紫草素对人绒癌耐药细胞株增殖的抑制及凋亡的作用

目的 研究紫草素对体外培养的人绒癌耐药细胞株(JAR/MTX)抑制增殖、促进凋亡及诱导细胞周期停滞的作用.方法 经不同浓度的紫草素分别作用24 h、48 h、72 h后,应用cck-8试剂盒检测其细胞毒性,应用流式细胞仪分析细胞周期分布及凋亡率变化,应用荧光显微镜观察凋亡现象.结果 当紫草素浓度从0.1875 μg/ml增加到3μg/ml时,其48h抑制率从46.48±12.0%升高到92.05±9.2%,0.75μg/ml紫草素分别作用24 h、48 h、72 h,其抑制率分别为43.94±10.1%、68.56±10.2%、84.97 ±18.63%,与对照组相比差异具有显著性(P＜0.05或P＜0.01),可见随着紫草素剂量的增加和作用时间的延长,对绒癌耐药细胞生长的抑制率也明显增加.当紫草素浓度从0.1875 μg/ml增加到3μg/ml时,与细胞作用48h后,凋亡率由12.13±5.67%升高到30.08±7.85%(P＜0.05或P＜0.01),随着药物浓度增加凋亡率亦增加,并可见典型的凋亡细胞核形态学变化.细胞周期分布也呈浓度依赖性改变,一方面增高C,0/G1期细胞比例(P＜0.05),另一方面降低S期和G2/M期细胞比例(P＜0.05).结论 紫草素对JAR/MTX具有明确的抗增殖、促凋亡、阻滞细胞周期进程的作用,值得进一步深入研究与探讨.     

脂联素对成骨细胞核因子κB受体活化素配体表达的影响

背景:成骨细胞分泌的核核因子kκ B受体活化素配体的主要作用为保持破骨细胞的分化和活性,抑制破骨细胞的凋亡.目的:观察脂联素对成骨细胞核因子kκ B受体活化素配体表达的影响,拟进一步探讨其对破骨细胞生成的作用.设计、时间及地点:单一样本观察,于2005-08/2006-03在中南大学湘雅二医院代谢内分泌研究所完成.材料:外科手术中弃之5份取正常成人(35～55岁)髂前上棘松质骨由供者自愿提供;人重组脂联素蛋白购自Calbiochem公司.方法;正常成人髂前上棘松质骨体外培养成骨细胞.分别用0,3,10和30 mg/L脂联素干预人成骨细胞48 h.成骨细胞和CD14 外周血单核细胞共培养14 d,用30 mg/L脂联素干预14 d,以25μg/L 巨噬细胞集落刺激因子 50 μg/L核因子k B受体活化素配体干预14 d作为诱导破骨细胞阳性对照.主要观察指标:分别采用荧光定量聚合酶链反应和酶联接免疫吸附剂测定的方法检测核因子k B受体活化素配体的表达;并用脂联素蛋白干预成骨细胞与外周血单核细胞共同培养系统,观察对破骨细胞生成的作用.结果:①脂联素呈剂量和时间依赖性促进人成骨细胞核因子κ B受体活化素配体的表达.②脂联素呈时间和剂量依赖性促进人成骨细胞可溶性破骨细胞异化因子蛋白的分泌.③脂联素干预成骨细胞与CD14 外周血单核细胞共同培养系统可诱导破骨细胞生成.结论:脂联索可通过诱导成骨细胞核因子κ B受体活化素配体表达,诱导破骨细胞生成.     

The apoptotic effect of ozone therapy on mitochondrial activity of highly metastatic breast cancer cell line MDA-MB-231 using in vitro approaches

Ozone (O₃) gas is the triatomic state of oxygen and it is used as a disinfection agent due to its strong oxidizing effect, since its discovery in the mid-nineteenth century. Ozone therapy is also an alternative therapeutic approach for some diseases like circulatory disorders, AIDS, asthma, cardiovascular diseases, and certain types of cancer by increasing the oxygen levels in the blood by external addition of ozone to the body. In this study, the therapeutic potential of ozone therapy was examined by inhibiting the growth of breast cancer cells in a dose-dependent procedure. Ozone concentrations varying from 5 to 20 ​μg/ml were applied to the MDA-MB-231, human breast adenocarcinoma and HUVEC, human umbilical vein endothelium, cell lines, and MDA cells demonstrated an increased rate of death while its migration potential decreases. RT-PCR analysis showed mRNA expression levels of pro-apoptotic genes demonstrated higher folds in MDA cells after 10 ​μg/ml treatment. In the same context, Annexin V/PI and cell cycle analysis also concluded that ozone therapy causes apoptotic cell death on breast tumor cells. The use of ozone therapy for cancer treatment requires further and extensive research. However, this research has shown that ozone therapy is a promising source for cancer treatment in a way by inhibiting the proliferation of breast tumor cells.     

Genes commonly upregulated by hypoxia in human breast cancer cells MCF-7 and MDA-MB-231.

Hypoxia is a stress that causes alterations in signal transduction and gene instability. In the cancer microenvironment, hypoxia plays a significant role in forming a tumor phenotype and tumor progression. We aimed to identify the genes upregulated by hypoxia in human breast cancer cell lines, a hormone-dependent MCF-7 and a hormone-independent MDA-MB-231, using microarray analysis. These cells were exposed to two oxygen concentrations such as 21% and 1% in a time-course. Out of 12625 genes, 26 genes were identified as commonly upregulated in both MCF-7 and MDA-MB-231 cells. Some of these genes were already reported as hypoxia-related, but some of those were identified newly. These commonly upregulated genes between hormone-dependent and hormone-independent cells would be a clue to study hypoxia-related events and to explore the novel therapeutic targets in human breast cancer.     

青蒿琥酯对生存素在乳腺癌细胞株MDA-MB-231表达的影响

目的 探讨青蒿琥酯对生存素(survivin)在乳腺癌细胞株MDA-MB-231中表达的影响.方法 以不同浓度(0、25、50 μg/mL)的青蒿琥酯处理MDA-MB-231细胞,分别于药物处理后24、48和72 h收集细胞及培养上清液,用RT-PCR检测不同组别、不同时间点的细胞中survivin的基因表达情况,酶联免疫吸附试验(ELISA)检测各组、各时间点培养上清液中survivin的蛋白质表达水平.结果 PCR结果和ELISA结果均显示,随着药物浓度的增加和处理时间的延长,survivin基因水平和蛋白质水平的表达也逐渐降低,同一时间点各组间survivin的表达量进行单因素方差分析,差异有统计学意义(P＜0.05);对照组(0 μg/mL)在24 h和48 h survivin的表达量变化不大,经t检验分析,差异无统计学意义(P＞0.05),而各浓度经药物处理48 h后survivin的表达量明显低于24 h的表达,差异有统计学意义(P＜0.05).结论 青蒿琥酯可通过抑制survivin的表达促进乳腺癌MDA-MB-231细胞凋亡.     

沉默Kin17表达抑制乳腺癌细胞MDA-MB-231的增殖

目的 探讨沉默Kin17表达对乳腺癌细胞生长增殖的影响,为评估该分子作为未来药物靶点的潜能提供依据. 方法 分别用携带Kin17基因特异性siRNA与正常对照siRNA的慢病毒重组载体感染MDA-MB-231细胞,再用嘌呤霉素进行抗性筛选,然后在荧光显微镜下观察阳性细胞的比例;用Real-time PCR与Western blot方法检测稳定转染了慢病毒重组载体的MDA-MB-231细胞中的Kin17mRNA与蛋白表达水平;CCK-8实验检测细胞生长增殖状况. 结果 通过感染携带Kin17特异性siRNA的病毒重组载体,稳定、明显敲减了MDA-MB-231细胞中的Kin17 mRNA与蛋白表达水平,而且显著减缓了该乳腺癌细胞的生长增殖速度. 结论 沉默Kin17表达能抑制三阴表型乳腺癌细胞的增殖,并有可能成为一种潜在的乳腺癌治疗新策略.     

PI3K抑制剂对三阴性人乳腺癌细胞株MBA-MB-231/ADR的多药耐药逆转作用

目的探讨PI3K抑制剂对三阴性人乳腺癌细胞多药耐药的逆转作用及其与PI3K/Akt信号转导关系。方法采用MTT法测定三阴性乳腺癌细胞系MBA-MB-231及其多药耐药细胞株MBA-MB-231/ADR对经典化疗药物阿霉素的半数抑制浓度(IC50),以及MBA-MB-231/ADR细胞株在PI3K抑制剂LY294002给药前后对阿霉素的敏感性差异。Western Blot检测MDA-MB-231/ADR细胞株LY294002给药前后,P-Akt、Akt、IκBα、NF-κB、P-gp和cleaved-caspase-3表达水平差异。结果 1MBA-MB-231和耐药细胞株MBA-MB-231/ADR对阿霉素的IC50分别为(0.36±0.03)μmol/L和(16.77±1.57)μmol/L,耐药倍数为46.58倍。2LY294002给药后,耐药细胞株MBAMB-231/ADR对阿霉素的IC50降至(2.59±0.07)μmol/L,耐药倍数降至6.475,对药物敏感性显著增加。3耐药细胞株MBA-MB-231/ADR中PI3K/Akt和NF-κB通路被激活,细胞耐药相关蛋白P-gp处于高表达水平;LY294002处理之后,MBA-MB-231/ADR细胞中PI3K/Akt和NF-κB通路被抑制,P-gp表达水平下调,细胞凋亡相关的cleaved-caspase-3表达上调。结论 PI3K抑制剂LY294002能有效逆转耐药细胞株MBA-MB-231/ADR的耐药性,从而增强耐药细胞MBA-MB-231/ADR对化疗药物阿霉素的敏感性。该研究结果提示LY294002通过阻断PI3K/Akt通路抑制下游NF-κB通路的活化和P-gp表达上调,从而参与MBA-MB-231/ADR耐药性的逆转。     

survivin基因沉默对“三阴”乳腺癌细胞株中caspase3和caspase7基因的影响

目的 探讨“三阴”乳腺癌细胞中沉默survivin基因对抑癌基因caspase3和caspase7的影响.方法 针对survivin基因设计干扰片段并与真核表达载体pGCsilencerTMU6/Neo/GFP进行连接,之后转染“三阴”乳腺癌细胞MDA-MB-231;通过RT-PCR鉴定survivin基因mRNA水平沉默效果;用RT-PCR检测沉默survivin基因对caspase3和caspase7表达及细胞凋亡的影响.结果 survivin基因沉默可引起MDA-MB-231细胞凋亡;caspase3和caspase7表达升高,灰度分析结果显示差异具有统计学意义（P =0.008）.结论 （1）RNAi技术沉默MDA-MB-231细胞中survivin基因,达到了对其表达的抑制效果;（2）survivin基因沉默可上调caspase3和caspase7的表达;（3） survivin基因沉默可引起细胞凋亡;（4） survivin基因可作为“三阴”乳腺癌基因治疗的新靶点.     

肿瘤抑制基因WWOX转染MDA-MB-231细胞系的实验研究

目的探讨肿瘤抑制基因WWOX与乳腺癌疾病相关性,为进一步研究WWOX基因的作用机制及功能奠定基础。方法构建真核表达载体pcDNA4．0／Myc—His-WWOX,并转染至MDA．MB．231细胞中,采用RT-PCR及Westernblot方法,检测WWOXmRNA及融合蛋白在MDA-MB-231细胞中的表达。结果测序结果显示,RT-PCR法获得的WWOX序列与GenBank中报道的一致。真核表达载体pcDNA4．0／Myc．His—WWOX转染MDA—MB-231细胞48h后,从RT-PCR及Westernblot结果中观察到WWOX基因的有效转录。结论成功构建了肿瘤抑制基因WWOX真核表达载体pcDNA4．0／Myc．His—WWOX,为进一步研究WWOX在乳腺癌发生和进展中的作用及其靶向基因治疗奠定了实验基础。     

Apoptotic effect of tolfenamic acid on MDA-MB-231 breast cancer cells and xenograft tumors

Recent studies have indicated that non-steroidal anti-inflammatory drug (NSAID), particularly tolfenamic acid, can inhibit proliferation and induce apoptosis invarious cancer cells. Breast cancer represents one-third of all cancers diagnosed in women and is the second leading cause of cancer death in Western European and North American women. In the present study, we investigated the apoptotic effect of tolfenamic acid in MDA-MB-231 estrogen receptor-negative human breast carcinoma cells and in a xenograft tumor model. Treatment of cells with tolfenamic acid significantly decreased cell viability in a concentration-dependent manner. Notably, tolfenamic acid increased apoptosis-related proteins, such as p53 and p21, within 48 h. Furthermore, in vivo experiments showed that tolfenamic acid treatment resulted in a significant reduction in tumor volume over 5 weeks. Immunohistochemistry results showed that apoptosis-related protein induction by tolfenamic acid was significantly higher in the 50 mg/kg-treated group compared to the control group. Together, these results indicate that tolfenamic acid induces apoptosis in MDA-MB-231 breast cancer cells and tumor xenograft model and it may be a potential chemotherapeutic agent against breast cancer.