SOX7靶向ERK1/2/PD-L1通路抑制结直肠癌血管生成

目的探讨性别决定区Y框蛋白7(SOX7)对结直肠癌血管生成的影响及潜在作用机制。方法应用免疫荧光检测结直肠癌患者组织样本中SOX7表达水平,之后通过裸鼠、转染SOX7 mimic的人结直肠癌细胞系SW480细胞和人脐静脉内皮细胞(HUVEC)共培养进一步研究。用Western-blot验证SOX7与ERK1/2/PD-L1对结直肠癌细胞的相关蛋白表达的影响。用CCK8检测SOX7与ERK1/2/PD-L1对HUVEC增殖的影响。通过体外内皮细胞成管实验测定SOX7与ERK1/2/PD-L1对肿瘤血管生成的影响。结果SOX7在人结直肠癌组织中表达被抑制(P<0.01),同时SOX7的过表达抑制了小鼠体内肿瘤生长(P<0.01)。SW480细胞中SOX7的过表达抑制了ERK1/2、c-Jun的表达,并在ERK1/2的激动剂Senkyunolide I的作用下上调了SW480细胞的ERK1/2、c-Jun蛋白表达(P<0.01),逆转了SOX7对SW480细胞中ERK1/2、c-Jun蛋白表达的影响(P<0.01)。HUVEC中SOX7抑制了PD-L1、V-EGFR2、p-PI3K、HIF-1α的蛋白表达,Senkyunolide I上调了HUVEC的PD-L1、V-EGFR2、p-PI3K、HIF-1α的蛋白表达,并逆转了SOX7对HUVEC中上述相关蛋白表达的影响(P<0.01)。PD-1/PD-L1 Inhibitor 3抑制了PD-L1、V-EGFR2、p-PI3K、HIF-1α的蛋白表达,SOX7过表达在PD-1/PD-L1 Inhibitor 3的影响下并没有表现出抑制作用。CCK8实验结果显示SOX7过表达显著抑制了HUVEC的增殖能力,Senkyunolide I作用下的两组HUVEC增殖能力较SOX7 NC组与SOX7 mimic组明显上升,PD-1/PD-L1 Inhibitor 3作用下的两组HUVEC增殖能力较SOX7 NC组与SOX7 mimic组明显下降,以上均有明显统计学差异(P<0.01)。成管实验结果显示SOX7过表达抑制了HUVEC的血管生成,Senkyunolide I强烈加速了血管生成,而PD-1/PD-L1 Inhibitor 3血管生成则被显著抑制,以上均有明显统计学差异(P<0.01)。结论SOX7通过ERK1/2/PD-L1通路抑制结直肠肿瘤的增殖和血管生成,SOX7可能是晚期CRC患者临床治疗中潜在的抗血管生成靶点。

稳定表达人ACE2的Huh-7细胞系的建立及应用

为了构建稳定表达人血管紧张素转换酶2(human angiotensin converting enzyme 2,hACE2)的Huh-7细胞系,本研究构建了不带荧光的pWPXL-neo-hACE2慢病毒载体,并利用psPAX2和pMD2.G-VSVG共同转染HEK293T细胞获得慢病毒;将包装好的慢病毒感染Huh-7细胞后,利用潮霉素B筛选获得可表达hACE2的Huh-7细胞;通过间接免疫荧光法和蛋白质印迹法检测Huh-7细胞中hACE2蛋白的表达;采用流式细胞术分析Huh-7-hACE2细胞与严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2,SARSCoV-2)刺突(spike,S)蛋白受体结合结构域(receptor-binding domain,RBD)的结合情况,并用SARS-CoV-2假病毒进一步测定Huh-7-hACE2细胞对SARS-CoV-2的易感性,最后利用鉴定过的Huh-7-hACE2细胞测定SARS-CoV-2中和抗体REGN10987对假病毒的中和效价。结果显示,hACE2蛋白在Huh-7细胞中成功表达,且表达的hACE2蛋白能与SARS-CoV-2 S蛋白RBD结合;相较于Huh-7细胞,Huh-7-hACE2细胞对假病毒的易感性显著提高,且假病毒中和效价测定结果与文献报道的真病毒中和效价相似。总之,本研究成功构建了稳定表达hACE2的Huh-7细胞系,并且其能应用于新型冠状病毒感染(corona virus disease 2019,COVID-19)治疗性单抗的活性评价,是研究SARS-CoV-2的致病机制、开发抗病毒药物及疫苗的有利工具。

Anticancer activity of Tephrosia purpurea and Ficus religiosa using MCF 7 cell lines

Objective:To investigate anticancer activity of different fractions of Tephrosia purpurea[TP] （Sharapunkha,Fabaceae） and Ficus religiosa[FR]（Peepal,Moraceae）.Methods:The fractions of TP and FR were prepared and tested for in vitro anticancer activity using human MCF 7 cell line by trypan blue exclusion method.Results:The result showed that among all these fractions of TPI.TPIII.FRI and FRIII showed better anticancer activity compared to other fractions.The IC50 value for TPI（152.4μM）,TPIII（158.71μM）.FRI（160.3μM） and for FRIII（222.7μM） was observed.Conclusions:The present study shows anticancer potential of TP and FR fractions in MCF 7 cell line.

Hesperidin as a preventive resistance agent in MCF-7 breast cancer cells line resistance to doxorubicin

Objective:To evaluate of hesperidin to overcome resistance of doxorubicin in MCF-7 resistant doxorubicin cells(MCF-7/Dox)in cytotoxicity apoptosis and P-glycoprotein(Pgp)expression in combination with doxorubicin.Methods:The cytotoxic properties.50%inhibition concentration(IC_(50))and its combination with doxorubicin in MCF-7 cell lines resistant to doxorubicin(MCF-7/Dox)cells were determined using MTT assay.Apoptosis induction was examined by double staining assay using ethidium bromide-acridine orange.Immunocytochemistry assay was performed to determine the level and localization of Pgp.Results:Single treatment of hesperidin showed cytotoxic activity on MCF-7/Dox cells with IC_(50)value of 11μmol/L.Thus,combination treatment from hesperidin and doxorubicin showed addictive and antagonist effect(CI>1.0).Hesperidin did not increase the apoptotic induction,but decreased the Pgp expressions level when combined with doxorubicin in low concentration.Conclusions:Hesperidin has cytotoxic effect on MCF-7/Dox cells with IC_(50)of 11μmol/L.Hesperidin did not increased the apoptotic induction combined with doxorubicin.Cochemotherapy application of doxorubicin and hesperidin on MCF-7/Dox cells showed synergism effect through inhibition of Pgp expression.

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.

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.

Huh-7 Human Liver Cancer Cells: A Model System to Understand Hepatocellular Carcinoma and Therapy

In the last decades, the use of in vitro systems in liver research has grown exponentially. Important reasons promoting this work are the high throughput and ease of genetic manipulations afforded by these experiments relative to in vivo experiments. Thousands of investigations of hepatocellular carcinoma have been performed employing the human hepatoma Huh-7 cell line. The extensive body of knowledge produced attests to the importance and value of this in vitro cell system to study the characteristics of hepatomas and the potential of natural and synthetic compounds to prevent and eliminate this liver cancer. The necessarily brief summary provided here attempts to summarise some of the most recent achievements and limitations of investigations with Huh-7 cells and derivatives.

STUDY OF ENHANCED IMMUNOGENECITY OF B7-1 GENE TRANSFECTED HUMAN HELA CELL LINE

This work was supposed by CMB (No. 96—635) This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). Although cervical carcinoma cells may express the human papillomavirus protein E6 and E7, they fail to induce an effective specific cytotoxic T lymphocyte response. Recent studies suggest that expression of CD 80 (B7 1) on tumor cells is effective to induce antitumor immune responses. 1,2 In our study, CD 80 gene was transfected into human Hela cell line with a CD 80 expression plasmid (B7 1 +pcDNA 3) by electroporation, then the immunogenecity of the modified Hela cell was tested in TLMC (tumor lymphocyte mixed culture) system. Thymidine lymphocyte proliferation assays showed that the response of human peripheral blood lymphocytes (PBLS) to CD 80 positive Hela cells demonstrated a substantial increase in cell proliferation compared to the response to control cells. Cocultivation of allogeneic PBLs with CD 80 positive tumor cells for three days can induce an increased secretion of IL 2. Our results demonstrate an immunostimulatory effect of CD 80 expression on cervical cancer cells, which provides a basis for the development of a therapeutic tumor vaccine.

Effects of 4-(3-Chloro-Benzyl)-6,7-Dimethoxy-Quinazoline on Kinetics of P120-Catenin and Periplakin in Human Buccal Mucosa Squamous Carcinoma Cell Line

In order to detect molecular markers for the epidermal growth factor inhibitor 4-(3-chloro-benzyl)- 6,7-dimethoxy-quinazoline (tyrphostin), we investigated the kinetics of p120-catenin and periplakin in the human buccal mucosa squamous cancer cell line BICR 10 treated with 3 nM tyrphostin. Growth of BICR 10 cells was inhibited by treatment with tyrphostin. Although changes were not observed in the expression of EGFR and p120-catenin, expression of Akt, Src and periplakin in BICR 10 treated with 3 nM tyrphostin tended to decrease. In addition, phosphorylation of EGFR, Akt and Src was inhibited by treatment with tyrphostin. On immunocytochemical staining, immunoreactions with phosphorylated EGFR, phosphorylated Akt and phosphorylated p120-catenin were weak in BICR 10 treated with tyrphostin. There was a slight immunocy to chemical reaction to periplakin in BICR 10 cells induced by tyrphostin. In conclusion, the decrease in phosphorylation in EGFR and p120-catenin by tyrphostin, following the decrease in Src or Akt phosphorylation, may inhibit expression of several growth factors associated with the proliferation and migration of cancer cells.

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.

Construction of Cox7a2 fluorescent vector and its effect on cytochrome C oxidase activity in mouse Sertoli cell line TM4

Objective To construct Cox7a2 fluorescent vector and study its effect on cytochrome C oxidase ( COX) activity in mouse Sertoli cell line TM4. Methods The coding region of CoxTa2 was amplified from mouse Sertoli cell line TM4 by RT-PCR. PCR product was

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.

黎药海南地不容氧化克班宁对人乳腺癌MCF-7细胞微管位点和微管蛋白的调控机制研究

目的:本论文深入探究黎药海南地不容抗乳腺癌活性化合物氧化克班宁对微管网络的破坏能力,研究氧化克班宁在分子层面和细胞层面对微管网络稳态的影响。方法:首先采用EBI位点竞争法和分子对接来确定氧化克班宁对微管位点的占据力;其次,采用Western Blot法检测STAT3、PKA1、CAMK4和PKA检测氧化克班宁对微管蛋白的影响。结果:EBI位点竞争法结果显示,EBI与β-微管蛋白加合物比β-微管蛋白出现在分子量更小的区域(ctrl2)。分子对接结果显示,氧化克班宁可以占据微管蛋白的秋水仙碱位点。Western Blot结果显示,低、中、高3个浓度的氧化克班宁或阳性药Taxol作用MCF-7细胞48 h后,显著降低STAT3蛋白表达水平(P<0.01),显著降低PKA1和CAMK4蛋白表达水平(P<0.05,P<0.01),并且可降低PKA蛋白表达水平,与对照组差异均有统计学意义(P<0.01)。结论:氧化克班宁结合在微管蛋白秋水仙碱位点扰乱微管蛋白聚合,造成MCF-7细胞有丝分裂,从而导致MCF-7细胞死亡。氧化克班宁可通过抑制MCF-7细胞中STAT3、PKA1、CAMK4和PKA蛋白的表达水平,干扰纺锤体形成,最终造成MCF-7细胞有丝分裂灾难。

青蒿素和青蒿琥酯对人乳腺癌MCF-7细胞的体外抑制作用比较研究

目的 对比研究青蒿素及其衍生物青蒿琥酯对人乳腺癌 MCF- 7细胞增殖的影响并探讨其作用机制。方法采用体外培养的人乳腺癌 MCF- 7细胞株 ,利用 SRB法测定青蒿素和青蒿琥酯对 MCF- 7细胞增殖的影响 ,FCM法测定细胞周期的变化 ,亚 G1 期含量测定和 DAPI荧光染色法观察细胞凋亡。结果 10 μmol/L 青蒿素和 1μmol/L青蒿琥酯能明显改变 MCF- 7细胞的细胞周期 ,使 S期细胞显著减少 ,G0 +G1 期细胞明显增加。青蒿素对 MCF-7细胞增殖仅有微弱抑制作用 ,但其衍生物青蒿琥酯却有显著的抑制作用 ,IC50 为 0 .31μmol/L。同样 ,1μmol/L 青蒿琥酯引起 MCF- 7细胞的凋亡和直接的细胞毒作用明显强于 10μm ol/L青蒿素的作用。结论 体外研究表明 ,对肿瘤细胞增殖的抑制青蒿琥酯比青蒿素作用强。

苦参碱对MCF-7细胞Fas、VEGF及端粒酶活性的影响

目的研究苦参碱对人乳腺癌MCF-7细胞Fas、VEGF及端粒酶活性的影响。方法体外培养人乳腺癌MCF-7细胞,随机分组,实验组细胞加入苦参碱溶液,对照组或阴性对照组细胞加入等量培养液,阳性对照组细胞加入端粒酶抑制剂莪术油。采用倒置显微镜下观察细胞形态学变化;TRAP-ELISA法检测端粒酶活性;免疫细胞化学法检测MCF-7细胞中Fas、VEGF蛋白表达情况。结果苦参碱对乳腺癌细胞有明显的生长抑制作用和促凋亡作用;不同浓度苦参碱处理MCF-7细胞24、48、72h后,端粒酶活性随苦参碱浓度增加和作用时间延长而逐渐下降,呈剂量—效应正相关和时间—效应正相关;苦参碱能够上调MCF-7细胞Fas蛋白表达和下调MCF-7细胞VEGF蛋白表达。结论苦参碱对MCF-7细胞具有明显的生长抑制作用和促凋亡作用,可能是通过上调Fas蛋白表达、抑制端粒酶活性诱导乳腺癌细胞凋亡及通过下调VEGF蛋白表达,抑制肿瘤血管形成等实现的。

人参皂甙Rh_2逆转P-gp介导的MCF-7/ADM多药耐药性的基础研究

目的:研究人参皂甙Rh2在逆转多药耐药(MDR)方面的作用及其机理。方法:Rh2和阿霉素单独或联合作用于MCF-7及MCF-7/ADM细胞,应用MTT法确定各组细胞的IC50。罗丹明123加入各组细胞,流式细胞仪分析Rh2和维拉帕米抑制罗丹明123外排的情况。RT-PCR检测各组mdr1 mRNA表达量及流式细胞仪检测各组P-gp的表达情况。结果:Rh2可以显著降低MCF-7/ADM的ADM IC50(P<0.05),对MCF-7细胞没有影响。Rh2和维拉帕米可以增加MCF-7/ADM细胞内罗丹明123荧光表达率(P<0.05),Rh2比维拉帕米抑制罗丹明123外排作用更强。在MCF-7细胞内Rh2和维拉帕米无此作用。Rh2对MCF-7/ADM细胞mdr1 mRNA表达及P-gp表达没有影响。结论:人参皂甙Rh2可以有效逆转P-gp介导的人乳腺癌细胞耐药细胞系MCF-7/ADM的耐药性。

植物雌激素对乳腺癌细胞MCF-7增殖的影响

目的 : 探讨植物雌激素大豆异黄酮 (genistein,GS)和玉米赤霉烯酮 (zearalenone,ZEA)对乳腺癌细胞株 MCF- 7增殖的影响。方法 : 雌激素依赖性 MCF- 7细胞在 DMEM培养液(含小牛血清 1 0 % )中采用开放式单层贴壁培养 ,于加受试物前 5 d将细胞用 PBS洗涤后改为无酚红高糖 DMEM(含 5 %经活性碳 -葡聚糖苷处理的胎牛血清 ,CDT- FBS)培养 ,实验设溶剂对照、雌激素对照、抗雌激素对照及两种受试物各四个剂量组 ,采用噻唑蓝 (MTT)法、3H- Td R掺入法及流式细胞术对 MCF- 7细胞的增殖情况进行分析。结果 : 与溶剂对照组相比较 ,GS(96μmol/ L,2 4h)可明显抑制 MCF- 7细胞增殖和细胞 DNA合成 ,并将细胞周期阻滞在 G2 / M;8μmol/ L GS处理96 h也能产生类似的抑制效果。 96 nmol/ L ZEA处理 2 4 h可明显促进 MCF- 7细胞增殖和细胞DNA合成 ,并将细胞周期由 G0 / G1向 S期推进 ,提高细胞分裂增殖指数。结论 : ZEA和 GS均属环境雌激素 ,但对乳腺癌细胞 MCF- 7增殖产生的影响不同 ,ZEA可促进 MCF- 7增殖 ,而 GS能够抑制 MCF- 7细胞的增殖 ,即

环境雌激素对乳腺癌细胞株MCF-7凋亡作用的影响

[目的 ]通过观察对 壬基酚 (nonylphenol ,NP)、双酚A(bisphenolA ,BisA)和邻苯二甲酸二丁酯 (dibutylphthalate ,DBP)对乳腺癌细胞株MCF 7凋亡的影响 ,探讨环境雌激素促进MCF 7细胞增殖的生物学机制。 [方法 ]将在DMEM培养液 (含 10 %小牛血清 )中的MCF 7细胞采用开放式单层贴壁培养 ,加受试物前 5d将培养细胞用PBS洗涤后改为在无酚红DMEM(含 5 %经活性碳 葡聚糖苷处理的胎牛血清 ,CDT FBS)中培养连续 5d ,其目的是耗尽细胞内储存的雌激素。实验设溶剂对照组、雌激素对照组、抗雌激素 (它莫西芬 )对照组及三个实验组 ,采用流式细胞术、DNA片段凝胶电泳和细胞苏木素染色 (HE) ,观察环境雌激素对雌激素耗尽所诱导的细胞凋亡作用的影响。 [结果 ] 3 2× 10 -6mol/LNP和 3 2×10 -5mol/LBisA对MCF 7细胞处理 72h ,与对照组相比 ,流式细胞仪分析结果表明 ,二倍体细胞 (G1期细胞 )明显增加 ,亚二倍体细胞峰 (即细胞凋亡率 )消失 ,DNA凋亡片段凝胶电泳不显示典型的凋亡DNA片段梯带 ,细胞苏木素染色结果也显示凋亡细胞明显减少。 [结论 ]与溶剂对照组相比 ,NP和BisA均能够抑制MCF 7细胞的凋亡作用 ,而 3 2× 10 -4mol/LDBP对细胞凋亡的影响作用不明显。这一结果提示 ,该类物质有可能是通过抑制细胞凋亡而?

鱼藤素对乳腺癌细胞株MCF-7增殖和凋亡及PI3K/Akt信号通路的影响

目的:观察鱼藤素对MCF-7细胞株细胞增殖和凋亡及磷脂酰肌醇-3激酶/蛋白激酶B(phosphatidylinositol 3-kinase/protein kinase B,PI3K/Akt)信号通路的影响,旨在研究其抗肿瘤机制。方法:细胞计数试剂盒8(cell counting kit-8,CCK8)检测0、1、5、10、15和20μmol/L鱼藤素作用6、24、48和72h后对MCF-7细胞增殖的影响,膜联蛋白V-异硫氰酸荧光素/碘化丙啶双染法检测细胞凋亡率,透射电子显微镜观察细胞凋亡形态,蛋白质印迹法检测细胞内PI3K/Akt通路相关分子的蛋白表达。结果:5、10、15和20μmol/L鱼藤素作用6、24、48和72h后能明显抑制MCF-7细胞增殖(P<0.01),抑制率随着浓度升高和时间延长而增加,各组间两两比较差异有统计学意义(P<0.05);而1μmol/L鱼藤素作用6、24、48和72h后对MCF-7细胞的增殖无明显影响(P>0.05)。5、10、15和20μmol/L鱼藤素作用6h后能诱导MCF-7细胞凋亡,透射电子显微镜下可观察到典型的凋亡细胞形态,而相同条件下1μmol/L鱼藤素对MCF-7细胞的凋亡诱导作用不明显。5μmol/L鱼藤素作用6h后,MCF-7细胞内磷酸化Akt(p-Akt)(Thr308)、磷酸化糖原合成酶激酶-3β(phosphorylated glycogen synthase kinase-3β,p-GSK-3β)(Ser9)、磷酸化磷酸肌醇依赖性激酶1(phosphorylated 3-phosphoinositide-dependent protein kinase1,p-PDK1)(Ser241)和磷酸化人第10号染色体缺失的磷酸酶及张力蛋白同源的基因编码的蛋白(phosphorylated phosphatase and tensin homologue deleted on chromosome10,p-PTEN)(Ser380)的表达量明显减少,而总Akt蛋白的表达量则无明显变化;1μmol/L鱼藤素作用6h后,细胞内上述所有蛋白的表达量均无明显变化。结论:鱼藤素可能通过抑制PTEN(Ser380)和PDK1(Ser241)蛋白的磷酸化,进而抑制Akt(Thr308)的磷酸化,间接抑制其下游GSK-3β(Ser9)的磷酸化,最终诱导MCF-7细胞凋亡和抑制其增殖。

大蓟炭中香叶木素诱导人乳腺癌MCF-7细胞凋亡及其机制研究

研究大蓟炭中香叶木素诱导人乳腺癌MCF-7细胞凋亡及其作用机制。采用硅胶和Sephadex LH-20柱层析从大蓟炭中分离鉴定了三个黄酮类化合物,经NMR和MS鉴定他们的结构分别为香叶木素(1)、刺槐素(2)和柳川鱼黄素(3)。采用MTS方法检测不同浓度的香叶木素对MCF-7的细胞活力的影响;流式细胞术检测不同浓度的香叶木素处理对MCF-7细胞凋亡的作用;Western blot法检测香叶木素处理对细胞PARP、P-JNK等细胞凋亡相关蛋白表达的影响。MTS及流式细胞术结果显示香叶木素能显著抑制MCF-7的增殖并且诱导细胞凋亡;香叶木素可上调P-JNK促进细胞凋亡。结果表明香叶木素在体外实验能通过激活JNK细胞凋亡通路抑制MCF-7的增殖及促进细胞凋亡。