Melatonin and Doxorubicin synergistically induce cell apoptosis in human hepatoma cell lines

AIM:To investigate whether Melatonin has synergistic effects with Doxorubicin in the growth-inhibition and apoptosis-induction of human hepatoma cell lines HepG2 and Bel-7402.METHODS:The synergism of Melatonin and Doxorubicin inhibited the cell growth and induced cell apoptosis in human hepatoma cell lines HepG2 and Bel-7402.Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT)assay.Cell apoptosis was evaluated using TUNEL method and flow cytometry.Apoptosis-related protein Bax,Bcl-2 and caspase-3 expressions were measured by immunohistochemical staining.RESULTS:Treatment with Melatonin(10 -8 -10 -5 mol/L) alone had a dose-related inhibitory effect on cell proliferation but no cytotoxic effect on hepatoma cell lines HepG2 and Bel-7402.Interestingly,when combined with Doxorubicin,Melatonin significantly increased the effects of cell growth inhibition and cell apoptosis.Furthermore,TUNEL staining and flow cytometry revealed that cooperative apoptosis induction was associated with decreased expression of Bcl-2 as well as increased expression of Bax and Caspase3.CONCLUSION:The synergism of Melatonin and Doxorubicin inhibits hepatoma cell growth and induces cell apoptosis.

Inhibitory effect of parvovirus H-1 on the formation of colonies of human hepatoma cell line in vitro and its tumors in nude mice

The inhibitory effect of parvovirus H-1 on the colonyforming ability in vitro of QGY-7703, a cultured human hepatoma cell line, and on the formation and growth of its tumors in nude mice was studied. With higher multiplicity of infection (MOI) of H-1 given, survival of the QGY-7703 cells was found to be decreased. H-1 DNA amplification level at 30 h postinfection(p.i.) was detected to be 7.4 times higher than that at 2 h by dispersed cells assay, while the cells were delayed to enter into S phase.Plaques were formed in the indicator cells (new-born human kidney cell line, NBK) by progeny H-1 virus particles released from the infected QGY-7703 cells by infectious cell center assay. The formation of tumors in nude mice by QGY-7703 cells which were injected s c at 2 h postinfection was observed to be prevented in 2 groups with given MOI 25 and 50. The tumor growth of MOI 10 group occurred at a lower exponential rate than that of control,after a 20 d latent period. It was evident that parvovirus H-1 exhibited a direct inhibitory effect on the formation and growth of human hepatoma cells in vivo as well as in vitro.

Effect of 80.55 MeV//u^(12)C^(6+) Ions on Radiosensitivity and Cell Cycle of Human Hepatoma Cell Lines

In this paper, the relationship between radiosensitivity, cell cycle alteration and the change of apoptosis in different human hepatoma cell lines irradiated by heavy ions were studied with the aim of building up the base data for clinical therapy. Exponentially growing hepatoma cell lines were irradiated by 80.55 MeV/u12C6＋ ions at a dose of 0 Gy, 0.5 Gy, 1 Gy, 2 Gy, 4 Gy and 8 Gy. The radiosensitivity was assessed by means of the colony-forming assay. The DNA content, the percentage of each cell-cycle phase and the apoptosis rate were obtained with flow cytometry methods. After the irradiation, the SF2 （survival fraction at 2 gray） of SMMC-7721 cells were evidently lower than that of HepG2 cells. The S phase arrest, G2/M phase arrest delay and the apoptosis in the two hepatoma cell lines varied with the increase of the dose and repair time. The heavy ions could obviously kill the human hepatoma cell lines. Compared to HepG2 cells, SMMC-7721 cells were more radiosensitive to 12C^6＋ ions.

Effects of Terminalia arjuna bark extract on apoptosis of human hepatoma cell line HepG2

AIM：To investigate the effects of Terminalia arjuna （T. arjuna） extract on human hepatoma cell line （HepG2） and its possible role in induction of apoptosis.METHODS： Human hepatoma cells were treated with different concentrations of ethanolic extract of T. arjuna and its cytotoxicity effect was measured by trypan blue exclusion method and lactate dehydrogenase leakage assay. Apoptosis was analyzed by light and fluorescence microscopic methods, and DNA fragmentation. The mechanism of apoptosis was studied with expression of p53 and caspase-3 proteins. Glutathione （GSH） content was also measured in HepG2 cells after T. arjuna treatment.RESULTS： T. arjuna inhibited the proliferation of HepG2 cells in a concentration-dependent manner. Apoptotic morphology was observed in HepG2 cells treated with T. arjuna at the concentrations of 60 and 100 mg/L. DNA fragmentation, accumulation of p53 and cleavage of procaspase-3 protein were observed in HepG2 cells after the treatment with T. arjuna. The depletion of GSH was observed in HepG2 cells treated with T. arjuna.CONCLUSION： T. arjuna induced cytotoxicity in HepG2 cells in vitro. Apoptosis of HepG2 cells may be due to the DNA damage and expression of apoptotic proteins. Depletion of GSH may be involved in the induction of apoptosis of HepG2 cells.

ApoB-containing lipoproteins promote infectivity of chlamydial species in human hepatoma cell line

AIM:To evaluate the direct binding of two main chlamydial biovars(C.trachomatis and C.pneumoniae) to plasma lipoproteins and its effect on chlamydial infection rate in human hepatoma cell line(HepG2 cells). METHODS:Murine plasma lipoproteins were fractionated and isolated using fast-performance liquid chromatography(FPLC),spotted on nitrocellulose membrane and incubated with chlamydial suspensions. Direct binding of chlamydial particles to lipoprotein fractions has been studied using lipopolysaccharide-specific antibodies in immuno-dot blot binding assay and immunoprecipitation analysis.Immunostaining protocol as well as flow cytometry analysis have been employed to study the infectivity rate of chlamydial species in HepG2 cells. RESULTS:Elementary bodies of both C.trachomatis and C.pneumoniae bind ApoB-containing fractions of plasma lipoproteins.That binding becomes stronger when heat-denatured FPLC fractions are used, suggesting a primary role of apolipoproteins in interaction between chlamydial particle and lipoprotein. Both chlamydial biovars efficiently propagate in human hepatoma cell line-HepG2 cells even in serum free conditions forming late-stage inclusion bodies and releasing extracellular elementary bodies.Preincubation of C.trachomatis and C.pneumoniae with native ApoB-containing lipoproteins enhances the rate of chlamydial infection in HepG2 cells.CONCLUSION:A productive infection caused by C. trachomatis and C.pneumoniae may take place in human-derived hepatocytes revealing hepatic cells as possible target in chlamydial infection.Obtained results may suggest the participation of lipoprotein receptors in the mechanism of attachment and/or entry of chlamydial particles into target cells.

和枢消积方对人肝癌细胞系HepG2增殖凋亡的影响

目的探讨和枢消积方对人肝癌细胞系HepG2增殖凋亡的影响,揭示可能的分子机制。方法使用和枢消积方作用于人肝癌细胞系HepG2,采用Cell Counting Kit-8(CCK-8)、平板克隆实验检测细胞增殖能力。采用蛋白质印迹法(Western blot)检测B淋巴细胞瘤-2基因(BCL-2)、BCL-2相关X蛋白(BAX)、丙型肝炎病毒(HCV)非结构5A蛋白(NS5A)反式激活基因13(NS5ATP13)及蛋白激酶B(AKT)/糖原合酶激酶(GSK)/雷帕霉素靶蛋白(MTOR)相关通路蛋白的表达水平。结果和对照组相比,和枢消积方各组可使HepG2细胞活性、增殖率显著降低(P<0.05);同时可上调BAX的蛋白表达,下调BCL-2及磷酸(p)-AKT、p-GSK、p-MTOR及NS5ATP13的表达(P<0.05),呈浓度依赖性。结论和枢消积方可以抑制HepG2细胞的增殖并诱导凋亡,这可能与和枢消积方抑制NS5ATP13的表达,继而抑制AKT/GSK/MTOR信号转导通路的活化有关。

Effect of Calmodulin and Voltage-dependent Ca^(2+) Channel on the Proliferation of Heptoma Cells Induced by Epidermal Growth Factor

The effect of thyrosine kinase, calmodulin and voltage-dependent Ca 2+ channel on the proliferation of hepatoma cells induced by EGF was studied. Hepatoma cell line SMMC7721 was cultured in RPMI1640 serum-free medium. DNA synthesis rate of hepatoma cells was measured by 3H-TdR incorporation. 10 -9 mol/L EGF could significantly stimulate the proliferation of hepatoma cells (P<0.05), and this effect might be significantly inhibited by tyrosine kinase inhibitor (P<0.001). Calmodulin inhibitor W-7 had no effect on the basic phase of cultured hepatoma cells (P> 0.05), but it had very significantly inhibitory effect on the proliferation of hepatoma cells induced by EGF (P<0.001). Voltage-dependent Ca 2+ channel inhibitor Varapamil had no inhibition on the proliferation of hepatoma cells induced by EGF (P>0.05). It had no effect on the basic phase of cultured hepatoma cells (P>0.05). It is suggested that tyrosine kinase and Ca 2+-calmodulin-dependent pathway may play a critical role on the proliferation of heptoma cells induced by EGF, and voltage-dependent Ca 2+ channel is independent of the effect of EGF.

阿霉素对热处理的人肝癌细胞-7721/Adm耐药株细胞毒性的影响

目的： 探讨比较阿霉素（ ADM）与 43℃加热单独或合并处理人肝癌细胞 7721敏感株（简称 7721细胞）和人肝癌细胞 7721/Adm耐药株（简称 7721/Adm细胞）的细胞毒作用。方法：以体外培养的人肝癌细胞 7721敏感株和已经建立的人肝癌细胞 7721/Adm耐药株为研究对象，采用水浴加温法 ,体外细胞毒试验（ MTT法） ,观察 ADM与加热处理对细胞生长抑制的影响；采用流式细胞技术检测热处理对 7721细胞和 7721/Adm细胞胞内阿霉素浓度的影响。结果： (1)热处理可以明显提高两种细胞对阿霉素的敏感性： 7721细胞、 7721/Adm细胞经阿霉素及 43.5℃热处理，其细胞存活率分别下降 35.2％（ 30 min）、 24.8％（ 60 min）和 29.4％（ 30 min）、 22.8％（ 60 min）； (2)流式细胞仪检测显示，热处理可明显提高这两种细胞尤其是 7721/Adm细胞内的阿霉素浓度： 7721细胞组提高 30.8％， HCC 7721/Adm组提高 51％。结论：热处理可以显著提高人肝癌细胞 7721敏感株和人肝癌细胞 7721/Adm耐药株对阿霉素的敏感性。

应用基因芯片技术研究白花蛇舌草豆甾醇抑制人肝癌细胞体外生长的靶基因调控

目的:应用基因芯片技术研究白花蛇舌草豆甾醇(Stigmasterol from Hedyotis diffusa willd.,SHD)抑制人肝癌细胞SMMC-7721生长的靶基因调控。方法:MTT法评价SHD在0、5、10、50、100mg/L浓度下,于24、48、72h对人肝癌细胞SMMC-7721的抑制率变化。分别提取人正常肝细胞、人肝癌SMMC-7721细胞和SHD作用后的SMMC-7721细胞的总RNA,逆转录合成单链、双链cDNA后,体外转录合成生物素标记的cRNA与人HO4基因表达谱芯片杂交,扫描杂交芯片图像,利用软件获得SHD抑制人肝癌的靶基因,对其进行生物信息学分析。结果:SHD对SMMC-7721具有体外抑制作用,且呈剂量依赖性和时间依赖性;SHD使癌基因fos、myc、ras、pim-1、met、rel下调至正常水平,使抑癌基因NF-2和磷酸激酶MAP2K6的表达上调至正常水平。结论:SHD对人肝癌细胞SMMC-7721具有显著的体外抑制作用;SHD抑制SMMC-7721细胞的作用由多条靶基因协同,并通过胞内外信号转导途径协调完成。

白花蛇舌草总黄酮抑制人肝癌细胞的靶基因调控

目的:研究白花蛇舌草总黄酮(flavonoids from Hedyotis diffusa willd．,FHD)抑制人肝癌细胞SMMC-7721的靶基因调控．方法:分别提取人正常肝细胞、人肝癌SMMC-7721细胞和FHD作用后的SMMC- 7721细胞的总RNA,逆转录合成单链、双链cDNA后,体外转录合成生物素标记的cRNA与人HO4基因表达谱芯片杂交,扫描杂交芯片图像,利用软件获得FHD抗肝癌的靶基因,对靶基因进行生物信息学分析．结果:共找到20条FHD抑制肝癌细胞的有效靶基因,即给予FHD后,通过上调或下调,这些显著异常表达的基因被恢复至正常水平．其中,癌基因pim-1(Hs．81170)、rel(Hs．858)、ras(Hs．204354)、fos(Hs．25647)、myc (Hs．79070)、met(Hs．285754)以及编码Bcl-2相关蛋白的基因(Hs．227817)被显著下调;成纤维细胞生长因子(Hs．284244)、胰岛素样生长因子1受体(Hs．239176)、胰岛素样生长因子结合蛋白(Hs．1516)、G蛋白偶联受体(Hs．23016)、酪氨酸蛋白磷酸化酶(Hs．227777)、转录因子12(Hs．21704)、转录因子CP2(Hs．154970)等与细胞生长相关的信号转导分子被显著下调;细胞因子IL-1(Hs．1722)被显著下调;丝裂原活化的蛋白激酶(MAPK)信号传导通路成员MAP2K6(Hs．118825)和MAP3K12(Hs．211601)被显著上调;抑癌基因NF-2(Hs．902)被显著上调;编码T细胞活化共刺激信号分子的TNFSF9(Hs．1524)、TNFSF7(Hs．99899)基因被显著上调．这些基因均与肝癌的发生、发展密切相关．结论:FHD抑制SMMC-7721细胞的作用由多条靶基因协同,并通过胞内、胞外信号转导途径协调完成．

黄芪多糖对人肝癌细胞HepG2凋亡相关基因表达的影响

目的研究黄芪多糖(APS)联合斑蝥酸钠(SCA)对人肝癌细胞HepG2细胞凋亡及Bcl-2基因表达的影响。方法实验分为对照组、SCA处理组、APS处理组、APS联合SCA处理组,采用免疫组化染色法(IH)观察APS联合斑蝥酸钠对HepG2细胞增殖的抑制作用,采用Western印迹法检测各组细胞Bcl-2基因表达的变化。结果与对照组相比,各处理组HepG2细胞中Bcl-2基因表达均明显减少,APS联合SCA处理组减少最为明显。结论 APS联合SCA可明显抑制HepG2细胞Bcl-2基因的表达。

水红花子黄酮类成分对人肝癌细胞株SMMC-7721的影响

目的:研究水红花子黄酮类成分对人肝癌细胞株SMMC-7721增殖、细胞周期及细胞凋亡的影响。方法:采用MTT法研究水红花子黄酮类成分对人肝癌细胞SMMC-7721的抑制作用及时效量效关系;并通过PI染色法和Annexin V-EGFP/PI双染法观察水红花子黄酮类成分作用于人肝癌细胞株SMMC-7721后细胞周期DNA含量变化及细胞凋亡率。结果:水红花子黄酮类成分能调节SMMC-7721人肝癌细胞株G1/S转换,使肿瘤细胞发生S期阻滞,造成S期细胞堆积,阻断细胞的DNA合成和复制,阻滞肿瘤细胞进入G2/M期,从而抑制肿瘤细胞的增殖,诱导SMMC-7721细胞凋亡,且具有明显的时效及量效关系。结论:水红花子黄酮类成分对人肝癌细胞株SMMC-7721具有明显的抑制作用,且抑制作用和时间剂量成线性关系,其作用机制为抑制肿瘤细胞的增殖和诱导该细胞的凋亡。

丝裂霉素C热化疗对人肝癌细胞-7721的细胞毒作用

目的：探讨比较丝列霉素C（MMC）化疗与加热化疗对人肝癌细胞（HCC－7721）的细胞毒作用．方法：以体外培养的HCC－7721为研究对象，采用水浴加温法，体外细胞毒试验（MTT法），观察了MMC化疗与加热化疗对细胞的生长抑制规律的影响二结果：①43℃30min以上的单独热疗对细胞具有较强的细胞毒作用．②热疗能增强肿瘤细胞对MMC的敏感性，热与MMC联合应用的效果强弱依次为热化同时（HM组）优于先热后化（H→M组）或先化后热（M→H组）．结论：加热可以显著提高丝裂霉素C对HCC－7721的细胞毒作用．

葡萄籽原花青素诱导人肝癌HepG2细胞凋亡及自噬性死亡

目的:探讨原花青素对肝癌HepG2细胞的抑制作用及其可能的作用机制。方法:改良MTT法(WST-8法)及克隆形成抑制实验观察原花青素对肝癌HepG2细胞的生长抑制作用,碘化丙锭(PI)单染色检测细胞周期改变,Annexin V-FITC/PI双染流式细胞术检测细胞凋亡水平,激光共聚焦显微镜观察和Western blotting检测细胞自噬发生。结果:原花青素作用HepG2细胞后,不同质量浓度的原花青素对肝癌细胞的生长均有抑制作用,且呈剂量-效应关系(P<0.01),原花青素作用于人肝癌HepG2细胞48 h的IC50为1.304×10-1g/L;与对照组相比随着原花青素作用于HepG2细胞的浓度增加,细胞克隆逐渐减少;随着原花青素浓度的增加,人肝癌HepG2细胞出现明显G1期阻滞,且高浓度原花青素组出现明显的亚二倍体峰,当原花青质量素浓度达到1.6×10-1g/L时,亚二倍体百分率为81%;不同质量浓度原花青素作用后,出现明显的凋亡细胞及坏死细胞、自噬性死亡和非特异性死亡细胞群;经原花青素处理转染GFP-LC3质粒的HepG2细胞胞浆内,LC3呈现明显的点状聚集;细胞自噬标志蛋白LC3-II的蛋白表达水平随着原花青素浓度增加逐渐增多。结论:原花青素通过诱导细胞凋亡及自噬性死亡的方式抑制人肝癌细胞的生长。

白茅根水提物对人肝癌细胞株SMMC-7721细胞周期及细胞凋亡的影响

目的研究白茅根水提物对人肝癌细胞株SMMC-7721增殖抑制率、细胞周期及细胞凋亡的影响。方法采用MTT法研究白茅根水提物对人肝癌细胞SMMC-7721的抑制率及抑制率与时间剂量关系;并通过PI染色法和Annexin V-EGFP/PI双染法研究白茅根水提物作用于人肝癌细胞株SMMC-7721后细胞周期DNA含量变化及对细胞凋亡率的影响。结果不同浓度的白茅根水提物处理肝癌SMMC-7721细胞24,48,72,96 h后,均呈现出显著的细胞增殖抑制作用,抑制作用具有明显的时间-剂量-效应关系,差异有统计学意义(P<0.05);细胞周期与细胞凋亡实验结果显示不同浓度的白茅根水提物处理肝癌SMMC-7721细胞46 h后可显著增加肝癌细胞凋亡率,差异有统计学意义(P<0.001),作用36 h后,可增加S期比例同时降低G2/M期细胞比例,差异有统计学意义(P<0.001)。结论白茅根水提物对人肝癌细胞株SMMC-7721具有明显的增殖抑制作用并可诱导其凋亡,该作用是通过抑制G2/M期细胞比例,将细胞周期阻滞在S期实现的。

人血浆转甲状腺素蛋白的提纯及其对肝癌细胞生长的抑制作用

目的:在人原发性肝癌中,转甲状腺素蛋白(transthyretin,TFR)基因转录严重受阻遏.在原发性肝癌患者的血浆中,TTR含量明显降低.因此,有必要从人血浆中提取TTR,观察TIR对人肝癌细胞生长的抑制作用.方法:先用40%饱和硫酸铵,再用5%酚预沉淀人血浆,采用DEAE-Cellulose离子交换层析提取TTR,所提蛋白经蛋白质印迹鉴定并于体外观察TTR对肝癌细胞生长的抑制作用.结果:从血浆中提取的TTR纯度为85%,经蛋白质印迹鉴定正确;体外实验初步证实,TTR对肝癌细胞的生长有明显抑制作用.结论:TTR对肝癌细胞的生长有明显抑制作用,这一性质为生物工程生产TTR,用于临床治疗,提供了可行性依据,从而在蛋白水平进一步证实TTR基因可能是与人肝癌相关的抑癌基因候选者.

6种鸢尾黄素曼尼希碱衍生物的合成及其抗肿瘤活性研究

目的:对鸢尾黄素进行结构修饰,寻求新的具有抗肿瘤活性的化合物。方法:以鸢尾黄素为先导化合物,分别加入乙醇胺、甲胺、乙胺、二甲胺、二乙胺、正丙胺等胺类试剂和甲醛溶液,经曼尼希(Mannich)反应得到鸢尾黄素曼尼希碱衍生物,根据红外光谱、紫外光谱、质谱、核磁共振等确定其结构。采用溶解度试验法考察鸢尾黄素及其衍生物的水溶性;采用MTT法考察鸢尾黄素及其衍生物对人结肠癌细胞株HCT116、人肺癌细胞株A549、人肝癌细胞株HepG2的增殖抑制作用,并计算半数抑制浓度(IC50);以H22肝癌荷瘤小鼠为模型,考察鸢尾黄素及其衍生物(剂量均为100 mg/kg)的体内抑瘤率。结果:共合成6个鸢尾黄素曼尼希碱衍生物,分别为8-(N-羟乙基)-亚甲基胺基-5,7,4′-三羟基-6-甲氧基异黄酮、8-(N-甲基)-亚甲基胺基-5,7,4′-三羟基-6-甲氧基异黄酮、8-(N,N-二乙基)-亚甲基胺基-5,7,4′-三羟基-6-甲氧基异黄酮、8-(N,N-二甲基)-亚甲基胺基-5,7,4′-三羟基-6-甲氧基异黄酮、8-(N-乙基)-亚甲基胺基-5,7,4′-三羟基-6-甲氧基异黄酮、8-(N-正丙基)-亚甲基胺基-5,7,4′-三羟基-6-甲氧基异黄酮(依次记为化合物1~6)。与鸢尾黄素比较,6个衍生物的水溶性明显提高,溶解度是鸢尾黄素的5~20倍;其中化合物1、3、5对HCT116细胞的IC50分别为(34.82±3.27)、(16.21±4.13)、(33.12±3.25)μmol/L,均强于鸢尾黄素的IC50[(45.23±5.74)μmol/L];对A549细胞的IC50分别为(37.05±5.74)、(26.88±4.52)、(30.13±6.23)μmol/L,均强于鸢尾黄素的IC50[(53.24±6.34)μmol/L];对HepG2细胞的IC50分别为(23.74±1.45)、(18.96±2.34)、(30.95±2.87)μmol/L,均强于鸢尾黄素的IC50[(48.98±2.58)μmol/L];对H22肝癌荷瘤小鼠的抑瘤率分别55.51%、57.20%、49.15%,且均高于鸢尾黄素的抑瘤率(33.05%),其余3个化合物相比鸢尾黄素的抗肿瘤活性无明显优势。结论:在本研究合成的6个鸢尾黄素曼尼希碱衍生物中,化合物1、3、5均具有强于鸢尾黄素的抗肿瘤活性。

基于人肝癌细胞HepG2的仙鹤草挥发性成分体外抗肝肿瘤活性评价研究

目的研究仙鹤草挥发性成分物质组成及其体外抗肝肿瘤活性,为其作为天然抗肝肿瘤药物的开发利用奠定实验基础。方法采用GC-MS法对仙鹤草挥发性成分进行化学成分分析,采用MTT比色法对仙鹤草挥发性成分及其主要单体成分棕榈酸、反式角鲨烯、α-亚麻酸作用于人肝癌细胞株HepG2的增殖抑制率进行研究;采用AnnexinV-FITC/PI双染法对仙鹤草挥发性成分作用HepG2细胞后凋亡率的变化进行研究。结果仙鹤草挥发性成分中共鉴定出23种化合物,其中主要包括醇类成分(26.54%)、脂肪酸类成分(15.70%)、甾醇类成分(13.96%)、烃类成分(7.49%)和酯类成分(13.82%);仙鹤草挥发性成分能显著抑制HepG2细胞的增殖、促进HepG2细胞凋亡,其主要单体成分棕榈酸、反式角鲨烯、α-亚麻酸均表现出显著体外抗HepG2细胞增殖活性。结论仙鹤草挥发性成分通过抑制癌细胞增殖、促进其凋亡发挥抗肝肿瘤作用,其发挥药效的单体成分有棕榈酸、反式角鲨烯、α-亚麻酸,该研究为仙鹤草挥发性成分作为天然抗肝肿瘤药物的开发利用及进一步的抗肿瘤单体研究等提供理论依据。

姜黄素下调PI3K/AKT/mTOR通路抑制人肝癌细胞系增殖

目的观察姜黄素对体外培养人肝癌细胞系HL-7702增殖的影响,并探讨其作用机制。方法体外培养HL-7702细胞,不同浓度的姜黄素(0、10、20、40和80μmol/L)处理48 h。PI3K/AKT抑制剂LY294002联合姜黄素处理细胞。分别用MTT法检测细胞增殖,用Western blot法检测细胞内PI3K、AKT、m TOR、Bax、Bcl-2及活化的caspase-3的蛋白含量。结果姜黄素可以浓度依赖性的抑制HL-7702细胞增殖,增加细胞中PI3K、AKT和m TOR的磷酸化水平(P<0.05)。姜黄素可诱导HL-7702细胞凋亡,增加Bax和活化的caspase-3的含量(P<0.05),减少Bcl-2的含量(P<0.05)。LY294002与姜黄素联用后,姜黄素对细胞增殖及凋亡无明显作用。结论姜黄素可抑制人肝癌细胞系HL-7702增殖,诱导细胞凋亡,作用机制可能与其下调PIK/AKT/m TOR信号通路的活性有关。

人肝癌细胞株VEGF/VEGFR的检测及意义探讨

目的:筛选血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)高表达肝癌细胞株,为进一步研究VEGF在肝癌治疗中的作用提供理论依据,并探讨VEGF受体在肝癌细胞株的表达及意义。方法:ELISA法及Westernblot法分别检测人肝癌细胞株培养上清及细胞内VEGF蛋白的表达,免疫细胞化学方法检测VEGFR在人肝癌细胞中的表达。结果:5株肝癌细胞株均见VEGF蛋白表达,其中SMMC-7721的VEGF表达量最高,VEGF特异性受体Flt-1在HepG2、HHCC、SMMC-7721、Bel-7402见阳性表达,KDR在HepG2、HHCC、Bel-7402、QGY-7701见阳性表达。结论:肝癌细胞株中VEGF表达量不尽一致,VEGF在肝癌发生发展中可能存在自分泌作用方式。