乳癌术后方对HER2/neu转基因小鼠乳腺癌发生中免疫应答的影响

目的探讨癌基因人类表皮生长因子受体2(HER2/neu)在乳腺癌发生中引发的免疫应答和乳癌术后方在防治乳腺癌中的免疫学机制。方法选用HER2/neu转基因自发乳腺癌小鼠模型,自5周龄起灌饲中药乳癌术后方,观察小鼠的乳腺癌发生情况,并在15及25周龄时检测小鼠肿瘤发生过程中T细胞免疫反应及相关细胞因子的变化。结果乳癌术后方能够明显延缓和减少转基因小鼠原发乳腺癌的生成,同时还能上调荷瘤小鼠脾淋巴细胞中T细胞含量,促进荷瘤小鼠T淋巴细胞增殖作用,并可诱导白细胞介素-2(IL-2)、白细胞介素-12(IL-12)和干扰素-γ(IFN-γ)等细胞因子的分泌。结论HER2/neu转基因小鼠与正常同品系未转基因小鼠的免疫功能存在着明显的差别。乳癌术后方预防和延缓乳腺癌发生的作用可能是通过提高转基因小鼠的自身抗肿瘤免疫反应来实现的。     

血脂灵片对脂肪酸合酶的体外抑制作用

目的:研究血脂灵片对脂肪酸合酶(fatty acid synthase,FAS)的体外抑制作用,并初步探索其作用机制。方法:以乙酰辅酶A(AcCoA),丙二酰辅酶A(MalCoA),乙酰乙酰辅酶A(AcAcCoA),乙酰乙酸乙酯,丁烯酸乙酯,原型辅酶Ⅱ(NADPH)等为底物,采用紫外分光光度法,通过测定340 nm下NADPH吸光度值的变化进行FAS活性测定,研究不同剂量血脂灵片对FAS全反应及不同活性中心的体外抑制作用。结果:血脂灵片对FAS具有抑制作用,给药浓度达到150 mg·L-1时,能够抑制51%的酶活性,且对FAS的抑制具有剂量和时间依赖关系。对于FAS的不同活性中心,血脂灵片作用不同,其对烯酰还原反应和AcAcCoA还原反应的抑制稍强于酮酰还原反应,随着给药浓度的增加,对各活性中心的抑制能力逐渐增强,当给药浓度达到150 mg·L-1时,各个活性中心剩余活性均小于70%,但仍保留有50%以上的剩余活性。结论:血脂灵片对FAS具有一定的抑制作用,且对FAS的抑制是通过作用于多个位点实现的。实验为血脂灵片降血脂作用与靶点FAS有关的推断提供了实验依据,并为血脂灵片应用于肥胖症等FAS靶点相关疾病提供了参考。     

雷公藤内酯醇对结肠癌细胞COX-2和iNOS表达的抑制作用

 目的研究雷公藤内酯醇(TP)抑制结肠癌SW114细胞株环氧化酶-2(COX-2)、诱导型一氧化氮合酶(iNOS)及其产物PGE2和NO的表达,探讨TP的抗肿瘤机制。方法不同浓度的TP作用于结肠癌细胞株24h,通过RT-PCR,Western印迹杂交,ELISA检测环氧化酶-2(COX-2)、诱导型一氧化氮合酶(iNOS)及其产物,同时提取各组细胞蛋白质,TransAM测定核转录因子NF-κB活性。结果TP对结肠癌细胞株COX-2和iNOS的表达及其产物PGE2和NO的合成有抑制作用,而且也抑制SW114细胞的NF-κB活性,这些作用与剂量呈依赖关系。结论TP对SW114细胞COX-2和iNOS的表达及其产物PGE2和NO的合成有抑制作用,这种作用可能通过增强TP对核转录因子NF-κB活性的抑制作用而实现,揭示了TP抗肿瘤的部分依据。     

Ramalin‐Mediated Apoptosis Is Enhanced by Autophagy Inhibition in Human Breast Cancer Cells

Breast cancer, the most commonly diagnosed cancer in women worldwide, is treated in various ways. Ramalin is a chemical compound derived from the Antarctic lichen Ramalina terebrata and is known to exhibit antioxidant and antiinflammatory activities. However, its effect on breast cancer cells remains unknown. We examined the ability of ramalin to induce apoptosis and its mechanisms in MCF‐7 and MDA‐MB‐231 human breast cancer cell lines. Ramalin inhibited cell growth and induced apoptosis in both cell lines in a concentration‐dependent manner. By upregulating Bax and downregulating Bcl‐2, ramalin caused cytochrome c and apoptosis‐inducing factor to be released from the mitochondria into the cytosol, thus activating the mitochondrial apoptotic pathway. In addition, activated caspase‐8 and caspase‐9 were detected in both types of cells exposed to ramalin, whereas ramalin activated caspase‐3 only in the MDA‐MB‐231 cells. Ramalin treatment also increased the levels of LC3‐II and p62. Moreover, the inhibition of autophagy by 3‐methyladenine or Atg5 siRNA significantly enhanced ramalin‐induced apoptosis, which was accompanied by a decrease in Bcl‐2 levels and an increase in Bax levels. Therefore, autophagy appears to be activated as a protective mechanism against apoptosis in cancer cells exposed to ramalin. These findings suggest that ramalin is a potential anticancer agent for the treatment of patients with non‐invasive or invasive breast cancer. Copyright © 2015 John Wiley & Sons, Ltd.     

去氢木香内酯诱导乳腺癌SK-BR-3 细胞凋亡的机制研究

目的观察去氢木香内酯(Dehydrocostuslactone,Dehy)对乳腺癌SK-BR-3细胞增殖和凋亡的影响,并探讨其分子机制。方法体外培养乳腺癌SK-BR-3细胞,分别加入不同浓度Dehy(5、10、20、30、40、50、60、80、100μmol·L-1)作用24、48、72 h,采用CCK-8法检测细胞增殖抑制率。将SK-BR-3细胞分为空白对照组(0μmol·L-1)和Dehy 10、20、30μmol·L-1浓度组,干预48 h后,利用倒置显微镜观察乳腺癌SK-BR-3细胞的形态;采用流式细胞术检测细胞周期;Annexin V-FITC/PI双染法检测细胞凋亡率;Hoechst 33258荧光染色法检测细胞凋亡的形态学变化;Western Blot法检测Bcl-2、Bax、Caspase-3和Cleaved Caspase-3蛋白的表达。结果Dehy干预SK-BR-3细胞24、48、72 h后的IC50值分别为24.84、19.39、11.45μmol·L-1,且呈现浓度和时间依赖性。与空白对照组比较,Dehy 10、20、30μmol·L-1浓度组的SK-BR-3细胞数量明显减少,细胞结构松散、轮廓消失、变圆,贴壁不良;Dehy 10、20、30μmol·L-1浓度组的G2/M期细胞比例及细胞凋亡率均显著升高(P<0.05,P<0.01),呈明显的浓度依赖性;Dehy 10、20、30μmol·L-1浓度组的SK-BR-3细胞出现不同程度的细胞核浓染、固缩及碎裂等凋亡现象,且细胞核致密浓染的比例显著升高(P<0.05,P<0.01);Dehy 10、20、30μmol·L-1浓度组的Bax、Caspase-3和Cleaved Caspase-3蛋白表达显著上调(P<0.05,P<0.01),Bcl-2蛋白表达明显下调(P<0.05,P<0.01),Bax/Bcl-2比值明显升高(P<0.05,P<0.01)。结论Dehy能够抑制乳腺癌SK-BR-3细胞的增殖及诱导其凋亡,可能与其调控Bax/Bcl-2/Caspase-3凋亡信号通路来抑制乳腺癌细胞的抗凋亡能力有关。     

丁硫氨酸亚砜胺逆转人乳腺癌多药耐药细胞株耐药性的体外研究

 目的 探讨丁硫氨酸亚砜胺(BSO)对体外培养的人乳腺癌细胞株多药耐药性的影响。方法 以谷胱甘肽（GSH）还原酶循环法检测丁硫氨酸亚砜胺处理前后细胞内谷胱甘肽含量的变化;四甲基偶氮唑蓝比色法检测丁硫氨酸亚砜胺预处理对多柔比星( ADM) 50%抑制浓度（IC50）的影响并进一步计算耐药倍数和逆转倍数;流式细胞仪检测丁硫氨酸亚砜胺对乳腺癌多耐药细胞株MCF-7/ADM凋亡及细胞周期的影响。结果 耐药细胞MCF-7/ADM内谷胱甘肽含量较人乳腺癌MCF-7细胞内谷胱甘肽含量明显增高;丁硫氨酸亚砜胺显著抑制MCF-7/ADM细胞内谷胱甘肽的合成,而对MCF-7细胞内谷胱甘肽合成影响较小;丁硫氨酸亚砜胺在一定浓度范围内能降低多柔比星对MCF-7/ADM细胞的IC₅₀,在50,100,200,400,800 μmol·L^-1浓度时的耐药的逆转倍数分别为1.25、2.02、 8.42、12.65和9.71倍,而对MCF-7细胞的IC₅₀无明显影响;与单纯应用多柔比星组相比,丁硫氨酸亚砜胺及多柔比星联合用药组凋亡细胞比例明显增加,G0/G1期细胞比例增加。结论 丁硫氨酸亚砜胺可通过抑制细胞谷胱甘肽的合成,部分逆转乳腺癌耐药细胞的耐药性,这种作用可能是通过诱导细胞凋亡实现的。     

解毒祛瘀方对乳腺癌细胞MCF-7/ADM的耐药逆转作用

目的:研究解毒祛瘀方对人乳腺癌耐药细胞MCF-7/ADM耐药逆转的作用及机制。方法:以MCF-7/ADM细胞为研究对象,利用噻唑蓝(MTT)比色法检测解毒祛瘀方对人乳腺癌耐药细胞MCF-7/ADM生长的影响;应用流式细胞术检测肿瘤细胞内罗丹明123(Rh-123)的含量;分别利用实时荧光定量聚合酶链式反应(Real-time PCR)及蛋白免疫印迹法(Western blot)检测肿瘤细胞内多药耐药蛋白1(MDR1),乳腺癌耐药相关蛋白(BCRP)mRNA及蛋白表达变化。结果:与空白组比较,经1.25,2.5 g·L~(-1)解毒祛瘀方作用后,阿霉素对人乳腺癌耐药细胞MCF-7/ADM的逆转倍数(RF)分别提升1.7倍和3.0倍(P0.05);人乳腺癌耐药细胞MCF-7/ADM中Rh-123含量分别提高了1.8倍和2.5倍(P0.05),MDR1和BCRP蛋白和mRNA表达水平明显下降(P0.05),1.25,2.5 g·L~(-1)解毒祛瘀方MDR1 mRNA表达分别降低35.5%和56.0%(P0.05),BCRP mRNA表达分别降低41.6%和49.5%(P0.05)。结论:解毒祛瘀方可提高人乳腺癌耐药细胞MCF-7/ADM对阿霉素的敏感性,逆转该细胞对阿霉素的耐药性,其机制可能与降低MDR1和BCRP蛋白和mRNA的表达,抑制细胞药物外排作用相关。     

Zerumbone Suppresses IL‐1β‐induced Cell Migration and Invasion by Inhibiting IL‐8 and MMP‐3 Expression in Human Triple‐negative Breast Cancer Cells

Inflammation is a key regulatory process in cancer development. Prolonged exposure of breast tumor cells to inflammatory cytokines leads to epithelial‐mesenchymal transition, which is the principal mechanism involved in metastasis and tumor invasion. Interleukin (IL)‐1β is a major inflammatory cytokine in a variety of tumors. To date, the regulatory mechanism of IL‐1β‐induced cell migration and invasion has not been fully elucidated. Here, we investigated the effect of zerumbone (ZER) on IL‐1β‐induced cell migration and invasion in breast cancer cells. The levels of IL‐8 and matrix metalloproteinase (MMP)‐3 mRNA were analyzed by real‐time polymerase chain reaction. The levels of secreted IL‐8 and MMP‐3 protein were analyzed by enzyme‐linked immunosorbent assay and western blot analysis, respectively. Cell invasion and migration was detected by Boyden chamber assay. The levels of IL‐8 and MMP‐3 expression were significantly increased by IL‐1β treatment in Hs578T and MDA‐MB231 cells. On the other hand, IL‐1β‐induced IL‐8 and MMP‐3 expression was decreased by ZER. Finally, IL‐1β‐induced cell migration and invasion were decreased by ZER in Hs578T and MDA‐MB231 cells. ZER suppresses IL‐1β‐induced cell migration and invasion by inhibiting IL‐8 expression and MMP‐3 expression in TNBC cells. ZER could be a promising therapeutic drug for treatment of triple‐negative breast cancer patients. Copyright © 2014 John Wiley & Sons, Ltd.     

二氢硫酰胺–S–琥珀酰转移酶在HER2阳性乳腺癌中的功能初探

目的:分析人类表皮生长因子受体2(HER2)阳性乳腺癌患者中二氢硫酰胺–S–琥珀酰转移酶(DLST)的表达水平,评估其对患者生存预后的影响,同时探讨DLST在HER2阳性乳腺癌发生发展中的潜在机制。方法:(1)使用CancerSEA数据库进行筛选,分析乳腺癌中DLST表达的特异性,再通过Kaplan–Meier Plotter数据库研究DLST对不同分型乳腺癌患者预后的影响。(2)采用CancerSEA数据库探索和验证DLST相关的信号通路。通过免疫沉淀、GST–pull down实验确定在HER2阳性乳腺癌中与DLST相互作用的蛋白。(3)利用TIMER 2.0数据库对DLST与免疫细胞浸润的相关性进行分析。结果:DLST在乳腺癌患者中表达升高,DLST表达越高,HER2阳性乳腺癌患者的预后就会越差并且其生存期也会越短;DLST抑制HER2阳性乳腺癌细胞的凋亡;DLST在HER2阳性乳腺癌的M2巨噬细胞中升高。Neddylation修饰后的PTEN蛋白与DLST存在相互作用。结论:DLST在HER2阳性乳腺癌患者中高表达,与其恶性进程呈正相关,且不利于HER2阳性乳腺癌患者的总体生存...     

Resistance‐modifying Activity in Vinblastine‐resistant Human Breast Cancer Cells by Oligosaccharides Obtained from Mucilage of Chia Seeds (Salvia hispanica)

The multidrug resistance (MDR) phenotype is considered as a major cause of the failure in cancer chemotherapy. The acquisition of MDR is usually mediated by the overexpression of drug efflux pumps of a P‐glycoprotein. The development of compounds that mitigate the MDR phenotype by modulating the activity of these transport proteins is an important yet elusive target. Here, we screened the saponification and enzymatic degradation products from Salvia hispanica seed's mucilage to discover modulating compounds of the acquired resistance to chemotherapeutic in breast cancer cells. Preparative‐scale recycling HPLC was used to purify the hydrolysis degradation products. All compounds were tested in eight different cancer cell lines and Vero cells. All compounds were noncytotoxic at the concentration tested against the drug‐sensitive and multidrug‐resistant cells (IC₅₀ > 29.2 μM). For the all products, a moderate vinblastine‐enhancing activity from 4.55‐fold to 6.82‐fold was observed. That could be significant from a therapeutic perspective. Copyright © 2017 John Wiley & Sons, Ltd.     

开郁清热方干预自发2型糖尿病大鼠腹腔脂肪组织SREBP-1c、FAS表达的实验研究

目的:研究开郁清热方对自发2型糖尿病大鼠(OLETF大鼠)腹腔脂肪组织SREBP-1c、FAS蛋白及mRNA表达的影响。方法:将成模OLETF大鼠随机分为模型组、二甲双胍组、开郁清热方组,以LETO大鼠为空白对照组。采用免第疫组化、RT-PCR法检测腹腔脂肪组织SREBP-1c、FAS蛋白及mRNA的表达。结果:开郁清热方组的脂肪组织SREBP-1c、FAS蛋白及mRNA表达水平较模型组明显减低(P<0.01,P<0.05)。结论:开郁清热方具有降低自发2型糖尿病大鼠脂肪组织SREBP-1c、FAS蛋白及mRNA表达的作用。     

银杏叶提取物对乳腺癌MCF-7细胞增殖、凋亡及Caspase-3表达的影响

目的:探讨银杏叶提取物(EGB)对乳腺癌MCF-7细胞增殖、凋亡及半胱氨酸蛋白酶(Caspases)-3表达的影响.方法:将质量浓度为0,10,20,40,80,160 mg·L-1的EGB作用于体外培养的人乳腺癌MCF-7细胞上,培养24h或48 h,然后应用四甲基偶氮唑蓝染色法(MTT法)检测细胞增殖;Annexin V/PI双染色流式细胞仪检测细胞凋亡和细胞周期;酶联免疫吸附法(ELISA)检测Caspases-3蛋白表达.结果:EGB对MCF-7细胞的体外增殖具有抑制作用,量效关系显著,与对照组比较有统计学差异(P＜0.01),半数抑制浓度(IC50)为83.65 mg· L-1.经流式细胞仪检测表明,EGB能使MCF-7细胞G0-G1期逐渐增加,G2-M期和S期逐渐减少,并且随着质量浓度的增加,MCF-7细胞凋亡率明显增加(P＜0.05或P＜0.01).EGB能增强MCF-7细胞Caspases-3蛋白的表达(P＜0.05或P＜0.01),并呈浓度依赖性.结论:EGB能有效抑制人乳腺癌MCF-7细胞Caspases-3蛋白表达,诱导MCF-7细胞凋亡,抑制肿瘤细胞增殖.     

桂枝茯苓丸抑制人乳腺癌细胞MCF-7增殖机制

目的:通过观察桂枝茯苓丸对人乳腺癌细胞MCF-7增殖的影响,并检测细胞周期的变化和蛋白表达的改变,从而探讨桂枝茯苓丸对乳腺癌细胞产生抑制的作用机制。方法:体外培养人乳腺癌细胞MCF-7,以5-氟尿嘧啶(5-Fu,25 mg·L~(-1))作为阳性药,噻唑蓝(MTT)比色法检测不同剂量桂枝茯苓丸培养液和在不同作用时间对细胞的抑制作用;选用1.8,2.7 g·L~(-1)的桂枝茯苓丸培养液作用48 h,流式细胞技术检测5-Fu组和桂枝茯苓丸培养液组的周期,实时荧光定量聚合酶链式反应(Real-time PCR)检测表皮生长因子(EGFR),周期素A2(Cyclin A2)及周期素依赖性激酶2(Cdk2)mRNA表达,蛋白免疫印迹法(Western blot)检测其EGFR,Cyclin A2,Cdk2蛋白表达。结果:桂枝茯苓丸对人乳腺癌细胞MCF-7细胞有抑制作用(P0.05),且具有时间-剂量依赖性。与空白组比较,1.8,2.7 g·L~(-1)桂枝茯苓丸作用MCF-7细胞48 h后S期细胞明显增加(P0.05),EGFR,Cdk2,Cyclin A2mRNA表达明显降低(P0.01);桂枝茯苓丸各质量浓度组中EGFR,Cdk2蛋白表达均下降(P0.05),但Cyclin A2蛋白表达仅2.7 g·L~(-1)组有明显降低(P0.05)。结论:桂枝茯苓丸在S期阻滞MCF-7细胞增殖,这可能与下调Cyclin A2,Cdk2,EGFR mRNA和其蛋白的表达有关。     

川楝素调节丙酮酸激酶M2抑制乳腺癌糖酵解

目的:观察川楝素对乳腺癌糖酵解的干预及糖酵解相关酶的影响。方法:采用人乳腺癌细胞株MDA-MB-231,MCF-7;通过噻唑蓝(MTT)比色法考察川楝素(0,2.5,5,10,20,40,60,80μmol·L-1)对乳腺癌细胞增殖的抑制作用,检测10,20,40μmol·L-1川楝素干预后乳腺癌细胞中葡萄糖消耗,乳酸含量,评价川楝素对乳腺癌细胞糖酵解的干预作用;检测乳腺癌细胞中三磷酸腺苷(ATP)及烟酰胺腺嘌呤二核苷酸(NAD+)/还原型烟酰胺腺嘌呤二核苷酸磷酸(NADH)水平,评价乳腺癌细胞能量供应水平;检测己糖激酶2及丙酮酸激酶活性,考察川楝素对糖酵解相关酶活性影响。蛋白免疫印迹法检测川楝素对乳腺癌细胞中丙酮酸激酶M2蛋白表达的调控作用。结果:川楝素对人乳腺癌MDA-MB-231,MCF-7细胞增殖具有明显抑制作用(P0.05),并呈浓度依赖性;川楝素可以明显降低不同乳腺癌细胞株中葡萄糖消耗及乳酸含量(P0.05),并降低细胞ATP含量(P0.05),升高NAD+/NADH含量(P0.05),抑制肿瘤细胞糖酵解水平。此外川楝素可抑制丙酮酸激酶活性,但对己糖激酶2活性无影响,蛋白检测结果表明,川楝素可以下调丙酮酸激酶M2蛋白表达水平(P0.05)。结论:川楝素可以明显抑制乳腺癌细胞增殖,并影响乳腺癌细胞糖酵解水平,其机制与其干预乳腺癌细胞中丙酮酸激酶M2的表达相关。     

Th1/Th2细胞漂移与乳腺癌化疗疗效的关系及中医“扶正”法对其影响的研究思路

乳腺癌是女性最常见的恶性肿瘤之一,其发病率呈逐年上升趋势。目前,化疗已成为乳腺癌的常规治疗手段之一。化疗作为杀伤性治疗手段,虽然对恶性肿瘤细胞有杀伤作用,但对高度敏感的淋巴细胞也有杀伤作用,对内环境的免疫平衡有"致虚"作用,这一定程度上降低了化疗疗效,因此,通过改善内环境的免疫平衡提高化疗疗效具有极其重要的意义。中医扶正法能够调节机体免疫功能,提高机体各种抗癌细胞因子活性,通过研究中医扶正法对Th1/Th2漂移的影响,可以探讨中医扶正法通过改善肿瘤生存的内环境,达到"增效"的机制。     

乌索酸调节PI3K/AKT/mTOR信号通路在结直肠癌中的研究进展

乌索酸（Ursolic acid,UA）是一种广泛存在于植物的草、叶、花和果实中的具有抗氧化,抗菌,抗炎,肝保护,免疫调节,抗肿瘤,化学预防,心脏保护、抗高脂血症和降低血糖等活性的五环三萜类化合物。本文综述了乌索酸结构与抗肿瘤机制、PI3K/AKT/mTOR信号通路参与结直肠癌进程以及乌索酸调节PI3K/AKT信号通路阻碍结直肠癌进展。     

Curcumin Suppresses Lung Cancer Stem Cells via Inhibiting Wnt/β‐catenin and Sonic Hedgehog Pathways

Cancer stem cells (CSCs) are highly implicated in the progression of human cancers. Thus, targeting CSCs may be a promising strategy for cancer therapy. Wnt/β‐catenin and Sonic Hedgehog pathways play an important regulatory role in maintaining CSC characteristics. Natural compounds, such as curcumin, possess chemopreventive properties. However, the interventional effect of curcumin on lung CSCs has not been clarified. In the present study, tumorsphere formation assay was used to enrich lung CSCs from A549 and H1299 cells. We showed that the levels of lung CSC markers (CD133, CD44, ALDHA1, Nanog and Oct4) and the number of CD133‐positive cells were significantly elevated in the sphere‐forming cells. We further illustrated that curcumin efficiently abolished lung CSC traits, as evidenced by reduced tumorsphere formation, reduced number of CD133‐positive cells, decreased expression levels of lung CSC markers, as well as proliferation inhibition and apoptosis induction. Moreover, we demonstrated that curcumin suppressed the activation of both Wnt/β‐catenin and Sonic Hedgehog pathways. Taken together, our data suggested that curcumin exhibited its interventional effect on lung CSCs via inhibition of Wnt/β‐catenin and Sonic Hedgehog pathways. These novel findings could provide new insights into the potential therapeutic application of curcumin in lung CSC elimination and cancer intervention. Copyright © 2017 John Wiley & Sons, Ltd.     

Rutin,a Quercetin Glycoside,Restores Chemosensitivity in Human Breast Cancer Cells

Several studies have documented the ability of flavonoids to sensitize cancer cells to chemotherapeutics and reverse multidrug resistance by inhibition of efflux pumps (adenosine triphosphate‐binding cassette transporters), apoptosis activation, and cell cycle arrest. In this study, the flavonoid rutin (quercetin 3‐O‐β‐d ‐rutinoside) was investigated as chemosensitizer towards two different human epithelial breast cancer cell lines: (i) MB‐MDA‐231, selected as representative for triple‐negative breast cancer and (ii) MCF‐7 used as a well‐characterized model of HER2‐negative breast cancer. To assess the cytocompatibility of rutin against non‐cancer cells, primary human mammary fibroblasts were used as control and non‐target cells. In MDA‐MB‐231 cells, 20 μM rutin enhanced cytotoxicity related to cyclophosphamide and methotrexate. Rutin significantly (p < 0.05) increased the anticancer activity of both chemotherapeutics, at 24–48–72 h, and decreased the activity of the adenosine triphosphate‐binding cassette transporters, namely, P‐glycoprotein (P‐gp) and breast cancer resistance protein (BCRP). Flow cytometry analysis showed 20 μM and 50 μM rutin arrested cell cycle at G2/M and G0/G1 phases, respectively, significantly promoting cell apoptosis. Rutin, via non‐selective inhibition of P‐gp and BCRP pumps, efficiently reverses multidrug resistance and restores chemosensitivity to cyclophosphamide and cyclophosphamide of human chemoresistant, triple‐negative breast cancer cells, successfully arresting cell cycle progression. Copyright © 2017 John Wiley & Sons, Ltd.     

Selective Inhibition of Cell Proliferation by Lycopene in MCF‐7 Breast Cancer Cells In vitro: A Proteomic Analysis

Lycopene, a red pigmented carotenoid present in many fruits and vegetables such as tomatoes, has been associated with the reduced risk of breast cancer. This study sought to identify proteins modulated by lycopene during cell proliferation of the breast cancer cell line MCF‐7 to gain an understanding into its mechanism of action. MCF‐7 breast cancer cells and MCF‐10 normal breast cells were treated with 0, 2, 4, 6, 8, and 10 μM of lycopene for 72 h. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) tetrazolium reduction assay was used to measure cell proliferation and two‐dimensional fluorescence difference gel electrophoresis to assess the changes in protein expression, which were identified using MALDI‐ToF/ToF (matrix‐assisted laser desorption ionization tandem time‐of‐flight) and Mascot database search. MTT and cell proliferation assays showed that lycopene selectively inhibited the growth of MCF‐7 but not MCF‐10 cells. Difference gel electrophoresis analysis revealed that proteins in the MCF‐7 cells respond differently to lycopene compared with the MCF‐10 cells. Lycopene altered the expression levels of proteins such as Cytokeratin 8/18 (CK8/18), CK19 and their post translational status. We have shown that lycopene inhibits cell proliferation in MCF‐7 human breast cancer cells but not in the MCF‐10 mammary epithelial cells. Lycopene was shown to modulate cell cycle proteins such as beta tubulin, CK8/18, CK19 and heat shock proteins. Copyright © 2012 John Wiley & Sons, Ltd.