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.     

氧化苦参碱诱导人乳腺癌细胞MCF-7凋亡的实验研究

目的　研究氧化苦参碱对MCF 7细胞的诱导凋亡作用机制。方法　用光学显微镜、电子显微镜、激光共聚焦显微镜、流式细胞仪和DNA凝胶电泳等技术观察细胞凋亡。结果　实验显示氧化苦参碱作用于体外培养的MCF 7细胞可诱导发生凋亡 ,凋亡细胞表现为细胞固缩 ,核染色质聚集或碎裂、胞质空泡化等 ;DNA电泳可见DNA梯形条带 ;激光共聚焦显微镜示DNA含量下降 ,流式细胞仪检测sub G1峰在G1期前出现 ,S期细胞比例增高。结论　氧化苦参碱对体外培养MCF 7细胞生长有抑制作用 ,机制与通过阻止细胞周期的进程 ,启动细胞自身调控程序 ,诱导肿瘤细胞凋亡有关     

MiR-182对乳腺癌细胞顺铂耐药的相关性研究

目的 探讨miR-182与乳腺癌细胞顺铂耐药性的关系。方法 MTT法检测miR-182对顺铂杀伤乳腺癌细胞能力的影响。利用生物信息学、定量PCR及western blot法验证miR-182是否能调节乳腺癌细胞BNIP3的表达。运用JC-1染色、Annexin V染色及western blot法研究miR-182影响顺铂疗效的信号通路。结果 miR-182模拟物可减弱顺铂对MCF-7细胞的杀伤活性,而miR-182抑制剂则增强顺铂对MCF-7细胞的杀伤活性。定量PCR及western blot实验表明miR-182的靶基因可能为BNIP3。miR-182抑制剂联合顺铂可引起MCF-7细胞线粒体膜电位显著下降并诱导caspase-3的活化和凋亡的发生,转染BNIP3 siRNA后miR-182抑制剂联合顺铂对MCF-7细胞的凋亡诱导效应显著降低。结论 MiR-182在乳腺癌中通过下调BNIP3的表达影响顺铂对乳腺癌细胞的杀伤活性。     

保护性自噬对顺铂诱导人乳腺癌 MCF-7细胞凋亡的抑制作用探讨

目的：探讨顺铂对乳腺癌 MCF-7细胞自噬的影响及自噬在顺铂诱导凋亡中的作用。方法顺铂处理乳腺癌 MCF-7细胞,MTT 检测细胞增殖的能力,Hoechst 33342染分析细胞的凋亡,吖啶橙染色分析细胞的自噬,Western blot 分析自噬蛋白 LC3Ⅰ／Ⅱ和 p62的表达和凋亡蛋白多聚 ADP-核糖聚合酶 PARP 表达。结果顺铂呈时间和剂量依赖性抑制乳腺癌 MCF-7细胞的增殖,并且凋亡细胞数量随顺铂浓度的递增而增加;同时顺铂能诱导微管相关蛋白轻链3-Ⅱ（LC3Ⅱ）蛋白的增加,p62蛋白的减少以及酸性自噬溶酶体的增加,顺铂联合氯喹明显增加了 LC3Ⅱ和 p62的蛋白的表达;与单药顺铂相比,自噬抑制剂氯喹明显降低细胞存活率（89．17％±2．56％）vs （74．63％±1．51％）,（P ＜0．05）,而且 PARP 蛋白发生了明显的裂解（P ＜0．05）。结论顺铂诱导乳腺癌 MCF-7细胞保护性自噬,抑制自噬可以增加顺铂诱导乳腺癌 MCF-7细胞凋亡,自噬抑制剂联合顺铂为乳腺癌提供了新的治疗策略。     

尿石素A对乳腺癌细胞MCF-7增殖、凋亡的影响及其机制研究

目的 研究尿石素A对乳腺癌细胞MCF-7增殖、凋亡的影响并探讨其作用机制。方法 CCK-8法考察不同浓度尿石素A作用12、24、36、48 h对MCF-7细胞增殖能力的影响;细胞凋亡染色法考察20、40 μmol/L的尿石素A对MCF-7细胞凋亡的影响;实时荧光定量PCR（RT-qPCR）检测c-Myc、Cyclin D1、Bcl-2、Bax mRNA的表达水平;Western blotting法检测c-Myc、Cyclin D1、Bcl-2、Bax蛋白的表达水平。结果 尿石素A对MCF-7细胞增殖具有抑制作用且呈时间浓度相关性;细胞凋亡染色显示,20、40 μmol/L尿石素A给药后均能够诱导MCF-7细胞凋亡;RT-qPCR及Western blotting结果显示,20、40 μmol/L尿石素A能够显著降低MCF-7细胞中c-Myc、Cyclin D1、Bcl-2 mRNA及蛋白的表达水平（P<0.05、0.01）,升高Bax mRNA及蛋白的表达水平（P<0.05、0.01）。结论 尿石素A具有抑制MCF-7细胞增殖并诱导其凋亡的作用,其作用机制可能与抑制c-Myc、Cyclin D1、Bcl-2表达,升高Bax表达水平有关。     

乳腺癌MCF-7细胞系中侧群细胞分选及其生物学特性

目的 分离乳腺癌MCF-7细胞系中的侧群细胞(SP)并观察其生物学特性.方法 利用流式细胞荧光分选法将乳腺癌MCF-7细胞系分成SP和非SP细胞两个亚群.对两个亚群细胞采用软琼脂克隆形成实验观察其增殖能力.结果 MCF-7细胞株中分选出SP细胞占(6.5±0.4)％;SP细胞的体外克隆形成率为(38.5±9.4)％,高于非SP细胞的(8.4±2,6)％(t=5.34,P＜0.05).结论 乳腺癌MCF-7细胞中的SP细胞富集了乳腺癌于细胞,其增殖能力强于非SP细胞,表明SP表型的肿瘤细胞在乳腺癌的生长中具有重要的地位.     

天花粉对人乳腺癌MCF-7细胞凋亡及相关基因表达的影响

目的研究天花粉对人乳腺癌MCF-7细胞凋亡及相关基因表达的影响。方法取对数生长期人乳腺癌MCF-7细胞以30,60,90,120μg·m L^-1的天花粉蛋白处理,作为实验组,对照组用等量的0.9%Na Cl处理,继续培养24,48,72h。观察并比较各组细胞形态学及细胞核凋亡形态学变化,以噻唑蓝(MTT)比色法检测各组人乳腺癌MCF-7细胞增殖抑制情况,分光光度法检测天花粉蛋白对人乳腺癌MCF-7细胞胱天蛋白酶(caspase)-3和caspase-8表达的影响。结果实验组人乳腺癌MCF-7细胞呈现明显的细胞凋亡及核凋亡现象,且随天花粉蛋白质量浓度的增加,其细胞核凋亡现象越明显;干预24 h后,30,60,90,120μg·mL^-1实验组增殖抑制率分别为(1.61±0.94)%,(2.81±1.01)%,(7.05±1.03)%和(9.59±1.12)%;干预48 h后增殖抑制率分别为(2.13±1.01)%,(6.14±1.12)%,(9.05±1.09)%和(19.60±1.15)%;干预72 h后增殖抑制率分别为(3.28±1.07)%,(7.18±1.51)%,(18.39±1.81)%和(29.59±1.63)%。实验组人乳腺癌MCF-7细胞增殖抑制率随作用时间的延长及天花粉蛋白质量浓度的增大而逐渐升高(均P<0.01);90μg·m L^-1实验组24,48,72 h caspase-3分别为1.49±0.15,2.36±0.25,2.15±0.23;caspase-8分别为1.94±0.26,1.56±0.19,1.39±0.20。对照组人乳腺癌MCF-7细胞caspase-3及caspase-8随作用时间的延长无显著变化(均P>0.05),而90μg·mL^-1实验组caspase-3先升高后降低(P<0.05或P<0.01),以48 h时最高;caspase-8则逐渐降低(P<0.01);且各时间点90μg·m L^-1实验组caspase-3及caspase-8均显著高于对照组(均P<0.01)。结论天花粉蛋白可有效促进人乳腺癌MCF-7细胞凋亡,抑制其增殖,且增殖抑制作用呈时间-剂量依赖性,其作用机制可能与上调人乳腺癌MCF-7细胞caspase-3及caspase-8表达相关。     

绞股蓝次级皂苷H诱导人乳腺癌MCF-7细胞凋亡的作用研究

目的 探讨绞股蓝次级皂苷H （Gypensapogenin H,GH）对人乳腺癌MCF-7细胞的诱导凋亡作用。方法 采用5、10、20、40、60、80 μmol/L的GH处理人乳腺癌MCF-7细胞48 h后,MTT法测定GH对细胞增殖的影响;20 μmol/L的GH作用细胞24 h后,相差显微镜下观察细胞的形态学变化,DAPI染色,荧光显微镜下观察凋亡小体的形成;GH作用细胞6、12、24 h后,流式细胞仪测定细胞凋亡率;免疫印迹法检测GH对Bcl-2、Bax、Cytochrome C、Caspase 3等蛋白表达的影响。结果 GH抑制细胞增殖作用呈明显的浓度相关性,半数抑制浓度（IC₅₀）为（8.67±1.22）μmol/L;GH组细胞形态与对照组比较发生显著变化,主要表现为细胞皱缩、染色质浓缩、细胞核变形;细胞经DAPI染色后在荧光显微镜下可观察到有凋亡小体形成;随GH作用时间延长,细胞凋亡率明显上升,与对照组比较,GH作用12、24 h细胞早期凋亡率显著升高（P<0.05、0.01）;蛋白免疫印迹显示,与对照组比较,GH作用6、24 h Bax,6、12、24 h Cleaved Caspase 3和Cytochrome C蛋白水平显著增加（P<0.05、0.01）;6、12、24 h Bcl-2和12、24 h Caspase 3蛋白表达量显著减少（P<0.05、0.01）。结论 GH通过线粒体通路诱导乳腺癌MCF-7细胞凋亡。     

槐米中槲皮素提纯、鉴定以及诱导人乳腺癌MCF-7细胞凋亡作用

目的:研究从槐米中槲皮素(Quercetin,Que)提取、鉴定和对人乳腺癌MCF-7细胞生长的抑制以及诱导凋亡作用.方法:采用碱溶解酸沉淀法提纯槐米中槲皮素,并进行红外光谱分析;采用体外培养人乳腺癌MCF-7细胞,用不同浓度槲皮素处理;采用四甲基偶氮唑蓝(MTT)比色法测定细胞生长抑制率;采用细胞凋亡DNA Lad　der和FITC-Annexin V/PI荧光标记流式细胞仪检测,槲皮素作用后MCF-7细胞凋亡情况.结果:不同浓度槲皮素对人乳腺癌MCF 7细胞有生长抑制作用,并呈浓度和时间依赖性(P＜0.05);10.0 mmol/L槲皮素作用MCF-7细胞2d,DNA电泳出现特征性的凋亡条带;10.0 mmol/L槲皮素处理MCF-7细胞1d、2d和3d,细胞凋亡率分别为(9.2±1.5)％、(30.0±11.8)％和(60.8±10.6)％.结论:用碱溶解酸沉淀法可从槐米中提纯槲皮素,提取的槲皮素对人乳腺癌MCF-7细胞有生长抑制和诱导凋亡作用.     

乙酰氧基胡椒酚乙酸酯对人乳腺癌MCF-7细胞凋亡与侵袭的影响

目的:研究乙酰氧基胡椒酚乙酸酯(ACA)对人乳腺癌MCF-7细胞凋亡与侵袭的影响。方法:通过RT-PCR法检测ACA对人乳腺癌MCF-7细胞B细胞淋巴瘤/白血病-2(Bcl-2)、Bcl-2相关X蛋白(Bax)基因表达的影响,免疫细胞化学法检测细胞中基质金属蛋白酶(MMP)-2和MMP-9的表达。结果:MCF-7细胞经50、100、150μmol·L-1ACA干预后,Bcl-2 mRNA表达显著下降,Bax mRNA表达显著升高(P<0.01);50、100、150μmol·L-1ACA作用后细胞中MMP-2和MMP-9的蛋白表达显著减少(P<0.01)。结论:ACA诱导的Bcl-2 mRNA表达的下调和Bax mRNA表达的上调可能参与了其诱导人乳腺癌MCF-7细胞凋亡作用。ACA能抑制人乳腺癌MCF-7细胞中MMP-2和MMP-9的蛋白表达从而抑制其侵袭。     

The secretome of non-tumorigenic mammary cells MCF-10A elicits DNA damage in MCF-7 and MDA-MB-231 breast cancer cells

Radiotherapy is used in breast cancer to destroy tumor cells lingering after surgery. It is accepted that lethal effects of ionizing radiation occur as a result of damage to DNA in irradiated (IR) cells. However, response mechanisms may promote cell survival with efficient DNA repair or genomic alterations. Chromosomal aberrations are frequent in surviving cells and may enhance chromosomal instability (CIN) which is associated with increased risk of recurrence and metastasis. Intercellular communication can affect the response in IR cells and cause damage in non-irradiated (N-IR) cells. We evaluated the effect of the secretome of non-tumorigenic mammary cells (MCF-10A) on proliferation and DNA damage in breast cancer cells (MCF-7 and MDA-MB-231). Results showed that conditioned media from IR and N-IR MCF-10A cells produced cycles of DNA double-strand breaks in N-IR and IR tumor cells leaving them with residual damage. CIN markers (micronuclei, nucleoplasmic bridges, nuclear buds) were also increased in IR and N-IR tumor cells, being the effect of conditioned media from IR MCF-10A greater in many cases. The inhibition of phosphorylation/activation of Src kinase in cancer cells hindered CIN markers' increment. Besides, clonogenic survival of tumor cells was differentially modulated by conditioned media from MCF-10A: decreased in MCF-7 and enhanced in MDA-MB-231 cells. These results signal the relevance of tumor-host interaction in tumor behavior and the response to radiotherapy.     

Autophagy preceded apoptosis in oridonin-treated human breast cancer MCF-7 cells

Recent studies have shown that MCF-7 cells undergo autophagy under some conditions, such as tamoxifen treatment and starvation. In this study, we investigated autophagy in MCF-7 cells under oridonin treatment and further examined the relationship between autophagy and apoptosis. After 3-MA (the specific inhibitor of autophagy) pre-culture, MCF-7 cells were exposed to oridonin, and the growth inhibitory ratio, morphologic changes, DNA fragmentation, proteins expression, autophagic ratio and apoptotic ratio were evaluated. Oridonin inhibited the proliferation of MCF-7 cells and induced autophagy in vitro. MDC (a specific dye for autophagosome) recruitment and typical apoptotic features, including apoptotic bodies, membrane blebbing as well as nuclear condensation, were induced by oridonin. Oridonin downregulated the phosphorylation of ERK, whereas those of JNK and P38 kinase were upregulated. In the condition of oridonin treatment, 3-MA significantly reduced the autophagic level, and the apoptotic cell ratio was also declined. Furthermore, combined treatment with oridonin and 3-MA upregulated ERK phosphorylation and downregulated JNK and P38 kinases phosphorylation compared with oridonin alone treatment groups, indicating that autophagy facilitated apoptosis in oridonin-induced MCF-7 cells. In addition, 3-MA application downregulated DNA ladder and Bax expression but upregulated Bcl-2 expression, compared with oridonin alone treatment. Taken together, oridonin simultaneously induced MCF-7 cells both apoptosis and autophagy, and in this settings, inhibition of autophagy induced lowered apoptotic level, therefore, autophagy participated in upregulation of apoptosis.     

Phthalates inhibit tamoxifen-induced apoptosis in MCF-7 human breast cancer cells

Environmental estrogens represent a class of compounds that can mimic the function or activity of the endogenous estrogen 17 -estradiol (E2). Phthalates including butyl benzyl phthalate (BBP), di(n-butyl) phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP) are used as plasticizers, and also widely used in food wraps and cosmetic formulations. Phthalates have been shown to mimic estrogen and are capable of binding to the estrogen receptor (ER). It has been demonstrated that estrogen promotes drug resistance to tamoxifen (TAM) in breast cancer. In order to further evaluate the potential role of the phthalates as environmental estrogens, the effect of phthalates was investigated on TAM-induced apoptosis in MCF-7 human breast cancer cells. Our results show that phthalates, BBP (100 M), DBP (10 M), and DEHP (10 M), significantly increased cell proliferation in MCF-7, but not in MDA-MB-231 cells. In addition, BBP, DBP, and DEHP mimicked estrogen in the inhibition of TAM-induced apoptosis in MCF-7 cells. Our data suggest that the inhibitory effect of phthalates on TAM-induced apoptosis involves an increase in intracellular Bcl-2 to Bax ratio. Given that the phthalates are widely used in cosmetics mainly for women, our findings that revealed the promoting effect of BBP, DBP, and DEHP on chemotherapeutic drug resistance to TAM in breast cancer may be of biological relevance.     

苦参碱对人乳腺癌细胞MCF-7增殖、凋亡的影响

目的探讨苦参碱对人乳腺癌细胞MCF-7的增殖、凋亡的影响。方法实验组MCF-7细胞加入苦参碱溶液,对照组加入等量培养液。MTT比色法检测苦参碱对MCF-7细胞的生长抑制率;镜下观察细胞形态学变化;流式细胞术检测MCF-7细胞Bax、Bcl-2蛋白表达。结果与对照组比较,实验组苦参碱呈时间、剂量依赖性明显抑制MCF-7细胞生长,诱导MCF-7细胞凋亡,上调Bax蛋白表达,下调Bcl-2蛋白表达。结论苦参碱对MCF-7细胞具有明显的生长抑制和促凋亡作用,与上调Bax和下调Bcl-2表达有关。     

Chimaphilin induces apoptosis in human breast cancer MCF-7 cells through a ROS-mediated mitochondrial pathway

Chimaphilin, 2,7-dimethyl-1,4-naphthoquinone, is extracted from pyrola [Passiflora incarnata Fisch.]. In this study, the anticancer activity and underlying mechanisms of chimaphilin toward human breast cancer MCF-7 cells are firstly investigated. Chimaphilin could inhibit the viability of MCF-7 cells in a concentration-dependent manner, and the IC₅₀ value was 43.30 μM for 24 h. Chimaphilin markedly induced apoptosis through the investigation of characteristic apoptotic morphological changes, nuclear DNA fragmentation, annexin V-FITC/propidium iodide (PI) double staining. Flow cytometry assay revealed that chimaphilin triggered a significant generation of ROS and disruption of mitochondrial membrane potential. Additionally, western blotting assay showed that chimaphilin suppressed Bcl-2 level and enhanced Bad level, then activated caspase-9 and caspase-3, and further activated the poly ADP-ribose polymerase (PARP), finally induced cell apoptosis involving the mitochondrial pathway. Furthermore, free radical scavengers N-acetyl-L-cysteine (NAC) pretreatment test testified that chimaphilin could increase the generation of ROS, then induce cell apoptosis. In general, the present results demonstrated that chimaphilin induced apoptosis in human breast cancer MCF-7 cells via a ROS-mediated mitochondrial pathway.     

Leccinum vulpinum Watling induces DNA damage,decreases cell proliferation and induces apoptosis on the human MCF-7 breast cancer cell line

The current work aimed to study the antitumour activity of a phenolic extract of the edible mushroom Leccinum vulpinum Watling, rich essentially in hydroxybenzoic acids. In a first approach, the mushroom extract was tested against cancer cell growth by using four human tumour cell lines. Given the positive results obtained in these initial screening experiments and the evidence of some studies for an inverse relationship between mushroom consumption and breast cancer risk, a detailed study of the bioactivity of the extract was carried out on MCF-7 cells. Once the selected cell line to precede the work was the breast adenocarcinoma cell line, the human breast non-malignant cell line MCF-10A was used as control.Overall, the extract decreased cellular proliferation and induced apoptosis. Furthermore, the results also suggest that the extract causes cellular DNA damage. Data obtained highlight the potential of mushrooms as a source of biologically active compounds, particularly with antitumour activity.     

Growth inhibition and induction of apoptosis in MCF-7 breast cancer cells by oridonin nanosuspension

The mechanism for anti-tumor activity of oridonin (ORI) nanosuspension, prepared by the high pressure homogenization method, was studied using MCF-7 human breast carcinoma cells in vitro. MTT assay, observation of morphologic changes, flow cytometric analysis, and western blot analysis indicated that ORI nanosuspension could significantly intensify the in vitro anti-tumor activity to MCF-7 cells, as compared with ORI solution. Furthermore, ORI nanosuspension induced G?/M stage proliferation arrest and apoptosis in MCF-7 cells depending on its concentration. In addition, western blot analysis indicated that the pro-caspase-3 protein was not cleaved into the activated form and the expression of anti-apoptotic Bcl-2 protein decreased, on the contrary, the expression of pro-apoptotic Bax protein increased in a dose-dependent manner in ORI nanosuspension-treated cells. These observations indicated that the anti-tumor activity of ORI nanosuspension was intensified by cell-cycle arrest and apoptosis induction.     

Growth inhibition and induction of apoptosis in MCF-7 breast cancer cells by oridonin nanosuspension

The mechanism for anti-tumor activity of oridonin (ORI) nanosuspension, prepared by the high pressure homogenization method, was studied using MCF-7 human breast carcinoma cells in vitro. MTT assay, observation of morphologic changes, flow cytometric analysis, and western blot analysis indicated that ORI nanosuspension could significantly intensify the in vitro anti-tumor activity to MCF-7 cells, as compared with ORI solution. Furthermore, ORI nanosuspension induced G₂/M stage proliferation arrest and apoptosis in MCF-7 cells depending on its concentration. In addition, western blot analysis indicated that the pro-caspase-3 protein was not cleaved into the activated form and the expression of anti-apoptotic Bcl-2 protein decreased, on the contrary, the expression of pro-apoptotic Bax protein increased in a dose-dependent manner in ORI nanosuspension-treated cells. These observations indicated that the anti-tumor activity of ORI nanosuspension was intensified by cell-cycle arrest and apoptosis induction.     

Genistein modulates the anti-tumor activity of cisplatin in MCF-7 breast and HT-29 colon cancer cells

The function of genistein (GEN) on tumor prevention and tumor promotion is discussed controversially. A possible interference of GEN with chemotherapy has been only rarely addressed so far. In this study, effects of GEN on the anti-tumor activity of cisplatin (CIS) were investigated in the presence and absence of estradiol (10^?10 M) in MCF-7 breast and HT-29 colon cancer cells. Cells were treated with graded concentrations of GEN (10^?4–10^?6 M), E₂, CIS and combinations. Cell growth, proliferation and apoptosis were determined as well as the expression level of PCNA, Ki67 and BCL-2 family members. CIS and GEN 10^?4 M inhibited cell growth and induced apoptosis in MCF-7 and HT-29 cells in the presence and absence of E₂. Co-treatment with CIS and 10^?4M GEN resulted in additive effects. In concentrations of 10^?5 and 10^?6 M, GEN stimulated cell growth in MCF-7 cells. It promoted proliferation, inhibited apoptosis and counteracted the anti-tumor activity of CIS in MCF-7 and HT-29 cells. Particularly the ability of CIS to induce apoptosis was antagonized. In ER alpha-positive MCF-7 cells, but not in ER alpha-negative HT-29 cells, E₂ was able to neutralize the anti-CIS effects of GEN. Our data provide evidence that GEN in the absence of E₂, a situation which occurs in postmenopausal women, directly affects the anti-tumor activity of cytostatic drugs like CIS. The exact molecular mechanism has to be investigated in future studies.