雷公藤内酯醇通过调控miR-142-3p/HSP70通路抑制人乳腺癌MCF-7细胞增殖、侵袭和迁移

目的:探究雷公藤内酯醇(TP)通过miR-142-3p/HSP70信号通路对人乳腺癌MCF-7细胞恶性生物学行为的影响。方法:常规培养MCF-7细胞,将其分为6组:对照组、TP组、miR-142-3p inhibitor组、TP+inhibitor组、miR-142-3p mimic组和TP+mimic组,用转染试剂将相应的核酸或质粒转染MCF-7细胞。qPCR法、EdU细胞增殖实验、Transwell小室实验、细胞划痕实验、WB法分别检测转染后各组MCF-7细胞中miR-142-3p和HSP70 mRNA的表达,MCF-7细胞的增殖、侵袭、迁移能力和HSP70蛋白表达水平。结果:TP或miR-142-3p过表达能显著促进MCF-7细胞中miR-142-3p和HSP70的表达,敲减miR-142-3p则可明显抑制MCF-7细胞中miR-142-3p和HSP70的表达,TP可逆转由敲减miR-142-3p对MCF-7细胞中miR-142-3p和HSP70表达的影响;TP、过表达miR-142-3p均可明显抑制MCF-7细胞的增殖、迁移和侵袭能力(均P<0.05),敲减miR-142-3p则均可促进MCF-7细胞的增殖、迁移和侵袭能力(均P<0.05),TP可逆转由敲减miR-142-3p对MCF-7细胞恶性生物学行为的影响(均P<0.05)。结论:TP可通过调控miR-142-3p/HSP70信号通路,进而抑制MCF-7细胞的增殖、侵袭和迁移能力。

DCN通过VEGF因子抑制乳腺癌MCF-7细胞增殖的实验研究

目的探讨核心蛋白聚糖(decorin,DCN)通过下调血管内皮生长因子(Vascular endothelial growth factor,VEGF)表达抑制乳腺癌MCF-7肿瘤细胞增殖的分子机制。方法体外培养MCF-7细胞,质粒转染诱导MCF-7细胞高表达核心蛋白聚糖为DCN组,不转染的MCF-7细胞为正常对照组。MTT法、流式细胞术细胞观察各自细胞增殖情况,RT-PCR、Western blot法检测各组细胞VEGF mRNA和蛋白表达变化。结果与对照组比较,流式细胞术检测DCN转染24、48、72 h后DCN组MCF-7细胞数目明显减少(P<0.05),MTT结果显示DCN组细胞增殖能力受到显著抑制(P<0.05),Western blot检测DCN组细胞VEGF蛋白表达水平有下降趋势。结论核心蛋白聚糖通过降低VEGF mRNA表达水平,使细胞内生成的VEGF蛋白减少,抑制MCF-7细胞增殖。

TNF-ɑ调控LRG1促进乳腺癌MCF-7细胞增殖、侵袭和迁移

目的:研究TNF-α对乳腺癌MCF-7细胞中LRG1蛋白表达的调控及其对乳腺癌MCF-7细胞增殖、侵袭和迁移能力的影响及相关分子机制。方法:MTT实验检测不同浓度TNF-α处理后MCF-7细胞活力;EdU实验、Transwell实验和划痕实验分别检测抑制LRG1表达后细胞增殖、侵袭以及迁移能力;Western blot检测细胞内MAPK信号通路中p-p38蛋白表达。结果:低浓度TNF-α处理乳腺癌MCF-7细胞,细胞活力增强;抑制LRG1表达后细胞增殖能力下降,侵袭细胞数、细胞迁移率以及p-p38蛋白表达均下降。结论:TNF-ɑ通过调控LRG1的表达促进乳腺癌MCF-7细胞增殖、侵袭和迁移,这一过程可能通过激活p38MAPK信号通路来实现。

毛酸浆内酯通过抑制STAT3诱导人乳腺癌MCF-7细胞凋亡

[目的]旨在探讨信号转导和转录激活因子3(STAT3)在毛酸浆内酯(PPB)诱导人乳腺癌MCF-7细胞凋亡中发挥的作用。[方法]采用荧光染色法分析PPB诱导MCF-7细胞凋亡;使用生物信息学方法预测PPB抗乳腺癌的潜在机制;采用噻唑蓝(MTT)法考察STAT3抑制剂S3I-201以及STAT3小干扰RNA(siRNA)对PPB抑制MCF-7细胞生长的作用;采用蛋白免疫印迹(Western Blot)法考察PPB单独处理或STAT3 siRNA预处理后对MCF-7细胞中STAT3、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、半胱氨酸天冬氨酸蛋白酶8(Caspase8)、半胱氨酸天冬氨酸蛋白酶9(Caspase9)、细胞色素c(Cytochrome c)以及多聚ADP核糖聚合酶(PARP)蛋白表达的影响。[结果]MCF-7细胞经PPB作用后凋亡形态特征明显,凋亡比例上升;生物信息学结果显示PPB与乳腺癌疾病的共同靶点STAT3在乳腺癌组织中高表达,单基因GSEA结果提示STAT3高表达与凋亡信号通路呈负相关;Western Blot法检测结果显示PPB能够抑制STAT3的磷酸化;S3I-201抑制剂或siRNA敲降STAT3均能进一步促进PPB抑制MCF-7细胞生长;此外,敲降STAT3进一步增加PPB对促凋亡蛋白Bax、Cytochrome c、裂解的Caspase8(Cleaved-Caspase8)、裂解的Caspase9(Cleaved-Caspase9)以及裂解的PARP(Cleaved-PARP)的促进作用,并增加PPB对抗凋亡蛋白Bcl-2的抑制作用。[结论]PPB通过抑制STAT3诱导人乳腺癌MCF-7细胞凋亡。

香豆酸诱导MCF-7细胞凋亡的代谢与氧化应激影响

目的 探讨香豆酸诱导乳腺癌细胞MCF-7凋亡的机制及氧化应激与代谢的影响。方法 采用氧化相关蛋白活性研究香豆酸对MCF-7氧化应激的影响;液相质谱仪结合代谢组学探索香豆酸对MCF-7细胞代谢的影响。结果 香豆酸呈浓度依赖式对MCF-7细胞凋亡具有一定的促进作用,并上调细胞的氧化应激性导致MCF-7细胞氧化系统失衡;同时香豆酸影响MCF-7的细胞代谢,主要是体现糖代谢,富集显著通路集糖酵解;并筛选到差异代谢物563个,其中上调463个,下调100个。结论 香豆酸诱导MCF-7细胞凋亡作用机制可能是通过影响细胞的氧化应激性以及调控细胞糖代谢来实现。

LMAN2在HR阳性乳腺癌组织中的表达与患者预后的关系及其对MCF-7细胞增殖和迁移的影响

目的:探究甘露糖结合凝集素2(LMAN2)在激素受体(HR)阳性乳腺癌组织中的表达水平与乳腺癌患者预后的关系及其对MCF-7细胞增殖和迁移的影响。方法:通过TCGA、Bc-GenExMiner、GEPIA和Kaplan-Meier Plotter数据库分析LMAN2在乳腺癌组织和正常乳腺组织中的差异性表达及其与患者预后的关系。采用小RNA干扰技术将si-LMAN2#1、si-LMAN2#2及si-NC转染至MCF-7细胞,将过表达LMAN载体(pc-LMAN)及空载体pcDNA3.1阴性对照(pc-NC)转染至MCF-7细胞,实验分为si-LMAN2#1、si-LMAN2#2、si-NC、pc-LMAN2和pc-NC组。通过qPCR和WB实验检测各组细胞中LMAN2 mRNA和蛋白的表达水平,CCK-8、克隆形成、Transwell迁移、WB等实验检测敲低和过表达LMAN 2对MCF-7细胞增殖、克隆形成、迁移及AKT信号通路相关蛋白表达的影响。结果:LMAN2在乳腺癌组织中的表达水平显著高于正常乳腺组织(P<0.001)。HR阳性乳腺癌组织中LMAN2表达水平显著高于HR阴性乳腺癌组织(P<0.001);LMAN2高表达与HR阳性乳腺癌患者不良预后有关联。敲低LMAN2可显著降低MCF-7细胞的增殖和迁移能力(P<0.01或P<0.001),过表达LMAN2可显著提高MCF-7细胞的增殖和迁移能力(均P<0.001)。敲低LMAN2组MCF-7细胞中PTEN和P21蛋白表达水平均显著升高,p-AKT蛋白表达水平显著降低(均P<0.01)。结论:LMAN2在乳腺癌组织和HR阳性乳腺癌组织中高表达,且与不良预后有关联。LMAN2高表达与MCF-7细胞增殖和迁移有关联,其作用机制可能涉及AKT信号通路。

羟基积雪草酸对乳腺癌MCF-7细胞增殖、凋亡和自噬的影响

目的探讨羟基积雪草酸(madecassic acid,MA)对乳腺癌MCF-7细胞增殖、凋亡及自噬的影响。方法将MCF-7细胞分为阴性对照组、不同浓度的MA(80、100、120、140、160μmol/L)组、不同浓度的他莫昔芬(10、20、30、40、50、35μmol/L)组,干预24、36、48 h。初步确定MA发挥抗乳腺癌作用的最佳浓度和最佳时间后,采用MTT法检测细胞活力,计算相应的半抑制浓度(half maximal inhibitory concentration,IC50)值;流式细胞术检测细胞凋亡;JC-1荧光探针检测线粒体膜电位变化;Western blot法检测细胞增殖蛋白细胞核抗原蛋白(proliferating cell nuclear antigen,PCNA)、自噬蛋白苄氯素-1(Beclin-1)、微管相关蛋白1轻链3-Ⅱ/Ⅰ(microtubule-associated protein1 light chain 3Ⅱ/Ι,LC3Ⅱ/Ι)、螯合体1(protein 62,p62)的蛋白相对表达水平。透射电镜检测自噬小体。结果发挥抗肿瘤作用的他莫昔芬最佳浓度为35μmol/L,MA最佳浓度为140μmol/L,最佳时间均为48 h。与阴性对照组相比,MA140μmol/L组和他莫昔芬35μmol/L组的细胞凋亡率,细胞荧光相对强度以及LC3Ⅱ/Ⅰ、Beclin-1蛋白相对表达水平均升高(P<0.05,P<0.01);PCNA、P62蛋白相对表达水平降低(P<0.05,P<0.01)。与MA 140μmol/L组相比,他莫昔芬35μmol/L组细胞凋亡率、细胞荧光相对强度以及Beclin-1蛋白相对表达水平明显升高(P<0.01),PCNA蛋白相对表达水平明显降低(P<0.01)。阴性对照组MCF-7细胞膜完整,核膜清晰,细胞形态良好;MA 140μmol/L组细胞膜、细胞核形态不规则,线粒体基质密度较高、嵴扩张,可见自噬小体;他莫昔芬35μmol/L组细胞膜局部溶解、破损,可见双核仁,线粒体肿胀、基质溶解,可见自噬小体。结论MA可抑制乳腺癌MCF-7细胞的增殖、诱导细胞凋亡和自噬。

蒽贝素对MCF-7乳腺癌细胞荷瘤裸鼠肿瘤生长的影响

目的探讨蒽贝素对7乳腺癌MCF-细胞荷瘤裸鼠肿瘤生长的影响。方法取Balb/c-nu雌性裸鼠30只,随机分为模型组[等体积0.025%氨水溶液(pH 8.2)],5-氟尿嘧啶组(20 mg/kg),以及(蒽贝素)高、中、低剂量组(400,200,100μg/kg),各6只。取0.1 mL MCF-7细胞悬液皮下接种于裸鼠双侧腋下,以复制乳腺癌荷瘤裸鼠模型。建模成功后,各组裸鼠灌胃(或腹腔注射)相应药物或等体积0.025%氨水溶液(pH 8.2),均每日1次,连续14 d。末次给药后,称定瘤体质量并计算抑瘤率;苏木素-伊红(HE)染色观察肿瘤细胞形态学,Tunel染色分析肿瘤细胞凋亡情况并计算凋亡率;采用酶联免疫吸附试验(ELISA)法检测血清中肿瘤坏死因子-α(TNF-α)和白细胞介素6(IL-6)水平;免疫组化染色法检测Caspase-3蛋白表达水平。结果与模型组比较,5-氟尿嘧啶组和高剂量组裸鼠瘤体质量显著减小(P<0.01或P<0.05);各给药组细胞凋亡率显著升高;5-氟尿嘧啶组和高、中剂量组裸鼠血清TNF-α水平显著升高(P<0.01或P<0.05);各给药组Caspase-3蛋白表达水平显著升高(P<0.01)。结论蒽贝素可促进荷瘤裸鼠MCF-7细胞凋亡,其机制可能与上调Caspase-3蛋白表达有关。

菊藻丸含药血清调控PTEN对乳腺癌MCF-7细胞生长和转移的作用研究

目的 研究菊藻丸含药血清调控10号染色体上缺失的磷酸酶和张力蛋白同源物基因(PTEN)对人乳腺癌MCF-7细胞生长和转移的作用。方法 8周龄、体重(200±20)g的SPF级Wistar雌性大鼠12只,采用随机数字表法分为菊藻丸组和对照组,各6只。各组分别以5.4 g/(kg·d)菊藻丸和等量生理盐水灌胃,制备含药血清和空白对照血清。将培养好的人乳腺癌MCF-7细胞分为20%空白血清组、5%含药血清组、10%含药血清组、15%含药血清组和20%含药血清组,分别使用含20%空白对照血清和含5%、10%、15%、20%含药血清的培养基进行培养干预。采用CCK-8检测细胞增殖、集落形成实验观察克隆形成能力、TUNEL染色检测凋亡、流式细胞术检测周期分布、划痕实验和Transwell检测细胞迁移和侵袭能力,q PCR和Western blot检测PTEN m RNA和蛋白表达水平。结果 与20%空白血清组比较,10%、15%、20%含药血清组细胞增殖活性降低、克隆形成率减少、侵袭能力降低(P<0.05);5%、10%、15%、20%含药血清组细胞凋亡水平升高、迁移能力降低、细胞周期阻滞于G1期、PTEN的m RNA和蛋白表达水平均升高(P<0.05)。与5%含药血清组比较,10%、15%、20%含药血清组细胞增殖活性降低、克隆形成率降低、细胞凋亡水平升高、迁移能力降低、侵袭能力降低、细胞周期阻滞于G1期、PTEN m RNA和蛋白表达水平均升高(P<0.05)。结论 菊藻丸含药血清能抑制MCF-7细胞生长和转移,其机制可能与激活PTEN的表达有关。

β-苦茄碱通过Fas介导的死亡受体途径诱导乳腺癌MCF-7细胞凋亡

目的探讨β-苦茄碱(Beta-solamarine,BSM)诱导乳腺癌MCF-7细胞凋亡及其对Fas介导的死亡受体途径相关蛋白的影响。方法将不同浓度的BSM对体外培养的乳腺癌MCF-7细胞进行干预。采用MTT法测定细胞增殖抑制率,细胞侵袭试验观察细胞侵袭能力,TUNEL法检测细胞凋亡情况,采用Western Blot对Fas、FADD、Cleaved Caspase-8、Cleaved Caspase-3、Cleaved PARP和PARP蛋白表达水平进行检测。结果BSM处理后的细胞组显示出了较高的抑制率、侵袭细胞数明显下降、细胞凋亡率显著增加,各BSM组的细胞抑制率、侵袭细胞数和凋亡率与正常对照组相比,差异均具有统计学意义(P<0.01)。Caspase-8抑制剂Z-IETD-FMK处理组的细胞凋亡率显著降低,相较于与BSM同剂量组,细胞凋亡率差异具有统计学意义(P<0.01)。在BSM的作用下,MCF-7细胞中Fas、FADD、Cleaved Caspase-8、Cleaved Caspase-3以及Cleaved PARP的表达水平显著提升,而PARP的表达水平下降明显,与正常对照组相比差异均具有统计学意义(P<0.05或P<0.01)。结论BSM在抑制MCF-7细胞的增殖、侵袭和促进细胞凋亡方面显示出显著效果,激活Fas介导的死亡受体途径可能是BSM诱导细胞凋亡的机制之一。

TO901317经LXRα/NF-κB抑制MCF-7乳腺癌细胞迁移

目的探究肝X受体(LXR)激动剂TO901317对MCF-7人乳腺癌细胞迁移能力的作用及机制。方法体外培养MCF-7细胞。先运用不同浓度的TO901317处理MCF-7细胞24 h,然后通过LXRαsiRNA转染或核因子κB(NF-κB)抑制剂PDTC处理细胞,划痕愈合实验检测MCF-7细胞迁移能力的改变,同时运用蛋白免疫印迹法检测LXRα、NF-κB p65与IκBα的表达。结果随着TO901317处理浓度的增加,MCF-7细胞的迁移能力明显得到抑制,差异具有统计学意义(P<0.05);同时LXRα与IκBα的表达逐渐增强,而NF-κB p65的表达则显著降低。LXRαsiRNA可显著延缓TO901317的上述作用,PDTC处理则进一步增强TO901317对乳腺癌细胞迁移的抑制作用。结论TO901317可激活LXRα,下调NF-κB p65、上调IκBα的表达,抑制乳腺癌细胞迁移。

Hesperidin as a preventive resistance agent in MCF-7 breast cancer cells line resistance to doxorubicin

Objective:To evaluate of hesperidin to overcome resistance of doxorubicin in MCF-7 resistant doxorubicin cells(MCF-7/Dox)in cytotoxicity apoptosis and P-glycoprotein(Pgp)expression in combination with doxorubicin.Methods:The cytotoxic properties.50%inhibition concentration(IC_(50))and its combination with doxorubicin in MCF-7 cell lines resistant to doxorubicin(MCF-7/Dox)cells were determined using MTT assay.Apoptosis induction was examined by double staining assay using ethidium bromide-acridine orange.Immunocytochemistry assay was performed to determine the level and localization of Pgp.Results:Single treatment of hesperidin showed cytotoxic activity on MCF-7/Dox cells with IC_(50)value of 11μmol/L.Thus,combination treatment from hesperidin and doxorubicin showed addictive and antagonist effect(CI>1.0).Hesperidin did not increase the apoptotic induction,but decreased the Pgp expressions level when combined with doxorubicin in low concentration.Conclusions:Hesperidin has cytotoxic effect on MCF-7/Dox cells with IC_(50)of 11μmol/L.Hesperidin did not increased the apoptotic induction combined with doxorubicin.Cochemotherapy application of doxorubicin and hesperidin on MCF-7/Dox cells showed synergism effect through inhibition of Pgp expression.

Effects of Mitofusin-2 Gene on Cell Proliferation and Chemotherapy Sensitivity of MCF-7

In order to evaluate the effect of mitofusin-2 gene （mfn2） on proliferation and chemotherapy sensitivity of human breast carcinoma cell line MCF-7 in vitro, pEGFPmfn2 plasmid carrying full length of mitofusin-2 gene was transfected, by using sofast, into MCF-7 cells. Mitofusin-2 gene expression in MCF-7 cells transfected by sofast after 48 h was detected by PCR and Western blotting, and the stable expression of GFP protein in MCF-7 cells by Western blot analysis. The proliferation of MCF-7 cells was assayed by MTT and cell counting. By using PI method, the effects of mfn2 on the cell cycle distribution of MCF-7 were measured. Annexin-Ⅴ/PI double labeling method was employed to detect the changes in apoptosis induced by chemotherapeutics before and after transfection. The results showed that the MCF-7 cells transfected with mfn2 gene could stably and highly express GFP protein. MTT assay revealed that after transfection of mfn2 cDNA, the proliferation of MCF-7 cells was significantly inhibited. DNA histogram showed that cells arrested in S phase, and the percentage of S phase cells was 42.7, 17.2 and 19.6 in mfn2 cDNA transfection group, blank plasmid transfection group and blank control group, respectively （P〈0.05）. The apoptosis ratio of the cells transfected with mfn2 gene was increased from 3.56% to 15.95%, that of the cells treated with camptothecin （CAMP） followed by mfn2 gene transfection was 69.6%, and that in blank plasmid transfection group and blank control group was 31.0% and 23.4% respectively （P〈0.05）. It was suggested that transfection of mfn2 gene could significantly inhibit the proliferation of MCF-7 cells and promote their sensitivity to CAMP with a synergic effect.

Fucoidan Induces G_1 Phase Arrest and Apoptosis through Caspases-dependent Pathway and ROS Induction in Human Breast Cancer MCF-7 Cells

Fucoidan is an active component of seaweed, which inhibits proliferation and induces apoptosis of several tumor cells while the detailed mechanisms underlying this process are still not clear. In this study, the effect of Fucoidan on the proliferation and apoptosis of human breast cancer MCF-7 cells and the molecular mechanism of Fucoidan action were investigated. Viable cell number of MCF-7 cells was decreased by Fucoidan treatment in a dose-dependent manner as measured by MTT assay. Fucoidan treatment resulted in G1 phase arrest of MCF-7 cells as revealed by flow cytometry, which was associated with the decrease in the gene expression of cyclin D 1 and CDK-4. Annexin V/PI staining results showed that the number of apoptotic cells was associated with regulation of cytochrome C, cas- pase-8, Bax and Bcl-2 at transcriptional and translational levels. Both morphologic observation and Hoechst 33258 assay results confirmed the pro-apoptotic effect of Fucoidan. Meanwhile, the ROS pro- duction was also increased by Fucoidan treatment, which suggested that Fucoidan induced oxidative damage in MCF-7 cells. The results of present study demonstrated that Fucoidan could induce GI phase arrest and apoptosis in MCF-7 cells through regulating the cell cycle and apoptosis-related genes or proteins expression, and ROS generation is also involved in these processes.

Triterpenoid of avocado (Persea americana) seed and its cytotoxic activity toward breast MCF-7 and liver HepG2 cancer cells

Objective:To determine the structure of triterpenoid isolated from avocado seeds and the cytotoxic effect on MCF-7 and Hep G2 cells.Methods:The powder sample was macerated with ethanol,followed with separation of the extract by column chromatography.The target compound was monitored on thin layer chromatography plate and reagent Lieberman–Buchard.The isolated compound was characterized by spectral analysis,mainly ultraviolet,infrared,and liquid chromatographymass spectroscopy and their spectroscopic data with those reported in literature were compared.In vitro cytotoxic activity was investigated against Vero,MCF-7,and Hep G2 cell lines using MTT assay.Results:A triterpenoid compound was isolated from ethanol extract.The extracts,fraction(F3),and the isolated compound showed a significant cytotoxic activity against all investigated cell lines.MTT assay showed that the triterpenoid isolate inhibited cell proliferation of MCF-7 and Hep G2 cell line with the IC50 values of 62 mg/m L and 12 mg/m L,respectively,and was safe to normal cells.Conclusions:The results of the present study reveal that triterpenoid from avocado seeds have the potential for further development as anticancer agents.

Dietary Daidzein Enhances Antiapoptotic Effect of 17β-Estradiol (E_2) on Breast Cancer MCF-7 Cells

Objective： To investigate whether dietary daidzein interact with endogenous 17β-Estradiol （E2） to give rise to additive or inhibitory effects on proliferation and apoptosis in breast cancer cells. Methods： Cell cycle distribution and apoptosis induction were analyzed by using flow cytometry when breast cancer cell lines MCF-7 were cotreated with daidzein （1, 5 μmol/L） and E2 （0.1-10 nmol/L） for 5 days. Whether daidzein could alter E2-modulated mRNA expression of estrogen receptor alpha （ERα）, estrogen receptor beta （ERI3） and ERβ-estrogen response element （ERE） dependent transcription was investigated by RT-PCR and luciferase induction assays. The effects of daidzein on E2-modulated expression of proapoptotic p53, bax and antiapoptotic bcl-2 at both mRNA and protein levels were also investigated by RT-PCR and Western blot. Results： Daidzein enhanced the antiapoptotic effect in an Ea dose-dependent manner, but had no effect on E2-induced proliferation. Daidzein antagonized E2-induced ERβ mRNA expression and ERβ-ERE dependent transcription. In addition, daidzein only antagonized E2-upregulated expression of p53 and bax, but had no effect on E2-upregulated expression of bcl-2. Conclusion： Daidzein enhances the antiapoptotic effect of E2 on breast cancer cells by inhibiting E2-mediated p53-bax proapoptotic pathway. These results suggest that dietary daidzein may enhance deleterious effect of endogenous E2 in hormone-dependent breast cancer.

Investigation of anticancer effect of Xanthoceraside in vitro and the mechanism of Xanthoceraside-induced human breast cancer MCF-7 cell death

Objective To investigate the anticancer effect of xanthoceraside in vitro and the possible mechanisms involved in the potent antiproliferative effect on human breast cancer MCF-7 cell.Methods The inhibition rate of different tumor cells and human peripheral blood lymphocyte cells was investigated by MTT assay.AO/EB double fluorescent dye staining was used to investigate the morphology changes of MCF-7.The DNA agarose gel electrophoresis was further used to observe the DNA Fragmentation.Flow cytometry was employed to investigate the volume changes,the cell cycle distribution and the mitochondrial membrane potential of MCF-7.The antioxidant N-acetylcysteine(NAC)was chosen to detect the influence on oxidant-stress system of MCF-7 cells.Necrostatin-1 was next chosen to detect the influence on antiproliferative effect of xanthoceraside-treated MCF-7 cells.Results Xanthoceraside could inhibit the proliferation of tumor cells significantly in a dose-dependent manner and it has no cytotoxic effects on human peripheral blood lymphocyte cells in vitro.Cytoplasm vacuole was observed but no significant condense of nuclear chromatin was found,meanwhile,MCF-7 cells were bigger and smear was observed by agarose gel electrophoresis after MCF-7 cells were exposed to xanthoceraside.The cell cycle distribution of MCF-7 was greatly changed after exposure to xanthoceraside with an obvious G1 arrest.The mitochondrial membrane potential showed significant decrease.NAC attenuate the antiproliferative effect of xanthoceraside-treated MCF-7 cells but necrostatin-1 had no effects.Conclusions Xanthoceraside-induced necrosis might be dependent of mitochondria,meanwhile reactive oxygen species(ROS)participated in it.The xanthoceraside-induced MCF-7 cell death might not be the cell necrosis which initiated by Fas/TNFR and must be through RIP1 kinase.

Anticancer property of sediment actinomycetes against MCF-7 and MDA-MB-231 cell lines

ObjectiveTo investigate the anticancer property of marine sediment actinomycetes against two different breast cancer cell lines.MethodsIn vitro anticancer activity was carried out against breast (MCF-7 and MDA-MB-231) cancer cell lines. Partial sequences of the 16s rRNA gene, phylogenetic tree construction, multiple sequence analysis and secondary structure analysis were also carried out with the actinomycetes isolates.ResultsOf the selected five actinomycete isolates, ACT01 and ACT02 showed the IC50 value with (10.13±0.92) and (22.34±5.82) μg/mL concentrations, respectively for MCF-7 cell line at 48 h, but ACT01 showed the minimum (18.54±2.49 μg/mL) level of IC50 value with MDA-MB-231 cell line. Further, the 16s rRNA partial sequences of ACT01, ACT02, ACT03, ACT04 and ACT05 isolates were also deposited in NCBI data bank with the accession numbers of GQ478246, GQ478247, GQ478248, GQ478249 and GQ478250, respectively. The phylogenetic tree analysis showed that, the isolates of ACT02 and ACT03 were represented in group I and III, respectively, but ACT01 and ACT02 were represented in group II. The multiple sequence alignment of the actinomycete isolates showed that, the maximum identical conserved regions were identified with the nucleotide regions of 125 to 221st base pairs, 65 to 119th base pairs and 55, 48 and 31st base pairs. Secondary structure prediction of the 16s rRNA showed that, the maximum free energy was consumed with ACT03 isolate (-45.4 kkal/mol) and the minimum free energy was consumed with ACT04 isolate (?7.6 kkal/mol).ConclusionsThe actinomycete isolates of ACT01 and ACT02 (GQ478246 and GQ478247) which are isolated from sediment sample can be further used as anticancer agents against breast cancer cell lines.

<i>Vernonia amygdalina</i>—Induced Growth Arrest and Apoptosis of Breast Cancer (MCF-7) Cells

Breast cancer is the second leading cause of cancer-related deaths of women in the United States. Fortunately, the mortality rate from breast cancer has decreased in recent years due to an increased emphasis on early detection and more effective treatments. Although great advancements have been made in the treatment and control of cancer progression, significant deficiencies and room for improvement remain. The central objective of this research was to further determine the in vitro mechanisms of Vernonia amygdalina (VA) leaf extracts as an anticancer candidate for the treatment of breast cancer. To achieve our objective, MCF-7 cells were treated with different concentrations of VA for 24 hand 48 h. Cell viability, live and dead cells were determined by the means of trypan blue exclusion test. Live and dead cells were further evaluated by propidium iodine (PI) assay using the Cellometer Vision. Cell apoptosis was measured by flow cytometry assessment using annexin V/PI kit. Data obtained from the trypan blue test demonstrated that VA treatment reduces cell viability in a concentration- and time-dependent manner. Result of the PI assay showed a gradual increase in the population of necrotic cells (fluorescence positive cells) in VA-treated cells compared to the control cells (fluorescence negative cells). Treatment of these cancer cells (MCF-7) for 48 h at concentrations ranging from 250 μg/mL to 1000 μg/mL caused early signs of apoptosis resulting from phosphatidylserine externalization as judged by annexin V assay. We observed a strong concentration-response relationship with regard to VA exposure and annexin V/PI positive cells. In summary, our finding demonstrates that VA-induced cytotoxicity and apoptosis in MCF-7 cells involve phosphatidylserine externalization accompanied by secondary necrotic cell death. With previous findings in our laboratory, the data generated in the present study confirms that VA is a valuable botanical therapeutic agent for the treatment of breast cancer.

EFFECT OF CIS-9, TRANS-11-CONJUGATED LINOLEIC ACID ON CELL CYCLE OF MAMMARY ADENOCARCINOMA CELLS(MCF-7)

Objective: To determine the effect of cis-9, trans-1 1-conjugated linoleic acid on the cell cycle of mammary cancer cells (MCF-7) and the possible mechanism of the inhibitory effect of c9,t11-CLA. Methods: Using cell culture and immunocytochemical techniques, we examined the cell growth, DNA synthesis, expression of PCNA, cyclin A, B1, D1, p16ink4a and p21cip/waf1 of MCF-7 cells at various c9,t11-CLA concentrations (25μM, 50μM, 100μM and 200μM), at 24h and 48h. 96% ethand was used as negative control. Results: The cell growth and DNA synthesis of MCF-7 cells were inhibited by c9,t11-CLA. After treatment with various doses of c9,t11-CLA mentioned above for 8 days, the inhibition frequency was 27.18%, 35.43%, 91.05%, and 92.86%, respectively. Inhibitory effect of c9,t11-CLA on DNA synthesis (except for 25μM, 24h) was demonstrated by significantly less incorporation of 3H-TdR than the negative control (P<0.05 and P<0.01). To further investigate the influence of the cell cycle progression, we found that c9,t11-CLA may arrest the cell cycle of MCF-7 cells. Immunocytochemical staining demonstrated that incubation with different concentration of c9,t11-CLA at various times significantly decreased the expression of PCNA, Cyclin A, B1, D1 in MCF-7 cells compared to the negative control (P<0.01), whereas the expression of p16ink4a and p21cip/waf1, cyclin-dependent kinases inhibitors (CDKI), were increased. Conclusions: The cell growth and proliferation of MCF-7 cells is inhibited by c9,t11-CLA via blocking cell cycle, accompanying reduced expression of cyclin A, B1, D1 and enhanced expression of CDKI (p16ink4a and p21cip/waf1).