共轭亚油酸诱导人胃腺癌细胞(SGC-7901)凋亡的作用

目的 研究共轭亚油酸单体（c9,t11-CLA)诱导人体胃腺癌细胞（SGC－7901）凋亡作用。方法 采用细胞生长曲线,凋亡细胞的荧光显微镜、电镜观察,流式细胞光度术的检测以及P53蛋白表达方法。结果 显示出c9,t11-CLA对SGC－7901细胞有明显的抑制作用,并可诱导SGC－7901细胞产生凋亡,并随着c9,t11-CLA浓度的增加,细胞凋亡率逐渐增加;而P53蛋白表达则随着c9,t11-CLA浓度的增加呈逐渐降低的趋势。结论 这可能是c9,t11-CLA抑制肿瘤细胞机制之一。     

金雀异黄素诱导人乳腺癌细胞凋亡作用机制研究

目的探讨金雀异黄素对体外培养的人乳腺癌MCF7细胞凋亡的影响及作用机制。方法采用MMT法、凋亡细胞的荧光显微镜、电镜观察和流式细胞仪的检测,观察了不同剂量的金雀异黄素诱导细胞凋亡。同时采用免疫组化法检测凋亡相关基因Bax和癌基因erbB2蛋白的表达。结果通过荧光显微镜和电镜技术观察到凋亡的MCF7细胞。流式细胞仪也检测到了金雀异黄素诱导MCF7细胞产生凋亡,并随着金雀异黄素浓度的增加,细胞凋亡率显著增加。蛋白水平检测表明金雀异黄素促进MCF7细胞Bax表达升高,抑制erbB2表达。结论金雀异黄素可诱导MCF7细胞凋亡,并主要是通过调节Bax和erbB2蛋白表达实现的。     

共轭亚油酸对正常动物细胞和人体肿瘤细胞间通讯功能的影响

为探讨c9,t11-共轭亚油酸 (CLA)的抑癌作用可能机制 ,在促癌物 (TPA)存在下 ,对正常细胞(CHL)以及人体肿瘤细胞 (SGC 790 1细胞和MCF 7细胞 )的细胞间隙连接通讯功能 (GJIC)的影响 ,采用划痕标记染料示踪技术 (SLDT) ;c9,t11 CLA剂量为 2 5 (mol L ,5 0 (mol L ,10 0 (mol L和 2 0 0 (mol L ,阴性对照为乙醇。结果显示 ,c9,t11 CLA可明显地提高TPA对CHL细胞的GJIC的抑制效应 ,当c9,t11 CLA浓度为 2 0 0 (mol L作用 48h时 ,细胞间隙通讯功能基本上与阴性对照组相近 ;当用c9,t11 CLA作用SGC 790 1细胞和MCF 7细胞2 4h和 48h时 ,可见 (2 4h 10 0 μmol L的MCF 7细胞 ) 2 4h 2 0 0 μmol L和 48h 10 0、2 0 0 μmol L剂量组的肿瘤细胞有一定的细胞间隙通讯功能。提示c9,t11 CLA可提高SGC 790 1细胞和MCF 7细胞的GJIC的功能 ,并且不同程度的拮抗TPA对CHL细胞GJIC的抑制效应     

β-紫罗兰酮诱导人乳腺癌细胞(ER~+)凋亡作用

目的为了研究β-紫罗兰酮对雌激素阳性的人乳腺癌细胞(MCF-7)凋亡诱导作用的影响。方法采用细胞生长曲线,凋亡细胞的荧光显微镜和电镜观察,TUNEL方法及流式细胞光度术以及Western blot的检测方法,观察了用不同浓度β-紫罗兰酮(25、50、100和200μmol/L)对MCF-7细胞的抑制作用及诱导该细胞产生凋亡情况。结果β-紫罗兰酮可明显抑制MCF-7细胞生长,抑制率分别为6.57%、34.58%、65.22%和81.87%。通过荧光显微镜和电镜技术观察到了MCF-7细胞有凋亡的形态特征;TUNEL(末端脱氧核苷酸转移酶缺口末端标记)方法和流式细胞光度术均检测到β-紫罗兰酮可诱导MCF-7细胞产生凋亡,并随着β-紫罗兰酮浓度的增加,细胞凋亡率逐渐增加。TUNEL凋亡指数(AI)分别为20.74%(24h)和33.15%(48h);流式细胞光度术的凋亡指数(AI)分别为27.96%(24h)和38.59%(48h)。通过Western blotting方法观察到β-紫罗兰酮可对MCF-7的细胞增殖相关蛋白PCNA及bcl-2蛋白表达有明显地抑制作用,呈现明显地剂量-反应关系。结论β-紫罗兰酮可明显地抑制雌激素阳性(ER+)人乳腺癌MCF-7细胞的增殖,并诱导该细胞产生凋亡,其作用机制需要进一步探讨。     

共轭亚油酸对乳腺癌细胞系SKBR 3增殖的抑制作用

目的比较共轭亚油酸(CLA)和亚油酸(LA)对乳腺癌细胞生长的影响,以探讨共轭亚油酸的抗肿瘤作用.方法采用体外培养乳腺癌细胞系SKBR 3,用细胞生长曲线和MTT试验观察细胞的生长状况,透射电镜观察细胞形态学变化,流式细胞仪检测细胞周期.结果细胞生长曲线和MTT试验均表明,CLA对SKBR 3细胞生长有明显的抑制作用,且随着作用浓度和作用时间的增加,抑制作用增强.细胞生长曲线显示,CLA各浓度组(200、100、50 μmol·L-1)作用5 d后抑制率分别为75.0%、57.9%、33.1%;LA各浓度组(200、100、50 μmol·L-1)作用5 d后抑制率分别为38.4%、25.4%、10.1%.电镜观察可见CLA可以引起细胞凋亡,而LA未观察到明显的病理变化.流式细胞仪检测表明,200 μmol·L-1可使细胞周期分布发生明显改变.作用6 d后G1期为72.2%,并出现凋亡峰,而LA组及对照组G1期分别为为56.6%,50.6%.结论 CLA可能通过抑制细胞增殖,诱导细胞凋亡等途径抑制癌症的发展.     

共轭亚油酸对人胃腺癌细胞侵袭能力的影响及其作用机制

研究c9,t11-共轭亚油酸 (CLA)对人胃腺癌细胞 (SGC 790 1)侵袭能力的影响 ,探讨其抑制肿瘤转移的可能机理。用 0、2 5、5 0、10 0和 2 0 0 μmol LCLA处理细胞 2 4h后 ,分别用重组基底膜侵袭实验评价癌细胞侵袭能力 ;PAGE底物酶谱方法检测Ⅳ型胶原酶活性 ;RT PCR方法检测SGC 790 1细胞TIMP 1和TIMP 2mR NA表达。研究结果表明 :c9,t11 CLA处理后 ,SGC 790 1细胞侵袭重组基底膜的能力下降、SGC 790 1细胞培养上清中的Ⅳ型胶原酶活性降低、SGC 790 1细胞中TIMP 1和TIMP 2mRNA的表达增加。因此 ,c9,t11 CLA抑制SGC 790 1细胞侵袭重组基底膜 ,并且c9,t11 CLA的抗侵袭活性与降低肿瘤细胞培养上清中Ⅳ型胶原酶活性和诱导肿瘤细胞TIMP 1和TIMP 2mRNA的表达等有关     

β-紫罗兰酮对人乳腺癌细胞抑制作用

目的　研究 β 紫罗兰酮对人乳腺癌细胞 (MCF 7)生长的影响。 方法　采用细胞核分裂 ,生长曲线 ,集落形成和DNA合成实验 ,观察了用不同浓度 β 紫罗兰酮 (2 5、5 0、10 0和2 0 0 μmol L)对MCF 7细胞生长作用。 结果　β 紫罗兰酮可明显抑制MCF 7细胞增殖、细胞核分裂、集落形成和细胞DNA的合成 ,随着剂量的增加 ,抑制作用增强 ,IC50 值为 10 4 μmol L。细胞核分裂的抑制率分别为 2 4h 12 88%～ 6 8 6 7%。 4 8h 2 0 79%～ 87 79% ;集落形成抑制率分别为 2 4h 14 11%～ 6 5 18% ,4 8h 6 5 8%～ 72 4 8% ;DNA合成实验抑制率为 2 4h 16 75 %～6 5 33% ,4 8h 35 10 %～ 81 89%。结论　β 紫罗兰酮可抑制MCF 7细胞的生长 ,其机制需要进一步探讨。     

神经酰胺诱导人结肠癌细胞凋亡的作用

目的 探讨外源性神经酰胺诱导结肠癌HT-29细胞凋亡的作用。方法 采用噻唑兰(MTT)显色法、荧光显微镜、电镜观察以及通过免疫组化方法检测Fas、P53的表达情况。结果 神经酰胺对HT-29细胞的生长有明显抑制作用，并可诱导HT-29细胞产生凋亡，并随着神经酰胺浓度的增加，细胞凋亡率逐渐增加；Fas蛋白的表达随着神经酰胺浓度的增加呈现逐渐升高的趋势，p53蛋白的表达随着神经酰胺浓度的增加呈现降低的趋势。结论 神经酰胺能诱导HT-29细胞产生凋亡。     

姜黄素诱导人结肠癌细胞凋亡作用

目的探讨姜黄素对人的结肠癌细胞系(HT-29)体外增殖及凋亡的影响。方法采用噻唑蓝(MTT)比色法测定姜黄素在不同浓度对HT-29细胞的抑制作用;利用流式分光光度技术、荧光显微镜技术和电镜技术,观察姜黄素对HT-29细胞诱发凋亡及细胞周期的变化。结果姜黄素可明显抑制HT-29细胞的生长,其抑制率与药物浓度成剂量依赖关系,半数抑制浓度为(15.9±1.96)μmol/L。流式细胞分析仪结果表明,姜黄素能使HT-29在加药后24h出现凋亡峰;荧光显微镜下可见姜黄素处理组织细胞核呈现深染、致密的颗粒块状荧光。电镜观察可见姜黄素能使细胞发生凋亡,出现核边集及染色质浓缩成块状。结论姜黄素可抑制大肠癌细胞的生长,其机制可能与诱导细胞凋亡有关。     

共轭亚油酸对人乳腺癌细胞生长的抑制作用

目的 研究共轭亚油酸（c9,t11-CLA)对人乳腺癌细胞（MCF－7）生长的影响。方法 采用细胞核分裂指数、细胞生长曲线、细胞集落形成试验、^3H-TdR掺入试验和软琼脂培养方法,所设剂量（μmol/L）为25,50,100,200,以96％乙醇为溶剂对照。结果 在细胞核分裂指数、细胞生长曲线和细胞集落形成试验中,可见c9,t11-CLA对MCF－7细胞生长有明显的抑制作用,其作用于MCF－7细胞8d后的抑制率（％）分别为27．18、35．43、91．05和92．86;在^3H-TdR掺入试验中,可见随着c9,t11-CLA剂量的增加,^3H-TdR掺入到MCF－7细胞中明显的减少,与阴性对照组相比差异有显性;由软琼脂培养试验结果可见,随着c9,t11-CLA剂量的增加,MCF－7细胞的集落形成逐渐降低,除了25 μmol/L剂量组外与阴性对照组相比差异有显性。结论 c9,t11-CLA对MCF－7细胞的生长有明显的抑制作用。     

Effects ofcis-9,trans-11-conjugated linoleic acid on cancer cell cycle

Objectives To determine the effect of cis-9, trans-11-conjugated linoleic acid on the cell cycle of mammary cancer cells (MCF-7) and its possible mechanism of inhibition cancer growth. Methods Using cell culture and immunocytochemical techniques, we examined the cell growth, DNA synthesis, expression of PCNA, cyclin A, B₁, D₁, p16^ink4a and p21^cip/wafl of MCF-7 cells which were treated with various c9, t11-CLA concentrations (25 mM, 50 mM, 100 mM and 200 mM) of c9, t11-CLA for 24 and 48 h, with negative controls (0.1% ethanol). Results The cell growth and DNA synthesis of MCF-7 cells were inhibited by c9, t11-CLA. MCF-7 cells, after treatment with various c9, t11-CLA doses mentioned above for 8 days, the inhibition frequency was 27.18%, 35.43%, 91.05%, and 92.86%, respectively and the inhibitory effect of c9, t11-CLA on DNA synthesis (except for 25 mM, 24 h) incorporated significantly less³H-TdR than did the negative control (P<0.05 andP<0.01). To further investigate the influence on the cell cycle progression, we found that c9, t11-CLA may arrest the cell cycle of MCF-7 cells. Immunocytochemical staining demonstrated that MCF-7 cells preincubated in media supplemented with different c9, t11-CLA concentrations at various times significantly decreased the expressions of PCNA, and Cyclin, A, B₁, D₁ compared with the negative controls (P<0.01), whereas the expressions of p16^ink4a and p21^cip/wafl, cyclin-dependent kinases inhibitors (CDKI), were increased. Conclusions The cell growth and proliferation of MCF-7 cells is inhibited by c9, t11-CLA by blocking the cell cycle, which reduces expressions of cyclin A, B₁, D₁ and enhances expressions of CDKI (p16^ink4a and p21^cip/wafl).     

Conjugated linoleic acid (CLA)-enriched milk fat inhibits growth and modulates CLA-responsive biomarkers in MCF-7 and SW480 human cancer cell lines

Milk enriched in conjugated linoleic acid (CLA) was obtained from cows on pasture supplemented with full-fat rapeseeds (FFR; 2.26 g cis 9, trans 11 (c9,t11)-CLA/100 g fatty acid methyl esters) and full-fat soyabeans (1.83 g c9,t11-CLA100 g fatty acid methyl esters). A control milk fat (1.69 g c9,t11-CLA/100 g fatty acid methyl esters) was obtained from cows fed on pasture only. The present study assessed the potency of the CLA-enriched milk fats to modulate biomarkers that had previously been observed to respond to c9,t11-CLA in the MCF-7 and SW480 cell lines. Cell numbers decreased (P<0.05) by up to 61 and 58% following the incubation of MCF-7 and SW480 cells, respectively, for 4 d with milk fats (yielding CLA concentrations between 60.2 and 80.6 microM). The FFR milk fat, containing the highest CLA content, increased (P<0.05) [14C]arachidonic acid (AA) uptake into the monoacylglycerol fraction of MCF-7 and SW480 cells while it decreased (P<0.05) uptake into the phospholipid fraction of the latter. This milk fat also decreased (P<0.05) [14C]AA conversion to prostaglandin (PG) E2 while increasing conversion to PGF2alpha in both cell lines. All milk-fat samples increased (P<0.05) lipid peroxidation as measured by 8-epi-PGF2alpha in both cell lines. In SW480 cells the milk-fat samples decreased (P<0.05) bcl-2 and cytosolic glutathione levels while increasing (P<0.05) membrane-associated annexin V levels. All milk-fat samples decreased (P<0.05) the expression of ras in SW480 cells. These data suggest that milk-fat CLA was effective at modulating synthetic CLA-responsive biomarkers.     

共轭亚油酸对肿瘤细胞亚油酸代谢途径中限速酶的影响

目的采用体外细胞培养方法,研究不同浓度c9,t11-共轭亚油酸(c9,t11-CLA)对人胃腺癌细胞(SGC-7901)中亚油酸代谢途径的限速酶的影响。方法用200、100、50和25μmol／L浓度的c9,t11-CLA处理SGC-7901细胞24h,四甲基偶氮唑盐实验检测c9,t11-CLA对SGC-7901细胞增殖的抑制作用,采用逆转录聚合酶链反应检测c9,t11-CLA对SGC-7901细胞中亚油酸代谢途径的Δ6-脱氢酶、△5-脱氢酶、环氧合酶(COX)-1、COX-2和5-脂氧合酶(5-LOX)mRNA表达的影响。结果在200、100、50和25μmol／L浓度时,c9,t11-CLA对SGC-7901增殖的抑制率分别为54．3％、20．5％、10．5％、2．93％;均可下调COX-2mRNA的表达,上调Δ6-脱氢酶、COX-1mRNA的表达,但对Δ5-脱氢酶和5-LOXmRNA表达的影响不显著。结论c9,t11-CLA可通过调节Δ6-脱氢酶和COX的表达抑制肿瘤细胞的增殖,说明c9,t11-CLA通过影响亚油酸代谢途径中限速酶的基因表达而改变类二十碳烷酸的形成,推测c9,t11-CLA影响肿瘤细胞中亚油酸代谢途径的限速酶是其发挥抗癌活性的另一作用机制。     

共轭亚油酸对人胃腺癌细胞侵袭及转移相关基因表达的影响

目的 研究c9,t11－共轭亚油酸（CLA）对人胃腺癌细胞（SGC－7901）侵袭能力的影响,探讨其抑制肿瘤转移的可能机制。方法 用重组基底膜侵袭实验评价癌细胞侵袭能力;用逆转录聚合酶链反应（RT－PCR）检测SGC－7901细胞中组织基质金属蛋白酶抑制剂（TIMP）－1、TIMP－2和nm23-H1mRNA的表达。结果 在200、100和50μmol/L浓度时,c9,t11-CLA对SGC－7901细胞侵袭重组基底膜的抑制率分别为53.7%、40.9%和29.3%。c9,t11-CLA可诱导SGC－7901细胞中TIMP－1、TIMP－2和nm23-H1mRNA的表达。结论 c9,t11-CLA抑制SGC-7901细胞侵袭重组基底膜。c9,t11-CLA的抗侵袭活性与诱导肿瘤细胞中TIMP－1、TIMP－2和nm23-H1mRNA的表达等有关。     

Conjugated linoleic acid inhibits cell proliferation through a p53-dependent mechanism: effects on the expression of G1-restriction points in breast and colon cancer cells

Previous reports have documented the antiproliferative properties of a mixture of conjugated isomers (CLA) of linoleic acid [LA (18:2)]. In this study, we investigated the mechanisms of CLA action on cell cycle progression in breast and colon cancer cells. Treatment with CLA inhibited cell proliferation in breast cancer MCF-7 cells containing wild-type p53 (p53(+/+)). At cytostatic concentrations, CLA elicited cell cycle arrest in G1 and induced the accumulation of the tumor suppressors p53, p27 and p21 protein. Conversely, CLA reduced the expression of factors required for G1 to S-phase transition including cyclins D1 and E, and hyperphoshorylated retinoblastoma Rb protein. In contrast, the overexpression of mutant p53 (175Arg to His) in MFC-7 cells prevented the CLA-dependent accumulation of p21 and the reduction of cyclin E levels suggesting that the expression of wild-type p53 is required for CLA-mediated activation of the G1 restriction point. To further elucidate the role of p53, the effects of CLA in colon cancer HCT116 cells (p53(+/+)) and p53-deficient (p53(-/-)) HCT116 cells (HCTKO) were examined. The treatment of HCT116 cells with CLA increased the levels of p53, p21, p27 and hypophosphorylated (pRb) protein and reduced the expression of cyclin E, whereas these effects were not seen in p53-deficient HCTKO cells. The t10,c12-CLA isomer was more effective than c9,t11-CLA in inhibiting cell proliferation of MCF-7 breast cancer cells and enhancing the accumulation of p53 and pRb. We conclude that the antiproliferative properties of CLA appear to be a function, at least in part, of the relative content of specific isomers and their ability to elicit a p53 response that leads to the accumulation of pRb and cell growth arrest.     

trans-11 18:1 Vaccenic Acid (TVA) Has a Direct Anti-Carcinogenic Effect on MCF-7 Human Mammary Adenocarcinoma Cells

Trans vaccenic acid (TVA; trans-11 18:1) is a positional and geometric isomer of oleic acid and it is the predominant trans isomer found in ruminant fats. TVA can be converted into cis-9, trans-11 conjugated linoleic acid (c9, t11-CLA), a CLA isomer that has many beneficial effects, by stearoyl CoA desaturase 1 (SCD1) in the mammary gland. The health benefits associated with CLA are well documented, but it is unclear whether trans fatty acids (TFAs) from ruminant products have healthy effects. Therefore, the effects of TVA on the proliferation of MCF-7 human breast adenocarcinoma cells and MCF-10A human breast epithelial cells were investigated in the present study. Results showed that TVA inhibited the proliferation of MCF-7 cells but not MCF-10A cells by down-regulating the expression of Bcl-2 as well as procaspase-9. In addition, the suppressive effect of TVA was confirmed in SCD1-depleted MCF-7 cells. Our results suggested that TVA exerts a direct anti-carcinogenic effect on MCF-7 cells. These findings provided a better understanding of the research on the anti-carcinogenic effects of TVA and this may facilitate the manufacture of TVA/c9, t11-CLA fortified ruminant products.     

FTY720对人乳腺癌MCF-7细胞、喉癌Hep-2细胞增殖的影响

目的:探讨FTY720抑制人乳腺癌MCF-7细胞和喉癌Hep-2细胞增殖作用。方法:将人乳腺癌MCF-7细胞和喉癌Hep-2细胞用不同浓度FTY720作用48 h,MTT法检测细胞活性,流式细胞术检测其对细胞周期及凋亡率的影响。结果:MTT结果显示,FTY720对乳腺癌MCF-7细胞和喉癌Hep-2细胞增殖均有抑制作用,而且对喉癌Hep-2细胞抑制作用的浓度依赖性高于对乳腺癌细胞的作用;流式细胞术检测结果显示,FTY720可将乳腺癌MCF-7细胞阻滞于G1期,将喉癌Hep-2细胞阻滞于G2/M期,并明显促进乳腺癌MCF-7细胞凋亡。结论:一定浓度的FTY720能明显抑制体外培养的乳腺癌和喉癌细胞增殖,调节其细胞周期,诱导乳腺癌MCF-7细胞凋亡。