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

Objective:To investigate the anticancer property of marine sediment actinomvceles against two different breast cancer cell lines.Methods:In 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.Results:Of the selected five actinomycete isolates,ACT01 and ACT02 showed the IC_(50)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±2.49μg/mL)level of IC_(50)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 groupⅠandⅢ,respectively,but ACT01 and ACT02 were represented in groupⅡ.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(-57.6 kkal/mol).Conclusions:The 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.

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.

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.

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。

Wnt5a/Dvl2/Rac1信号通路调控MDA-MB-231人乳腺癌细胞的迁移

目的:探讨Wnt5a信号通路调控MDA-MB-231人乳腺癌细胞迁移的分子机制。方法:在建立了划痕实验检测MDAMB-231人乳腺癌细胞迁移模型的基础上,研究Wnt5a/Dvl2/Rac1信号通路对MDA-MB-231人乳腺癌细胞迁移的调控。结果:高表达的Rac1可促进MDA-MB-231人乳腺癌细胞的迁移,干扰Rac1的表达可显著降低其迁移,Rac1活性受Wnt5a/Dvl2信号通路的调控。结论:Wnt5a/Dvl2/Rac1信号通路可调控MDA-MB-231人乳腺癌细胞的迁移,此为深入阐明乳腺癌细胞转移的分子调控机制提供了新线索。

非甾体类抗炎药对乳腺癌细胞MDA-MB-231增殖影响的实验室研究

目的通过研究阿司匹林、塞来昔布及两者分别联合阿那曲唑对乳腺癌细胞MDA-MB-231的抑制作用,探讨并比较阿司匹林和塞来昔布的抗肿瘤作用。方法采用MTT法检测不同浓度的阿司匹林、塞来昔布及两者分别联合阿那曲唑对乳腺癌细胞MDA-MB-231增殖的影响。结果阿司匹林、塞来昔布单药对MDA-MB-231细胞生长均有抑制作用,表现为浓度、时间依赖性,统计学差异具有统计学意义(P<0.05);不同浓度的阿司匹林、塞来昔布分别联合阿那曲唑后对MDA-MB-231细胞的抑制作用较单用阿那曲唑增强,亦表现为浓度依赖性,差别具有统计学意义(P<0.05)。结论阿司匹林和塞来昔布均有抑制乳腺癌MDA-MB-231细胞的作用,两者分别联合阿那曲唑后有协同抗肿瘤的作用。

复方山慈菇醇提物对人乳腺癌MDA-MB-231细胞增殖与凋亡的影响

目的:探讨复方山慈菇醇提物对人三阴性乳腺癌(TNBC)MDA-MB-231细胞增殖与凋亡的影响。方法:将人乳腺癌MDA-MB-231细胞分为溶剂对照组和复方山慈菇醇提物组,0.1%DMSO或不同浓度的复方山慈菇醇提物作用于MDA-MB-231细胞24 h、48 h后,CCK-8法检测细胞活性;Hoechst33342染色法观察细胞形态学变化;Annexin V-APC/7-AAD双染色流式分析检测细胞凋亡率;Western blot检测凋亡相关蛋白Bcl-2、Bax和Caspase-3的表达。结果:复方山慈菇醇提物可浓度和时间依赖性地抑制MDA-MB-231细胞的增殖(P<0.05),24 h、48 h的IC50分别为0.51 mg生药/mL和0.26 mg生药/mL;0.25 mg生药/mL、0.5 mg生药/mL、1.0 mg生药/mL复方山慈菇醇提物处理24 h后,Hoechst33342染色显示细胞出现凋亡样变化;流式细胞术检测结果表明,与溶剂对照组比较,复方山慈菇醇提物可浓度依赖性地增加MDAMB-231细胞凋亡率(P<0.05);Western blot法显示,与溶剂对照相比,0.5 mg生药/mL复方山慈菇醇提物组Bax、Caspase-3蛋白表达升高,Bcl-2蛋白表达下降(均P<0.05)。结论:复方山慈菇可体外抑制人乳腺癌MDA-MB-231细胞的增殖,机制可能与其下调Bcl-2及上调Bax、Caspase-3蛋白表达而诱导凋亡有关。

精氨白桦脂酸的制备及其对三阴性人乳腺癌细胞MDA-MB-231增殖的影响

目的:制备精氨白桦脂酸,并考察其对三阴性人乳腺癌细胞MDA-MB-231增殖的影响。方法:以精氨酸为增溶载体,采用共研磨法将等摩尔比的白桦脂酸与精氨酸制成精氨白桦脂酸。采用粉末X射线衍射法、红外光谱法、差示扫描量热法对精氨白桦脂酸进行表征;比较白桦脂酸和精氨白桦脂酸的溶解度;采用MTT法检测15、30、60、120μg/mL的白桦脂酸、精氨白桦脂酸和5氟尿嘧啶(5-FU)对MDA-MB-231细胞增殖的影响。结果:所制精氨白桦脂酸为不同于精氨酸与白桦脂酸物理叠加的新的物相,其中白桦脂酸的羧基与精氨酸中氨基进行了成盐反应,其未见明显的熔点峰。白桦脂酸几乎不溶于水,精氨白桦脂酸水溶液中白桦脂酸的溶解度为50.72μg/mL。与白桦脂酸比较,精氨白桦脂酸对MDA-MB-231细胞的增殖抑制率明显升高(P<0.05),且与5-FU比较差异无统计学意义(P>0.05)。结论:成功制得溶解度较好的精氨白桦脂酸,其对MDA-MB-231细胞的增殖具有抑制作用。

红毛五加多糖对人乳腺癌细胞系MDA-MB-231增殖和核转录因子p53、c-myc蛋白表达的影响

目的探讨红毛五加多糖(AGP)对人乳腺癌细胞系MDA-MB-231增殖以及对细胞核转录因子p53、c-myc表达的影响。方法在DMEM培养基内加入不同浓度AGP(0.15625、0.3125、0.625、1.25、2.5 g/L)体外培养人乳腺癌细胞系MDA-MB-231 1d、3d、5d、7d后,用细胞增殖及细胞毒性检测试剂盒WST-1测定人乳腺癌细胞的增殖,倒置显微镜观察其形态变化;用免疫荧光法、免疫印迹法检测人乳腺癌细胞凋亡相关蛋白p53、c-myc的表达。结果 WST-1法显示,不同浓度AGP作用3d、5d、7d后对人乳腺癌细胞系MDA-MB-231的增殖具有抑制作用,与阴性对照组相比差异有显著性(P<0.05);抑制率与AGP剂量、作用时间呈依赖性。免疫荧光法及免疫印迹法显示,AGP作用于人乳腺癌细胞系MDA-MB-231后,其细胞的c-myc表达明显减弱,并向细胞质内聚集;而免疫印迹法显示p53表达显著增强。结论 AGP具有抑制人乳腺癌细胞系MDA-MB-231增殖的作用,这可能与AGP下调c-myc表达、上调p53表达有关。

鲍鱼肽的制备及其抑制人乳腺癌MDA-MB-231细胞增殖作用

将鲍鱼内脏进行蛋白酶解、超滤和纳滤制备鲍鱼肽,研究不同质量浓度鲍鱼肽对体外培养人乳腺癌MDA-MB-231细胞增殖和凋亡的影响。结果表明:鲍鱼肽中除含有71.62%(质量分数,下同)蛋白以外,还含有3.38%碳水化合物和11.48%灰分;鲍鱼肽的分子质量主要分布在350～1 000 Da,丰度较高的蛋白肽分子质量分布在350 Da附近,表明鲍鱼肽中由2～3个氨基酸组成的寡肽占比较高。根据四甲基偶氮唑蓝法检测的结果,发现不同质量浓度(1、2、4、8 mg/mL)鲍鱼肽均能抑制MDA-MB-231细胞的生长增殖,并呈现出明显的剂量依赖性。伴随鲍鱼肽质量浓度的增加,贴壁细胞数量逐渐减少,细胞变圆,且部分细胞核出现浓缩。流式细胞术分析结果表明,鲍鱼肽主要将MDA-MB-231细胞阻滞在S期和G2期,诱导MDA-MB-231细胞凋亡和坏死,进而抑制肿瘤细胞增殖。因此,利用鲍鱼内脏制备的蛋白肽是一种具有发展潜力的辅助抗肿瘤功能性食品。