体外观察雷公藤内酯醇对乳腺癌细胞MCF-7增殖及凋亡的影响

目的:探讨雷公藤内酯醇(triptolide,TP)对人乳腺癌细胞MCF-7增殖及凋亡的影响。方法:MTT法检测不同条件下TP对MCF-7细胞的增殖抑制作用;倒置显微镜观察TP对MCF-7细胞形态学影响;流式细胞仪检测MCF-7细胞的凋亡情况;Caspase检测试剂盒测定Caspase-3,9的变化。结果:TP以剂量及时间依赖性方式明显抑制MCF-7细胞的增殖;TP作用MCF-7细胞后,细胞出现明显的形态学改变(形态不规则、脱落,细胞碎片等)。流式细胞仪检测5μg/mL的TP明显诱导MCF-7细胞凋亡;Caspase-3,9表达水平明显升高,和对照组相比差异有统计学意义(P<0.05)。结论:TP可能通过线粒体通路诱导MCF-7细胞凋亡而发挥其抑制作用。     

姜黄素诱导乳腺癌MCF-7细胞凋亡

目的 研究姜黄素对人乳腺癌细胞株MCF-7细胞增殖抑制和诱导凋亡作用.方法 MTT法检测姜黄素对MCF-7细胞的增殖抑制作用;流式细胞术(FCM)PI单染检测细胞周期;Annexin V/PI双染法检测细胞凋亡;Western blot法检测Bcl-2和Bax蛋白的表达.结果 姜黄素对MCF-7细胞生长有明显抑制作用,并呈剂量、时间依赖性;姜黄素能使MCF-7细胞阻滞在G1/S期,可以诱导细胞凋亡,Bax蛋白表达上调,而Bcl-2的表达减少.结论 姜黄素对人乳腺癌MCF-7细胞的增殖具有显著的抑制作用并可诱导细胞凋亡.其分子作用机制可能与其上调Bax基因表达水平的同时下调Bcl-2基因表达水平,从而诱导细胞凋亡有关.     

葫芦素B纳米脂质载体对结肠癌和乳腺癌细胞抑制及凋亡作用的研究

目的：研究葫芦素B纳米脂质载体（CuB-NLC）对结肠癌Lovo细胞,乳腺癌MCF-7细胞的体外细胞毒性。方法：结肠癌Lovo细胞,乳腺癌MCF-7细胞常规复苏、培养及传代,取处于对数生长期的细胞用于实验。采用CCK-8法检测质量浓度为0、0.0625、0.25、1.00、4.00、16.0 mg/L的CuB-NLC对结肠癌Lovo细胞,乳腺癌MCF-7细胞的毒性,流式细胞仪检测结肠癌Lovo细胞,乳腺癌MCF-7细胞的细胞周期进程及Annexin V/PI双染法检测细胞的凋亡率。结果：与葫芦素B （CuB）相比CuB-NLC对结肠癌Lovo细胞,乳腺癌MCF-7细胞生长抑制作用明显增强（P＜0.05）,且这种抑制作用随药物浓度增加而增强。CuB组及CuB-NLC组作用于结肠癌Lovo细胞、乳腺癌MCF-7细胞48 h后,与NLC空白组及DMSO对照组相比较,CuB及CuB-NLC均能够引起结肠癌Lovo细胞、乳腺癌MCF-7细胞G2/M期阻滞,同时伴有G0/G1期细胞减少, CuB-NLC组的作用更加明显,有统计学差异（P＜0.05）。Annexin V/PI双染法检测结果表明,CuB-NLC能显著诱导结肠癌Lovo细胞,乳腺癌MCF-7细胞凋亡。结论：葫芦素B纳米脂质载体能够抑制结肠癌Lovo细胞,乳腺癌MCF-7细胞的增殖,诱导细胞凋亡。     

铜绿假单胞茵注射液对人乳腺癌细胞的体外杀伤及促凋亡作用研究

目的研究铜绿假单胞菌（pseudo—monas aeruginosa,PA-MSHA）注射液在体外实验中对人乳腺癌细胞（MCF-7）凋亡和增殖的影响,并探讨其可能的作用机制。方法应用MTT比色法检测铜绿假单胞菌注射液对体外培养的MCF-7细胞增殖抑制作用,应用流式细胞术检测铜绿假单胞菌注射液诱导乳腺癌细胞凋亡,检测其对细胞周期的影响。用Hoechst33258染色法染色,荧光显微镜检测铜绿假单胞菌注射液诱导体外培养的MCF-7肿瘤细胞凋亡的形态学改变。结果铜绿假单胞菌注射液抑制MCK7细胞增殖,呈剂量和时间依赖性;与对照组相比,铜绿假单胞菌注射液组MCF7细胞的凋亡率明显增高（P〈0．01）、G0／G1期细胞比例明显增高、S期细胞所占百分比明显降低（P〈0．05）,染色荧光显微镜检测发现PAMSHA能诱导体外培养的肿瘤细胞呈现明显的凋亡图像。结论铜绿假单胞菌注射液可能通过对细胞周期中G0／G1期阻滞,诱导MCF-7细胞凋亡,从而抑制MCF-7细胞的增殖。     

Erk信号传导通路在雷公藤甲素诱导人乳腺癌MCF-7细胞自噬与凋亡中的影响

目的：探讨雷公藤甲素通过Erk信号传导通路对人乳腺癌细胞MCF-7增殖、自噬和凋亡的影响。方法：培养MCF-7细胞,MTT法检测细胞存活率,Western-blot方法分析凋亡相关蛋白Bax、Bcl-2和Caspase-3,自噬相关蛋白LC3B、p62和Beclin-1和有关MAPK信号通路p38和Erk1/2蛋白水平的变化。结果：10 nmol·L^-1雷公藤甲素显著抑制人乳腺癌细胞MCF-7的增殖,促进凋亡,且呈剂量-时间依赖性;TPI能够增加LC3BⅡ和Beclin-1的表达,降低p62的蛋白水平,诱导MCF-7细胞自噬。雷公藤甲素促进p38和Erk1/2磷酸化,当联用自噬抑制剂时,磷酸化水平下降。结论：雷公藤甲素能够显著抑制人乳腺癌细胞MCF-7增殖,促进凋亡,通过诱导细胞自噬及促进p38及Erk1/2磷酸化等多途径发挥抗肿瘤作用,并首次证明其自噬的发生可能与Erk1/2的激活有关。     

阿司匹林对人乳腺癌细胞株MCF-7增殖和凋亡的影响

目的 研究阿司匹林对人乳腺癌癌细胞株MCF-7增殖和凋亡的影响.方法 MTT法、FCM法、电镜等技术.结果 MTT法显示阿司匹林对人乳腺癌MCF-7细胞有较强的抑制作用;FCM法细胞的凋亡率随阿司匹林浓度的增大而增加;电镜可见典型的细胞凋亡形态学特征.结论 阿司匹林能够显著抑制MCF-7细胞增殖及诱导凋亡.     

雷公藤甲素对ERα蛋白介导的人乳腺癌MCF-7细胞增殖抑制的影响

目的：研究雷公藤甲素对激素依赖性人乳腺癌细胞MCF-7增殖的抑制作用及可能的机制。方法：MTT法检测雷公藤甲素对MCF-7细胞增殖的抑制作用,Hoechst染色法检测其对细胞凋亡的影响,Western blotting法观察雷公藤甲素对雌激素受体（ER）α蛋白表达的影响。结果：雷公藤甲素对MCF-7细胞增殖有显著的抑制作用,并且呈现良好的时效和量效关系,雷公藤甲素能有效诱导MCF-7细胞凋亡,并且对ERα具有明显的下调作用。结论：雷公藤甲素能抑制人乳腺癌细胞MCF-7增殖并且诱导其凋亡,其诱导MCF-7细胞凋亡的作用机制可能与其下调ERα的表达有关。     

葫芦素B通过激活线粒体途径诱导人肺癌NCI-H460细胞凋亡

目的探讨葫芦素B对人肺癌NCI-H460细胞增殖及凋亡的影响,并探讨其机制。方法体外培养NCI-H460细胞,MTT法观察葫芦素B对细胞增殖的影响,倒置相差显微镜观察细胞形态的变化,采用流式细胞术检测细胞凋亡率。采用罗丹明123(Rhodamine 123)染色,通过流式细胞仪检测线粒体膜电位(△ψm),采用Western blot方法检测线粒体内和胞浆内的细胞色素C。结果葫芦素B对NCI-H460细胞的增殖有抑制作用,且呈剂量、时间依赖性;葫芦素B处理组细胞形态发生显著改变,细胞皱缩、变圆,可见胞核染色质浓缩;流式细胞仪检测结果显示葫芦素B诱导NCI-H460细胞凋亡,呈剂量依赖性。葫芦素B处理后线粒体膜电位显著下降,细胞色素C由线粒体释放到胞浆中。结论葫芦素B可以抑制人肺癌NCI-H460细胞的增殖并诱导细胞凋亡,线粒体途径参与葫芦素B诱导的NCI-H460细胞凋亡。     

野马追总黄酮的体内外抗乳腺癌活性及机制研究

目的 探究野马追总黄酮(TFE)的体内外抗乳腺癌活性及相关的作用机制。方法 MTT法检测TFE对乳腺癌细胞(MCF-7、T47D、MDA-MB-231、MDA-MB-468)和人正常乳腺上皮细胞MCF-10A增殖的影响;流式细胞术检测TFE对乳腺癌细胞周期和凋亡的影响;吖啶橙(AO)染色法检测TFE对细胞自噬的影响;Western blot检测细胞周期、凋亡、自噬相关蛋白的变化,以及PI3K/Akt信号通路相关蛋白的变化;建立MDA-MB-231细胞的裸鼠移植瘤模型,观察TFE的体内抗肿瘤活性。结果 TFE能明显抑制乳腺癌细胞增殖,并呈剂量依赖性,而对人正常乳腺上皮细胞无显著的抑制作用;TFE能增加G₂/M期细胞比例,上调p-cdc-2蛋白表达,下调cdc-2和Cyclin B1蛋白表达;TFE能显著增加乳腺癌细胞凋亡比例,上调促凋亡蛋白Bad和Bax表达,下调抗凋亡蛋白Bcl-2表达;TFV能够诱导乳腺癌细胞产生自噬,自噬相关蛋白LC3-II表达上升,p62表达降低;TFE能够抑制显著抑制PI3K和Akt的磷酸化水平;TFE能够在体内抑制裸鼠肿瘤的体积。结论 TFE通过抑制PI3K/Akt信号通路,阻滞细胞周期、诱导凋亡和自噬,进而在体内外抑制乳腺癌细胞的生长。     

芹黄素联合紫杉醇对人乳腺癌MCF-7细胞株增殖、迁移及凋亡的影响

目的 探讨芹黄素联合紫杉醇对人乳腺癌MCF-7细胞株增殖、迁移及凋亡的影响.方法 采用MTT法测定人乳腺癌MCF-7细胞的增殖活性;用Transwell法测试细胞的迁移情况;用流式细胞仪检测细胞的凋亡.结果 芹黄素与紫杉醇单独用药对细胞的抑制作用随药物浓度的提高而增强,呈浓度依赖性,联合用药有协同作用;两药联用后,抑制细胞的迁移能力和诱导细胞的凋亡作用增强.结论 芹黄素与紫杉醇联用可协同抑制人乳腺癌MCF-7细胞的增殖和迁移,并诱导细胞的凋亡.     

Growth inhibitory activity of cucurbitacin glucosides isolated from Citrullus colocynthis on human breast cancer cells

Our aim was to study the effects of cucurbitacin glucosides extracted from Citrullus colocynthis leaves on human breast cancer cell growth. Leaves were extracted, resulting in the identification of cucurbitacin B/E glucosides. The cucurbitacin glucoside combination (1:1) inhibited growth of ER(+) MCF-7 and ER(-) MDA-MB-231 human breast cancer cell lines. Cell-cycle analysis showed that treatment with isolated cucurbitacin glucoside combination resulted in accumulation of cells at the G(2)/M phase of the cell cycle. Treated cells showed rapid reduction in the level of the key protein complex necessary to the regulation of G(2) exit and initiation of mitosis, namely the p34(CDC2)/cyclin B1 complex. cucurbitacin glucoside treatment also caused changes in the overall cell morphology from an elongated form to a round-shaped cell, which indicates that cucurbitacin treatment caused impairment of actin filament organization. This profound morphological change might also influence intracellular signaling by molecules such as PKB, resulting in inhibition in the transmission of survival signals. Reduction in PKB phosphorylation and inhibition of survivin, an anti-apoptosis family member, was observed. The treatment caused elevation in p-STAT3 and in p21(WAF), proven to be a STAT3 positive target in absence of survival signals. Cucurbitacin glucoside treatment also induced apoptosis, as measured by Annexin V/propidium iodide staining and by changes in mitochondrial membrane potential (DeltaPsi) using a fluorescent dye, JC-1. We suggest that cucurbitacin glucosides exhibit pleiotropic effects on cells, causing both cell cycle arrest and apoptosis. These results suggest that cucurbitacin glucosides might have therapeutic value against breast cancer cells.     

Cucurbitacin B and cucurbitacin I suppress adipocyte differentiation through inhibition of STAT3 signaling

Cucurbitacin B, a member of the cucurbitaceae family, can act as a STAT3 signaling inhibitor to regulate the growth of hepatocellular carcinoma. STAT3 signaling has been shown to inhibit adipocyte differentiation through C/EBPα and PPARγ. Based on these studies, we hypothesized that cucurbitacin B would prevent PPARγ mediated adipocyte differentiation through STAT3 signaling. To test this hypothesis, mesenchymal C3H10T1/2 and 3T3-L1 preadipocyte cells were treated with a sub-cytotoxic concentration of cucurbitacin B. Cucurbitacin B treatment inhibits lipid accumulation and expression of adipocyte markers including PPARγ and its target genes in a dose-dependent manner. Cucurbitacin B treatment impairs STAT3 signaling as manifested by reduced phosphorylation of STAT3 and suppression of STAT3 target gene expression in preadipocytes. The anti-adipogenic effects of cucurbitacin B are significantly blunted in cells with STAT3 silenced by introducing small interfering RNA. Finally, our data show that cucurbitacin I, another cucurbitacin family member, also inhibits adipocyte differentiation by suppressing STAT3 signaling. Together, our data suggest the possibility of utilizing cucurbitacins as a new strategy to treat metabolic diseases and implicate STAT3 as a new target for the development of functional foods and drugs.     

Activated kRas protects colon cancer cells from cucurbitacin-induced apoptosis: the role of p53 and p21

Cucurbitacins have been shown to inhibit proliferation in a variety of cancer cell lines. The aim of this study was to determine their biological activity in colon cancer cell lines that do not harbor activated STAT3, the key target of cucurbitacin. In order to establish the role of activated kRas in the responsiveness of cells to cucurbitacins, we performed experiments in isogenic colon cancer cell lines, HCT116 and Hke-3, which differ only by the presence of an activated kRas allele. We compared the activity of 23, 24-dihydrocucurbitacin B (DHCB) and cucurbitacin R (CCR), two cucurbitacins that we recently isolated, with cucurbitacin I (CCI), a cucurbitacin with established antitumorigenic activity. We showed that cucurbitacins induced dramatic changes in the cytoskeleton (collapse of actin and bundling of tubulin microfilaments), inhibited proliferation and finally induced apoptosis of both HCT116 and Hke-3 cells. However, the presence of oncogenic kRas significantly decreased the sensitivity of cells to the three cucurbitacins tested, CCR, DHCB and CCI. We confirmed that mutational activation of kRas protects cells from cucurbitacin-induced apoptosis using nontransformed intestinal epithelial cells with inducible expression of kRasV12. Cucurbitacins induced the expression of p53 and p21 predominantly in HCT116 cells that harbor mutant Ras. Using HCT116 cells with targeted deletion of p53 or p21 we confirmed that p53 and p21 protect cells from apoptosis induced by cucurbitacins. These results demonstrated that sensitivity of human colon cancer cell lines to cucurbitacins depends on the kRas and p53/p21 status, and established that cucurbitacins can exert antitumorigenic activity in the absence of activated STAT3.     

STAT3-independent inhibition of lysophosphatidic acid-mediated upregulation of connective tissue growth factor (CTGF) by cucurbitacin I

Cucurbitacins are recognised as anti-tumour agents because of their interference with STAT3 signalling, but may also affect the integrity of the actin cytoskeleton. In the present study the effect of cucurbitacin I was investigated in fibroblasts. In these cells, cucurbitacin I interfered with lysophosphatidic acid (LPA) signalling. It inhibited tyrosine phosphorylation of focal adhesion proteins and induction of connective tissue growth factor (CTGF), a potent profibrotic protein. Inhibition of Src family kinases with PP2, but not the inactive analogue PP3, also interfered with LPA-mediated tyrosine phosphorylation and induction of CTGF. Jak2-STAT3 signalling seemed to be the connecting link, because CTGF induction was sensitive to AG490, an inhibitor of Jak2, and cucurbitacin I, an inhibitor of Jak2 and STAT3. However, LPA did not activate tyrosine phosphorylation of STAT3. Furthermore, cucurbitacin I was as effective in STAT3 knock out cells as in control cells. Therefore, the inhibitory effect of cucurbitacin I was not related to inhibition of STAT3. Immunocytochemical analysis of cucurbitacin I-treated cells revealed disassembly of F-actin fibres, reorganisation into F-actin patches and resolution of focal adhesions. The phenotypic changes resembled changes observed after treatment of the cells with cytochalasin D, which has been shown to interfere with CTGF induction. Concentrations of cucurbitacin I, which have been shown to target Jak2-STAT3 signalling, thus, profoundly affect the actin cytoskeleton and may therefore modulate cell morphology, migration, adherence and gene expression also in non-tumour cells.     

Cucurbitacin B, a small molecule inhibitor of the Stat3 signaling pathway, enhances the chemosensitivity of laryngeal squamous cell carcinoma cells to cisplatin

We have previously shown that the simultaneous exposure of Hep-2 cells to cucurbitacin B and docetaxel significantly enhances anticancer activity of these cells by suppressing Stat3 activation and down-regulating the expression levels of key cell cycle and anti-apoptosis regulators. In order to determine whether cucurbitacin B can also enhance the sensitivity of Hep-2 laryngeal cells to cisplatin, we treated Hep-2 cells with either cucurbitacin B, cisplatin, or the combination and evaluated these cells for proliferation, cell cycle distribution, and apoptosis. Our results demonstrate that, in comparison to single agent cucurbitacin B or cisplatin treated cells, Hep-2 cells treated with a cucurbitacin B/cisplatin combination display synergistic effects on growth inhibition, cell cycle arrest, and apoptosis induction. Western blot analysis using protein extracts from Hep-2 cells treated with cucurbitacin B, cisplatin, or the combination largely recapitulated the observations made when treated with the cucurbitacin B/docetaxel combination. More specifically, Hep-2 cell lines treated with the cucurbitacin B/cisplatin combination demonstrated a significantly reduced level of p-Stat3 in comparison with single agent treated cells. In addition, cucurbitacin B/cisplatin treated Hep-2 cells also demonstrated a significant reduction in Bcl-2 and Cyclin B1 protein levels compared to single agent cucurbitacin B or cisplatin treated cells. Xenograft models containing Hep-2 cells in mice also demonstrated that this cucurbitacin B/cisplatin combination led to the synergistic inhibition of tumor growth. Taken together, these results suggest that the cucurbitacin B/cisplatin combination treatment may be a potentially useful therapeutic option for individuals diagnosed with laryngeal cancer.     

葫芦素B-聚乳酸-羟基乙酸共聚物载药纳米粒的构建与药效学评价

目的 以聚乳酸-羟基乙酸共聚物（PLGA）作为纳米制剂载体材料将葫芦素B制备成纳米粒,并考察其对HepG2肝癌细胞的抑制效果。方法 使用乳化溶剂蒸发法制备葫芦素B-PLGA载药纳米粒,以PLGA浓度（X₁）、PVA浓度（X₂）和药物浓度（X₃）作为考察因素,以载药纳米粒的粒径大小（Y₁）和包封率（Y₂）作为评价指标,应用中心复合设计-效应面法优化葫芦素B-PLGA载药纳米粒处方;测定了纳米粒的粒径分布和Zeta电位值,通过透射电镜观察其微观形态,并考察了葫芦素B-PLGA载药纳米粒的体外药物释放特性;比较了葫芦素B与葫芦素B-PLGA载药纳米粒对HepG2肝癌细胞的抑制效果。结果 葫芦素B-PLGA载药纳米粒的最优处方组成为：PLGA浓度为9.0%,PVA浓度为2.0%,药物浓度为4.5%,制备的纳米粒粒径为（145.4±15.8） nm,Zeta电位值为（-7.6±0.8） mV;透射电镜下可观察到纳米粒表面光滑,分布均匀;葫芦素B-PLGA载药纳米粒释药前期出现突释,后期平缓,48 h药物释放达到86%;葫芦素B-PLGA载药纳米粒对HepG2肝癌细胞的抑制作用显著高于葫芦素B。结论 葫芦素B-PLGA载药纳米粒可延缓药物释放,提高对HepG2肝癌细胞的抑制活性,为进一步临床研究奠定实验基础。     

葫芦素B对人胃癌BGC-823细胞增殖及凋亡的影响

目的探讨葫芦素B对人胃癌BGC-823细胞增殖及凋亡的影响及其作用的分子机制。方法体外培养BGC-823细胞,MTT法观察葫芦素B对细胞增殖的影响,采用流式细胞术检测细胞凋亡率,采用分光光度法检测Caspase-3、Caspase-9的活性,采用Western blot方法检测葫芦素B对Bcl-2、Bax蛋白表达的影响。结果葫芦素B对BGC-823细胞的增殖有抑制作用,且此作用呈剂量和时间依赖性;流式细胞仪检测结果显示,葫芦素B诱导BGC-823细胞凋亡,呈剂量依赖性。葫芦素B处理后Caspase-3、Caspase-9活性升高,细胞抗凋亡蛋白Bcl-2表达减少,促凋亡蛋白Bak的表达增加。结论葫芦素B可以抑制人胃癌BGC-823细胞的增殖并诱导细胞凋亡。