谷胱甘肽耗竭促成紫花牡荆素诱导肝癌细胞凋亡

目的研究紫花牡荆素（casticin）诱导肝癌细胞（HCC）凋亡作用及其作用分子机制。方法体外培养人肝癌PLC/PRF/5细胞系细胞,MTT测定细胞活性;细胞凋亡ELISA检测试剂盒和碘化丙啶（PI）染色流式细胞术（FCM）检测凋亡性细胞死亡。二氯二氢荧光素二乙酯（DCFH-DA）探针标记FCM测定活性氧（ROS）生成。谷胱甘肽检测试剂盒测定细胞内谷胱甘肽（GSH）含量。结果 Casticin以剂量依赖方式抑制PLC/PRF/5细胞生长（P〈0.05）。Casticin诱导PLC/PRF/5细胞系Sub-G1细胞百分率增加（P〈0.05）;并增加细胞组蛋白/DNA碎片的含量,呈浓度依赖性。Casticin降低PLC/PRF/5细胞内GSH含量（P〈0.05）,但不影响胞内ROS的生成。巯基抗氧化剂,N乙酰半胱氨酸和添加外源性GSH能恢复GSH含量,并减弱casticin诱导细胞凋亡作用;而不含巯基的抗氧化剂,丁羟茴醚和甘露醇无明显作用。结论 Casticin诱导肝癌细胞凋亡涉及细胞内GSH耗竭。     

紫花牡荆素对宫颈癌HeLa 细胞凋亡及DAPK 基因甲基化的影响

目的探讨紫花牡荆素(casticin)对人宫颈癌HeLa细胞的凋亡和DAPK基因甲基化以及DAPK蛋白表达的影响。方法用不同浓度的casticin处理体外培养的HeLa细胞;AnnexinV-PI染色流式细胞术定量分析细胞凋亡率;DNA琼脂糖凝胶电泳法观察细胞DNA断裂;基因甲基化特异性PCR检测DAPK基因甲基化状态;Western blotting检测DAPK蛋白表达。结果 casticin可以浓度依赖性的方式有效诱导HeLa细胞凋亡;casticin作用于宫颈癌HeLa细胞48小时后,DAPK基因甲基化程度显著降低;casticin以浓度依赖的方式上调DAPK蛋白表达。结论 casticin可能通过使DAPK基因去甲基化上调DAPK蛋白的表达,进而诱导HeLa细胞凋亡。     

儿茶素对人肝癌细胞HepG2的影响

目的研究儿茶素[(+)-catechin,Cat]不同时间、不同浓度对人肝癌细胞(HepG2)的增殖、迁移能力的抑制及诱导凋亡作用。方法 HepG2细胞分别与不同浓度Cat作用,MTT法检测细胞增殖率的变化,显微镜观察细胞形态学变化,划痕法检测细胞的迁移能力,流式细胞术检测细胞凋亡率,免疫组织化学染色法检测HepG2的Bcl-2、Bax和Caspase-3蛋白表达。结果 Cat(4~100mg·mL-1)能明显抑制人肝癌细胞HepG2的增殖和迁移能力,并呈浓度依赖性。流式细胞术检测结果显示Cat(4mg.L-1)作用于HepG2细胞24h即可诱导细胞凋亡。免疫组织化学结果显示Cat(4~20mg·mL-1)的Bax和Caspase-3的表达呈浓度依赖性升高,而Bcl-2的表达呈浓度依赖性降低。结论 Cat可以一定程度的抑制HepG2细胞的增殖和迁移能力并诱导其凋亡,其诱导凋亡机制可能与其下调HepG2细胞内Bcl-2蛋白的表达,上调Bax蛋白的表达,从而促进Caspase-3活化有关。     

新木脂素VB1 对宫颈癌HeLa 细胞凋亡的影响

目的探讨新木脂素即6-羟基-4-(4-羟基-3-甲氧基苯基)3-羟甲基-5-甲氧基-3,4-二氢(3R,4S)-2-醛基萘(VB1)诱导人宫颈癌HeLa细胞凋亡的作用和机制。方法体外培养HeLa细胞,碘化丙啶(PI)染色后,用流式细胞术(FCM)分析细胞的凋亡率;酶联免疫吸附法(ELISA)测定细胞组蛋白/DNA碎片水平;Westernblot检测细胞内Mcl-1蛋白的表达。结果 VB1以浓度依赖性方式增加HeLa细胞的凋亡率和细胞内组蛋白/DNA碎片水平(P<0.05),同时降低HeLa细胞内Mcl-1蛋白的表达。结论 VB1可以浓度依赖的方式诱导宫颈癌HeLa细胞的凋亡,这种作用可能与其下调细胞内Mcl-1蛋白的表达有关。     

三-(2,3-二溴丙基)异氰脲酸酯通过死亡受体信号通路诱导HepG2细胞凋亡

目的探讨环境外源性污染物三-(2,3-二溴丙基)异氰脲酸酯(TBC)诱导人肝癌细胞株HepG2凋亡的死亡受体途径。方法采用MTT法、流式细胞术确定TBC对HepG2细胞的毒性作用、细胞凋亡率,Western blot法对死亡受体信号通路关键蛋白Caspase-8、FADD、CD95/FAS、DR4、DR5、PARP和TRAIL的蛋白水平表达进行检测。结果 TBC处理浓度增加(0、12.5、25和50)μg/ml对HepG2细胞的增殖抑制作用增强,凋亡峰越明显,表明DNA合成受到抑制。且细胞内PARP蛋白表达量逐渐降低,细胞内的Caspase-8、FADD、CD95/FAS、DR4、DR5和TRAIL蛋白表达量逐渐升高,呈现剂量-效应关系。结论环境外源性污染物TBC具有细胞毒性,且可以通过死亡受体途径进行诱导细胞凋亡,为其他外源性化合物的毒理学研究和早期干预提供了理论基础。     

三氧化二砷对人肝癌细胞凋亡及Bcl-2、caspase-3蛋白表达的影响

目的研究三氧化二砷（arsenic trioxide,As2O3）诱导HepG2细胞凋亡及其机制。方法采用MTT法、形态学观察及流式细胞术方法检测As2O3对HepG2细胞的生长抑制、凋亡作用的影响,用Western blot检测As2O3处理后HepG2细胞内凋亡相关蛋白Bcl-2和caspase-3的表达。结果As2O3对HepG2细胞有明显的抑制增殖作用,且呈浓度和时间依赖性,细胞呈典型的凋亡形态学改变,As2O3呈时间依赖性诱导HepG2细胞凋亡。As2O3处理不同时间后,Bcl-2蛋白表达水平下调,caspase-3蛋白表达水平升高。结论As2O3具有诱导人肝癌HepG2细胞凋亡的作用,其机制可能与其下调Bcl-2蛋白的表达,促进caspase-3活化有关。     

古抑菌素对人肝癌细胞作用的研究

目的:通过组蛋白去乙酰化酶(histone deacetylase,HDACS)抑制剂古抑菌素A(Trichostatin A,TSA)对人肝癌细胞HepG2(以下简称HepG2)和正常肝细胞LO2(以下简称LO2)增殖与凋亡作用的比较,探讨TSA对肝癌的作用机制.方法:应用光学显微镜、透射电镜、四氮唑蓝(MTT)法、免疫细胞化学法观察经不同浓度TSA处理后的HepG2和LO2的增殖、凋亡与凋亡相关蛋白的改变.结果:HepG2细胞经TSA处理后,电镜下超微结构发生了凋亡早期改变;小剂量TSA对HepG2细胞具有较强的抑制作用,对LO2细胞影响不明显,当TSA浓度达到1000 nmol/L以上时,对LO2表现出明显的细胞毒性作用;TSA可诱导HeptG2细胞凋亡,并增加凋亡相关蛋白Bax的表达.结论:TSA可明显抑制肝癌细胞HepG2的增殖,其机制可能与上调Bax的表达,诱导细胞凋亡有关.     

氧化苦参碱抗肝癌作用及机制的药理作用研究进展

氧化苦参碱能防治二乙基亚硝胺或2-乙酰氨基芴诱发大鼠原发性肝癌和小鼠肝癌H22细胞移植瘤在小鼠体内的生长。体外研究发现氧化苦参碱能浓度相关地抑制肝癌HepG2细胞、SMMC-7721细胞、BEL-7402细胞、BEL-7404细胞、QGY细胞、QGY-7703细胞、97H细胞的增殖并诱导其凋亡,还可能诱导HepG2细胞、BEL-7402细胞、PLC/PRF/5细胞的分化,也能提高荷瘤机体的免疫调节功能。综述氧化苦参碱抗肝癌作用及机制的药理作用文献,并对其研究进展做了分析。     

FK228对人肝癌细胞HepG2凋亡及细胞周期基因表达的影响

目的：探讨FK228对人肝癌细胞HepG2凋亡及细胞周期基因p 21,cdk4表达的影响。方法：培养HepG2,应用四氮唑蓝(MTT)比色法观察FK228对HepG2的生长抑制作用,琼脂糖凝胶电泳分析细胞DNA特征,流式细胞术分析细胞周期,以RT-PCR检测HepG2细胞中p 21,cdk4基因表达水平。结果：组蛋白去乙酰化酶抑制剂FK228能抑制人肝癌细胞HepG2生长,并具有时间和剂量依赖性；FK228引起细胞周期G1期阻滞并诱导凋亡；FK228能明显促进p21mRNA转录,同时抑制cdk4mRNA的转录。结论：FK288能抑制HepG_2细胞增殖,诱导HepG_2细胞凋亡和周期阻滞；调节p21和cdk4基因的表达可能是FK228抑制HepG_2细胞生长的重要机制。     

槲皮素对肝癌HepG2细胞生长影响的体外研究

目的 观察槲皮素对肝癌HepG2细胞生长及hTERT基因表达的影响.方法 以台盼蓝拒染法计数肝癌细胞的生长抑制率,用透射电镜从形态变化方面了解凋亡的发生,流式细胞术检测细胞周期变化,Western-blot检测hTERT基因表达改变,PCR-TRAP法检测端粒酶活性.结果 槲皮素抑制肝癌HepG2细胞增殖的作用明显,且呈浓度和时间依赖性,槲皮素处理48 h后的半数抑药浓度（IC5o）为25.5μmol/L;形态学检测显示出了细胞凋亡的特征变化,经10-20 μm/L的槲皮素处理,肝癌HepG2细胞周期阻滞于G0/G1期,且HepG2细胞hTERT蛋白降低,端粒酶活性被抑制.结论 槲皮素能呈时间、剂量依赖性地抑制肝癌细胞的生长,能诱导HepG2细胞发生凋亡,其抑制增生与诱导凋亡的机制可能与下调hTERT基因表达、抑制端粒酶活性、破坏端粒稳定性有关.     

紫花牡荆素对卵巢癌CoC1 细胞凋亡和Mcl-1 表达的影响

目的研究紫花牡荆素（casticin）诱导人卵巢癌CoC1细胞凋亡作用。方法用不同浓度的casticin处理体外培养的CoC1细胞,碘化丙啶（PI）染色流式细胞术（FCM）分析细胞凋亡率,比色法测定细胞caspase-3活性,Western Blot分析Mcl-1蛋白表达水平。结果紫花牡荆素以浓度依赖方式增高CoC1细胞凋亡率和激活caspase-3（P〈0.05）。1.0μmoL·L-1casticin以时间依赖方式降低Mcl-1蛋白表达水平（P〈0.05）。结论 casticin诱导CoC1细胞凋亡与其抑制Mcl-1蛋白表达相关。     

The preclinical activity of the histone deacetylase inhibitor PXD101 (belinostat) in hepatocellular carcinoma cell lines

The activity of the histone deacetylase inhibitor PXD101 was investigated in three hepatocellular carcinoma (HCC) cell lines. PXD101was found to inhibit cell growth at a dose-dependent manner and induce histone acetylation in PLC/PRF/5, Hep3B and HepG2 cells. In PLC/PRF/5 and Hep3B cells which express hepatitis B-related genes (HBx, HBc and HBc), treatment with PXD101 resulted in apoptosis without a significant effect on viral gene expression. Exposure to PXD101 for up to 48 h had varying effects on the expression of 12 cellular genes with tumor suppressor functions, including p21, SOCS1, CMTM5, RASAL1, DLEC1, SFRP (-1, -2, -4 and -5), ADAMTS (-8 and -9). This study provided the basis for a phase II clinical trial of PXD101 in inoperable hepatitis-B associated HCC.     

Induction of apoptosis in cells by cadmium: quantitative negative correlation between basal or induced metallothionein concentration and apoptotic rate.

Metallothionein (MT) often reduces the adverse effects of cadmium (Cd), but how it may alter Cd-induced apoptosis is unclear. The goal of this study was to define the role of MT in Cd-induced apoptosis using cell lines with widely varying sensitivity to Cd. Effects of Cd on growth of human hepatocellular carcinoma cell lines (HepG2 and PLC/PRF/5) were investigated and compared with Chang cells. These cells were cultured with 0, 5, 10, 20, 40, 80, and 120 microM of Cd for 3, 6, 12, and 24 h. Significant cytolethality was observed in HepG2 and PLC/PRF/5 cells in a time- and concentration-dependent manner, with LC(50) values of 24 microM and 13 microM, respectively. However, Chang cells were much less sensitive to Cd-induced cytotoxicity (LC(50), 64 microM). Apoptotic cell death occurring at cytolethal concentrations was demonstrated in all cell lines by DNA fragmentation on agarose gel electrophoresis or by ELISA. When MT was measured, there was a highly significant negative linear correlation between the basal cellular MT concentration or Cd-induced MT and the rate of apoptosis induced by Cd in these cell lines. Treating HepG2 cells with zinc (Zn) made the relatively sensitive HepG2 cell line resistant to Cd-induced apoptosis, likely due to Zn-induced MT. In fact, there was also a significant negative linear correlation between the amount of Zn-induced MT in HepG2 cells and the rate of Cd-induced apoptosis. These findings revealed that basal or induced MT perturbs Cd-induced apoptotic cell death in various cell lines, and a strong negative correlation exists between cellular MT content and the rate of apoptosis induced by Cd.     

Casticin impairs cell growth and induces cell apoptosis via cell cycle arrest in human oral cancer SCC‐4 cells

Casticin, a polymethoxyflavone, present in natural plants, has been shown to have biological activities including anti‐cancer activities. Herein, we investigated the anti‐oral cancer activity of casticin on SCC‐4 cells in vitro. Viable cells, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS) production, and Ca²⁺ production, levels of ΔΨ_m and caspase activity were measured by flow cytometric assay. Cell apoptosis associated protein expressions were examined by Western blotting and confocal laser microscopy. Results indicated that casticin induced cell morphological changes, DNA condensation and damage, decreased the total viable cells, induced G₂/M phase arrest in SCC‐4 cells. Casticin promoted ROS and Ca²⁺ productions, decreases the levels of ΔΨ_m, promoted caspase‐3, ‐8, and ‐9 activities in SCC‐4 cells. Western blotting assay demonstrated that casticin affect protein level associated with G2/M phase arrest and apoptosis. Confocal laser microscopy also confirmed that casticin increased the translocation of AIF and cytochrome c in SCC‐4 cells. In conclusion, casticin decreased cell number through G₂/M phase arrest and the induction of cell apoptosis through caspase‐ and mitochondria‐dependent pathways in SCC‐4 cells.     

Combinational treatment of 5‐fluorouracil and casticin induces apoptosis in mouse leukemia WEHI‐3 cells in vitro

Leukemia is one of the major diseases causing cancer‐related deaths in the young population, and its cure rate is unsatisfying with side effects on patients. Fluorouracil (5‐FU) is currently used as an anticancer drug for leukemia patients. Casticin, a natural polymethoxyflavone, exerts anticancer activity against many human cancer cell lines in vitro, but no other reports show 5‐FU combined with casticin increased the mouse leukemia cell apoptosis in vitro. Herein, the antileukemia activity of 5‐FU combined with casticin in WEHI‐3 mouse leukemia cells was investigated in vitro. Treatment of two‐drug combination had a higher decrease in cell viability and a higher increase in apoptotic cell death, the level of DNA condensation, and the length of comet tail than that of 5‐FU or casticin treatment alone in WEHI‐3 cells. In addition, the two‐drug combination has a greater production rate of reactive oxygen species but a lower level of Ca²⁺ release and mitochondrial membrane potential (ΔΨ_m) than that of 5‐FU alone. Combined drugs also induced higher caspase‐3 and caspase‐8 activities than that of casticin alone and higher caspase‐9 activity than that of 5‐FU or casticin alone at 48 hours treatment. Furthermore, 5‐FU combined with casticin has a higher expression of Cu/Zn superoxide dismutase (SOD [Cu/Zn]) and lower catalase than that of 5‐FU or casticin treatment alone. The combined treatment has higher levels of Bax, Endo G, and cytochrome C of proapoptotic proteins than that of casticin alone and induced lower levels of B‐cell lymphoma 2 (BCL‐2) and BCL‐X of antiapoptotic proteins than that of 5‐FU or casticin only. Furthermore, the combined treatment had a higher expression of cleaved poly (ADP‐ribose) polymerase (PARP) than that of casticin only. Based on these findings, we may suggest that 5‐FU combined with casticin treatment increased apoptotic cell death in WEHI‐3 mouse leukemia cells that may undergo mitochondria and caspases signaling pathways in vitro.     

紫花牡荆素对人宫颈癌细胞凋亡和侵袭迁移的影响

目的 观察紫花牡荆素(CAT)对人宫颈癌HeLa和SiHa细胞凋亡和侵袭转移的影响。方法 不同浓度CAT作用于HeLa和SiHa细胞不同时间后,采用MTT法观察药物对细胞活力的影响,流式细胞仪检测凋亡率,划痕试验观察细胞迁移率,基质胶法测定细胞粘附百分率,Transwell试验检测侵袭细胞数,Western blotting分析CAT对SiHa细胞抑制转移蛋白nm23-H1和促转移蛋白MTA1表达的影响。结果 CAT显著抑制HeLa和SiHa细胞活力,增加细胞凋亡率;降低细胞迁移百分率和黏附百分率;减少侵袭细胞数;明显增加SiHa细胞nm23-H1蛋白表达,降低MTA1蛋白表达。结论 CAT显著诱导人宫颈癌HeLa和SiHa细胞凋亡,抑制其侵袭迁移,提示其具有潜在的抗宫颈癌作用。     

紫花牡荆素诱导人肺腺癌A549细胞凋亡及其机制的探讨

目的探讨紫花牡荆素（CAS）诱导人肺腺癌A549细胞凋亡及其机制。方法平皿集落法测定CAS对A549细胞生长的抑制作用;碘化丙啶（PI）染色流式细胞术（FCM）分析细胞凋亡率;丫啶橙／溴乙啶（AO／EB）荧光染色观察细胞凋亡形态;Westernblot检测FoxMl（forkhead box protein M1）表达水平。结果CAS能抑制人肺腺癌A549细胞生长,呈浓度依赖性,半数抑制浓度（IC50）值为7．26p．mol·L^-1;CAS处理后A549细胞呈典型凋亡细胞形态学改变,诱导细胞凋亡呈浓度依赖性;CAS诱导A549细胞FoxM1蛋白表达下调,呈浓度和时间依赖性。结论CAS抑制人肺腺癌A549细胞的生长并诱导其凋亡,其作用机制可能与FoxM1表达下调有关。