Cytotoxicity study of ethanol extract of the stem bark of asam kandis (Garcinia cowa Roxb.) on T47D breast cancer cell line

Objective:To investigate the cytotoxic effect of ethanol extract of the stem bark of asam kandis[Garcinia cowa Roxb.(G.cowa)]on T47 D breast cancer cell line.Methods:The cytotoxicity of ethanol extract was carried out against human breast cancer cell line(T47D) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay.The extract was added at various concentrations(0.1.1,10 and 100 μg/mL).The level of cytotoxicity was determined by calculating the level of IC_(50),that was based on the percentage of the cell death after 24 h treatment with the extract.Cell morphological changes were observed by using inverted microscope.Results:The 3-(4.5-dimelhylthiazol-2-yl)-2.5-diphenyltelrazolium bromide assay showed that ethanol extract of G.cowa exhibited significant cytotoxic effect on T47 D with IC_(50) value of(5.10+1.68) μg/mL.Morphological alteration of the cell lines after exposure to ethanol extract of G.cowa was observed under phase contrast microscope in a dosc-dependent manner.ConclusionsThe results suggest the possible use of ethanol extract of asam kandis for preparing herbal medicine for cancer-related ailments.

Cytotoxic Effect of Chitosan Based Nanocomposite Synthesized by Radiation： In Vitro Liver and Breast Cancer Cell Line

A silver nanoparticle （AgNP） is likely to provide an attractive object for combining a variety of biochemical properties with great therapeutic potential by using radiation. The present study explores the ICs0 value of chitosan-poly （vinyl alcohol） hydrogel （Cs/PVA） and Ag-doped chitosan-poly （vinyl alcohol） （Cs/PVA/Ag） nanocomposite in view of their anticancer application. The aim was to develop （Cs/PVA） based hydrogel synthesized by gamma radiation which could behave both as a nanoreactor for Ag nanoparticle with promising anticancer applications. The （Cs/PVA/Ag） nanocomposite was confirmed by FTIR （Fourier transform infrared） spectroscopy, XRD （X-ray diffraction） and EDX （energy dispersive X-ray） analysis. The anti-cancer activity of the prepared nanocomposites was demonstrated in human liver cancer cell line （HEPG2） and breast cancer cell lines （MCF7）. It has significant effects against human liver cancer cell line HEPG2 compared to breast cancer cell line MCF7. Further quantitative analysis on the molecular and protein levels is still required to confirm the impact of chitosan on genotoxic effect before reaching a final conclusion and starting its biomedical application.

Inhibitory effect of gold nanoparticles conjugated with interferon gamma and methionine on breast cancer cell line

Objective: To develop a gold nanoparticles complex conjugated with interferon-gamma(IFN-g) and methionine along with application of hyperthermia using near-infrared laser beams for the treatment of cancer cells.Methods: Gold nanorods(10 nm) were conjugated with IFN-g and methionine using carbodiimide family and characterized after purification by dialysis bags. Breast cancer cells were cultured and incubated with gold nanorods at different concentrations followed by irradiation with near-infrared laser beam. Samples were then evaluated for their viability in order to determine the effect of treatment and variables by MTT assy.Results: Zetasizer results confirmed the conjugation of gold nanorods with methionine and IFN-g. The median percentage of cell viability in 0.30 mg/m L concentration of gold nanorods was 82%. The cell viability reached to 85% at the same concentration of gold nanorods, which existed in the assayed complex. The results of MTT assay showed that the 0.60 mg/m L concentration of gold nanoparticles complex was toxic on tumor cells(P < 0.05). After exposure to hyperthermia, the viability of cells at 6 min decreased to77% in 0.30 mg/m L concentration of gold nanorods complex.Conclusions: The size and concentration of gold nanorods was not cytotoxic. However,their presence during irradiation near-infrared laser increased the number of dead cells during the treatment of cells.

THE EFFECTS OF ESTRADIOL ON BREAST CANCER CELL LINES

The estradiol effects on breast cancer cell lines including estrogen receptors (ER) positive and negative were studied with flow cytometry analysis, scanning and transmission electron microscopy (SEM and TEM), immunogold and immunofluorescence staining techniques. The results showed that estradiol markedly stimulated the division and proliferation of the ER( + ) MCF-7 cells at 10 nM, but had no marked effect on the cell cycle of the ER(-) H466B cells at the same concentration, and that tamo-xifen inhibited the stimulation of estradiol on MCF-7 cells. Estradiol obviously influenced the ultrastruc-ture of MCF-7 cells. Immunocytochemical localization of epidermal growth factor receptor (EGFR) on the MCF-7 cell membrane surface indicated that one of the mechanisms involving the growth of MCF-7 breast cancer cell and the stimulating effect on MCF-7 cells growth by estradiol is autocrine secretion.

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.

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.

In Vivo Animal Model Evaluation of a Powerful Oral Nanomedicine for Treating Breast Cancer in BALB/c Mice Using 4T1 Cell Lines without Chemotherapy

Nanopharmaceuticals containing quantum dot nanoparticles (Q-Dot NPs) for treating serious cancers such as breast cancer have made fantastic proposals. In this study, ZnO quantum dot NPs are formulated via ZnO@PVP nanopolymer as co-assistants coordinating with efficacious suitable wetting agents, PEG-binding compound, and W/O emulsifier for producing eco-friendly water-based nanodrug. Several characterization techniques containing SEM, TEM, FTIR, photoluminescence, zeta potential, and UV-Vis absorption were employed for ZnO Q-Dot NPs in nanodrug. This work aims to investigate the anti-tumor effects of such nanomedicine on the 4T1 breast cancer cell line in BALB/c mice, being elaborated through intraperitoneal, injection (IVP) and oral therapy. The impressive findings showed that ZnO nanodrug caused changes in blood factors, having the most effectiveness at 40 μg/ml concentration after two weeks of oral treatments. The significant increase in white blood cells (WBC) neutrophils and meaningful decreases in lymphocytes and especially cholesterol were powerful simultaneous impacts, successfully treating malignant breast cancer masses. In this significant animal model research for breast cancer, the sick mice recovered entirely and even had a safe space to mate. Histopathological results showed no evidence of breast tumor formation or metastasis in the group treated with nanodrug and their children. This nanomedicine has a therapeutic effect, and is ready to be applied for treating volunteer breast cancer patients. However, its prevention (inhibitory) effect can also be analyzed and added to current data in future studies.

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.

Quantitative expression of MMP-2 and FN in high metastatic and low metastatic cell lines of breast cancer

To analyze the relation of matrix metalloproteinase-2(MMP-2) and Fibronection (FN) mRNA expression with metastasis of breast cancer and elucidate the role of MMP-2 and FN in breast cancer metastasis.Methods The expression of MMP-2 and FN mRNA in breast cancer cell lines was detected by fluorescence-quantitative RT-PCR.The expression of MMP-2 and FN protein was detected by Western blots.Results The expression of MMP-2 and FN mRNA was down-regulated in high metastatic cell lines MDA-MB-231,MDA-MB-435,but up-regulated in low metastatic cell lines MDA-453,T47D,SK-BR-3 and non-metastatic cell line MCF-7,ZR-75-30.The protein expression of MMP-2 and FN was up-regulated in high mestastic cell lines,and down-regulated in low metastatic cell lines.Conclusion The mRNA and protein expression of MMP-2 and FN was related with breast cancer metastasis.The mRNA expression of MMP-2 and FN is feed-back regulated with protein expression.6 refs,4 figs,2 tabs.

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.

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.

Tea polyphenols inhibit the growth and angiogenesis of breast cancer xenografts in a mouse model

Objective:To investigate the anti-angiogenic effect of tea polyphenols(TPS)on breast cancer and normal tissues in a mouse model.Methods:Breast cancer was successfully implanted into 48 BALB/c mice,which were then randomly divided into a TP oral gavage group,a TP local injection group,a ginsenoside Rg3 group,and a model control group according to a random number table.The tumor inhibitory rates of each group were calculated,while microvessel density(MVD)and the expression of vascular endothelial growth factor(VEGF),basic fibroblast growth factor(bFGF),and tissue inhibitor of metalloproteinase(TIMP-2)were detected by immunohistochemistry.Results:TPs could inhibit the growth of breast cancer xenografts in the mouse model.The tumor inhibition rates of the TP oral gavage and TP local injection groups were 37.43%and 40.94%,respectively.Compared with the model control group,MVD and VEGF and bFGF expression was downregulated(all P<.05),whereas TIMP-2 expression was elevated in the TP oral gavage and TP local injection groups(P=.015 and P=.032).TPs showed no significant effect on MVD and VEGF and TIMP-2 expression in the heart,brain,and kidney of the mouse model.Conclusion:TPs can restrict the growth of breast cancer by specifically inhibiting the angiogenesis of breast tumor tissue while having little effect on the normal tissue of important organs including the heart,brain,and kidney.

乳腺癌原代细胞系为药物筛选和基础研究提供癌症新模型

背景和目的:2016年美国国家癌症研究所(National Cancer Institute,NCI)宣布不再使用NCI-60细胞系进行药物筛选,提示传统的肿瘤细胞系失去作为药物研发和基础研究工具的价值。NCI-60细胞“退休”原因是基于癌症细胞系和动物的实验结果没有在临床试验中获得对应的预期,导致绝大部分潜在药物临床试验失败。癌症细胞系失去价值归因于肿瘤细胞经过长期培养后,其增殖和转移等主要生物学行为和与之有关的关键蛋白质系统发生了根本改变,已不能代表患者的真实癌症特征。现阶段需要创立一种来源于患者新鲜癌症组织和具有清晰临床背景的新癌症模型。本研究旨在为药物研发和基础研究建立经济的患者来源的可以无限传代的乳腺癌原代细胞系。方法:乳腺癌组织在贵州医科大学附属医院乳腺外科收集。肿瘤组织样本收集得到贵州医科大学附属医院伦理委员会批准(伦理编号:2022伦理第313号),收集和使用肿瘤组织均遵守赫尔辛基宣言,患者的乳腺癌组织消化分离后在BCMI培养基中培养,待乳腺癌细胞增殖到一定数量时更换成DMEM培养基。乳腺癌细胞经短串联重复序列(short tandem repeat,STR)检测确定细胞特异性遗传学标志和来源。克隆形成实验和动物实验分析乳腺癌原代细胞系形成肿瘤的能力。结果:成功建立了6种乳腺癌原代细胞系。他们具有清晰的临床病理学特征,包括病理学标志性分子检测、临床诊断、治疗方案和结果以及确定的预后结果。STR检测确定了6种乳腺癌原代细胞系特异性遗传标志和确定了该细胞系的来源。克隆形成实验和动物移植实验说明乳腺癌原代细胞系增殖能力显著大于传统乳腺癌细胞系,二者在形成肿瘤能力方面存在明显的差异。结论:构建的6种乳腺癌原代细胞系为乳腺癌药物研发和基础研究提供了新的癌症模型。

Tetrandrine:A Potent Abrogator of G_2 Checkpoint Function in Tumor Cells and Its Mechanism

Objective To assess the ability of tetrandrine （Tet） to enhance the sensitivity to irradiation and its mechanism in cell lines of human breast cancer p53-mutant MCF-7/ADR, p53-wild-type MCF-7 and human colon carcinoma p53-mutant HT-29 as well as in C26 colorectal carcinoma-bearing BALB/c mice. Methods MCF-7/ADR, HT-29 and MCF-7 cells were exposed to irradiation in the absence or presence of tetrandrine. The effect of Tet on the cytotoxicity of X-irradiation in these three cells was determined and the effect of tetrandrine on cell cycle arrest induced by irradiation in its absence or presence was studied by flow cytometry. Moreover, mitotic index measurement determined mitosis of cells to enter mitosis. Western blotting was employed to detect cyclin B1 and Cdc2 proteins in extracts from irradiated or non-irradiated cells of MCF-7/ADR, HT-29 and MCF-7 treated with tetrandrine at various concentrations. Tumor growth delay assay was conducted to determine the radio-sensitization of tetrandrine in vivo. Results Clonogenic assay showed that tetrandrine markedly enhanced the lethal effect of X-rays on p53-mutant MCF-7/ADR and HT-29 cells and the sensitization enhancement ratio （SER） of tetrandrine was 1.51 and 1.63, but its SER was only 1.1 in p53-wt MCF-7 cells. Irradiated p53-mutant MCF-7/ADR and HT-29 cells were only arrested in G2/M phase while MCF-7 cells were arrested in G1 and G2/M phases. Radiation-induced G2 phase arrests were abrogated by tetrandrine in a concentration-dependent manner in MCF-7/ADR and HT-29 cells, whereas redistribution within MCF-7 cell cycle changed slightly. The proportion of cells in M phase increased from 1.3% to 14.7% in MCF-7/ADR cells, and from 1.5% to 13.2% in HT-29 cells, but 2.4% to 7.1% in MCF-7 cells. Furthermore, the levels of cyclin B 1 and Cdc2 expression decreased after X-irradiation in MCF-7/ADR and HT-29 cells, and the mitotic index was also lower. Tet could reverse the decrease and induce the irradiated cells to enter mitosis （M phase）. Endosomatic experiment showed that tetrandrine caused tumor growth delay in irradiated mice. Conclusion Tetrandrine boosts the cell killing activity of irradiation both in vitro and in vivo. Tetrandrine is a potent abrogator for G2 checkpoint control and can sensitize the cells to radiation.

Effect of 1,25(OH)_2D_3 on the growth and apoptosis of breast cancer cell line MCF-7

Objective To study the effect of 1,25 dihydroxyvitamin D 3 (1,25(OH) 2D 3) on the growth and apoptosis of breast cancer cell line MCF 7 Methods Cell number was determined using the MTT method Flow cytometric analysis was performed on cell cycles, and the percentage of apoptosis was counted Apoptotic cells were quantified by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL), and bcl 2 protein expression was estimated with Western blotting Results After incubation with 1,25(OH) 2D 3 10 7 mol/L for 48 hours, MCF 7 cells exhibited significant growth in a dose and time dependent manner Flow cytometric analysis indicated that cell numbers in G 0/G 1 increased along with increasing apoptotic peak and percentage With microscope and electron microscope observation, characteristics of apoptosis such as typical apoptotic bodies were commonly found TUNEL also showed that 1,25(OH) 2D 3 10 8 mol/L and 10 7 mol/L groups had significantly high apoptosis percentage than control group with dose dependence on induction apoptosis And Western blot showed that 1,25(OH) 2D 3 10 8 mol/L could down regulate bcl 2 protein and 10 7 mol/L could almost block bcl 2 protein expression Conclusions 1,25(OH) 2D 3 can inhibit cell growth with G 0/G 1 arrest, enhance the proliferation inhibition action of adriamycin, and induce apoptosis which may result from the down regulation of the anti apoptotic bcl 2 protein

圣草酚通过miR-128-3p/MAPK轴对乳腺癌细胞增殖、凋亡的影响

目的圣草酚是一种重要的类黄酮,普遍存在于植物界,但少有对圣草酚的抗癌活性的报道。该研究旨在探究其对人乳腺癌(breast cancer,BC)的抗癌潜力及可能的机制。方法体外培养人乳腺癌细胞MCF-7和人乳腺上皮细胞FR2,通过MTT法检测圣草酚诱导的初始细胞毒性。再次培养MCF-7细胞,MTT法和集落形成实验评估圣草酚对MCF-7细胞增殖的影响;流式细胞术评估圣草酚对MCF-7细胞凋亡和线粒体膜电位(mitochondrial membrane potential,MMP)的作用;RT-qPCR和Western Blot法检测miR-128-3p和MAPK相关基因(p38 MAPK和HSP27)在圣草酚发挥抗癌功能中的作用。裸鼠体内异种移植模型中分析圣草酚对肿瘤生长的作用,TUNEL法检测圣草酚对细胞凋亡的影响。结果当圣草酚浓度超过12.5μmol·L^(-1)时,MCF-7细胞活力随着圣草酚浓度的增高而逐渐降低(P<0.05);圣草酚干预后,MCF-7细胞活力、集落形成数量和MMP均下调,细胞凋亡率增高(P<0.05);细胞中miR-128-3p水平增高,p38 MAPK和HSP27磷酸化水平均降低(P<0.05)。转染miR-128-3p抑制物在一定程度上可以逆转圣草酚对MCF-7细胞的影响(P<0.05);在转染miR-128-3p抑制物的基础上添加MAPK通路抑制剂可以削弱这种逆转作用(P<0.05)。此外,裸鼠体内异种移植模型实验证明了圣草酚可呈剂量依赖性降低裸鼠肿瘤组织生长,促进细胞凋亡(P<0.05)。结论圣草酚可有效抑制人乳腺癌细胞增殖并诱导细胞凋亡,这可能与其调控miR-128-3p/MAPK轴有关。

A comparison study of the cytotoxicity of salinomycin and salinomycin sodium toward human breast cancer stem cells as well as breast cancer cells

Salinomycin（SAL）,a polyether antibiotic isolated from Streptomyces albus,is widely used as an anticoccidial drug in poultry and other livestock and is furthermore fed to ruminescent animals to improve nutrient absorption and feed efficiency.It has recently been shown to act as a specific inhibitor of cancer stem cells.At present,the price of salinomycin sodium（SAL-Na） is 10 fold lower than that of salinomycin,however,there is no report about the comparison of the inhibitory effects of SAL and SAL-Na on cancer stem cells as well as cancer cells.In the present study,side population cells（SP cells）and non-SP cells （NSP cells）sorted from human breast cancer cell line MCF-7 were chosen as the models of cancer stem cells and cancer cells, respectively.SRB assay was performed to compare the cytotoxicity of SAL and SAL-Na.First of all,SP cells were sorted from MCF-7 cells via FACSDiva flow cytometry.Secondly,the sorted SP cells were identified with the surface makers（CD44~＋/CD24^-） of breast cancer stem cells.Finally,the inhibitory effects of SAL and SAL-Na were evaluated on the sorted SP cells and NSP cells.Results showed that,as compared to breast cancer cells,the inhibitory effect of free SAL or free SAL-Na was more potent in breast cancer stem cells.Furthermore,the inhibitory effects of free SAL and free SAL-Na had no significant difference for the SP cells as well as the NSP cells when they were in the same concentration.Thus,it suggested that salinomycin sodium should be considered as a potential candidate to take the place of salinomycin in cancer stem cells research,due to their similar inhibitory effects on cancer stem cells.

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。

MiR-142-3p enhances chemosensitivity of breast cancer cells and inhibits autophagy by targeting HMGB1

MiR-142-3p has been reported to act as a tumor suppressor in breast cancer.However,the regulatory effect of miR-142-3p on drug resistance of breast cancer cells and its underlying mechanism remain unknown.Here,we found that miR-142-3p was significantly downregulated in the doxorubicin(DOX)-resistant MCF-7 cell line(MCF-7/DOX).MiR-142-3p overexpression increased DOX sensitivity and enhanced DOXinduced apoptosis in breast cancer cells.High-mobility group box 1(HMGB1)is a direct functional target of miR-142-3p in breast cancer cells and miR-142-3p negatively regulated HMGB1 expression.Moreover,overexpres sion of HMGB1 dramatically reversed the promotion of apoptosis and inhibition of autophagy mediated by miR-142-3p up-regulation.In conclusion,miR-142-3p overexpression may inhibit autophagy and promote the drug sensitivity of breast cancer cells to DOX by targeting HMGB 1.The miR-142-3 p/HMGB1 axis might be a novel target to regulate the drug resistance of breast cancer patients.