表没食子儿茶素没食子酸酯诱导人肝癌细胞HepG2凋亡与TGF-β1-Smad通路激活有关

目的 探讨表没食子儿茶素没食子酸酯(EGCG)对人肝癌细胞HepG2细胞周期和凋亡的影响及其机制.方法 四甲基偶氮唑蓝(MTT)法检测EGCG对HepG2细胞增殖的影响,流式细胞术检测EGCG对HepG2细胞周期的影响以及细胞凋亡情况,逆转录聚合酶链反应(RT-PCR)和萤光素酶报告基因系统检测验证HepG2细胞中TGF-β1-Smad通路的完整性,实时聚合酶链反应(realtime PCR)检测EGCG对HepG2细胞中Smad2、Smad3、Smad4和Smad7 mRNA表达的影响.结果 高浓度EGCG干预时,HepG2细胞的增殖能力随着EGCG浓度和作用时间的增加而下降,呈明显的时效和量效关系,作用72 h,HepG2细胞的IC50为111.76 μmol/L.随EGCG剂量增大,HepG2细胞中G0/G1期细胞的比例逐渐增高,80、120和160 μmol/L EGCG处理组分别为44.9%、54.8%和91.3%;相反,S期细胞比例逐渐降低,80、120和160 μmol/L EGCG处理组依次为38.5%、29.2%和3.0%.随着EGCG剂量增大,HepG2细胞的早期凋亡增加,80、120和160 μmol/L EGCG处理组的早期凋亡率分别为1.82%、4.22%和6.83%;晚期凋亡也随之增加,80、120和160 μmol/L EGCG处理组的晚期凋亡率分别为7.92%、24.19%和27.92%.HepG2细胞中TGF-β1-Smad通路是完整的.EGCG对HepG2细胞中Smad2、Smad3和Smad4 mRNA的表达无明显影响,但下调Smad7 mRNA的表达.结论 EGCG能诱导人肝癌细胞HepG2的凋亡,其机制可能涉及TGF-β1-Smad通路的激活.     

表没食子儿茶素没食子酸酯诱导人胃癌BGC823细胞凋亡

[目的]观察表没食子儿茶素没食子酸酯（EGCG）诱导人胃癌BGC823细胞凋亡的生物学效应及分子机制。[方法]通过MTT法检测EGCG对BGC823细胞生长的影响;用形态学观察、流式细胞术和DNA琼脂糖凝胶电泳研究EGCG诱导BGC823细胞凋亡。West-ern blot法检测EGCG处理后BGC823细胞NF-κB（p65）、Bcl-2、Bax和Caspase-3蛋白的表达。[结果]EGCG显著性抑制BGC823细胞的生长,呈浓度依赖性。EGCG处理后,光镜下细胞呈典型的凋亡形态学改变;流式细胞术分析表明不同浓度EGCG处理48h后,亚G1期细胞逐渐增加;EGCG（80μg/ml）作用48、72h后,DNA凝胶电泳出现典型梯形条带;Western blot表明EGCG处理48h后,NF-κB（p65）和Bcl-2蛋白表达下调,Bax和Caspase-3蛋白表达升高。[结论]EGCG具有诱导人胃癌BGC823细胞凋亡的作用,其机制可能与抑制NF-κB活化,导致Bax/Bcl-2比值上调,促进Caspase-3活化有关。     

表没食子儿茶素没食子酸酯诱导人胃癌MGC-803细胞凋亡及机制

[目的]探讨表没食子儿茶素没食子酸酯(EGCG)诱导人胃癌MGC-803细胞凋亡的生物学效应及抗肿瘤机制.[方法]通过MTT还原法检测EGCG对该细胞系生长的影响;用普通光镜、流式细胞仪和DNA断裂片段分析研究EGCG诱导的细胞凋亡.S-P免疫组化法检测细胞内Bcl-2、Bax、Caspase-3蛋白的表达.[结果]EGCG能抑制MGC-803细胞的生长,抑制作用呈时间和剂量依赖性关系;EGCG处理MGC-803细胞后,普通光镜下细胞呈凋亡特征性改变;流式细胞仪示同一时间不同浓度EGCG(60、80、100、120μmol/L,48h)处理MGC-803细胞和同一浓度不同时间(80μmol/L,48、72h)处理MGC-803细胞,亚G1期细胞都逐渐增多;MGC-803细胞经EGCG(80、100、120μmol/L,48 h)后,其DNA电泳图中出现梯形条带;S-P免疫组化结果表明80μmol/L EGCG处理细胞48h后,Bcl-2蛋白表达下降,Bax和Caspase-3蛋白表达升高.[结论]EGCG有诱导人胃癌MGC-803细胞凋亡的作用,其机制可能与Bax/Bcl-2比值增高导致Caspase-3的活化从而启动细胞凋亡有关.     

表没食子儿茶素没食子酸酯抗肿瘤分子机制

茶多酚及其主要成分表没食子儿茶素没食子酸酯（EGCG）具有明显的抗肿瘤作用,既可通过抑制核转录因子-κB（NF-κB）、丝裂原活化蛋白激酶（MAPK）、表皮生长因子受体、胰岛素样生长因子、环氧合酶（COX）-2等相关信号通路防止肿瘤发生,也可通过抑制血管内皮生长因子、基质金属蛋白酶（MMP）、尿激酶纤溶酶原激活物等途径阻止肿瘤转移,有望成为一种天然的抗肿瘤药物。     

表没食子儿茶素没食子酸酯抗肿瘤分子机制

茶多酚及其主要成分表没食子儿茶素没食子酸酯(EGCG)具有明显的抗肿瘤作用,既可通过抑制核转录因子-κB(NF-κB)、丝裂原活化蛋白激酶(MAPK)、表皮生长因子受体、胰岛素样生长因子、环氧合酶(COX)-2等相关信号通路防止肿瘤发生,也可通过抑制血管内皮生长因子、基质金属蛋白酶(MMP)、尿激酶纤溶酶原激活物等途径阻止肿瘤转移,有望成为一种天然的抗肿瘤药物。     

表没食子儿茶素没食子酸酯诱导人胃癌BGC-823细胞凋亡的机制

目的:探讨表没食子儿茶素没食子酸酯(epigallocatechin-3-gallate,EGCG)对人胃癌BGC-823细胞增殖的影响及其可能的机制。方法:不同浓度EGCG单独或联合c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)抑制剂SP600125作用BGC-823细胞后,应用MTT法检测BGC-823细胞的增殖抑制率,显微镜下观察细胞的形态学改变,FCM检测细胞凋亡率,蛋白质印迹法检测细胞中p-JNK和p-c-jun蛋白的表达情况,免疫细胞化学法检测细胞中caspase-3的表达。结果:EGCG可抑制BGC-823细胞的增殖(P<0.05),呈时间和剂量依赖效应;EGCG可诱导BGC-823细胞凋亡,细胞凋亡率呈剂量依赖效应(P<0.05);EGCG可上调BGC-823细胞中p-JNK、p-c-jun和caspase-3的表达(P<0.05)。EGCG引起的BGC-823细胞增殖抑制和caspase-3表达水平的上调可被SP600125部分抑制。结论:EGCG可诱导人胃癌BGC-823细胞凋亡,其作用机制可能与激活JNK信号转导途径并上调caspase-3的表达有关。     

表没食子儿茶素没食子酸酯正常组织辐射防护研究进展

表没食子儿茶素没食子酸酯(EGCG)是绿茶中儿茶素的主要成分,具有保护神经、降血糖、抗氧化、抗菌、抗病毒、抗肿瘤等多种生物学功能,已被广泛应用于食品添加剂和保健品。放疗是治疗恶性肿瘤的主要手段之一,但由于其对肿瘤周围正常组织的损害,限制了放疗的治疗剂量,进而影响了肿瘤的局控率。因此,寻找一种高效无毒且具有限制肿瘤生长效...     

表没食子儿茶素没食子酸酯诱导人胃癌细胞裸鼠移植瘤凋亡的研究

背景与目的探讨绿茶提取物表没食子儿茶素没食子酸酯(epigallocatechin-3-gallate,EGCG)诱导人胃癌细胞裸鼠移植瘤凋亡及分子机制。方法建立人胃腺癌(SGC7901)细胞裸鼠异种移植瘤模型,用不同剂量的EGCG进行治疗,并设对照,用流式细胞分析术检测肿瘤组织中细胞凋亡情况,免疫组织化学方法检测肿瘤组织的凋亡相关基因Bcl-2、Bax、Caspase-3的表达情况。结果裸鼠异种移植瘤治疗实验结果显示,EGCG对移植瘤生长有明显抑制作用(其中20mg/kg、EGCG抑制率54.64%与对照组比较P<0.05);PI染色FCM分析发现,EGCG20mg/kg能诱导移植瘤细胞凋亡率17.2%与对照组比P<0.05;SP免疫组织化学结果表明EGCG可上调移植瘤细胞中Bax、Caspase-3蛋白的表达,下调Bcl-2蛋白的表达。结论表没食子儿茶素没食子酸酯(EGCG)具有体内诱导人胃腺癌细胞凋亡的作用,其机制可能与Bcl-2/Bax比值降低导致Caspase-3的活化从而启动细胞凋亡有关。     

表没食子儿茶素没食子酸酯(EGCG)抗肿瘤研究进展

表没食子儿茶素没食子酸酯（EGCG）是绿茶中主要活性成分之一，具有抑制肿瘤细胞增殖的活性。文章从EGCG在生物体内的分布及其代谢特点，诱导细胞凋亡、细胞周期阻滞以及调控癌基因、抑癌基因表达等分子机制方面综述近年来国内外对EGCG抗肿瘤研究的新进展。     

不同肿瘤细胞对表没食子儿茶素没食子酸酯细胞毒敏感性的差 …

目的探讨表没食子儿茶素没食子酸酯（ＥＧＣＧ）对大肠癌ＬｏＶｏ细胞、胃癌ＭＧＣ－８０３细胞和肝癌ＢＥＬ－７４０２细胞细胞毒作用，及其作用的差异性和可能的分子机制。方法在有或无谷胱甘肽合成酶抑制剂ＤＬ－ｂｕｔｈｉｏｎｉｎｅ－」Ｓ，Ｒ「－ｓｕｌｆｏｘｉｍｉｎｅ（ＢＳＯ）预处理的情况下，采用ＭＴＴ法和台盼蓝拒染法测定ＥＧＣＧ对３株肿瘤细胞的细胞毒作用。采用紫外分光光度法和流式细胞术分别测定经ＢＳＯ处理的３     

MAC related mitochondrial pathway in oroxylin A induces apoptosis in human hepatocellular carcinoma HepG2 cells

Oroxylin A is a flavonoid isolated from the root of Scutellaria baicalensis Georgi. Our previous work demonstrated that the anti-tumor activity of oroxylin A was mainly attributed to its apoptosis inducing effect in cells. The present study explores the exact molecular mechanism of oroxylin A-induced apoptosis in tumor cells. We showed that oroxylin A-induced apoptosis in HepG2 cells was achieved through mitochondrial pathway. We also investigated which mitochondrial channels, PTP or MAC or both, were involved in the permeabilization of the mitochondrial outer membrane after treatment with oroxylin A. The results showed that oroxylin A-induced apoptosis in a PTP-independent manner; therefore, we focused our attention on MAC. As Bax is an essential constituent of MAC in certain systems, we examined the activation, subcellular location, oligomeric structure of Bax in HepG2 cells treated with oroxylin A. Moreover, our results showed that overexpression of Bcl-2 inhibited oroxylin A-induced apoptosis. In summary, we have demonstrated that opening of MAC, but not PTP, played a key role in oroxylin A-induced activation of mitochondrial apoptotic pathway in HepG2 cells.     

酸性环境诱导肝癌HepG2细胞EMT

目的 研究酸性环境对肝癌HepG2细胞上皮细胞间质转化(EMT)的影响。方法分别在酸性和碱性条件下培养HepG2细胞,观察细胞形态的区别。划痕实验检测两组细胞的迁移能力,Matrigel侵袭实验检测细胞的侵袭能力。RT-PCR检测两组细胞EMT相关基因mRNA的表达水平,Western blot检测两组细胞EMT相关基因蛋白的表达水平。结果 酸性条件下培养的HepG2细胞形态明显从上皮型转变为间质型;酸性条件下HepG2细胞的迁移能力明显强于碱性条件下;酸性条件下HepG2细胞穿越Matrigel的数量明显多于碱性条件下;酸性条件下HepG2细胞EMT相关基因Vimentin、Slug、Snail及Zeb1的mRNA表达以及EMT相关蛋白Vimentin和MMP9的表达强度均明显高于碱性条件下。结论 酸性环境能诱导肝癌HepG2细胞EMT的发生。     

氯喹通过激活P38MAPK通路诱导人肝癌HepG2细胞凋亡

目的：研究氯喹对人肝癌HepG2细胞增殖和凋亡的影响,并初步研究其可能的机制。方法：体外培养HepG2细胞,采用MTT法检测不同浓度（0、10、20和40 μmol/L）氯喹作用不同时间（24、48和72 h）后对细胞增殖的影响;用DAPI染色观察氯喹处理细胞24 h后细胞核的变化;流式细胞术检测氯喹对HepG2细胞凋亡的影响;Western blot技术检测氯喹对HepG2细胞中Caspase-3、Bcl-2、Bax、P-P53、P38MAPK和P-P38MAPK蛋白表达的影响。结果：与对照组比较,在上述3个时间点10、20、40 μmol/L氯喹（10 μmol/L氯喹作用24 h组除外）对人肝癌HepG2细胞的增殖均有明显抑制作用（P均 < 0.05）;荧光显微镜下发现,10、20、40 μmol/L氯喹处理24 h后均可引起HepG2细胞不同程度的核浓集、固缩等典型凋亡形态变化;流式细胞术结果提示10、20、40 μmol/L氯喹能诱导HepG2细胞凋亡（P均 < 0.05）;Western blot结果显示20和40 μmol/L氯喹作用HepG2细胞后,P-P53、P-P38MAPK、剪切后活化型Caspase-3和Bax蛋白表达量增加（P均 < 0.05）,Bcl-2表达下降,Caspase-3和P38MAPK表达无明显变化（P > 0.05）。结论：氯喹能够抑制人肝癌HepG2细胞的生长并诱导其凋亡,其机制可能与P38MAPK通路有关。     

Furanodiene induces G2/M cell cycle arrest and apoptosis through MAPK signaling and mitochondria-caspase pathway in human hepatocellular carcinoma cells

Furanodiene (C15H20O), a pure compound isolated from Traditional Chinese medicine, Curcuma wenyujin, named Ezhu in Chinese, which structure was determined on the basis of NMR, MS and UV spectrum. In this study, we attempted to characterize in detail the signaling cascades resulted from furanodiene-induced apoptosis in human hepatoma HepG2 cells. Furanodiene inhibited HepG2 cell growth by causing cell cycle arrest at G2/M and inducing apoptosis as evidenced by DNA fragmentation assay. We found that furanodiene induced mitochondrial transmembrane depolarization, release of mitochondrial cytochrome c, activation of caspases-3 and the cleavage of PARP. The furanodiene mediated mitochondria-caspase apoptotic pathway also involved activation of p38 and inhibition of ERK mitogen-activated protein kinase (MAPK) signaling. These results for the first time have identified the biological activity of furanodiene against HepG2 cells and provide rationales for further development of essential oil of Ezhu and its ingredients such as furanodiene on treatment of liver diseases.     

Survivin deficiency induces apoptosis and cell cycle arrest in HepG2 hepatocellular carcinoma cells

The postulated dual roles of survivin as an anti-apoptotic factor and a mitotic inducer have placed this factor in the spotlight of cancer research. The purpose of this study was to investigate whether survivin might connect the cell cycle with apoptosis. Here, by simultaneously monitoring survivin deficiency-induced morphological changes of HepG2 cells using time-lapse imaging as well as determining apoptosis progression, we observed synchronized defective mitosis characterized by multinucleated and polyploid cells and cell cycle arrest at S phase or G2/M phase followed by apoptosis, the processes of which depended on the simultaneous destruction of specialized subcellular compartments of survivin and activation of caspase-3-like protease. These findings showed that the survivin protein acted as mitotic regulator and apoptosis inhibitor, but may also possess the role of a bridge in integrating apoptosis and cell division. An essential prerequisite of this pathway was the specialized subcellular localization of survivin. The overexpression of survivin was required to maintain cell viability and proper cell cycle transitions, and to preserve genetic fidelity during cell division in HepG2 cells.     

番茄红素对人肝癌HepG2细胞增殖和凋亡的影响

目的 研究番茄红素(Lycopene,LP)对人肝癌HepG2细胞生长的影响并初探其机制。方法取对数生长期HepG2细胞设空白对照组、LP(5 μg/mL)组、LP(10 μg/mL)组、LP(20 μg/mL)组和顺铂(40 μg/mL)组,每组设10个复孔;各组分别给药干预48 h后,噻唑蓝(MTT)比色法测定细胞增殖抑制率,流式细胞术(FCM)检测细胞周期和细胞凋亡状况,RT-PCR法检测Bax mRNA和Bcl-2 mRNA表达,Western blot法检测Caspase-3蛋白表达。结果 与空白对照组比较,经LP(10 μg/mL、20 μg/mL)或顺铂40 μg/mL干预48 h能够显著提高HepG2细胞增殖抑制率,延长细胞周期中G₀/G₁期而缩短G₂/M期,提高细胞凋亡率,上调促凋亡Bax mRNA表达并下调抑凋亡Bcl-2 mRNA表达,提高Bax/Bcl-2比值,上调Caspase-3蛋白表达,LP上述作用具有一定的剂量依赖性。结论 LP具有抑制人肝癌HepG2细胞增殖并促进其凋亡的作用,其机制可能与LP干预细胞周期分布和调节凋亡相关基因蛋白表达有关。     

补骨脂酚通过MAPK途径诱导人肝癌HepG2细胞凋亡的研究

目的:研究补骨脂酚对人肝癌细胞凋亡的影响及其作用机制。方法:应用噻唑蓝法（MTT法）和倒置显微镜技术考察补骨脂酚对HepG2细胞生长的影响;采用荧光显微镜观察补骨脂酚处理后细胞凋亡;利用蛋白免疫印迹法检测补骨脂酚对HepG2细胞中凋亡相关蛋白及MAPK家族蛋白表达的影响;引入MAPK家族蛋白抑制剂考察生长抑制率和凋亡相关蛋白表达的变化。结果:补骨脂酚可以剂量依赖性地抑制人肝癌HepG2细胞增殖,其生长抑制作用明显强于临床上常用的抗肿瘤药5-氟尿嘧啶,并且补骨脂酚对人正常肝L02细胞具有较低的毒性。进一步研究发现,补骨脂酚可以诱导HepG2细胞发生凋亡。此外,MAPK家族参与到补骨脂酚诱导的HepG2细胞凋亡过程中,补骨脂酚可以剂量依赖性激活JNK的表达发挥促凋亡的作用,同时抑制了ERK促存活通路,然而对p38无明显影响。结论:本研究首次阐明了补骨脂酚诱导人肝癌HepG2细胞生长抑制作用机制,为进一步的临床应用提供了理论依据。     

缺氧对人肝癌HepG2细胞凋亡及p38MAPK通路的影响

目的:探讨缺氧对人肝癌HepG2细胞凋亡及p38MAPK通路的影响。方法:用三气培养箱培养肝癌细胞HepG2,建立缺氧细胞模型,CCK-8 法检测HepG2细胞的增殖率,流式细胞术检测细胞凋亡率,Real-time PCR分析p38MAPK mＲNA的表达,Western blot法检测p38MAPK及p-p38MAPK蛋白的表达变化。结果:缺氧可抑制人肝癌HepG2细胞的增殖,抑制细胞凋亡（P<0.05）;缺氧处理人肝癌HepG2细胞后,p38MAPK mＲNA的表达量下调(P<0.05);Western blot结果显示缺氧可下调p38MAPK、p-p38MAPK蛋白的表达（P<0.05）。结论:缺氧通过抑制p38MAPK通路抑制人肝癌HepG2细胞凋亡。     

Cyclooxygenase-2 inhibition induces apoptosis signaling via death receptors and mitochondria in hepatocellular carcinoma

Inhibition of cyclooxygenase (COX)-2 elicits chemopreventive and therapeutic effects in solid tumors that are coupled with the induction of apoptosis in tumor cells. We investigated the mechanisms by which COX-2 inhibition induces apoptosis in hepatocellular carcinoma (HCC) cells. COX-2 inhibition triggered expression of the CD95, tumor necrosis factor (TNF)-R, and TNF-related apoptosis-inducing ligand (TRAIL)-R1 and TRAIL-R2 death receptors. Addition of the respective specific ligands further increased apoptosis, indicating that COX-2 inhibition induced the expression of functional death receptors. Overexpression of a dominant-negative Fas-associated death domain mutant reduced COX-2 inhibitor-mediated apoptosis. Furthermore, our findings showed a link between COX-2 inhibition and the mitochondrial apoptosis pathway. COX-2 inhibition led to a rapid down-regulation of myeloid cell leukemia-1 (Mcl-1), an antiapoptotic member of the Bcl-2 family, followed by translocation of Bax to mitochondria and cytochrome c release from mitochondria. Consequently, overexpression of Mcl-1 led to inhibition of COX-2 inhibitor-mediated apoptosis. Furthermore, blocking endogenous Mcl-1 function using a small-interfering RNA approach enhanced COX-2 inhibitor-mediated apoptosis. It is of clinical importance that celecoxib acted synergistically with chemotherapeutic drugs in the induction of apoptosis in HCC cells. The clinical relevance of these results is further substantiated by the finding that COX-2 inhibitors did not sensitize primary human hepatocytes toward chemotherapy-induced apoptosis. In conclusion, COX-2 inhibition engages different apoptosis pathways in HCC cells stimulating death receptor signaling, activation of caspases, and apoptosis originating from mitochondria.