Reversal of Multidrug Resistance by Neferine in Adriamycin Resistant Human Breast Cancer Cell Line MCF-7/ADM

Objective: To study the reversal effect of neferine on adriamycin (ADM) resistant human breast cancer cell line MCF-7/ADM. Methods: The cytotoxic effect of Nef or ADM was determined by 3-[4, 5-dimethylthiazol-2.-yl], 5-diphenyl tetraxolium bromid (MTT) assay. Apoptosis and the expression of P-glycoprotein (P-gp) were detected by flow cytometry (FCM). The intracellular ADM concentration was measured by HPLC. Results: Nef at 1, 5, 10 mol/L decreased the IC50 of ADM to MCF-7/ADM from 11.63 g/mL to 4.59, 2.44, 0.27 g/mL respectively. MCF-7/ADM could resist the apoptosis induced by ADM while Nef (1-10 mol/L) could augment ADR-mediated apoptosis. Nef (10 mol/L) increased the accumulation of ADM up to 2.88 fold in MCF-7/ADM but not in sensitive cells MCF-7/S and reduced the expression of P-gp in MCF-7/ADM cells. Conclusion: Nef can circumvent multidrug resistance (MDR) of MCF-7/ADM cells and the mechanism was associated with the increase of intracellular accumulation of ADM and the reduced expression of P-gp in MCF-7/ADM cells.

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.

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.

苦参碱诱导乳腺癌MCF-7细胞凋亡及其对Bax表达的影响

目的探讨苦参碱在体外诱导乳腺癌MCF-7细胞的凋亡作用及其机制。方法用MTT方法检测乳腺癌MCF-7细胞生长抑制率,用流式细胞仪(FCM)分别检测MCF-7细胞凋亡情况,MCF-7细胞线粒体跨膜电位及MCF-7细胞Bax蛋白表达情况。结果苦参碱对乳腺癌MCF-7细胞生长抑制率测定结果显示,不同浓度的苦参碱对MCF-7细胞生长抑制率与对照组相比存在明显差异(P<0.05),呈剂量-效应正相关及时间-效应正相关,流式细胞仪检测MCF-7细胞凋亡,与对照组相比均有显著差异(P<0.05),随着苦参碱浓度的增高,凋亡的发生率也相应提高,呈正相关。线粒体跨膜电位检测,苦参碱处理组MCF-7细胞罗丹明染色阳性数明显低于对照组,存在显著差异(P<0.05),并随苦参碱浓度的增高而减少,呈负相关。流式细胞仪检测Bax蛋白表达显示,Bax蛋白表达上调,与对照组相比,存在显著差异(P<0.05),且随作用浓度增高表达增强,呈正相关。结论中药苦参碱在体外能抑制乳腺癌MCF-7细胞之生长抑制,并能诱导该细胞凋亡。

Synthesis, Characterization, and Evaluation of Antitumor Potential in MCF-7 Cells of Ruthenium-Derived Compounds

To synthesize, characterize and evaluate the antitumor potential derived from ruthenium compounds was generated in this study, from the precursor K[RuCl4(bipy)] a route in a simple and reproducible synthesis for a novel compound of coordinating Ru+3 with bipy and L-trip. The spectroscopic characterization in the middle infrared region (FTIR) shows the interactions between Ru-(L-trip), evidenced by the displacement of the carboxylate ion band for higher energies, and also by the displacements of aliphatic amine bands, suggesting that bidentate coordination of the L-trip ligand occurred. Analysis of the results obtained with thermoanalytical techniques showed that the minimum formula of the compound, [RuCl2(bipy)(L-trip)]1/2H2O. Evaluation of the antitumor potential of precursor K[RuCl4(bipy)] showed the toxic effects on MCF-7 cell line, but did not show selectivity and not reached PBMC cells to the same extent. The evaluation of the antitumor potential of the newly synthesized compound, [RuCl2(bipy)(L-trip)], demonstrated that the insertion of an L-tryptophan molecule into the precursor coordination sphere made it selective when compared to PBMC cells, for MCF-7 type tumor cells.

Breast Cancer MCF-7 Cell Spheroid Culture for Drug Discovery and Development

In vitro 3D cancer spheroids (tumoroids) exhibit a drug resistance profile similar to that found in solid tumors. 3D spheroid culture methods recreate more physiologically relevant microenvironments for cells. Therefore, these models are more appropriate for cancer drug screening. We have recently developed a protocol for MCF-7 cell spheroid culture, and used this method to test the effects of different types of drugs on this estrogen-dependent breast cancer cell spheroid. Our results demonstrated that MCF-7 cells can grow spheroid in medium using a low attachment plate. We managed to grow one spheroid in each well, and the spheroid can grow over a month, the size of the spheroid can grow over a hundred times in volume. Our targeted drug experimental results suggest that estrogen sulfotransferase, steroid sulfatase, and G protein-coupled estrogen receptor may play critical roles in MCF-7 cell spheroid growth, while estrogen receptors α and β may not play an essential role in MCF-7 spheroid growth. Organoids are the miniatures of in vivo tissues and reiterate the in vivo microenvironment of a specific organ, best fit for the in vitro studies of diseases and drug development. Tumoroid, developed from cancer cell lines or patients’ tumor tissue, is the best in vitro model of in vivo tumors. 3D spheroid technology will be the best future method for drug development of cancers and other diseases. Our reported method can be developed clinically to develop personalized drugs when the patient’s tumor tissues are used to develop a spheroid culture for drug screening.

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).

Acid Water-ground Nano-realgar Is Superior to Crude Realgar in Promoting Apoptosis of MCF-7 Breast Cancer Cells

Objective:Realgar is a traditional mineral Chinese medicine with antitumor effects,but it has high toxicity and low efficacy in its crude form.The purpose of this study was to optimize realgar to increase its efficacy and therapeutic potential.Methods:Crude realgar(CR)was mechanically ground to obtain nano-realgar(NR),and then nano-realgar processed products(NRPPs)were obtained using three different traditional Chinese medicine processing methods:grinding in water,acid water,and alkali water,respectively.Results:By analyzing the size distribution of nanoparticles and the content of arsenic trioxide(As_(2)O_(3);ATO),we found that acid water-ground NRPPs had the characteristics of high purity and low toxicity.The effects of CR,NR,and NRPPs on proliferation,cell cycle,and apoptosis of MCF-7 cells were detected,and the ability of NRPPs to induce apoptosis in MCF-7 cells was analyzed.The results showed that the average particle size of acid water-ground NRPPs was 137.7 nm,and the content of ATO was 2.83 mg/g.Acid water-ground NRPPs showed better effects on inhibiting proliferation,cell cycle,and apoptosis of MCF-7 cells than CR and NR.Western blot assays further confirmed that acid water-ground NRPPs upregulated the protein expression of TP53,Bax,cytochrome c,caspase-9,and caspase-3 in MCF-7 cells(P<0.05)and inhibited the expression of Bcl-2(P<0.05).Conclusion:These results suggest that acid water-ground NRPPs can induce apoptosis of MCF-7 cells through regulating mitochondrial-mediated apoptosis,providing evidence for the clinical application of realgar.

Study on regulating mechanisms of oxocrebanine obtained from Stephania hainanensis H.S.Lo et Y.Tsoong on microtubule sites and tubulin in human breast cancer MCF-7 cells

Objective:To determine the destructive ability of oxocrebanine,an anti-breast cancer active compound obtained from Stephania hainanensis H.S.Lo et Y.Tsoong,on microtubule network,and investigate the effect of oxocrebanine on microtubule network homeostasis at both molecular and cellular levels.Methods:the EBI site competition method and molecular docking method were used to determine the occupation of the microtubule site of oxocrebanine.Western Blot was used to detect the effect of oxocrebanine on microtubule-associated proteins including STAT3,PAK1,CAMK4,and PKA.Results:The results of EBI site competition assay showed that the binding of EBI toβ-Tubulin covalent fusions produced adducts that appeared in regions of lower molecular weight thanβ-tubulin(ctrl 2).Molecular docking results showed that oxocrebanine could occupy the colchicine site of microtubule proteins.As revealed by Western Blot,the expression of STAT3 protein was decreased after MCF-7 cells have been treated with low,medium,and high concentration of oxocrebanine or the positive drug taxol for 48 h(P<0.01).The expression levels of PAK1 and Camk4 proteins aslo showed significant reductions(P<0.05,or P<0.01).Oxocrebanine also decreased the PKA protein in MCF-7 cells compared to the control group(P<0.01).Conclusions:Oxocrebanine,a ligand that binds at the colchicine site of tubulin,perturbs tubulin polymerization and causes mitosis in MCF-7 cells,thus leading to MCF-7 cell death.Oxocrebanine may promote microtubule dynamics through stathmin by inhibiting the expression levels of STAT3,PAK1,Camk4,and PKA proteins in MCF-7 cells.Oxocrebanine interfers with spindle formation,and ultimately causes mitotic catastrophe in MCF-7 cells.

Synthesis and Characterization of Trithiocarbonate-Organoclays Nanohybrids and Their Interaction with MCF-7 Cancer Cells

This work presents a new approach for the fabrication of organic/inorganic nanohybrids as anticancer drugs by an intercalation method using S,S-bis（α,α′-dimethyl-α″-acetic acid） （trithiocarbonate） as a modifier and two organoclays, such as reactive octadecylamine/MMT （montmorillonite） and non-reactive dimethyldidodecyl ammonium/MMT. The chemical and physical structures and the surface morphology of these covalently and non-covalently linked nanohybrids were investigated by FT-IR （Fourier translbrm infrared） spectroscopy, ^13C and ^29Si solid state NMR （nuclear magnetic resonance） spectroscopy, XRD （X-ray powder diffraction） and SEM （scanning electron microscopy） analyses, respectively. To evaluate the anticancer activities of the novel BATC/organoclay hybrids against MCF-7 breast cancer cells, a combination of different biochemical and biophysical testing techniques were used. Cell proliferation and cytotoxicity were detected in vitro using a real-time analysis. Cell death was confirmed by using apoptotic and necrotic analyses, the effects of which were detennined by the double staining and Annexin-V-FLUOS testing method. The results demonstrate that intercalated hybrid complexes containing a combination of various anticancer sites, such as free and complexed carboxyl, trithiocarbonate, amine and ammonium cations significantly induced cell death in breast cancer via their interactions with the DNA macromolecules of cancer cells by destroying the self-assemb｜ed structure of growing cells. Fabricated hybrid complexes may represent a new generation of effective and selective anticancer drug systems with a synthetic/natural origin for cancer chemotherapy.

Synthesis, Characterization of Ruthenium Compounds and Studies of Biological Effects in MCF-7 Tumors Cell Lines

This work presents the synthesis and characterization of compounds derived from the ruthenium transition metal with the nitrogenous ligand 4-aminopy- ridine (4-ampy). The synthesized compounds were characterized by FTIRmed spectroscopy and TG-DTA thermal analysis. For the cytotoxic evaluation of ruthenium compounds, a 66.0 μM aqueous solution containing the complex and the study of data observed in the biological assessment was performed using variance (ANOVA) analysis, followed by Tukey’s multiple comparisons test. Differences between treatments were considered significant when the p-value was less than 0.05 (p < 0.05). TG/DSC thermal analysis for the first complex suggests a stoichiometry of [Ru(Cl)3(4-ampy)(H2O)2]·1/2H2O, which, due to the low solubility in an aqueous medium, was modified to increase its solubility for biological tests. The analysis of the spectra in the medium infrared region (FTIR) for the complex [Ru(Cl)3(4-ampy)(H2O)2]·1/2H2O, shows displacements of the bands observed at 1625 - 1566 cm﹣1 ν(C=C) e (C=N), indicating that coordination to the metallic center occurred by this group. Band displacements were observed in the modified Ru (III) complex, which suggests the presence of the 4-ampy ligand and the coordination by the groups ν(C=C) and (C=N) after the modification. In recent years, researchers worldwide have concentrated on obtaining, developing, and modifying drugs used as chemotherapeutic agents. The evaluation of the cell viability of the modified Ru (III) compound demonstrated cytotoxic effects in the MCF-7 cell line (15.33% ± DP 2.7) but did not affect normal cells (PBMC), which reflects the potential for possible applications.

QCM Detection of Adhesion, Spreading and Proliferation of Human Breast Cancer Cells (MCF-7) on a Gold Surface

The quartz crystal microbalance （QCM） was used to monitor the one-day incubation of human breast cancer cells （MCF-7） on the gold electrode. In combination with an optical microscope simulation experiment, the cell-population pictures at various stages, the QCM responses to the cells＇ adhesion, spreading and proliferation on the electrode surface were discussed. The △f0 and △R1 responses were found mainly from mixed effects of viscodensity and surface stress, and in proportion to the cell coverage, rather than to the number of cells at the electrode. The significant fore-and-aft changes in cyclic voltammetry and electrochemical impedance spectroscopy of the ferri-ferrocyanide redox couple also proved that the cells were adhesion to the gold surface.

REVERSION OF MULTIDRUG RESISTANCE IN THE P-GLYCOPROTEIN POSITIVE BREAST CANCER CELL LINE(MCF-7/ADR) BY INTRODUCTION OF HAMMERHEAD RIBOZYME

A hammerhead ribozyme which site-specifically cleaved the GUC position in canon 880 of the mdr1 mRNA was designed. The target site was chosen between the two ATP binding sites, which may be important for the function of the P-Gp as an ATP-dependent pump. A DNA sequence encoding the ribozyme gene was then incorporated into a eukaryotic expression vector (pH Apr-1 neo) and transfected into the breast cancer cell line MCF-7/Adr, which is resistant to adriamycin and expresses the MDR phenotype. The ribozyme was stably expressed in the cell line by the RNA dot blotting assay. The result of Northern blot assay showed that the expressed ribozyme could decrease the level of mdrl mRNA expression by 83. 5 %; and the expressed ribozyme could inhibite the formation of p-glycoprotein detected by immuno- cy-tochemistry assay and could reduce the cell’s resistance to adrimycin; this means that the resistant cells were 1 000-fold more resistant than the parental cell line(MCF-7), whereas those cell clones that showed ribozyme expression were only 6-fold more resistant than the parental cell line. These results show that a potentially useful tool is at hand which may inactivate MDR1 mRNA and revert the multidrug resistance phenotype.

Studies on mechanism of cis9,trans11-CLA and trans10,cis12-CLA inducing apoptosis of human breast cancer cell line MCF-7

Objective： The aim of the study was to explore the activities of cis9, trans11-CLA （C9, t11-CLA） and transl0, cis12-CLA （t10, c12-CLA） inhibiting tumor, and investigate their relationships with PPARy and apoptotic proteins, and mechanism of anti-cancer. Methods： The inhibitory rate, cell growth curve and apoptotic morphological observation of MCF-7 cells were obtained by MTT assay, trypan blue staining and Hoechst33342 fluorescence staining. The apoptotic rate and cell cycle were detected with flow cytometry. Transcriptional level of genes was detected with RT-PCR semi-quantitative method, and Western blot was performed to detect proteins levels. Results： The two CLA isomers could reduce cell proliferation （P 〈 0.05）, increase apoptotic rate （P 〈 0.05）, and increase obviously the transcriptional and protein levels of PPARy （P 〈 0.01）. The synchronism and correlation between the effects of CLA to PPARy and apoptotic proteins Bax, Bcl-2, Caspase 3 changes were found with the dose- and time-dependent manners. There was cooperative relation between the levels of PPARy and the rates of Bax/Bcl-2, Caspase 3 （small fragment） by experiments of PPARy inhibitor GW9662 and ligand Rosiglitazone. Conclusion： The apoptotic pathway of PPARy-Bcl-2-Caspase 3 signaling was found. The C9, t11-CLA and tl0, c12-CLA could inhibit MCF-7 cell proliferation and promote apoptosis via activating PPARy-Bcl-2-Caspase 3 pathway. CLA may be a kind of activator of PPARv.

人参皂甙Rg3诱导乳腺癌细胞系MCF-7凋亡的实验研究

背景与目的:人参皂甙Rg3[20(R)-GinsenosideRg3]是从红参中提取的微量中药单体。近年研究表明人参皂甙Rg3尚具有抑制肿瘤细胞的增殖、抗肿瘤细胞浸润和转移等作用。肿瘤的发生和发展是一个极其复杂的过程,有多种转移相关的蛋白因子参与,并涉及多种转移途径和分子机制。人参皂甙Rg3抗肿瘤机制的研究为目前中药抗肿瘤研究热点之一。本研究的目的在于探讨Rg3抑制乳腺癌细胞的作用及其诱导凋亡的机制。材料与方法:四甲基偶氮唑蓝(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide,MTT)法检测人乳腺癌细胞MCF-7的细胞增殖活力;荧光染色观察凋亡细胞的形态学变化;流式细胞术分析细胞周期及细胞凋亡;琼脂糖凝胶电泳测定DNA梯状带。结果:Rg3与MCF-7细胞生长抑制率之间有浓度依赖关系,相关系数(r)=0.953,Rg3处理细胞48h的IC50为71.91μg/ml;荧光显微镜下观察到经Rg3作用后,MCF-7细胞出现染色质凝集、核片段化、凋亡小体等凋亡形态学特征;流式细胞术检测表明Rg3能诱导细胞凋亡及调节细胞周期,用150μg/ml的Rg3处理细胞48h后,S期和G2-M期的细胞比率增加,G0-G1的细胞比率下降。细胞凋亡率从对照组的(0.45±0.25)%上升到(34.86±4.65)%。DNA琼脂糖凝胶电泳结果显示,服150μg/ml的Rg3处理细胞24h和48h后,能够使细胞产生明显的梯形电泳图谱(DNAladder)。结论:Rg3可通过诱导MCF-7细胞凋亡而发挥其抑制细胞增殖的作用。

影响MCF-7细胞增殖试验相关因素的初步研究

目的 了解影响MCF 7细胞增殖试验相关因素 ,为MCF 7细胞增殖试验检测环境雌激素方法的标准化提供试验依据。方法 对不同来源的MCF 7细胞雌激素敏感性进行检测 ,对筛选出的敏感细胞在不同培养条件、去激素培养基中培养不同时间进行细胞增殖试验。结果 不同来源MCF 7细胞对雌激素敏感不同 ;培养基中酚红、血清中内源性雌激素对MCF 7细胞有刺激增殖作用 ;MCF 7细胞在去激素培养基中培养时间越长 ,对雌激素越敏感。结论 进行MCF 7细胞增殖试验前应进行雌激素敏感试验 ,选用敏感细胞 ;

FTY720对体外培养MCF-7细胞增殖及凋亡影响的研究

目的探讨FTY720对体外培养MCF-7细胞增殖及凋亡的影响。方法体外培养MCF-7细胞,将其培养液中加入不同浓度的FTY720,继续培养48小时,MTT法检测MCF-7细胞的增殖情况;瑞士-姬姆萨染色观察细胞形态变化;流式细胞仪检测FTY720对MCF-7细胞的细胞周期、凋亡率的影响。结果当FTY720浓度为6 400 ng/ml时,体外培养MCF-7细胞的增殖受到明显抑制,抑制率为62.0%(P<0.05),而且抑制率呈浓度依赖性;镜下可见细胞出现凋亡的形态;流式细胞仪检测分析显示FTY720可将MCF-7细胞阻滞于G1期,并促进其发生凋亡,凋亡率呈浓度依赖性。结论在体外培养的MCF-7细胞培养液中加入一定浓度的FTY720,能明显抑制该细胞的增殖,调节该细胞周期并诱导其凋亡。

二甲双胍联合紫杉醇诱导人乳腺癌细胞MCF-7凋亡的作用机制研究

目的探讨二甲双胍联合紫杉醇诱导人乳腺癌细胞MCF-7凋亡的作用机制。方法以CCK-8试剂盒检测不同浓度二甲双胍(0.25、0.50、1.00、2.00、4.00 mmol/L)、紫杉醇(0.025、0.050、0.100、0.200、0.400μmol/L)单独作用或联合作用MCF-7细胞48 h后对细胞增殖的半抑制浓度(IC50)值;以流式细胞仪检测二甲双胍、紫杉醇作用MCF-7细胞48 h后的细胞周期分布;以Western blot法检测紫杉醇、二甲双胍单独作用或联合作用MCF-7细胞48 h后MAPK通路蛋白及Bcl-2、Bax蛋白的表达。结果较低浓度的二甲双胍(0.25～4.00 mmol/L)与紫杉醇(0.025～0.400μmol/L)联合作用具协同效果(CI<1);sp600125可显著抑制MCF-7细胞增殖,联合二甲双胍与紫杉醇对MCF-7细胞增殖的抑制作用明显强于二者单独作用;二甲双胍与紫杉醇联合时G_2/M期细胞少于紫杉醇单药应用,多于二甲双胍单药应用;二甲双胍与紫杉醇联合作用MCF-7细胞48 h后p-JNK/SAPK、p-p38蛋白表达明显高于二者单用,p-ERK、Bcl-2蛋白表达降低(P <0.05)。结论二甲双胍联合紫杉醇作用人乳腺癌细胞MCF-7具协同效果,其与sp600125联合时对细胞的抑制作用显著增强。二甲双胍与紫杉醇联合作用还可抑制细胞在G_2/M期聚集及ERK通路,激活JNK、p38通路,降低Bcl-2与Bax蛋白比例。

FUT8基因RNAi慢病毒载体的构建及对MCF-7细胞增殖的影响

旨在构建FUT8基因RNA干扰(RNAi)慢病毒载体并观察其对人乳腺癌细胞MCF-7增殖的影响。针对FUT8基因设计3组短发夹RNA序列,退火合成双链DNA,通过连接线性化的p GC-LV-GFP载体,构建mi RNA慢病毒载体质粒,并将其转化至感受态细胞DH5α;测序验证正确后进行FUT8基因慢病毒载体的包装及病毒滴度测定,将获得的重组慢病毒p GC-sh FUT8转染MCF-7细胞,利用Real time-PCR、Western blot分别验证转染后MCF-7细胞中FUT8 m RNA及蛋白的表达,MTT法及克隆形成实验检测sh FUT8对MCF-7细胞增殖能力的影响。测序证实成功构建针对FUT8基因的RNAi慢病毒载体;慢病毒载体经293T细胞包装成功,测定病毒悬液滴度>5×108 TU/m L;荧光显微镜下观察各转染组细胞GFP的表达,转染效率达90%以上;Real-time PCR、Western blot结果显示干扰组FUT8的m RNA及蛋白表达水平较对照组显著降低,其中p GC-sh FUT8-2序列对FUT8基因的干扰效率可达80%,干扰效果最佳,FUT8沉默后MCF-7细胞增殖能力下降。

三苯氧胺(TAM)及靶向CLC-3反义核苷酸对MCF-7(ER+)增殖的影响

目的研究氯离子通道CLC-3反义核苷酸及三苯氧胺对乳腺癌MCF-7细胞株增值的影响,探讨其在乳腺癌治疗方面的生物学基础,为临床乳腺癌的内分泌治疗及生物治疗提供参考。方法将MCF-7细胞分成如下6组,对照组(control group);实验组1:CLC-3反义核苷酸;实验组2:TAM 10μM;实验组3:TAM 20μM;实验组4:CLC-3反义核苷酸+TAM 10μM;实验组5:CLC-3反义核苷酸+TAM 20μM。单纯给予TAM时,于给药后24h收集细胞,以MTT比色法分析。结果随着TAM浓度从0逐渐增加到25μM,MCF-7细胞较对照组的增殖抑制率逐渐增加,呈剂量依赖性。0-10(P<0.05),10-20μM(P<0.01),单纯用反义链阻断CLC-3时MCF-7细胞的增殖没有明显受到抑制。CLC-3反义核苷酸+TAM 10μM与对照组相比有差异(P<0.05);CLC-3反义核苷酸+TAM 20μM较对照组相比有明显差异(P<0.01)。CLC-3反义核苷酸+TAM 10μM与TAM 10μM对比两组之间有差异(P<0.05);CLC-3反义核苷酸+TAM20μM与TAM 20μM对比两组之间有明显差异(P<0.01)。结论 TAM有抑制乳腺癌细胞株MCF-7增殖的作用,CLC-3反义核苷酸可以增加这种作用,且随TAM的浓度增加两者之间的协同作用增大。为临床乳腺癌的内分泌治疗及生物治疗提供了参考。