纳米二氧化钛对人乳腺癌MCF-7细胞DNA损伤的研究

目的探讨纳米二氧化钛对人乳腺癌MCF-7细胞DNA损伤作用。方法不同粒径不同浓度的纳米二氧化钛对人乳腺癌MCF-7细胞作用,通过彗星实验检测细胞DNA损伤,评价遗传毒性效应。结果与对照组比较,30nm、50nm和100nm的纳米二氧化钛颗粒当浓度大于1μg/ml时均可对细胞产生遗传毒性效应,差异显著(P0.05),且随着浓度的增加毒性作用增强。结论纳米Ti O2颗粒对人乳腺癌MCF-7细胞具有遗传毒性作用,且遗传毒性与纳米Ti O2颗粒浓度呈剂量依赖效应。     

重组人骨形成蛋白-2提高人乳腺癌细胞MCF-7的迁移性

目的:探讨重组人骨形成蛋白-2(rhBMP2)对人乳腺癌细胞MCF-7迁移性的影响。方法:用rhBMP2诱导人乳腺癌细胞MCF-7,并利用原子力显微镜观察细胞的形态结构变化。通过划痕愈合和transwell实验研究rhBMP2诱导下人乳腺癌细胞MCF-7迁移能力的变化。结果:rhBMP2诱导组的细胞形态产生变化,多数细胞伸出板状伪足产生极性,细胞长度变长;相反,对照组细胞的伪足不明显,多数细胞趋于圆形,细胞直径短。划痕愈合和transwell实验显示,与对照组相比,rhBMP2诱导的MCF-7细胞的迁移和侵入能力明显加强。结论:rhBMP2能够诱导人乳腺癌细胞MCF-7获得迁移表型,并提高了MCF-7细胞的迁移和侵入能力。     

抗人P185erbB2 scFv-Fc-IL-2增强LAK样和ADCC杀伤作用及机制的实验研究

目的 将抗人P185erbB2 scFv-Fc-IL-2融合蛋白(HFI)分别作用于表达高、中、低3个水平erbB2受体的SKOV3、MCF-7、SGC-7901三株肿瘤细胞和健康人外周血单个核细胞(PBMC),探讨HFI调变肿瘤细胞表面分子,激活免疫效应细胞的机制;模拟体内肿瘤组织,将HFI-PBMC-肿瘤细胞混合培养,探讨HFI对分别表达高、中、低3个水平erbB2肿瘤细胞的淋巴因子激活的杀伤细胞(LAK)样和抗体依赖性细胞介导的细胞毒(ADCC)作用,为临床应用提供实验依据.方法 MTF法检测细胞增殖、杀伤活性;流式细胞术检测细胞表面分子的表达变化;应用非核素细胞毒试剂盒观察HFI介导ADCC杀伤作用.结果 HFI处理后SKOV3细胞表面杀伤相关分子细胞间黏附分子-1(ICAM-1)、Fas表达水平分别由24.85%、0.53%增高到85.36%、59.19%;SKOV3、MCF-7、SGC-7901三株肿瘤细胞erbB2表达水平分别由98.48%、42.60%、36.66%下降到94.01%、30.95%、12.36%.HFI刺激后人PBMC的增殖活性显著增强,呈时间依赖效应,CD3+ CD8+ T细胞和CD3- CD16+ CD56+NK细胞分别由24.37%、6.90%提高到38.80%、13.45%,CD25、淋巴细胞功能抗原-1(LFA-1)、FasL表达水平分别由3.99%、86.52%、5.02%提高到12.96%、99.06%、16.19%.HFI活化的人PBMC对不同erbB2表达水平肿瘤细胞的LAK样杀伤活性,在各效靶比均比对照组明显提高.HFI能够介导和增强人PBMC对表达erbB2肿瘤细胞的ADCC杀伤作用.结论 HFI上调SKOV3细胞表面杀伤相关分子ICAM-1、Fas表达,下调肿瘤细胞表面erbB2表达.HFI对人PBMC具有明显的激活增殖作用,活化的人PBMC对表达不同水平erbB2肿瘤细胞的LAK样杀伤作用均显著增强.HFI能够介导和增强人PBMC对肿瘤细胞的ADCC杀伤作用,且杀伤活性的高低与肿瘤细胞表面erbB2表达水平的高低呈平行关系.     

siRNA下调RRM2抑制人乳腺癌细胞增殖与迁移及其裸鼠皮下移植瘤的生长

目的: 探讨siRNA下调核糖核苷酸还原酶M2(ribonucleotide reductase M2,RRM2) 基因对人乳腺癌细胞MCF-7体外增殖、迁移和体内成瘤的影响。方法: 实时定量荧光PCR (real-time PCR) 及Western blotting技术检测人乳腺癌细胞MCF-7和人正常乳腺上皮细胞MCF-10A中RRM2 mRNA及蛋白的表达;用合成的siRNA-RRM2不同时点和不同剂量转染MCF-7细胞,用real-time PCR检测对RRM2基因的沉默效率;用CCK-8方法检测细胞增殖;用Transwell细胞迁移系统检测siRNA-RRM2对MCF-7细胞迁移能力的影响;裸鼠移植瘤实验检测siRNA-RRM2沉默MCF-7细胞的RRM2基因后对肿瘤生长的影响。结果: MCF-7细胞RRM2 mRNA和蛋白比MCF-10A细胞高表达;用siRNA-RRM2转染MCF-7乳腺癌细胞能时间及剂量依赖性下调RRM2基因表达;CCK-8方法结果显示下调RRM2基因会时间及剂量依赖性抑制MCF-7细胞增殖,而人正常乳腺上皮细胞增殖没有显著变化;Transwell细胞迁移系统检测显示下调RRM2基因显著抑制了MCF-7细胞的迁移能力;转染siRNA-RRM2下调RRM2基因能显著抑制裸鼠移植瘤的生长。结论: RRM2的过表达与人乳腺癌细胞的高增殖和迁移能力有关,抑制RRM2的功能是治疗乳腺癌的一个潜在的治疗策略。     

CISD2在乳腺癌组织中的表达及其对人乳腺癌MCF-7细胞增殖与侵袭的影响

目的检测CDGSH铁硫结构域2 (CDGSH iron sulfur domain 2, CISD2)在乳腺癌组织中的表达及其对人乳腺癌MCF-7细胞增殖与侵袭的影响。方法选取46乳腺癌组织及10例对应的癌旁正常组织,免疫组织化学方法与Western blot方法检测乳腺癌和癌旁组织中CISD2蛋白的表达。应用化学合成小干扰RNA技术沉默人乳腺癌MCF-7细胞中CISD2基因的表达,Western blot实验验证基因沉默效率。采用CCK-8和克隆形成实验检测转染后MCF-7细胞的增殖和侵袭情况。结果与癌旁正常组织相比,乳腺癌组织中CISD2蛋白表达的平均光密度值明显上调, siRNA能够明显抑制人乳腺癌MCF-7细胞CISD2的表达。CISD2基因沉默后,人乳腺癌MCF-7细胞的增殖能力和侵袭能力显著降低,P0.01。结论 CISD2可能是治疗乳腺癌的潜在靶点。     

MCF-7 乳腺癌细胞培养上清对树突状细胞抑制作用的研究

目的:应用MCF-7乳腺癌细胞分泌的上清液培养正常外周血树突状细胞,探讨MCF-7乳腺癌细胞分泌因子对正常树突状细胞分化、成熟及功能的影响.方法:应用MCF-7 乳腺癌细胞的培养上清和GM-CSF、IL-4及TNF-α培养正常外周血单个核细胞,检测所诱导的树突状细胞(DC)及其致敏的CTL活性.结果:MCF-7 乳腺癌细胞培养上清能够明显抑制正常树突状细胞的分化成熟及抗原提呈能力,CD80、CD83、CD86和HLA-DR的表达明显降低,与正常对照差异显著(P＜0.01);CTL对MCF-7细胞杀伤活性为17.35%与对照组56.14%比较差异显著(P＜0.01);IL-12分泌和共刺激T淋巴细胞所分泌的IFN-γ明显降低(P＜0.01).结论:MCF-7 乳腺癌细胞上清明显抑制所共培养的树突状细胞的分化、成熟及抗原提呈能力.     

HSP_(70BCG)-Daudi肿瘤肽复合物对γδT细胞的活化作用

用固相抗体法[1] 体外扩增人PBMC的γδT细胞 ,静息化处理后用HSP70BCG Daudi肿瘤肽复合物再次刺激研究HSP70BCG Daudi肿瘤肽复合物对γδT细胞的活化作用。MTT检测γδT细胞的细胞毒作用及TNF α生物学活性。3 H TdR掺入法测定细胞增殖。HSP70BCG Daudi肿瘤肽复合物活化的γδT细胞在效靶比为 10∶1及 5∶1时对靶细胞Daudi的杀伤活性分别为 88 36 %±8 2 1%及 75 2 3%± 16 36 % ,与对照组有显著性差别。 2 4及 4 8h增殖结果各组间无差别 ;未检测出各刺激组的上清中TNF α生物学活性有何差别。结论表明HSP70BCG Daudi肿瘤肽复合物活化的γδT细胞对Daudi有较高的杀伤活性     

B7-2基因联合自杀基因治疗乳腺癌移植瘤模型

目的观察树突状细胞活化抗原B7-2基因联合自杀基因系统EC-CD/5-FC于实验性乳腺癌的体、内外治疗的协同作用。方法用重组腺病毒构建CD和B2-7载体,体外感染人乳腺癌MCF-7细胞,荧光显微镜观察其感染率。然后给与前药5-FC,通过MTT法检测MCF-7细胞的增殖情况;Annexi V-FTTC/PI双染流式细胞术检测MCF-7细胞的细胞周期。BALB/C小鼠腋窝下注射MCF-7细胞制备乳腺癌移植瘤模型,待肿瘤直径达0.5 cm大小,分别在肿瘤局部直接注射Ad CD/B7-2,然后连续10 d腹腔注射5-氟胞嘧啶(5-FC),免疫组化法检测肿瘤组织中CD8+T表达。结果 MTT法检测显示MCF-7细胞对前药有较高的敏感性,Ad CD/5-FC/Ad B7-2和Ad CD/5-FC组MCF-7细胞的增殖均受到明显抑制(P<0.05);而Ad B7-2治疗基因对MCF-7细胞的增殖没有任何影响。在感染复数为100时流式细胞仪检测,Ad CD/5-FC/Ad-B7-2组和Ad CD/5-FC组均出现典型的凋亡峰,细胞周期分析显示治疗后G0~G1期比率增多,G2~M及S期细胞减少。在MCF-7移植瘤模型中,Ad CD/5-FC/Ad-B7-2治疗后移植瘤的生长明显受到抑制;肿瘤瘤体内或瘤体周围CD8+T细胞浸润增加。结论 B7-2联合自杀基因系统对乳腺癌MCF-7细胞及其MCF-7细胞移植瘤均有明显的抑制作用,B7-2联合自杀基因Ad CD/5-FC系统时,共刺激分子B7-2可通过增强和诱导的特异抗肿瘤免疫,有效减少肿瘤负荷,增强Ad-CD/5-FC系统对肿瘤的杀伤作用。     

用细胞-ELISA法检测抗P185抗体

以高表达P185蛋白的人乳腺癌细胞（SKBR-3）作为抗原,用固相-ELISA法检测抗P185单抗和免疫小鼠抗血清。比较了不同方法处理的固相细胞和待测血清经低表达P185的人乳腺癌细胞（MCF-7）吸收与未吸收对实验的影响。结果显示:待测样本用MCF-7预吸收后及用1％乙醛处理固相细胞组所得结果较理想。     

小干扰RNA抑制RUNX2对人乳腺癌MCF-7细胞增殖、凋亡与侵袭的影响

目的探讨小干扰RNA抑制人RUNT相关转录因子2(RUNX2)对人乳腺癌MCF-7细胞增殖、凋亡与侵袭的影响。方法应用化学合成小干扰RNA技术沉默人乳腺癌MCF-7细胞中RUNX2基因的表达,用逆转录-聚合酶链反应(RT-PCR)和Western blot实验验证基因沉默效率。应用MTT方法检测细胞增殖能力变化,流式细胞仪检测细胞凋亡的变化,Transwell实验检测细胞侵袭能力变化。结果设计的siRNA能够明显抑制人乳腺癌MCF-7细胞RUNX2的表达。RUNX2基因沉默后,人乳腺癌MCF-7细胞的增殖能力降低,细胞凋亡率明显提高,侵袭能力显著降低(P<0.01)。结论RUNX2基因是治疗人乳腺癌MCF-7细胞的潜在靶点。     

Targeting Ku protein for sensitizing of breast cancer cells to DNA-damage

Targeting molecular components that are critically involved in the maintenance of genome stability is a promising approach for overcoming intrinsic tumor cell resistance to DNA-damaging treatments. In mammalian cells, the Ku-dependent non-homologous end-joining repair pathway is the predominant process for the repair of double-strand breaks (DSBs) in DNA. Previously, RNA aptamers were selected to efficiently block DNA-binding activity of the Ku protein in vitro. In the present study, we have tested the efficacy of RNA aptamers against the Ku protein as molecular sensitizer of MCF-7 breast carcinoma cells to DNA-damage. Toward this end, we established MCF-7 cell sublines stably expressing SC4 aptamer RNAs under the control of the human 7SL small nuclear RNA gene promoter. Vector-transfected (MCF/7SL) cells and cells stably expressing SC4 aptamers (MCF/SC4) were exposed to the anticancer drug etoposide and cellular responses to DNA-damage were evaluated. We found that the presence of RNA aptamers against Ku protein enhanced etoposide-induced growth inhibition of MCF-7 breast cancer. The SC4 aptamer-mediated sensitization of MCF-7 cells to the anticancer drug is attributable to an increased susceptibility of these cells to apoptosis. The observed effects cannot be accounted for by the differential expression levels of Ku protein in control and SC4 aptamer-expressing cells, but are rather due to augmented DNA binding-capacity of Ku protein, as demonstrated in in vitro studies. Thus, RNA aptamers against Ku protein show potential to sensitize MCF-7 breast carcinoma cells to DNA-damaging agents.     

Tumor Burden Influences Cytotoxic T Cell Development in Metastatic Breast Cancer Patients—A Phase I/II Study

The influence of tumor burden on the generation of tumor antigen-specific cytotoxic T-lymphocytes (CTL) was investigated in a phase I/II clinical adoptive immunotherapy trial. Four previously treated metastatic breast cancer patients, two with macroscopic disease and two with no evidence of disease, in complete remission (CR), were enrolled. Each apheretic peripheral blood mononuclear cell (PBMC) sample was stimulated twice with MUC-1 before infusion back into the patients. CTL responses against MCF-7 cell line and cytokine production were measured before infusion. Patients received two monthly CTL infusions and were monitored for toxicity, tumor response as well as tumor marker levels. The CTL generated from patients with high tumor burdens had less cytokine production and lower cytotoxicity of MCF-7 than the CTL of patients in CR. The differences between the two groups were observed after the two MUC1 in vitro stimulations of the cells obtained in first apheresis. This difference increased after the two MUC1 stimulations of the cells obtained in the second apheresis. The cytotoxicity function was sustained from the first infusion to the second apheresis only for the patients in CR. This suggests that tumor burden had an inverse effect on the function of the generated CTL.     

KDR为靶的siRNA抑制乳腺癌细胞增殖的体内外研究

目的:采用化学修饰的小干扰RNA(siRNA)在体内外抑制含激酶插入区受体(KDR)基因表达,探讨化学修饰的siRNA介导的RNA干扰(RNAi)技术在乳腺癌基因治疗的可行性和特异性.方法:采用阳离子脂质体Lipofectamine2000TM作为转染试剂将针对人KDR基因的siRNA转染人类乳腺细胞株MCF-7,诱导RNAi,采用四甲基偶氮唑蓝(MTT)法,RT-PCR,Western blot试验等检测KDR基因和蛋白表达及细胞增殖变化.采用阳离子聚合物纳米粒In vivo jetPEITM为转染试剂将siRNA直接注射进裸鼠移植瘤,监测肿瘤生长变化,RT-PCR,免疫组化方法等监测KDR基因和蛋白表达变化.结果:靶向KDR基因siRNA转染MCF-7后,细胞增殖被抑制,KDRmRNA和蛋白的表达明显降低;裸鼠体内实验显示siRNA治疗组瘤组织的增长受到明显抑制;RT-PCR,免疫组化结果同时表明治疗组KDR表达下调.各对照组指标无明显变化.结论:化学修饰的siRNA介导的RNAi在体内外均能成功抑制靶基因的表达和MCF-7细胞增殖,是潜在的肿瘤治疗新方法,而KDR亦可作为肿瘤治疗的新靶点.     

Priming with dendritic cells can generate strong cytotoxic T cell responses to chronic myelogenous leukemia cells in vitro

Dendritic cells (DC) are antigen-presenting cells that can elicit potent antigen-specific responses. Since the development of techniques to cultivate these cells from peripheral blood, there has been a great deal of interest in their use in immunotherapeutic strategies. Here we show that morphologically, phenotypically, and functionally characteristic DC can be generated in vitro from peripheral blood mononuclear cells (PBMC) isolated from frozen apheresis product (AP) of cancer patients. These DC, when pulsed with whole-tumor lysate, protein, or RNA from a chronic myelogenous leukemia (CML) cell line, can induce anti-CML specific cytotoxicity in vitro by autologous cytotoxic T lymphocytes (CTL). RNA and protein-pulsed DC were more effective than lysate-pulsed DC at inducing cytotoxicity at low effector:target (E:T) ratios. These results were comparable to those obtained when fresh healthy peripheral blood was used as the source of PBMC, indicating that neither the malignant state of the patient nor the storage period detrimentally affected the generation or functionality of DC. CML cells were found to increase their level of MHC class I expression after exposure to CTL and pulsed DC thereby becoming better targets. These investigations lend support for the utilization of DC to generate anti-tumor responses in CML.     

Mitochondrial targeting liposomes incorporating daunorubicin and quinacrine for treatment of relapsed breast cancer arising from cancer stem cells

Breast cancer stem cells play a crucial role in the relapse of breast cancers because they are resistant to a standard chemotherapy and the residual cancer stem cells are able to proliferate indefinitely. The objectives of present study were to construct a kind of mitochondrial targeting daunorubicin plus quinacrine liposomes for treating and for preventing the recurrence of breast cancer arising from the cancer stem cells. MCF-7 cancer stem cells were identified as CD44⁺/CD24⁻ cells and cultured in free-serum medium. Evaluations were performed on MCF-7 cancer stem cells, MCF-7 cancer stem cell mammospheres, and the relapsed tumor by xenografting MCF-7 cancer stem cells into female NOD/SCID mice. The particle size of mitochondrial targeting daunorubicin plus quinacrine liposomes was approximately 98 nm. The mitochondrial targeting liposomes evidently increased the mitochondrial uptake of drugs, were selectively accumulated into mitochondria, activated the pro-apoptotic Bax protein, dissipated the mitochondrial membrane potential, opened the mitochondrial permeability transition pores, released cytochrome C by translocation, and initiated a cascade of caspase 9 and 3 reactions, thereby inducing apoptosis of MCF-7 cancer stem cells. The mitochondrial targeting liposomes showed the strongest efficacy in treating MCF-7 cancer cells in vitro, in treating MCF-7 cancer stem cells in vitro, and in treating the relapsed tumor in mice. Mitochondrial targeting daunorubicin plus quinacrine liposomes would provide a new strategy for treating and preventing the relapse of breast cancers arising from cancer stem cells.     

硒多糖对MCF-7乳腺癌小鼠的抗肿瘤作用研究

目的 探究硒多糖对MCF-7乳腺癌小鼠脾指数、胸腺指数、脾淋巴细胞转化率及SBP-1表达的影响,分析硒多糖对乳腺癌小鼠的抑瘤效果及作用机制。方法 将40只小鼠随机分为4组,每组10只,其中1组作为正常组,其余3组将MCF-7乳腺癌细胞悬液注射于小鼠左侧膈腧穴处建立乳腺癌模型,证明成瘤后予以给药,模型组（予等剂量的生理盐水）,硒多糖用药组（400 mg/kg硒多糖）、联合用药组（50 mg/kg环磷酰胺＋400 mg/kg硒多糖）,连续给药14 d。脱颈处死小鼠,测胸腺指数、脾指数,无菌条件下取脾脏研磨进行体外淋巴细胞培养,检测PHA诱导下的小鼠脾淋巴细胞转化率并应用免疫组化技术检测肿瘤组织中SBP-1的表达情况。结果 与正常组和模型组相比较硒多糖用药组、联合用药组的胸腺指数、脾指数及淋巴细胞转化率明显提高,差异有统计学意义（P＜0.05）;与硒多糖用药组比较联合用药组的胸腺指数、脾指数及淋巴细胞转化率均有所提高,差异有统计学意义（P＜0.05）;与模型组相比硒多糖用药组及联合用药组的SBP-1蛋白表达均有所提高,差异有统计学意义（P＜0.05）;与硒多糖用药组相比联合用药组的SBP-1蛋白表达有所增强,差异有统计学意义（P＜0.05）。结论 硒多糖可以通过改善MCF-7乳腺癌小鼠的免疫功能及增强SBP-1的表达来起到抗肿瘤作用,与环磷酰胺联合用药作用更显著。     

A monoclonal antibody directed against a human cell membrane antigen prevents cell substrate adhesion and tumor invasion.

It was the aim of this study to design mouse monoclonal antibodies (MAbs) that can inhibit the invasion of breast cancer cells in the host tissue. Therefore, MAbs were raised against epitopes on the extracellular domain of SK-BR-3 human breast cancer cells, and biological assays were performed to test the capability of the MAbs to inhibit cell substrate adhesion. MAb 14C5 bound an extracellular plasma membrane antigen of SK-BR-3 and MCF-7 human breast cancer cells and inhibited the cell substrate adhesion of these cells in vitro. The MAb delayed the adhesion of MCF-7 and SK-BR-3 cells on precultured embryonic heart fragments (PHFS). It inhibited the destruction of the PHF by MCF-7 cells and the invasion of the PHF by SK-BR-3 cells. The MAb reacted with an epitope on the cell membrane of in situ and invasive ductal carcinomas of the breast in immunohistochemistry. Poorly differentiated, highly invasive ductal carcinomas show extensive staining of long plasma membrane extensions. Normal multilayered epithelia, normal connective tissue, and tumors derived from these tissues as well as normal breast tissue were negative. From both cell lines a protein complex consisting of two subunits with molecular weight of 50 and 90 kd, respectively, was immunoprecipitated. It is concluded that the 14C5 antigen plays a role in cell substrate adhesion and subsequently also in invasion of breast cancer cells. The 14C5 MAb was able to inhibit cell substrate adhesion and invasion in vitro of breast cancer cells.     

Immunomodulatory Effects of Newcastle Disease Virus AF2240 Strain on Human Peripheral Blood Mononuclear Cells

Immunotherapy has raised the attention of many scientists because it hold promise to be an attractive therapeutic strategy to treat a number of disorders. In this study, the immunomodulatory effects of low titers of Newcastle disease virus (NDV) AF2240 on human peripheral blood mononuclear cells (PBMC) were analyzed. We evaluated cytokine secretion and PBMC activation by cell proliferation assay, immunophenotyping and enzyme linked immunosorbent assay. The proliferation of the human PBMC was measured to be 28.5% and 36.5% upon treatment with 8 hemaglutinin unit (HAU) and 2 HAU of NDV respectively. Interestingly, the percentage of cells with activating markers CD16 and CD56 were increased significantly. Furthermore, the intracellular perforin and granzyme levels were also increased upon virus infection. Human PBMC treated with NDV titer 8 HAU was found to stimulate the highest level of cytokine production including interferon-γ, interleukin-2 and interleukin-12. The release of these proteins contributes to the antitumor effect of PBMC against MCF-7 breast cancer cells. Based on the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay, activated human PBMC showed high cytolytic efficiency towards human breast tumor cells. In summary, NDV was able to stimulate PBMC proliferation, cytokine secretion and cytolytic activity.