γ-干扰素增强他莫昔芬抗乳腺癌作用的体外研究

研究γ-干扰素（γ-IFN）对他莫昔芬（TAM）抗乳腺癌细胞的增强作用。方法：在体外培养条件下，分别或联合应用γ-干扰素、TAM或雌二醇（E2）作用于雌激素受体（estrogen receptor，ER）阳性的MCF-7和ER阴性的MDA-MB-231人乳腺癌细胞株，用MTT比色法分析细胞生长抑制作用，流式细胞仪检测细胞周期分布，DNA凝胶电泳和流式细胞仪检测细胞凋亡。结果：TAM能抑制ER阳性和阴性的乳腺癌细胞的生长，阻滞细胞周期于GO／G1期，并可诱导细胞凋亡；相同浓度条件下，TAM对ER阳性乳腺癌细胞的抑制作用强于对ER阴性的乳腺癌细胞。同时，TAM能拈抗外源性雌激素对MCF-7细胞的促生长作用，而对MDA-MB-231细胞的生长抑制作用与雌激素的存在与否无关。γ-干扰素预处理细胞24h后，TAM抗乳腺癌细胞的作用增强。结论：体外条件下，TAM有抗ER阳性和阴性乳腺癌细胞作用，作用机制是通过影响细胞周期，诱导细胞凋亡，γ-干扰素能加强TAM的抗乳腺癌作用。     

环氧化酶-2在人、大鼠乳腺癌及人乳腺癌细胞株的表达及其意义

 目的 探讨环氧化酶-2（COX-2）在人、大鼠乳腺癌及人乳腺癌细胞株的表达及其意义。方法 应用免疫组织化学、Western bloting、RT-PCR法检测人乳腺癌组织及配对的癌旁组织、大鼠致癌组、选择性COX-2抑制剂尼美舒利（NIM）组、人乳腺癌细胞株中COX-2的表达，MMT法检测细胞株的生长率。结果 正常人、大鼠乳腺组织不表达COX-2m RNA、蛋白，癌旁组织表达明显增高，肿瘤组织COX-2 mRNA、蛋白显著增高，NIM明显下调大鼠乳腺癌COX-2的表达；MDA-MB-231细胞COX-2呈强表达，MCF-7细胞不表达COX-2；NIM显著抑制MCF-7、MDA-MB-231细胞的增生。结论 COX-2可作为预防乳腺癌的分子靶点；NIM对MDA-MB-231细胞的抑制更为有效，提示COX-2选择性抑制剂对ER（-）的乳腺癌有更好的预防作用，COX-2的分子靶向治疗将成为乳腺癌预防和治疗的新途径。     

西乐葆对不同受体状态乳腺癌细胞株的作用研究

[目的]探讨选择性COX-2抑制剂西乐葆对受体状态不同的MDA-MB-231和MCF-7乳腺癌细胞株的抑制作用.[方法]取对数生长期ER(-)的MDA-MB-231细胞和ER( )的MCF-7细胞,加入不同浓度的COX-2抑制剂西乐葆共同培养,以MTT法检测两种细胞的存活率;用流式细胞仪检测两种细胞的细胞周期变化;用Annexin-V-FITC双标法检测各自的细胞凋亡.[结果]西乐葆对MDA-MB-231和MCF-7细胞均有明显的生长抑制作用,且对前者的作用比后者显著,60μmol/L西乐葆作用72h后,对MDA-MB-231细胞的生长抑制率为81.70%;对MCF-7细胞的生长抑制率为70.8%(P＜0.05).60μmol/L西乐葆作用48h后,MCF-7细胞G0/G1期比例为82.72%±1.25%,MDA-MB-231细胞G0/G1期比例为43.58%±0.58%.60μmol/L西乐葆作用72h后,MCF-7细胞的凋亡率为13.25%,而MDA-MB-231细胞为70.10%(P＜0.01).[结论]选择性COX-2抑制剂西乐葆对ER( )或ER(-)的乳腺癌细胞均具生长抑制作用,但对ER(-)的乳腺癌细胞的抑制更为显著.西乐葆均能明显抑制两种细胞的增殖,可使ER( )的细胞周期停止在G0/G1期;对ER(-)的细胞则以促进凋亡为主.     

赖氨匹林抑制乳腺癌细胞增殖的机制初探

背景与目的:有研究证实非类固醇类抗炎药(nonsteroidal anti-inflammatory drugs,NSAIDs)通过抑制环氧合酶(cyclooxygenase,COX)-2干扰致癌作用,但并不是唯一机制。本实验探讨非选择性环氧合酶-2抑制剂赖氨匹林(aspisol)对体外培养的雌激素受体(ER)阴性(MDA-MB-231)和阳性(MCF-7)人乳腺癌细胞增殖的影响及其ERK(extracellular sigal-regulated kinase,细胞外信号调节蛋白激酶)信号通路的影响。方法:应用MTT比色法分析细胞生长抑制作用,流式细胞技术测定凋亡率,Western blot方法检测赖氨匹林对两种乳腺癌细胞外信号调节蛋白激酶(ERK)/磷酸化(P-ERK)的表达的影响。结果:1~10 mmol/L赖氨匹林可抑制MDA-MB-231、MCF-7细胞的生长,且其作用具有剂量和时间依赖性,药物浓度越大,时间越长,抑制作用越明显,差异有显著性(P<0.01)。赖氨匹林(1,5,10 mmol/L)作用24 h后诱导MDA-MB-231细胞的早期凋亡率分别为(5.76±1.02)%、(10.28±1.95)%、(15.41±2.14)%,与对照组(0.27±0.17)%比较,差异有显著性(P<0.01),并呈浓度依赖性。赖氨匹林(1,5,10 mmol/L)作用24 h后诱导MCF-7细胞的早期凋亡率分别为(4.62±1.05)%、(6.86±2.51)%、(11.40±3.56)%,与对照组(0.21±0.11)%相比,差异有显著性(P<0.01),并呈浓度依赖性。赖氨匹林可不同程度下调两种乳腺癌细胞P-ERK的表达水平(P<0.01),但不影响总ERK表达(P>0.05)。结论:赖氨匹林对ER阳性和ER阴性乳腺癌细胞均有抑制增生,诱导凋亡的作用,其作用机制与抑制乳腺癌ERK信号通路有关。     

维甲酸联合他莫昔芬对人乳腺癌细胞株作用的研究

目的:探讨他莫昔芬(TAM)与维甲酸(ATRA)联合对人乳腺癌他莫昔芬耐药株的作用.方法:在体外培养条件下,分别或联合应用ATRA和TAM作用于MCF-7人乳腺癌他莫昔芬耐药株(MCF-7/T)及敏感组(MCF-7/S).MTT比色法分析细胞生长抑制作用;用流式细胞仪(FCM)检测细胞周期分布、凋亡率及用药前后Bcl-2、Bax、Fas和FasL蛋白的变化.结果:TAM能抑制ER阳性MCF-7/S的生长,阻滞细胞周期于G0/G1期,并可诱导细胞凋亡,TAM不能抑制MCF-7/T的生长; ATRA预处理细胞24 h后,TAM抗乳腺癌细胞MCF-7/S的作用增强,且恢复了MCF-7/T对TAM的敏感性.ATRA与TAM联用后,MCF-7/T细胞Bcl-2蛋白表达下调,细胞Bax、Fas和FasL蛋白表达水平未见明显变化.结论:体外条件下,TAM通过影响细胞周期、诱导细胞凋亡而发挥抗ER阳性MCF-7/S作用;视黄酸能加强TAM对激素敏感细胞MCF-7/S的抗乳腺癌作用,恢复耐受细胞MCF-7/T对TAM的敏感性.同时恢复TAM对MCF-7/T的促凋亡作用.     

环氧化酶-2 抑制剂Nimesulide对膀胱癌T24细胞体外生长的抑制作用

 目的 观察环氧化酶-2（COX-2）抑制剂Nimesulide（NIM）对人膀胱癌T24细胞株体外生长的影响，并探讨其作用机制。方法 采用细胞形态学、MTT法、流式细胞术、吖啶橙-溴化乙啶双染法（AO-EB）等技术检测NIM对体外培养的人膀胱癌细胞株T24生长的抑制效应。结果 细胞形态学观察可见NIM对T24细胞生长具有明显的细胞毒作用；MTT法、流式细胞术分析显示NIM能明显抑制T24细胞的增殖，且呈剂量、时间依赖关系；细胞周期分析表明，NIM能使T24细胞G0／G1期细胞比例升高，S期和G2／M期细胞比例下降；流式细胞DNA直方图上出现典型的亚二倍体“凋亡峰”，细胞凋亡率与NIM作用时间和剂量相关；荧光显微镜检查显示NIM处理的T24细胞AO-EB双染色后，细胞核内可见浓染致密的颗粒荧光，典型细胞可见新月形改变，固缩或片段化的核。结论 COX-2抑制剂NIM对T24细胞生长具有明显的抑制作用，其作用机制可能与阻断细胞周期、诱导细胞凋亡等有关。     

5,4''-二-正辛烷氧基-7-二氟亚甲基异黄酮对人乳腺癌细胞增殖和凋亡的影响

目的:探讨金雀异黄素(gen)衍生物5,4'-二-正辛烷氧基-7-二氟亚甲基异黄酮(5,4'-Di-noctoxyl-7-gem-difluoromethylenegenisteinDOdFMG)体外选择性抑制人乳腺癌细胞增殖和诱导凋亡作用.方法:MTT法检测DOdFMG对MCF-7和HBL-100细胞生长的影响;流式细胞术和AO/EB荧光双染法测定DOdFMG诱导MCF-7细胞凋亡作用及对细胞周期的影响.结果:DOdFMG抑制MCF-7细胞生长,呈时间剂量依赖,比gen具有更强选择性和抗肿瘤活性;DOdFMG能诱导MCF-7细胞凋亡,DOdFMG40.0μM组比gen100μM组诱导凋亡的活性更强,DOdFMGMCF-7将MCF-7细胞阻滞于S期和G2期,呈浓度依赖.结论:DOdFMG能抑制人乳腺癌细胞系(MCF-7)细胞生长和诱导凋亡,是一种高效、毒副作用小的新型治疗乳腺癌候选药物.     

沙立度胺抑制乳腺癌细胞增殖的作用机制

目的研究沙立度胺抑制乳腺癌细胞增殖的机制。方法流式细胞仪检测沙立度胺对细胞凋亡和细胞周期的影响;半定量RT-PCR方法观察沙立度胺对MCF-7和MDA-MB-231细胞VEGF mR-NA表达的影响。结果沙立度胺作用后的乳腺癌细胞在流式细胞分析的DNA直方图上显现细胞凋亡峰(亚G1期);沙立度胺抑制两株细胞VEGF mRNA的表达。结论沙立度胺可能通过诱导MCF-7和MDA-MB-231细胞凋亡以及抑制细胞VEGF mRNA表达从而抑制MCF-7和MDA-MB-231细胞增殖。     

选择性COX-2 抑制剂对人乳腺癌细胞MCF-7的抑制作用及分子机制研究

目的:探讨选择性环氧化酶-2(cyclooxygenase-2,COX-2)抑制剂N-[2-(cyclohexyloxy)4-nitrophenyl]-methanesulfonamide(NS398)对人乳腺癌细胞系MCF-7增殖和凋亡的影响及其相关机制.方法:用不同浓度的选择性COX-2抑制剂NS398处理MCF-7细胞,采用四甲基偶氮唑蓝(MTT)法检测选择性COX-2抑制剂NS398对MCF-7细胞增殖的影响;流式细胞仪Annexin V-FITC/PI双染法检测人乳腺癌细胞系MCF-7的凋亡情况;Western-blot法测定NS398作用于MCF-7细胞后的COX-2蛋白表达水平;酶联免疫吸附试验(ELISA)检测NS398作用于MCF-7细胞后的细胞培养上清中血管内皮生长因子VEGF和前列腺素E2(PGE2)释放水平.结果:选择性COX-2抑制剂NS398能抑制人乳腺癌细胞系MCF-7细胞生长,NS398药物浓度不同,孵育时间不同时,其对人乳腺癌细胞MCF-7的增殖抑制效应不同.作用同一时间时,10、20、40、80 μmol/L 4个浓度之间差异有统计学意义(P<0.001);NS398作用于MCF-7细胞后能下调COX-2蛋白表达;NS398能明显抑制MCF-7细胞VEGF和PGE2的释放水平,且MCF-7细胞凋亡抑制率与VEGF和PGE2释放水平呈显著负相关.结论:选择性COX-2抑制剂NS398可抑制人乳腺癌细胞系MCF-7细胞增殖,其机制可能与选择性COX-2抑制剂NS398作用于MCF-7细胞后COX-2蛋白表达下调,VEGF和PGE2释放水平下降有关.     

5,4'-二-正辛烷氧基-7-二氟亚甲基异黄酮体外抗人类乳腺癌细胞作用

目的 探讨金雀异黄素(Gen)衍生物5,4'-二-正辛烷氧基-7-二氟亚甲基异黄酮(DOdFMG)体外抗人类乳腺癌细胞的作用.方法 平皿克隆形成法检测DOdFMG对人类乳腺癌MCF-7细胞抑制生长和增生作用,琼脂糖凝胶电泳法观测DOdFMG诱导MCF-7细胞凋亡作用,Western blotting 法测定DOdFMG对MCF-7细胞PTEN、pAkt、caspase-3蛋白的表达及活性.结果 DOdFMG抑制MCF-7细胞生长,呈剂量依赖性,比Gen具有更强的抗肿瘤活性,DOdFMG能诱导MCF-7细胞凋亡,DOdFMG处理的MCF-7细胞PTEN蛋白及caspase-3蛋白表达上调,pAkt蛋白表达下调,呈时间剂量依赖性.结论 DOdFMG具有抗人类乳腺癌MCF-7细胞的作用,其机制可能与抑制PKB/Akt通路的信号传导、激活PTEN及caspase-3有关,是一种新型治疗乳腺癌的候选药物.     

五味子对乳腺癌细胞抑制作用的体外研究

目的:评估中药五味子抗癌有效成分木酚素及其代谢产物对雌激素受体阳性以及阴性的乳腺癌细胞株的体外作用,并评价五味子对于乳腺癌的体外杀伤作用。方法:利用ATP 生物荧光药物敏感性检测技术(ATP-TCA),检测五味子木酚素对50例乳腺癌的体外杀伤作用,并检测不同浓度五味子木酚素及其代谢物（END、ENL）对于ER（＋）的MCF-7、T47D和ER（－）的MDA-MB-231、MDA-MB-435细胞株的杀伤作用。评价五味子的体外作用有效率及其与雌激素受体表型是否相关。结果:五味子对乳腺癌患者的乳腺癌细胞具有明显的体外杀伤作用,体外有效率为34.0%(17/50);五味子木酚素以浓度依赖的方式,显著降低乳腺癌细胞株MCF-7、T47D、MDA-MB-435、MDA-MB-231的存活率,且该抑制作用和细胞雌激素受体的关系并不明显（P＞0.05）,五味子木酚素在较低浓度（0.1-30μmol/L）下对雌激素受体阳性乳腺癌细胞株MCF-7、T47D表现出促进增殖的作用,当浓度提高至100μmol/L后,五味子木酚素对MCF-7、T47D增殖表现出显著的抑制作用,并呈剂量-效应关系。木酚素的低浓度促进乳腺癌细胞增殖作用在雌激素受体阴性乳腺癌细胞株MDA-MB-435、MDA-MB-231中并不明显,当浓度提高至100μmol/L后,五味子木酚素对MDA-MB-435、MDA-MB-231增殖表现出显著的抑制作用,并呈剂量-效应关系。ENL、END(3-1000μmol/L)在体外对乳腺癌细胞株存在显著抑制作用（P＜0.05）,并有剂量依赖效应,未发现其与细胞雌激素受体表型有关联（P＞0.05）。木酚素在较低浓度区间（0.1-30μmol/L）促进ER(＋)细胞株的增殖,但对ER(－)细胞株作用不显著。结论:五味子对乳腺癌细胞系以及乳腺癌患者细胞均具有较强的杀伤作用,值得进一步临床研究和应用。     

Huaier aqueous extract inhibits proliferation of breast cancer cells by inducing apoptosis

Aqueous extract of Trametes robiniophila murr (Huaier) has been commonly used in China for cancer complementary therapy in recent years; however, the mechanisms of its anticancer effects are largely unknown. In the present study, we aim to investigate its inhibitory effect on both MCF‐7 and MDA‐MB‐231 cells, and explore the possible mechanisms of its anticancer effect. Cell viability and motility were measured by MTT and invasive assays, migration and scratch assays in vitro, respectively. The distribution of cell cycle, PI‐Annexin‐V staining and Rhodamine 123 assay were analyzed by flow cytometry, and western blot were used to test the apoptotic pathways. We found that Huaier extract could strongly inhibit cell viability of MCF‐7 and MDA‐MB‐231 cells in a time‐ and dose‐dependent manner; however, MDA‐MB‐231 cells showed more susceptibility to the treatment. Furthermore, cell invasiveness and migration were also suppressed with exposure to Huaier extract. We also indicated that Huaier could induce G0/G1 cell‐cycle arrest, p53 accumulation and activation selectively in MCF‐7 cells. Inspiringly, the PI‐Annexin‐V staining assay and western blot analysis confirmed cell apoptosis executed by caspase‐3. Decreased mitochondrial membrane potential by Rhodamine 123 assay and down‐regulation of Bcl‐2 and up‐regulation of BCL2‐associated X protein (BAX) indicated that Huaier induced apoptosis through the mitochondrial pathway. Caspase activation during Huaier‐induced apoptosis was confirmed by pan‐caspase inhibitor, Z‐VAD‐fmk. As expected, the inhibitor decreased Huaier‐induced apoptosis in both cell lines. Based on our findings, Huaier can induce cell apoptosis in both ER‐positive and ER‐negative breast cancer cell lines and is an effective complementary agent for breast cancer treatment. (Cancer Sci 2010; 101: 2375–2383)     

细胞周期相关因子与乳腺细胞的癌变及生物学特性的相关性研究

目的：研究正常乳腺上皮细胞与乳腺癌细胞之间以及不同恶性程度的乳腺癌细胞之间的细胞周期相关因子的表达异同。方法：采用Western印迹法检测正常乳腺细胞株AG11132A、ER阳性和乳腺癌细胞株MCF－7及ER阴性的乳腺癌细胞株MDA－MB－231之间细胞周期蛋白D1、E及P21蛋白表达的异同及与其生物学特性的关系。结果：（1）正常乳腺上皮细胞株高表达P21蛋白,低表达周期蛋白E。与正常细胞相比,乳腺癌细胞株MCF－7、MDA－MB－231细胞高表达周期蛋白E,其中表达的周期蛋白E中存在异常的你分子量周期蛋白E成分,而正常乳腺上皮细胞不表达这种异常 的周期蛋白E。（2）在乳腺癌细胞株之间,相对ER阳性的MCF－7细胞,ER阴性的MDA－MB－231细胞则高表达周期蛋白E,基本无表达P21蛋白。结论L（1）正常细胞与这间、相对低恶性程度的民相对高恶性和蔼的癌细胞之间的差别是多环节的、质和量异常导致的结果;（2）周期蛋白E及P21均可反映乳腺癌细胞的增殖活性和恶性程度,可能是乳腺癌的临床预后指标。     

hCLP46基因在不同侵袭转移潜能乳腺癌细胞表达中的差异及其意义

目的 探讨hCLP46基因在MCF-7和MDA-MB-231乳腺癌细胞中表达的差异性及其意义。方法 采用RT-PCR的方法检测2个细胞系(乳腺癌低度侵袭转移细胞系MCF-7、中度侵袭转移细胞系MDA-MB-231)中hCLP46 mRNA的表达差异。取MCF-7和MDA-MB-231细胞株进行培养,分别加入100 μmol/L的转化生长因子-β(TGF-β)并设对照组,培养72 h,用Western-blot方法分析P15蛋白表达。结果 RT-PCR检测hCLP46结果显示,在MCF-7和MDA-MB-231细胞系中,内参基因GAPDH的表达量相近,hCLP46基因在两个细胞系中均表达,其中MDA-MB-231细胞系中的表达高于MCF-7细胞系。两个细胞系分别加入TGF-β培养72 h后,与相应的对照细胞系相比,P15的表达均有降低,hCLP46基因高表达的MDA-MB-231细胞中P15表达较MCF-7细胞显著降低。结论 hCLP46基因过表达可能抑制TGF-β对MDA-MB-231和MCF-7乳腺癌细胞P15基因的上调,hCLP46可能在乳腺癌的发病中起到一定作用。     

EGFRvIII‐induced estrogen‐independence,tamoxifen‐resistance phenotype correlates with PgR expression and modulation of apoptotic molecules in breast cancer

The tumor‐specific, ligand‐independent, constitutively active epidermal growth factor receptor (EGFR) variant, EGFRvIII, remains understudied in breast cancer. Here, we report that expression of EGFRvIII in the ErbB‐2‐overexpressing, estrogen‐dependent MDA‐MB‐361 breast cancer cell line resulted in significant estrogen‐independent tumor growth in ovariectomized, athymic nude mice in comparison to MDA‐MB‐361/wt cells. MDA‐MB‐361/vIII breast cancer cells maintained estrogen‐induced tumor growth, but were tamoxifen‐resistant in the presence of estrogen, while MDA‐MB‐361/wt cells had a significant reduction in tumor growth in the presence of estrogen and tamoxifen. Tamoxifen alone did not have a significant effect on EGFRvIII‐mediated estrogen‐independent tumor growth. Constitutive signaling from the EGFRvIII receptor resulted in an increased activation of both the Akt and MAPK pathways. Compared to estrogen‐dependent, tamoxifen‐sensitive MCF‐7/vIII breast cancer cells, which had unchanged levels of ERα, but an increase in progesterone receptor (PgR) in comparison to MCF‐7/wt cells, MDA‐MB‐361/vIII cells had a reduction in ERα expression as well as a more pronounced reduction in PgR compared with MDA‐MB‐361/wt cells. EGFRvIII expression was also significantly associated with an absence of PgR protein in invasive human breast cancer specimens. Alterations of proapoptotic proteins and antiapoptotic proteins were observed in EGFRvIII transfectants. In conclusion, constitutive signaling through EGFRvIII and its downstream effector proteins crosstalks with the ERα pathway, resulting in loss of PgR expression and alterations in the apoptotic pathway, which may result in the estrogen‐independent, tamoxifen‐resistant phenotype conferred to EGFRvIII‐expressing breast cancer cells. © 2009 UICC     

Comparing Apoptosis and Necrosis Effects of Arctium Lappa Root Extract and Doxorubicin on MCF7 and MDA-MB-231 Cell Lines

Objective: Breast cancer is a heterogeneous disease and very common malignancy in women worldwide. The efficacy of chemotherapy as an important part of breast cancer treatment is limited due to its side effects. While pharmaceutical companies are looking for better chemicals, research on traditional medicines that generally have fewer side effects is quite interesting. In this study, apoptosis and necrosis effect of Arctium lappa and doxorubicin was compared in MCF7, and MDA-MB-231 cell lines. Materials and Methods: MCF7 and MDA-MB-231 cells were cultured in RPMI 1640 containing 10% FBS and 100 U/ml penicillin/streptomycin. MTT assay and an annexin V/propidium iodide (AV/PI) kit were used respectively to compare the survival rate and apoptotic effects of different concentrations of doxorubicin and Arctium lappa root extract on MDA-MB-231 and MCF7 cells. Results: Arctium lappa root extract was able to reduce cell viability of the two cell lines in a dose and time dependent manner similar to doxorubicin. Flow cytometry results showed that similar to doxorubicin, Arctium Lappa root extract had a dose and time dependent apoptosis effect on both cell lines. 10μg/mL of Arctium lappa root extract and 5 μM of doxorubicin showed the highest anti-proliferative and apoptosis effect in MCF7 and MDA231 cells. Conclusion: The MCF7 (ER/PR-) and MDA-MB-231 (ER/PR+) cell lines represent two major breast cancer subtypes. The similar anti-proliferative and apoptotic effects of Arctium lappa root extract and doxorubicin (which is a conventional chemotherapy drug) on two different breast cancer cell lines strongly suggests its anticancer effects and further studies.     

乳腺癌细胞系中肿瘤干细胞相关亚群的初步研究

目的 通过乳腺癌细胞系及其干细胞的培养,化疗药干预和流式细胞仪筛选鉴定,探讨不同乳腺癌细胞系中CD44⁺CD24^-/low细胞比例,及富集乳腺癌干细胞相关亚群的方法。方法 通过细胞培养乳腺癌细胞系MCF-7、MDA-MB-231,观察生长曲线,比较化疗药物干预下生长情况;利用流式细胞仪检测两种乳腺癌细胞系中CD44⁺CD24^-/low细胞比例;无血清悬浮培养,化疗药(多西紫杉醇、表阿霉素)干预这两种乳腺癌细胞系,观察其是否形成细胞球。结果 (1)MDA-MB-231细胞系倍增时间短,生长速率高于MCF-7细胞系;(2)MCF-7细胞系中可能存在较大比例肿瘤干细胞,其对化疗抵制,能自我更新;(3)化疗敏感性用两独立样本t检验,MCF-7细胞,差异没有统计学意义;MDA-MB-231细胞,差异有统计学意义,提示MDA-MB-231细胞系对该方案化疗较敏感;(4)无血清悬浮培养,MDA-MB-231细胞系未发现明显细胞球;MCF-7细胞系初次无血清培养约6天出现细胞球。加入化疗药筛选后两种细胞,见大部分肿瘤细胞逐渐死亡,未发现明显细胞球;(5)流式细胞仪检测,MCF-7、MDA-MB-231两种细胞系中主要是CD44⁺CD24⁺亚群和CD44^-CD24⁺亚群,CD44⁺CD24^-/low细胞比例分别2.07%和0.20%。结论 (1)MDA-MB-231细胞系增值较快,恶性度相对较高,其对TA联合化疗药物较敏感;MCF-7细胞系中可能存在少量肿瘤干细胞,对化疗抵制,能自我更新;(2)无血清培养液培养MCF-7细胞系能形成悬浮细胞球;流式细胞仪检测两种细胞系中CD44⁺CD24^-/low细胞比例小;(3)CD44⁺CD24^-/low表型可能不是乳腺癌干细胞唯一特异性的表面标志。     

Inhibition of breast cancer growth by suramin.

In this study, the polyanionic compound suramin was shown to be a potent in vitro growth inhibitor of both hormone-insensitive, estrogen receptor-negative human breast cancer cells (MDA MB231 and SK-BR-3) and hormone-responsive, estrogen receptor-positive human breast cancer cells (ZR 75-1, T47D, and MCF7). The inhibitory effect of suramin was dose dependent, with a median effective dose varying from 7 microM for MDA MB231 cells to 50 microM for MCF7 cells. This result indicated that estrogen receptor-negative cells were more sensitive to the drug. In MCF7 cells, not only did suramin block the mitogenic action of growth factors such as epidermal growth factor (EGF) and insulin-like growth factors I and II (IGF-I and IGF-II, respectively), but it also totally abolished the increase in cell proliferation induced by the steroid hormone 17 beta-estradiol (E2). Maximal inhibition was obtained after 5 days of suramin treatment, and inhibition either was partially reversed by E2, IGF-I, and IGF-II or was not reversible by EGF following removal of drug. In addition, suramin significantly decreased synthesis and secretion of the lysosomal enzyme cathepsin D, which was shown to be associated with a high risk of breast tumor metastasis. These results therefore suggest that, because of its effects on growth and cathepsin D secretion, suramin might be a helpful additional therapeutic tool for breast cancer patients, especially for patients with estrogen receptor-negative tumors which are insensitive to antihormonal strategies.