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.

Methanolic extract of Abrus precatorius promotes breast cancer MDA-MB-231 cell death by inducing cell cycle arrest at G0/G1 and upregulating Bax

Objective:To determine the anti-proliferative activity of Abrus precatorius(A.precatorius)leaf extracts and their effect on cell death.Methods:A.precatorius leaves were extracted successively with hexane,ethyl acetate and methanol by Soxhlet extraction.Aqueous extract was prepared by decoction at 50 ℃.Extracts of A.precatorius leaves were used to treat selected cancer and normal cell lines for72 h.Furthermore,3-(4,5-dimethyl thiazol-2-yl)2,5-diphenyl tetrazolium bromide assay was performed to determine cell viability.Analysis of cell cycle arrest,apoptosis assay and apoptosis protein expressions were determined by flow cytometry.Results:Methanolic extract of A.precatorius leaves showed the lowest IC50 on MDA-MB-231 cells at(26.40±5.40)μg/mL.Flow cytometry analysis revealed that cell arrest occurred at G0/G1 phase and the apoptosis assay showed the occurrence of early apoptosis at 48 h in MDAMB-231 cells treated with methanolic extract of A.precatorius leaves.Methanolic extract of A.precatorius leaves induced apoptosis by upregulation of Bax,p53 and caspase-3 and downregulation of Bcl-2.Conclusions:Methanolic extract of A precatorius leaves promotes MDA-MB-231 cell death by inducing cell cycle arrest and apoptosis possibly via the mitochondrial-related pathway.

Effect of amlodipine on apoptosis of human breast carcinoma MDA-MB-231 cells

Objective： To elucidate the effects of amlodipine on the proliferation and apoptosis of human breast carcinoma MDA-MB-231 cells. Methods： Light microscopy was used to determine the effects of amlodipine on cell morphology; Flow cytometry was used to quantitate cells undergoing apoptosis; the expression of a cell cycle-related protein, proliferating cell nuclear antigen （PCNA） and an antiapoptosis protein, Bcl-2 were assessed by immunocytochemistry. Results： Amlodipine concentration of 8.25umol/L （1/2 of ICs0） affected the morphology, decreased the expression of PCNA and Bcl-2 and induced apoptosis of human breast carcinoma MDA-MB-231 cells. Conclusion： The effect of amlodipine on the antiproliferation of human breast carcinoma MDA-MB-231 cells is related to inducement of apoptosis, and the decrease of the expression of Bcl-2 and PCNA may be the possible mechanism for proliferation inhibitory and inducement of apoptosis.

Investigating the effects of Pentoxifylline on human breast cancer cells using Raman spectroscopy

Breast cancer is one of the leading causes of cancer-related deaths in a global scenario.In the present study,biochemical changes exerted upon Pentoxifylline(PTX)treatment had been ap-praised in human breast cancer cells using Raman spectrosecopy.There are no clinically approved methods to monitor such therapeutic responses available.The spectral profiling is suggestive of changes in DNA,protein and lipid contents showing a linear relationship with drug dosage.Further,multivariate analysis using principal component based linear-discriminant-analysis(PC-LDA)was employed for dlassifying the control and the PTX treated groups.These findings support the feasibility of Raman spectroscopy as an alternate/adjunct label-free,objective method for monitoring drug-induced modifications against breast cancer cells.

Sensitivity Evaluation of Two Human Breast Cancer Cell Lines to Tamoxifen through Apoptosis Induction

Tamoxifen citrate (TAM) has been used to treat breast cancer in women for many years. The com-parative effects of TAM in inducing apoptosis were evaluated in estrogen receptor-positive (ER- positive MCF-7) and estrogen receptor-negative (ER-negative MDA-MB-231) human breast cancer cell lines in vitro in order to determine if these two cell lines differ in their sensitivity to TAM. Mi-tochondrial membrane permeability potential disruption was assessed in both cell lines by a lip-ophilic cationic dye (DePsipher assay, Trevigen, Inc.) utilizing fluorescence microscopy. Using this specific fluorochrome, we were able to associate mitochondrial membrane disruption to early, mid-, and late apoptotic cells. TAM induced cell death via apoptosis in both ER-positive and ER- negative cells, however, apoptosis induction was more pronounced in ER-positive MCF-7 compared to ER-negative MDA-MB-231 breast cancer cells. These findings may have some therapeutic use in the treatment of estrogen dependent and estrogen independent breast cancer.

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.

The establishment of stable transfection of human breast cancer cell line MDA-MD-468 with exogenous PTEN gene

To investigate exogenous PTEN gene transfected human breast cancer cell line MDA-MD-468.Methods Using the lipofectamine 2000 transfection technique,wild type PTEN gene was transducted into an in vitro cultured highly metastatic breast cancer cell line MDA-MD-468.After transfection,the cells were selected by G418.The resistant clones were chosen and expanded in DMEM culture medium.RT-PCR,immunohistochemical method and western blot were used to determine the expression of target genes.Results An anti-G418 cell clone was established and expanded in culture.The transfected PTEN gene MDA-MD-468 cells showed expression of PTEN mRNA and PTEN protein.Conclusion Human breast cancer cell line MDA-MB-468 established in this study expresses consistently exogenous PTEN genes.4 refs,6 figs.

Piperine suppresses growth and migration of human breast cancer cells through attenuation of Rac1 expression

Objective:To investigate the effect of piperine on human breast cancer cells.Methods:The effect of piperine on proliferation and migration of human breast cancer cells,MCF-7 and MDA-MB-231,was investigated using colony formation assays,wound healing assays,Matrigel migration assays,flow cytometry,RT-qPCR,and Western blotting assays.Results:Piperine inhibited the growth of MCF-7 and MDA-MB-231 cells and suppressed colony formation.Cell reduction at the G_(0)/G_(1) phase and cell arrest at the G_(2)/M phase were observed in breast cancer cells.However,the significant effect was only demonstrated in MDA-MB-231 cells.Moreover,cancer cell migration was suppressed by piperine at low concentration.RT-qPCR and Western blotting assays showed that piperine downregulated Rac1 gene and protein expression.Conclusions:Piperine could inhibit growth and migration of breast cancer cells by reducing Rac1 gene and protein expression.

Effect of Guizhi Fuling capsule and its extracts on human breast cancer cells proliferation

OBJECTIVE To evaluate the effect of Guizhi Fuling Capsule active pharmaceutical ingredient(API)and its fractions on human breast cancer cells proliferation by high-throughput screening assay.METHODS The crude fractions were obtained from the extraction and elution of the API of Guizhi Fuling Capsule,and 929 standard fractions were obtained by the optimal separation conditions.Sulforhodamine B(SRB)method was used to evaluate the effects of the Guizhi Fuling capsule API and929 kinds of fractions on the proliferation of human breast cancer cells MCF-7 and MDA-MB-231.RESULTS The Guizhi Fuling capsule API had a strong ability to inhibit the proliferation of MCF-7 cells at high concentration and the ability to inhibit MDA-MB-231 cells' proliferate at low concentration following 72 h treatment;some samples of 929 fractions(5μg·mL^(-1))was found to have a breast cancer cell growth inhibition rate above 50%,without toxicity on HUVECs proliferation.CONCLUSION The API of Guizhi Fuling capsule had significant cytotoxicity effects on these two human breast cancer cells,with significant concentration-and time-dependent manner.

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.

青葙苷A抑制缺氧乳腺癌MDA-MB-231细胞增殖、迁移和侵袭能力的研究

目的探索中药青葙子中的齐墩果烷型三萜化合物青葙苷A(celosin A,CA)对缺氧人乳腺癌MDAMB-231细胞的抗肿瘤作用及其相关机制。方法CoCl2造模MDA-MB-231细胞缺氧状态,建立细胞体外缺氧的CA给药培养体系。采用细胞计数试剂盒(MTT)检测细胞活力,免疫荧光法观察细胞形态学和核凋亡变化。流式细胞术(FCM)法检测细胞凋亡比例;细胞划痕实验检测细胞迁移能力;Transwell法检测CA对肿瘤细胞迁移和侵袭的抑制能力;Western blot实验检测缺氧相关蛋白表达水平和EMT标志蛋白表达水平。结果在缺氧状态下,高剂量的CA(20、40μmol/L)能抑制乳腺癌MDA-MB-231细胞增殖,诱导肿瘤细胞核凋亡的形态学改变,并且能有效促进早晚期细胞的凋亡率(PI-Annexin V-FITC促凋亡率:20μmol/L:+6.09%;40μmol/L:+18.50%),有效抑制乳腺癌MDA-MB-231细胞的缺氧诱导因子-1α(HIF-1α)、单核细胞趋化蛋白(MCP)、血管内皮生长因子(VEGF)表达;同时低剂量的CA(5、10μmol/L)能抑制乳腺癌MDA-MB-231细胞的Vimentin和N-cadherin因子的表达,并减少乳腺癌MDA-MB-231细胞迁移和侵袭细胞的数量(转移抑制率:5μmol/L,26.90%;10μmol/L,66.13%;侵袭抑制率:5μmol/L,23.71%;10μmol/L,75.00%)。结论CA能对缺氧乳腺癌MDA-MB-231细胞起到有效地诱导凋亡、抗肿瘤血管形成以及抑制侵袭与转移的作用。

Inhibitory Effects of Mild Hyperthermia plus Docetaxel Therapy on ER(+/–) Breast Cancer Cells and Action Mechanisms

Summary： The purpose of this study was to verify that a combination of mild hyperthermia and do- cetaxel chemotherapy produces synergistic antitumor effects and to explore the action mechanisms of this treatment approach. The effects of docetaxel on the proliferation of cells from the estrogen receptor （ER）-positive human breast cancer cell line MCF-7 and the ER-negative human breast cancer cell line MDA-MB-453 were examined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, and effective experimental concentrations of docetaxel were determined. The effects of mild hy- perthermia plus docetaxel therapy on apoptosis rate in the MCF-7 and MDA-MB-453 human breast cancer cell lines were analyzed by using flow cytometry with Annexin-V fluorescein isothiocyanate （FITC）/propidium iodide （PI） staining. The effects of these combined treatments on cell cycle progres- sion in the MCF-7 and MDA-MB-453 human breast cancer cell lines were examined by using flow cy- tometry. The effects of these combined treatments on the expression of apoptosis-related proteins and proteins in the mitogen-activated protein kinase （MAPK） pathways were analyzed by using Western blotting. The effects of these combined treatments on the expression of the heat shock protein 70 （HSP70） and the multi-drug resistance （MDR） gene product P-glycoprotein （Pgp） were examined by using Western blotting. The results showed that the half-maximal inhibitory concentration （IC50） of do- cetaxel for MCF-7 and MDA-MB-453 cells was 19.57±1.12 and 21.64±2.31 gmol/L respectively. Mild hyperthermia with docetaxel therapy could increase apoptosis rate in the MCF-7 and MDA-MB-453 cells. Apoptosis rate in MCF-7 and MDA-MB-453 cells was increased from （23.66±3.59）% and （18.51±3.17）% in docetaxel treatment group to （47.12±6.73）% and （55.16±7.42）% in mild hyperthermia plus docetaxel group, indicating that the mild hyperthermia and docetaxel therapeutic approaches exhib- ited significant synergistic antitumor effects. Treatments of mild hyperthermia plus docetaxel induced G2/M cell cycle arrest in the MCF-7 and MDA-MB-453 cells. Western blotting demonstrated that pro- teins in the MAPK pathway were expressed at higher levels in docetaxel-treated cells following mild hypothermia than those in cells treated with docetaxel alone. As compared with blank control group, cells from the mild hyperthermia plus docetaxel group exhibited significantly decreased B-cell lym- phoma 2 （Bcl-2） protein expression but slightly increased Bcl-2-associated X protein （Bax） expression. Western blotting results revealed that HSP70 and Pgp expression levels were significantly increased following mild hypothermia. It was concluded that treatments of mild hyperthermia plus docetaxel in- hibited the proliferation of human breast cancer cells, promoted apoptosis of breast cancer cells, and produced synergistic antitumor effects.

Meclizine Chloridrate and Methyl-β-Cyclodextrin Associated with Monophosphoester Synthetic Phosphoethanolamine Modulating Proliferative Potential in Triple-Negative Breast Cancer Cells

Synthetic phosphoethanolamine(Pho-s)is a monophosphoester ester with anti-inflammatory and pro-apoptotic properties.Meclizine chloridrate(MC)is a histamine H1 receptor blocker that is also able to inhibit cellular respiration.However,MC does not inhibit cellular respiration in isolated mitochondria such as antimycin and rotenone.Methyl-β-cyclodextrin(MβCD)belongs to theβ-cyclodextrin family,which is capable of removing cholesterol from the plasma membrane.The aim of this study was to evaluate the proliferative effects of meclizine chloridrate and methyl-β-cyclodextrin compounds associated with synthetic phosphoethanolamine in a triple-negative human breast tumor line,MDA-MB-231 Cell viability of the tumor line and normal cells FN1 was evaluated by MTT colorimetric test;the production of free radicals was determined by lipoperoxidation(LPO)test;and the percentage of cell cycle phases and proliferative index was evaluated by flow cytometry.Cell viability demonstrated a significant decrease with the treatments of MβCD,MC and Pho-s associated with MC.The production of free radicals decreases significantly in all treatments.In addition,a significant increase of DNA fragment and decrease in G0/G1 cell cycle phase were observed in cellular percentage with concentrations of 20 and 30 mM of Pho-s in association with MC and MβCD,respectively.

羊肚菌多糖抑制人乳腺癌细胞MDA-MB-231增殖和诱导细胞凋亡研究

以黑脉羊肚菌多糖为原料,研究羊肚菌多糖对人乳腺癌细胞MDA-MB-231(以下简称MDA)增殖和凋亡的影响。结果表明:在无细胞毒性范围内,羊肚菌多糖能显著抑制人乳腺癌细胞MDA的增殖,半数有效浓度(median effective concentration,EC_(50))值为0.096 mg/m L,同时人乳腺癌细胞MDA表现出多种细胞凋亡的形态学变化。免疫印迹检测实验结果显示,羊肚菌多糖能抑制B淋巴细胞瘤-2(B-cell lymphoma-2,Bcl-2)蛋白表达,促进Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)表达,同时增加Bax/Bcl-2蛋白表达比值,并呈现出剂量依赖效应。说明羊肚菌多糖能抑制人乳腺癌细胞MDA增殖,促进细胞凋亡。

Livin靶向RNA干扰对MDA-MB-231细胞增殖和凋亡的影响

目的研究凋亡抑制蛋白Livin靶向RNA干扰MDA-MB-231对细胞增殖和凋亡的影响,探讨其可能的机制。方法构建3个靶向Livin的siRNA真核表达载体,分别转染乳腺癌细胞MDA-MB-231后,通过RT-PCR、Western blot技术检测干扰前后MDA-MB-231细胞Livin、Caspase-3和Smac/DIABLO在mRNA、蛋白水平的表达;采用MTT法检测对细胞增殖的抑制作用,流式细胞法测细胞周期,TUNEL法检测细胞凋亡以及观察细胞形态变化。结果成功构建了针对Livin基因的3个特异性siRNA表达载体。它们不同程度地抑制了MDA-MB-231细胞Livin基因的表达,以si-Livin2抑制效率最高,它对Livin的mRNA和蛋白的抑制率分别达76.4%,70.2%。si-Livin2转染48 h后,与未转染组相比,细胞增殖活力受到抑制,转染48 h抑制率达36.1%。细胞周期重新分布,G0/G1期上升为(71.75±1.31)%,S期下降为(18.06±1.46)%;细胞凋亡率上升为(13.28±1.65)%;电镜下可见典型的凋亡细胞特征。细胞内Caspase-3, Smac/DIABLO的mRNA、蛋白表达有所上升。结论 Livin靶向RNA干扰通过上调Caspase-3, Smac/DIABLO表达有效地抑制MDA-MB-231细胞增殖,促进凋亡。

甘精胰岛素和人胰岛素对人乳腺癌MDA-MB-231细胞的增殖作用

目的探讨甘精胰岛素(insulin glargine)和人胰岛素(human insulin)对人乳腺癌细胞株MDA-MB-231增殖的影响及细胞外信号调节激酶(ERK)的调节作用。方法使用不同浓度的甘精胰岛素和人胰岛素刺激人乳腺癌MDA-MB-231细胞株,检测不同时间段的细胞增殖作用,探讨抑制ERK1/2激活对细胞增殖的影响。使用cell counting kit-8(CCK-8)试剂检测细胞增殖,流式细胞术检测细胞周期分布。结果甘精胰岛素和人胰岛素在1、10、100IU.L-1刺激MDA-MB-231细胞96h后均可轻度促进MDA-MB-231细胞增殖,相同条件下甘精胰岛素和人胰岛素的促增殖效应无差异。甘精胰岛素与人胰岛素以10IU.L-1分别刺激48、72、96h后两药均诱导细胞增殖,比较两种药物间增殖效应的差异无统计学意义。甘精胰岛素和人胰岛素均使S+G2/M期细胞比例增加,但两处理组间差异无显著性。ERK1/2抑制剂PD98059可抑制MDA-MB-231细胞增殖;但PD98059不影响甘精胰岛素和人胰岛素对MDA-MB-231细胞增殖的促进作用。结论甘精胰岛素和人胰岛素对人乳腺癌细胞株MDA-MB-231增殖有类似的轻度促进作用,该作用不依赖于ERK的激活。

用于活体成像的人三阴性乳腺癌MDA-MB-231细胞系的构建

目的构建能稳定表达荧光素酶和绿色荧光蛋白的人三阴性乳腺癌MDA-MB-231细胞系以建立可用于活体成像的三阴性乳腺癌裸鼠移植瘤模型。方法采用磷酸钙共沉淀的方法构建表达荧光素酶和绿色荧光蛋白的慢病毒载体,体外感染MDA-MB-231细胞,经G418筛选得到稳定细胞系后,通过活体成像评价感染后细胞表达荧光素酶的情况,并通过MTT法、transwell肿瘤侵袭模型、细胞划痕实验等评价细胞的增殖、侵袭及转移能力是否改变;此外将细胞接种至雌性BALB/c-nu//nu裸小鼠的右侧第2对乳房垫内,构建乳腺癌原位肿瘤模型。利用活体成像系统监测体内肿瘤的生长及转移情况,并通过冰冻切片、HE染色评价细胞系在活体内的稳定性及成瘤能力。结果成功构建能稳定表达荧光素酶和绿色荧光蛋白的MDA-MB-231细胞系,荧光素酶的活性达到每细胞9689 photons/s,慢病毒的整合没有改变细胞的增殖、迁移及侵袭能力;成功建立了乳腺癌裸鼠原位移植瘤模型。结论(1)慢病毒以其高效稳定的感染率,应作为标记荧光素酶基因的首选载体;(2)带有荧光素酶的MDA-MB-231细胞在动物体内可被快速而灵敏的检测到,这将为人三阴性乳腺癌转移机制的研究及抗肿瘤药物的研发提供一个直观、方便及灵敏的平台;(3)荧光素酶和荧光蛋白基因双标记优于单标记。

二甲双胍联合多西他赛对乳腺癌细胞MDA-MB-231增殖和凋亡的影响

目的:通过二甲双胍联合多西他赛观察对乳腺癌细胞MDA-MB-231增殖和凋亡的抑制作用。方法:实验分为4组:多西他赛联合二甲双胍组、单用多西他赛组、单用二甲双胍组以及空白对照组。平板克隆实验检测多西他赛联合二甲双胍对MDA-MB-231细胞克隆形成能力的影响,MTT实验检测多西他赛联合二甲双胍对MDA-MB-231细胞克增殖能力的影响,流式细胞仪检测多西他赛联合二甲双胍对MDA-MB-231细胞凋亡能力的影响。结果:平板克隆实验、MTT实验和流式细胞仪凋亡检测实验结果分别显示:多西他赛联合二甲双胍中细胞的克隆率、增殖能力下降高于单用多西他赛组、单用二甲双胍组以及空白对照组(P<0.05),而凋亡率多西他赛联合二甲双胍组亦高于其它各对照组(P<0.05)。结论:二甲双胍联合多西他赛能够显著降低乳腺癌细胞MDA-MB-231的克隆和增殖能力,同时增加MDA-MB-231的凋亡能力,两者的联合具有协同杀伤肿瘤细胞的作用。

活化Notch3信号通路抑制MDA-MB-231细胞的增殖

目的 活化Notch3信号可以通过上调p27的表达抑制MDA-MB-231细胞的增殖.方法 用脂质体转染法将质粒转入体外培养的MDA-MB-231细胞,用Western印迹法和RT-PCR检测Notch3和p27基因的表达用CCK-8检测细胞增殖率;用平板克隆检测细胞克隆形成率;用流式细胞仪检测细胞周期.结果 Western印迹法和RT-PCR检测结果显示,在MDA-MB-231细胞中表达Notch3后,p27的表达上调.过表达Notch3后的MDA-MB-231细胞增殖减慢,第3天起差异均有统计学意义（P＜0.01）;克隆形成率降低,差异有统计学意义（P＜0.05）;细胞周期阻滞在G0/G1期,转目的基因组G0/G1期细胞所占比例（72.47±1.75）％与对照组（60.16±3.29）％相比差异有统计学意义（P＜0.01）.结论 活化的Notch3信号通路可以上调p27表达,使细胞周期阻滞于G0/G1期,抑制MDA-MB-231乳腺癌细胞的增殖.这一发现或许能为三阴性乳腺癌的分子靶向治疗提供新的思路.

Ghrelin抑制多柔比星诱导人乳腺癌细胞MDA-MB-231凋亡的实验研究

目的:探讨Ghrelin抑制多柔比星诱导人乳腺癌细胞MDA-MB-231凋亡的机制。方法 :通过细胞培养、MTT、流式细胞检测、Tunnel法和Western blot观察酰基化Ghrelin对多柔比星诱导的人乳腺癌细胞MDA-MB-231凋亡和凋亡相关蛋白表达的影响。结果:MTT检测证实多柔比星能有效诱导人乳腺癌细胞MDA-MB-231凋亡。流式细胞检测及Tunnel法检测发现Ghrelin能有效抑制多柔比星诱导的人乳腺癌细胞MDA-MB-231的凋亡。Western blot检测发现Ghrelin抑制多柔比星诱导人乳腺癌细胞MDA-MB-231凋亡的同时伴有bcl-2表达增加、bax表达下降、bcl-2/bax值升高。结论:Ghrelin能有效抑制多柔比星诱导人乳腺癌细胞MDA-MB-231凋亡,推测其抑凋亡机制可能与抗线粒体凋亡因子释放有关。