丁酸钠对人乳腺癌细胞株MCF-7细胞增殖及p27^kip1蛋白表达影响的研究

目的：通过观察组蛋白去乙酰化酶抑制剂（histon—deacetylase inhibitors，HDACIs）丁酸钠（sodium butyrate，NaB）对人乳腺癌细胞株MCF-7细胞的增殖影响以及p27^kip1蛋白表达改变，探讨NaB调控乳腺癌细胞增殖的分子机制。方法：乳腺癌MCF-7细胞经不同浓度NaB作用后，相差显微镜观察细胞形态变化和细胞增殖情况，流式细胞仪分析细胞周期分布，免疫组化检测p27^kip1蛋白表达。结果：NaB对MCF-7细胞有显著的增殖抑制作用，呈时间剂量依赖性，处理后的MCF-7细胞出现凋亡形态变化；细胞周期阻滞于（G0／G1期，NaB2 mmol／L组G0／G1，期达（62．2±2．2）％，4mmol／L组G0/G1，期达（78．1±3．8）％，空白组G0／C0期达（53．1±2．4）％，P〈0．05；p27蛋白表达水平上调。结论：NaB可抑制乳腺癌细胞的生长，该作用可能与p27蛋白表达增加有关。     

青蒿琥酯对乳腺癌MCF-7细胞株增殖功能及形态结构的影响

目的探讨青蒿琥酯（Artesunate,ART）对乳腺癌MCF-7细胞株的增殖、分化功能及细胞形态和结构的影响。方法ART作用乳腺癌MCF-7细胞后,采用MTT（四唑盐）比色法检测细胞增殖功能,观察细胞形态和结构的改变,流式细胞仪分析细胞周期相分布及细胞凋亡率。统计学分析采用重复测量设计资料的方差分析。结果ART对乳腺癌细胞MCF-7有抑制作用,随浓度增加和时间延长抑制作用增强（P〈0．05）,呈浓度依赖及时间依赖,并可导致细胞形态和结构的改变,抑制MCF-7细胞增殖,阻滞MCF-7细胞于S期和G2／M期。6 μmol／L和8 μmol／LART诱导MCF-7细胞的凋亡率分别为3．15％和8．43％。结论ART可导致MCF-7细胞形态的改变,抑制MCF-7细胞增殖和生长,阻滞MCF-7细胞于S期和G2／M期,并有诱导细胞凋亡的作用。     

三羟异黄酮对人乳腺癌MCF-7/ADM细胞体外抑瘤效应、细胞周期及凋亡的影响

 目的探讨三羟异黄酮（Genistein GEN）对体外培养人乳腺癌耐药细胞MCF-7/ADM抑瘤作用、细胞周期及细胞凋亡的影响。方法采用MTT法检测GEN单独及联合阿霉素对体外培养人乳腺癌MCF-7/ADM细胞的抑制作用;荧光分光光度法检测GEN对阿霉素在MCF-7/ADM细胞的蓄积作用;用流式细胞仪（FCM）检测细胞周期及凋亡率的变化。结果GEN单独及联合阿霉素对体外培养MCF-7/ADM细胞均有明显生长抑制作用,GEN单独作用48 h后表现为随时间的延长抑制作用明显增强,当GEN浓度达到60 μg/ml时,其抑制作用急剧上升（P<0.01）。联合阿霉素后与对照组相比抑制率明显上升（P<0.01）,并随GEN浓度的加大其抑制作用增强,细胞内阿霉素的浓度也随之升高。与对照组相比,细胞周期均有G2/M期阻滞作用,细胞凋亡百分比以联合组最高（P<0.01）,G₁期前出现典型的亚二倍体凋亡峰。结论GEN单独及联合阿霉素对体外培养人乳腺癌MCF-7/ADM细胞具有抑瘤增效作用,可以提高阿霉素在MCF-7/ADM细胞内的蓄积、对细胞周期具有G₂/M期阻滞作用,显著诱导MCF-7/ADM细胞凋亡,可能是其发挥逆转多药耐药分子生物学机制之一。     

格尔德霉素衍生物G0705的抗肿瘤作用及分子机制

目的格尔德霉素（Geldanamycin）属于苯醌胺莎类抗生素,其作用靶点为热休克蛋白90（Heat Shock Protein HSP90）,细胞水平实验表明格尔德霉素对肿瘤细胞有明显的杀伤作用,但动物实验中发现格尔德霉素具有肝毒性,而且水溶性很差。这些问题限制了格尔德霉素在动物实验的疗效。近年来,寻找溶解性好、肝脏毒性低的格尔德霉素衍生物成为新的研究热点。其中17-AAG和17-DMAG已经开始进行Ⅰ、Ⅱ期临床实验。G0705为本实验室合成的格尔德霉素衍生物。本实验研究了G0705对乳腺癌MCF-7细胞株的抗细胞增殖作用、诱导细胞凋亡作用及其对HSP90下游相关靶点及其下游信号分子的影响。方法采用MTT法测定G0705对乳腺癌MCF-7细胞的抗增殖作用。用Hoechst33258染色法、Hoechst-PI双染色法、活细胞Annexin-FITC／PI双染法测定G0705诱导MCF-7细胞早期凋亡作用。用Western blot测定G0705对MCF-7细胞中HSP90下游相关靶点及其下游信号分子的影响。结果MTT法测定G0705抑制乳腺癌MCF-7细胞增殖的IC50值为13．6μg／ml。Hoechst33258染色法、Hoechst-PI双染色法结果表明,使用G0705不同浓度0．0001mg/ml、0．001mg／ml、0．01mg／ml,细胞凋亡数量随浓度增高而明显增加,且呈剂量依赖性。活细胞Annexin-FITC／PI双染法检测表明,G0705浓度0．01mg／ml在给药24h后细胞早期凋亡率为7．79％,48h后细胞早期凋亡率35．85％,对照组则分别为2．44％和5．88％。与对照组相比G0705诱导MCF-7细胞的凋亡作用明显。Western blot法的结果表明,G0705不同浓度0．0001mg／ml、0．001mg／ml、0．01mg／ml,在给药48h后AKT、RAF-1、EGFR、HER-2等的蛋白水平均有明显降低,且呈剂量依赖性。结论实验结果显示G0705对乳腺癌MCF-7细胞有一定的增殖抑制作用。G0705可诱导MCF-7细胞凋亡,其诱导的细胞凋亡作用呈现明显的剂量依赖性和时间依赖性。G0705?     

致康胶囊对人乳腺癌MCF-7细胞增殖及凋亡的影响

目的:探讨致康胶囊对人乳腺癌细胞系MCF-7增殖及凋亡的影响。方法:采用0（对照组）、0.5、1.0、2.0 mg/ml 致康胶囊培养液分别处理乳腺癌细胞MCF-7,分别于培养后24、48和72 h计数MCF-7细胞数。采用MTT法检测致康胶囊对乳腺癌MCF-7细胞生长增殖的影响;采用流式细胞仪检测细胞周期;PI 单染流式细胞仪检测致康胶囊对MCF-7细胞凋亡的影响。结果:不同浓度致康胶囊能有效地抑制MCF-7细胞增殖,且随浓度增加和作用时间延长,细胞的增殖抑制率增加。0.5、1.0、2.0 mg/ml的致康胶囊作用MCF-7细胞72 h后,G0/G1期细胞所占细胞周期的比例分别为19.33%±10.38%、14.12%±5.37%和26.84%±2.13%;而对照组G0/G1期比例为51.83%±1.90%。0.5、1.0、2.0 mg/ml致康胶囊处理48 h后细胞的凋亡率分别为2.09%±0.74%、3.84%±0.78%和 5.35%±0.83%。结论:致康胶囊能抑制MCF-7细胞的体外增殖,且抑制作用表现为时效和量效关系;并能通过阻滞细胞周期于G2/M期,促进乳腺癌细胞凋亡。     

GCS在人乳腺癌细胞多药耐药中的作用及与P-gP的关系

目的探讨葡萄糖神经酰胺合成酶（GCS）在人乳腺癌细胞多药耐药中的作用及其与P-糖蛋白（P-gP）的关系。方法采用MTT法检测多柔比星（阿霉素）对人乳腺癌耐药细胞株MCF-7／Adr和敏感株MCF-7的抑制率和IC50。以GCS抑制剂D，L-threo-1-phenyl-2-decanoyl—amino-3-morpholino-1-propanol（PDMP）预处理MCF-7／Adr后检测抑制率和IC50。运用流式细胞术（FCM）检测人MCF-7及MCF-7／Adr中GCS、P-gp的表达，以PDMP预处理细胞后检测GCS、P-gP的表达。FCM法检测细胞中ADM的荧光强度。结果MCF-7／Adr对MCF-7的耐药倍数为22．7倍，PDMP作用后阿霉素对MCF-7／Adr的抑制率升高，IC50下降（P〈0．05）。MCF-7／Adr中GCS和P-gp的表达均高于MCF-7，PDMP使MCF-7／Adr中GCS表达下降（P〈0．05），对P—gp表达无明显影响（P〉0．05）。FCM检测显示PDMP可使阿霉素在MCF-7内潴留增多。结论GCS在MCF-7／Adr多药耐药中起重要作用，PDMP能影响P-gP功能，GCS与P-gP有-定关系。     

褪黑素对阿霉素抗雌激素受体阴性乳腺癌细胞MDA—MB-231作用的影响及其机制

目的探讨生理浓度（10^-9mol／L）褪黑素和药理浓度（10^-5moL／L）褪黑素对阿霉素抑制雌激素受体阴性乳腺癌细胞MDA-MB-231作用影响及其机制。方法（1）应用四甲基偶氮唑蓝（Mar）法检测经不同浓度褪黑素孵育后阿霉素对MDA—MB-231的抑制率和IC50变化。（2）应用流式细胞学方法观察不同浓度褪黑素、阿霉素以及两药联用时对MDA-MB-231细胞周期分布和凋亡的影响。（3）应用western blot法检测不同浓度褪黑素、阿霉素单药和两药联用对MDA—MB-231细胞p53和bcl-2蛋白表达的影响。结果（1）阿霉素对乳腺癌MDA—MB-231细胞具有明显的抑制作用,且呈剂量时间依赖性。IC50值为（1．00±0．09）μg／ml,经生理浓度和药理浓度褪黑素孵育后IC50分别降为（0．85±0.06）μg／ml和（0．47±0．03）μg／ml,前者与孵育前相比未,差异无统计学意义（P〉0．05）,后者相比差异无统计学意义（P〈0．01）。（2）流式细胞学检测结果显示,阿霉素对细胞MDA．MB-231有凋亡促进作用,随浓度增高凋亡率未见增加（P〉0．05）。生理浓度褪黑素联合阿霉素与相应浓度的阿霉素单药相比,凋亡率未见明显增加（P〉0．05）。药理浓度褪黑素联合阿霉素与相应浓度阿霉素单药比较,凋亡率明显提高（P〈0．05）,但联合组随着阿霉素浓度增加凋亡率并未见明显变化（P〉0．05）。（3）MDA-MB-231乳腺癌细胞株中呈p53蛋白低表达、bcl-2蛋白高表达。药理浓度褪黑素可显著增高细胞p53蛋白并降低bcl-2蛋白表达（P〈0．01）。药理浓度褪黑素联合不同浓度阿霉素对两蛋白表达未见显著性差异（P〉0．05）;阿霉素对两种蛋白表达未见明显影响（P〉0．05）。结论（1）生理浓度褪黑素（10^-9mol／L）对阿霉素的抗雌激素受体阴性乳腺癌细胞作用未见明显影响,药理浓度（10^-9mol／L）以上褪黑素表现出对阿霉素明显的增敏作用。（2）阿霉素较低浓度时,凋亡促进作用可能是褪黑素对其增敏机制的一部分,随着阿霉素浓度的提高,褪黑素的细胞毒增敏机制可能占主要地位。（3）药理浓度褪黑素能提高雌激素受体阴性乳腺癌细胞p53蛋白表达并降低bcl-2蛋白表达,并具有剂量依赖性。涉及p53和bcl-2的凋亡通路可能是褪黑素对阿霉素增敏机制的一部分。     

瘦素对人类乳腺癌细胞MCF-7增殖及凋亡的影响

 目的 观察不同浓度瘦素对人类乳腺癌细胞MCF-7增殖及凋亡的影响,探讨瘦素在乳腺癌发生及发展中的作用。方法 采用四甲基偶氮唑蓝（MTT）比色法检测不同浓度瘦素对体外培养的MCF-7细胞生长的增殖作用,流式细胞术分析细胞周期的分布, Annexin V-FITC／PI染色法检测细胞凋亡。结果 MTT比色法结果显示：不同浓度瘦素作用24、48、72 h能够促进MCF-7细胞增殖,浓度与时间不存在交互作用（F＝0.919,P＝0.523）,浓度及时间各自的主效应均差异有统计学意义（F＝12.699,P＝0.000; F＝647.881,P＝0.000）。多重比较结果显示：200　ng／ml及400　ng／ml瘦素组与对照组相比差异有统计学意义（P＝0.007;P＝0.000）,不同时间段之间均差异有统计学意义（P＝0.000）。流式细胞术分析显示100、400 ng／ml瘦素作用48 h后,G0／G1期细胞比例下降14.42 %（F＝10.464,P＝0.044）,S期比例分别上升7.57 %、22.19 %（F＝47.361,P＝0.005）,G2／M期变化差异无统计学意义（F＝1.77,P＝0.311）。未发现瘦素对MCF-7细胞早期凋亡的抑制作用。结论 瘦素能够促进乳腺癌细胞MCF-7的增殖并改变生长周期,但不会抑制凋亡,提示瘦素可能在乳腺癌的发展中发挥促进作用。     

PCNA的表达与人乳腺癌细胞凋亡的关系

目的：研究增殖细胞核抗原（PCNA）的表达与人乳腺癌细胞凋亡的关系。方法：以乳腺癌细胞株MCF-7／S（化疗敏感细胞株）为研究对象，应用MTT比色法检测阿霉素（ADR）对体外培养的MCF-7／S细胞增殖抑制作用，末端标记（TUNEL）法检测ADR诱导乳腺癌细胞凋亡，免疫细胞化学法检测ADR作用前后PCNA的表达。结果：ADR抑制MCF-7／S细胞增殖，旱剂量依赖性，IC50为0．128mg／L；ADR作用组MCF-7／S细胞的凋亡率（Apoptoticrate，AR）为0．261，与对照组细胞的凋亡率0．0449相比明显增高（P〈0．01）；PCNA阳性表达率为0．3371，与对照组PCNA阳性表达率0．5152相比明显降低（P〈0．01）。结论：乳腺癌肿瘤细胞的凋亡率（AR）和PCNA的阳性表达呈负相关；ADR能诱导MCF-7／S细胞凋亡，并能抑制其增殖。     

乳腺癌细胞耐药过程中p38MAPK活性与细胞凋亡的关系

目的研究乳腺癌细胞耐药过程中p38MAPK活性与细胞凋亡的关系,探讨p38MAPK信号转导途径在其中的作用。方法 以p38MAPK特异性抑制剂SB203580处理乳腺癌耐药细胞MCF-7／ADM,采用流式细胞技术分析对细胞凋亡的影响;MTT检测MCF-7／ADM细胞对阿霉素的半数药物抑制浓度（IC50）;Western blot检测SB203580处理MCF-7／ADM和MCF-7两株细胞后p38MAPK蛋白表达水平;RT—PCR检测细胞内MDR-1 mRNA水平。结果SB203580（10μmol／L）干预24h后MCF-7／ADM细胞的凋亡率为（26．73±4．90）％,与未干预组和对照组凋亡率相比差异有显著统计学意义（F=143．80,P〈0．001）;MCF-7／ADM细胞对阿霉素的敏感性明显提高（F=148927．10,P〈0．001）,相对逆转率达68．45％;与对照组和未干预组相比,干预组的MDR1 mRNA（F=9139．24,P〈0．001）及p38MAPK（F=685．42,P〈0．001）蛋白表达水平明显降低。结论p38MAPK信号转导途径与乳腺癌耐药密切相关,其可能机制为p38MAPK保护人乳腺癌耐药细胞（MCF-7／ADM）逃避凋亡,阻断该通路可增强乳腺癌耐药细胞发生凋亡。     

Idarubicin and idarubicinol effects on breast cancer multicellular spheroids

Despite extensive preclinical evaluation in several experimental models, no studies have determined the effect of idarubicin and its metabolite idarubicinol on multicellular spheroids, a model which mimics the microregions of solid tumors. The principal aim of the present study was to investigate the in vitro cytotoxicity of idarubicin and its metabolite idarubicinol on MCF-7 breast cancer cells growing as monolayers or multicellular spheroids and to evaluate the influence of the length of exposure on the cytotoxic effect of both drugs. Cytoxicity was evaluated on monolayer and spheroid cultures exposed to idarubicin and idarubicinol 0.01-1000 ng/ml for 24 h or treated for 6, 12, 24 and 48 h to 100 ng/ml of both drugs. The IC50 of idarubicin and idarubicinol were 3.3+/-0.4 and 3.6+/-0.7 ng/ml, respectively, on MCF-7 monolayers and 7.9+/-1.1 and 5.3+/-0.7 ng/ml in multicellular spheroids, respectively. The antiproliferative effects of 100 ng/ml idarubicin and idarubicinol on MCF-7 spheroids was characterized by a marked time-dependence, which was less evident on MCF-7 growing as monolayer. In conclusion, the present experimental data demonstrate, for the first time, that idarubicin and idarubicinol have significant cytotoxic activity against multicellular spheroids, comparable to the antiproliferative effects on monolayer cells. In contrast, spheroids displayed substantial resistance after short exposure times that was not present in the two dimensional cultures.     

Idarubicin and Idarubicinol Effects on Breast Cancer Multicellular Spheroids

Abstract

Despite extensive preclinical evaluation in several experimental models, no studies have determined the effect of idarubicin and its metabolite idarubicinol on multicellular spheroids, a model which mimics the microregions of solid tumors. The principal aim of the present study was to investigate the in vitro cytotoxicity of idarubicin and its metabolite idarubicinol on MCF-7 breast cancer cells growing as monolayers or multicellular spheroids and to evaluate the influence of the length of exposure on the cytotoxic effect of both drugs. Cytoxicity was evaluated on monolayer and spheroid cultures exposed to idarubicin and idarubicinol 0.01-1000 ng/ml for 24 h or treated for 6, 12, 24 and 48 h to 100 ng/ml of both drugs. The IC₅₀ of idarubicin and idarubicinol were 3.3±0.4 and 3.6±0.7 ng/ml, respectively, on MCF-7 monolayers and 7.9±1.1 and 5.3±0.7 ng/ml in multicellular spheroids, respectively. The antiproliferative effects of 100 ng/ml idarubicin and idarubicinol on MCF-7 spheroids was characterized by a marked time-dependence, which was less evident on MCF-7 growing as monolayer. In conclusion, the present experimental data demonstrate, for the first time, that idarubicin and idarubicinol have significant cytotoxic activity against multicellular spheroids, comparable to the antiproliferative effects on monolayer cells. In contrast, spheroids displayed substantial resistance after short exposure times that was not present in the two dimensional cultures.     

Resistance of MGH-U1 bladder cancer spheroids to vincristine.

We compared the cytotoxicity of vincristine in MGH-U1 human bladder cancer cells growing as exponential monolayer culture, spheroids and xenografts. Cells treated as spheroids were resistant to vincristine as determined by clonogenic survival and growth delay. The spheroid population had a smaller proportion of cells in G2 + M than monolayer cells. Cell derived from increasing depths of the spheroid viable rim had similar cell cycle distribution characteristics and sensitivity to vincristine. Prolonged treatment of spheroid did not increase vincristine cytotoxicity significantly. When cells derived from spheroids were treated as monolayers, the cytotoxicity was the same as that of cells maintained as monolayer cultures. The vincristine resistance observed in spheroids was also observed in xenografted tumours treated in vivo. Vincristine decreased the clonogenic survival of xenografted cells at in vivo doses which were greater than the LD10 for the mice. The in vitro cytotoxicity of the xenografted tumours at these lethal doses was similar to that of cells treated as spheroids. We conclude that vincristine resistance in spheroids may be attributed in part to the small proportion of cells traversing mitosis but not to the development of intrinsic resistance by passage through spheroid growth. Our results are consistent with cell cycle kinetics and limited penetration contributing to vincristine resistance in spheroids. The spheroid system can serve as a model of in vivo cytotoxicity for antineoplastic agents with cell cycle phase specificity such as vincristine.     

微囊化肿瘤细胞生长及其基因表达的研究

目的：以人乳腺癌细胞系（MCF-7）为模型，探讨肿瘤细胞在微囊化环境中的生长特性和对基因表达的影响。方法：使用大功率高压脉冲微胶囊制备仪制备微囊化MCF-7细胞，观察细胞的生长和代谢特性；待微囊内的细胞体外生长成团后固定、石蜡包埋、制作连续切片，HE染色并免疫组化检测HIF-1、cyclin D1、VEGF、p53、PCNA、BrdU等相关基因的表达。以平面培养细胞做对照。结果：人乳腺癌细胞微囊化后可继续生长增殖并聚集成团，同时消耗葡萄糖产生乳酸。微囊化肿瘤细胞表现出较强的增殖活性；当微囊内的细胞团增大到一定程度时中心可出现坏死区，但分布于团块外层的细胞仍具有增殖活性；HIF-1和cyclin D1主要在位于细胞团内部的细胞表达；VEGF的表达与细胞所处位置无关；未检测到p53的阳性表达。平面培养MCF-7细胞可检测到PCNA和VEGF的表达。结论：微囊化肿瘤细胞呈三维立体方式生长并存在相关基因的表达，是一种介于体外单层培养和体内移植瘤试验之间的新型肿瘤细胞特性研究、抗肿瘤药物筛选的模型，具有简单、方便和经济等特点。     

MCF-7 breast cancer cells grown as multicellular spheroids in vitro: effect of 17 beta-estradiol.

To obtain multicellular spheroids from MCF-7 human breast cancer cells we adhered to the following procedure: (a) limiting the adherence of cell to the substratum; (b) seeding more than the minimum number of cells; (c) guaranteeing the presence of estrogens in the culture medium. Charcoal-dextran (CD)-treated sera seemed to inhibit spheroid formation. A reduction in the concentration of CD-human sera (from 10% to 5%) added to phenol-red-free medium facilitated progress from cellular aggregates to multicellular spheroids. Once the spheroids became initiated, size increased at a rate that showed a good fit to a Gompertzian equation (A = 0.368 +/- 0.067 alpha = 0.065 +/- 0.013, r range = 0.890-0.989). Three different patterns of spheroid morphology and proliferative kinetic were defined: (a) spheroids with diameter less than 200 microns had a constant pattern of heterogeneity in the distribution of 3H-TdR-labelled cells and in the expression of estrogen receptors; (b) spheroids 250 to 700 microns in diameter showed a decrease in the proportion of 3H-TdR-labelled cells accompanying inward progression (50% in the outer shell, less than 10% in a cell layer located at a depth of 150 microns) while, at a depth of 170 microns, of signs of concurrent cellular degeneration and death were apparent; and (c) spheroids with a diameter of greater than 750 microns showed a crust of viable cells uniformly labelled with thymidine without impairment of the proportion of labelled cells when progressing inward from the spheroid crust. The larger the spheroid volume, the lower its growth fraction and the longer its volume doubling time. The hormone-dependence of MCF-7 cells in forming multicellular spheroids represents a unique experimental model for assessing estrogen action on cell organization and proliferation.     

Effects of nIFN β and rifn γ on growth and morphology of two human melanoma cell lines: Comparison between two-and three-dimensional culture

We compared the anti-proliferative effects of natural inter-feron β (nIFN β) and recombinant interferon γ (HFN γ) on 2 human melanoma cell lines, IGRI and SK-Me128, grown in 2-dimensional monolayer and in 3-dimensional spheroid culture. In monolayer culture, growth of both lines was inhibited in a dose-dependent manner by 5-day treatments with IFN in concentrations ranging between I and 5,000 IU/ml. Incubations with 120 IU/ml nIFN βor 25 IU/ml rIFN γ led to a 50% growth inhibition of IGRI cells. A 50% growth inhibition of SK-Me128 cells was obtained with 60 IU/ml nIFN β, whereas even 5,000 IU/ml rIFN γ inhibited the growth of this line by only 30%. Growing these melanoma cell lines in 3-dimensional spheroid culture for 5 days reduced their sensitivity to interferon. Growth inhibition values of 50% were achieved with 3,000 IU/ml rIFN γ or 9,000 IU/ml nIFN β for IGRI spheroids and 10,000 IU/ml nIFN β for SK-Me128 spheroids, while 10,000 IU/ml rIFN γ reduced the growth of SK-Me128 spheroids by only 25%. Outgrowth tests showed that the proliferative capacity after 5-day incubations with IFN was only reduced in IGRI spheroids treated with high doses of nIFN β. The macroscopically observed increased density of interferon-treated spheroids could be confirmed by light microscopy as corresponding to reduced intercellular space in these spheroids. Scanning electron microscopy furthermore showed variations on the surface of IFN-treated spheroids as well as in cellular organization and structures between cells, hinting at a possible involvement of extracellular matrix substances in the reaction to interferons. These findings show that the high anti-proliferative sensitivity of the melanoma cell lines in monolayer culture could not be achieved in spheroid culture. The volume decreases seen in the presence of interferon might be, at least in part, due to an increased packing density in combination with changes in the cellular organization of interferon-treated spheroids, rather than to direct antiproliferative effects.     

卵巢癌多细胞球体对紫杉醇耐药及其机制的探讨

背景和目的:多细胞球体(multicellularspheroids,MCS)对传统细胞毒化疗药物的敏感性明显低于单层细胞。本实验旨在探讨卵巢癌MCS耐药的分子机制。方法:以单层细胞为对照,以三维培养方法获得的人卵巢癌A2780MSC和CAOV3MCS为模型,采用台盼蓝拒染法比较紫杉醇对单层细胞和MCS生长的抑制作用,流式细胞仪比较单层细胞和MCS细胞周期的分布和细胞凋亡率;采用流式细胞仪、蛋白质免疫印迹法、激光共聚焦显微镜检测单层细胞及MCS的P-糖蛋白(P-glycoprotein,P-gp)表达及亚细胞分布;采用RT-PCR法检测mdr1mRNA表达水平。结果:(1)不同浓度的紫杉醇(0.2、2.0、10.0、20.0μmol/L)作用后,MCS细胞生长抑制率明显低于单层细胞(PA2780=0.003,PCAOV3=0.015);经20.0μmol/L的紫杉醇作用后,单层细胞的细胞凋亡率明显高于MCS,差异有统计学意义(PA2780=0.034,PCAOV3=0.032)。(2)流式细胞仪、蛋白质免疫印迹法、激光共聚焦显微镜检测提示P-gp在单层细胞中不表达,在MCS中表达明显升高(P均<0.05);RT-PCR证实MCS中有mdr1mRNA表达,而单层细胞中未检出其表达。(3)流式细胞仪检测提示将单层细胞培养成MCS时,G0/G1期细胞比率增加,S期和G2/M期细胞比率降低(P均<0.05)。结论:卵巢癌MCS对紫杉醇化疗耐药性增加,其高表达P-gp,并且与G0/G1期细     

毛蚶抗癌蛋白对人乳腺癌细胞MCF-7的生长抑制作用

目的:从毛蚶软体部位中分离出具有一定抗癌活性的毛蚶蛋白组分,研究其对人乳腺癌细胞MCF-7的生长抑制作用。方法:以新鲜毛蚶软体部分为原材料,分离获得毛蚶抗癌蛋白组分(命名为NS);倒置相差显微镜观察不同浓度(50、100、200、400μg/mL)NS组分对MCF-7癌细胞生长的影响,将200μg/mL NS组分作用MCF-7细胞不同时间(12、24、48 h)后,Giemsa染色观察癌细胞及核形态的变化,流式细胞术检测NS组分对MCF-7细胞周期及细胞凋亡的影响,Western blot检测细胞周期及细胞凋亡相关蛋白的表达。结果:与阴性对照组比较,各浓度NS组分对人乳腺癌MCF-7细胞生长均具有明显的抑制作用(P<0.05或P<0.01);倒置相差显微镜下可见200μg/mL NS组分作用MCF-7细胞12 h后,部分细胞收缩变圆、脱落,24、48 h后细胞脱落现象更加明显;Giemsa染色发现,NS组分处理12 h后细胞出现有丝分裂相增加,继而出现多核或核碎裂等现象;流式细胞术检测发现NS组分主要引起细胞G2-M期阻滞;NS处理组凋亡率均较对照组明显升高(P均<0.01),且随着药物作用时间的延长,细胞凋亡比例逐渐增加。Western blot检测发现NS组分作用MCF-7细胞后p53及procaspase-3蛋白表达量均上调。结论:毛蚶抗癌蛋白NS组分体外对人乳腺癌MCF-7细胞的细胞毒作用主要通过引起细胞发生G2-M期阻滞、诱导细胞凋亡实现的,期间伴随p53及procaspase-3蛋白表达上调。     

Wnt信号通路在姜黄素诱导乳腺癌MCF-7细胞凋亡中作用机制

目的 探讨Wnt通路在姜黄素诱导人乳腺癌MCF-7细胞凋亡中的作用机制.方法 将MCF-7细胞培养液随机分为5组,分别加入15、30、60、120μmol/L的姜黄素,对照组不加,培养12,24,48 h后采用CCK-8法检测细胞增殖能力.分A、B两组(剂量组、时间组)采用Annexin V-FITC/PI双染流式细胞术(FCM)观测细胞凋亡及细胞周期分布;Western Blotting法检测A、B两组的Wnt通路相关蛋白,并进行相应的相关性分析探讨Wnt通路与乳腺癌MCF-7细胞凋亡的关系.结果 CCK-8结果显示,随培养时间延长,姜黄素各浓度组MCF-7细胞增殖抑制率逐渐增高(均P<0.05);在同一时间点,随着姜黄素浓度升高,细胞增殖抑制率逐渐增高(均P<0.05).FCM染色结果显示,随着姜黄素浓度增加、作用时间延长MCF-7细胞凋亡指数逐渐上升(均P<0.05),且G1/S期细胞增加越多(P<0.05).Western Blotting实验结果显示MCF-7细胞中Wnt1、β-catenin的表达下调程度呈现剂量时间依赖性(P<0.05).相关性分析显示细胞抑制率、G0/G1期细胞百分比、细胞凋亡率均与Wnt通路相关蛋白Wnt1、β-catenin的表达呈现较明显的相关性(P<0.05).结论 姜黄素的抗癌活性与抗增殖能力具有明显的剂量时间依赖性,且Wnt通路在姜黄素诱导乳腺癌MCF-7细胞抑制、凋亡过程中发挥了重要作用.