP-9可有效抑制乳腺癌的浸润和转移。     

Relationship of human natural lymphocyte-mediated cytotoxicity to cytotoxicity of breast-cancer-derived target cells

Mononuclear cells from 115 individuals were tested in a 4-h chromium release assay against two breast-cancer-derived cell lines, G11 and MCF-7, and a myeloid line, K-562, shown previously to be sensitive to natural cytotoxicity. These data were analyzed in a manner designed to detect hyperreactivity against the breast cell lines relative to the level of reactivity against K-562. A high proportion of breast cancer patients were found to be relatively hyperreactive against G11 (12/18 or 67%) and against MCF-7 (10/18 or 56%). Fibroadenoma patients were very similar to the normal females, with 0/11 hyperreactive to G11 and 1/11 (9%) to MCF-7. However, several normal males (7/17 or 41%) were hyperreactive to G11 but not to MCF-7 (2/17 or 12%). Colon cancer and lung cancer patients were also more hyperreactive to G11, 4/8 or 50% and 4/6 or 67%, respectively, than they were to MCF-7, 1/8 or 13% and 1/6 or 17%, respectively. Only fibrocystic patients resembled the breast cancer patients, with some but not as many individuals being hyperreactive to G11 (3/8 or 38%) and to MCF-7 (2/8 or 25%). With another group of individuals reproducibility of the method was demonstrated, with only 1/14 or 7% of normal females and 12/17 or 70% of breast cancer patients being hyperreactive to G11. Thus, natural cytotoxicity toward K-562 can be related to breast cancer-associated cytotoxicity toward MCF-7 in a way that distinguishes a majority of brest cancer patients specifically from other groups of individuals.     

Inhibition of colon and breast carcinoma cell growth by interleukin-4.

Within human carcinomas, there is often an infiltration of lymphocytes and other cells of the immune system. A variety of cytokines are produced by such cells that could have a paracrine influence on the growth of tumor epithelium. The effect of one of these cytokines, interleukin-4 (IL-4), on human breast and colon cancer cell lines was therefore examined. IL-4 inhibited the growth of human colon (HT 29) and breast [MCF-7 wild type (MCF-7 WT), MCF-7 Adriamycin-resistant (MCF-7r), MDA-MB-231, and MDA-MB-468] carcinoma cells in culture. Competitive binding of 125I-IL-4 demonstrated the presence of 2000 high affinity IL-4-binding sites on HT 29 cells. The Kd for specific binding of 125I-IL-4 to HT 29 cells was 77 pM. Further studies were conducted on the estrogen-dependent MCF-7 WT and estrogen-independent MDA-MB-231 breast carcinoma lines. Concentrations of IL-4 of 10-100 nM were required to significantly inhibit growth of these carcinoma cell lines; e.g., with MCF-7 WT cells, half-maximal inhibition of growth occurred at 20 nM IL-4. Specific binding of 125I-IL-4 was detected to MCF-7 WT and MDA-MB-231 cells, but the low level of binding precluded Scatchard analysis. IL-4 inhibited 90% of the 17 beta-estradiol-stimulated growth of MCF-7 WT cells in a dose-dependent manner but without a change in estrogen receptor expression. Inhibition of growth by IL-4 was less in the absence of estrogens. Combined treatment with IL-4 and other known inhibitors of breast carcinoma cell growth [transforming growth factor-beta 1 (TGF-beta 1) and the antiestrogen tamoxifen] showed additive inhibition. The hormone-independent cell lines MCF-7r and MDA-MB-231 were additively inhibited by IL-4 and TGF-beta 1. This was not the case with MDA-MB-468 cells in which inhibition by IL-4 and TGF-beta 1 was of similar magnitude but no significantly greater effect was observed on combined treatment. No secretion of IL-4 was detected from these cell lines either basally or on treatment with TGF-beta 1 or tamoxifen, and we conclude that IL-4 is a nonautocrine inhibitor of breast carcinoma cell growth.     

Cyclooxygenase-2 uses the protein kinase C/ interleukin-8/urokinase-type plasminogen activator pathway to increase the invasiveness of breast cancer cells

Cyclooxygenase-2 (COX-2) increases breast cancer cell invasion. Expression of various pro-angiogenic and pro-invasive factors has been correlated with high expression of COX-2. However, whether these factors are essential to COX-2-mediated breast cancer invasion, and the mechanisms by which COX-2 increases the expression of these factors are unknown. Our microarray results indicate that higher COX-2 expression was associated with increased levels of interleukin-8 (IL-8), a key factor in breast cancer invasion and metastasis. COX-2 overexpressing cells (MCF-7/COX-2), generated by transfecting COX-2-encoding plasmids into the poorly invasive MCF-7 breast cancer cells, were more invasive and produced higher IL-8 levels than the parental cells. To investigate the role of IL-8 in COX-2-mediated invasion, MCF-7 parental cells were incubated with IL-8. Exogenous IL-8 increased the invasiveness of MCF-7 cells. IL-8 is one pathway by which COX-2 mediates breast cancer invasion. Protein kinase A (PKA) and protein kinase C (PKC) are activated by COX-2 and are involved in IL-8 regulation. Inhibition of PKC, not PKA, decreased IL-8 production and invasion in MCF-7/COX-2 cells. Activation of PKC, not PKA, increased IL-8 production and invasion in MCF-7 cells. Thus, the invasive effects of COX-2 are mediated by PKC, not PKA. Activity of the urokinase-type plasminogen activator (uPA) was increased in MCF-7 cells by COX-2 overexpression or by the addition of a PKC activator or by IL-8. Inhibition of PKC decreased uPA activity in MCF-7/COX-2 cells. Furthermore, inhibition of uPA activity decreased the invasiveness of MCF-7/COX-2 cells, indicating that uPA was essential to COX-2-mediated invasion. Herein we demonstrate for the first time a detailed mechanism by which COX-2 increases breast cancer invasion: the PKC/IL-8/uPA pathway.     

Hierarchical paracrine interaction of breast cancer associated fibroblasts with cancer cells via hMAPK-microRNAs to drive ER-negative breast cancer phenotype

Multiple juxtacrine and paracrine interactions occur between cancer cells and non-cancer cells of the tumor microenvironment (TME) that direct tumor progression. Cancer Associated Fibroblasts (CAFs) are an integral component of the TME, and the majority of breast tumor stroma is comprised of CAFs. Heterotypic interactions between cancer cells and non-cancer cells of the TME occur via soluble agents, including cytokines, hormones, growth factors, and secreted microRNAs. We previously identified a microRNA signature indicative of hyperactive MAPK signaling (hMAPK-miRNA signature) that significantly associated with reduced recurrence-free and overall survival. Here we report that the hMAPK-miRNA signature associates with a high metric of stromal cell infiltrate, and we investigate the role of microRNAs, particularly hMAPK-microRNAs, secreted by CAFs on estrogen receptor (ER) expression in breast cancer cells. ER-positive MCF-7/ltE2- cells were treated with conditioned media (CM) from CAFs derived from breast cancers of different PAM50 subtypes (CAF_BAS, CAF_HER2, and CAF_LA). CAF CM isolated specifically from ER-negative primary breast tumors led to ER repression in vitro. Nanoparticle tracking analysis and transmission electron microscopy confirmed the presence of CAF-secreted exosomes in CM and the uptake of these exosomes by the ER+ MCF-7/ltE2- cells. Differentially expressed microRNAs in CAF CM as well as in MCF-7/ltE2- cells treated with this CM were identified. Knockdown of miR-221/222 in CAF_BAS resulted in knockdown of miR221/222 levels in the conditioned media and the CM from CAF_BAS; miR221/222 knockdown rescued ER repression in ER-positive cell lines treated with CAF_BAS-CM. Collectively, our results demonstrate that CAF-secreted microRNAs are directly involved in ER-repression, and may contribute to the MAPK-induced ER repression in breast cancer cells.     

Dehydroepiandrosterone inhibits events related with the metastatic process in breast tumor cell lines

Dehydroepiandrosterone (DHEA), an adrenal hormone, has a protective role against cancer. We previously shown that DHEA inhibits the proliferation and migration of cell lines derived from breast cancer; however, the role of DHEA in others events related with these effects are unknown. We hypothesized that DHEA inhibits the expression of proteins and some events related with cell migration and metastasis. We determined the migration in Boyden chambers, the invasion in matrigel, anchorage-independent growth and the formation of spheroids in 3 cell lines (MCF-7, MDA-MB-231, ZR-75-30) derived from breast cancer exposed to DHEA. The secretion of metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and several pro-inflammatory molecules in the secretome of these cells was also evaluated. DHEA inhibited the migration in transwells and the invasion in matrigel of MCF-7 and MDA-MB-231 cells. Besides, DHEA inhibited the anchorage-independent growth on agar and decreased the size of spheroids, and also reduced the secretion of IL-1α, IL-6, IL-8, and TNF-α in all cell lines. Metalloproteinase-1 (MMP-1) secretion was slightly decreased by DHEA treatment in MDA-MB-231 cells. Our results also showed that inhibition of migration and invasion induced by DHEA in breast cancer cells is correlated with the decrease of cytokine/chemokine secretion and the diminution of tumor cells growth. MCF-7 cells were the most responsive to the exposure to DHEA, whereas ZR-75-30 cells responded less to this hormone, suggesting that DHEA could be used in the treatment of breast cancer in early stages.