超声辐照载紫杉醇微泡对大鼠血管平滑肌细胞凋亡的影响

目的 探讨超声辐照载紫杉醇微泡对大鼠血管平滑肌细胞(VSMCs)凋亡的影响及其作用机制.方法 将体外培养的大鼠胸主动脉VSMCs用血小板衍生生长因子-BB刺激后分组如下:对照组(A组)、超声辐照+微泡组(B组)、超声辐照+载紫杉醇微泡组(C组)、单纯载紫杉醇微泡组(D组)和紫杉醇组(E组).采用频率1MHz、声强0.3W/cm2的连续波超声辐照VSMCs 120s,用流式细胞仪、Annexin V/PI染色和免疫细胞化学技术检测各组细胞周期、细胞凋亡以及凋亡相关蛋白表达的变化.结果 与A组比较,各组S期细胞比例均显著降低(P＜0.01),B组G0/G1期细胞比例显著增高(P＜0.01),D组和E组G2/M细胞比例显著增高(P＜0.01),C组G0/G1期细胞比例和G2/M细胞比例均显著增高(P＜0.01).与A组比较,B组和C组VSMCs凋亡率显著增高(P＜0.01),Bax蛋白表达显著上调、而Bcl-2蛋白表达则显著降低(P＜0.01).结论 超声辐照载紫杉醇微泡可诱导VSMCs凋亡,其机制可能是微泡介导的超声空化效应,致Bax蛋白表达上调及Bcl-2蛋白表达下调.     

黄芪多糖对肝癌HepG2细胞的抑制作用及其机制

目的 研究黄芪多糖(APS)和5-氟尿嘧啶(5-fu)联合使用对肝癌HepG2细胞的生长抑制及其作用机制.方法 用RPMI1640培养液对低分化人肝癌细胞株HepG2进行传代培养,取对数生长期细胞, 分为5组:A组:对照组,不含药物,使用同体积的磷酸盐缓冲液(PBS);B组:APS组,只给予100 μg/mlAPS;C组:5-fu组,只给予100 μg/ml 5-fu;D组:5-fu+低浓度APS组,给予100 μg/ml 5-fu+100 μg/ml APS;E组:5-fu+高浓度APS组,给予100 μg/ml 5-fu+200 μg/ml APS.用噻唑蓝(MTT)法观察APS及5-fu对HepG2细胞增殖的影响;用流式细胞术方法测药物作用后细胞周期变化和细胞凋亡;western-blot检测凋亡相关蛋白表达.结果 APS和5-fu联合使用可抑制HepG2细胞的增殖,效应呈浓度和时间依赖性;APS和5-fu联合使用阻滞HepG2细胞周期于G1期;并可诱导HepG2细胞凋亡;APS和5-fu联合使用,可明显增高肝癌HepG2细胞中caspase-3、caspase-9蛋白的表达,同时检测到抑凋亡蛋白Bcl-2表达显著降低.在只使用5-fu的实验组细胞中均未检测到上述变化.结论 APS和5-fu联合使用能抑制肝癌HepG2细胞株的增殖,其机制之一是影响细胞周期使之阻滞于G1期,激活了细胞凋亡系统,从而诱导细胞凋亡.     

顺铂和苦参素对人肝癌细胞株HepG2端粒酶活性的影响

观察顺铂、苦参素对人肝癌细胞株HepG2端粒酶活性的影响,进一步探讨两种药物的可能作用机制。采用人肝癌细胞株HepG2作为研究对象,MTT法检测不同浓度和作用时间的药物对细胞增殖的抑制作用;流式细胞仪分析细胞周期的分布及凋亡;PCR-ELISA法检测端粒酶活性的变化。两种药物均具有抗HepG2细胞增殖、阻滞细胞周期、诱导凋亡及抑制端粒酶活性的作用。对端粒酶活性的抑制可能是两种药物发挥抗肿瘤作用的机制之一。     

莪术黄芪超滤膜提取物对人肝癌细胞株HepG2凋亡的诱导作用

目的观察莪术黄芪超滤膜提取物对人肝癌细胞株HepG2是否具有凋亡诱导作用。方法四氮唑蓝比色（MTT）法观察莪术黄芪超滤膜提取物对人肝癌细胞株HepG2细胞的抑制率;应用流式细胞术,DNA凝胶电泳方法检测细胞凋亡的发生。结果 （1）莪术黄芪超滤膜提取物对人肝癌细胞株HepG2的生长有明显的抑制作用,与对照组比较差异有统计学意义（P〈0.01）,抑制作用与剂量及时间呈显著性正相关;（2）莪术黄芪超滤膜提取物诱导人肝癌细胞株HepG2发生凋亡,1.6 g/L处理,72 h效果最佳。结论莪术黄芪超滤膜提取物抑制人肝癌细胞株HepG2生长并促其凋亡。     

熊去氧胆酸选择性诱导人肝肿瘤细胞凋亡及抑制增殖的实验研究

目的探讨熊去氧胆酸(UDCA)诱导肝肿瘤细胞株凋亡并抑制其增殖的作用和机制。方法用噻唑蓝法、流式细胞术、TUNEL法、Wright-Giemsa染色法、电镜及免疫细胞化学等方法，观察UDCA对肝肿瘤细胞株HepG2、BEL7402和正常人肝细胞株L-02的生长活力、细胞凋亡、细胞周期及Bax／bcl-2基因表达的影响。结果UDCA对HepG2、BEL7402细胞株具有显著的抑制生长、诱导凋亡、阻滞细胞周期于S期、降低bcl-2和提升Bax表达的作用。结论UDCA对HepG2、BEL7402细胞株有显著的抑制增殖及诱导凋亡作用，该作用可能与UDCA阻滞细胞周期、降低bcl-2和提升Bax的表达有关。     

淫羊藿苷对人肝癌HepG2细胞的作用及其机制研究

目的:探讨淫羊藿苷(ICA)对HepG2肝癌细胞的作用及其可能机制。方法:给人肝癌HepG2细胞施加不同浓度的ICA(0～40μM)培养,用CCK-8法和集落形成试验测定细胞增殖能力,通过流式细胞术分析检测细胞周期进程和细胞凋亡情况,蛋白免疫印迹法分析细胞周期相关蛋白CyclinD1、CDK4、凋亡相关蛋白Bcl-2、Bax、以及芳烃受体(AHR)蛋白的表达水平。结果:ICA可抑制HepG2细胞的集落形成和细胞增殖,诱导细胞周期阻滞于G0～G1期,并诱导肝癌细胞凋亡。此外,ICA上调AHR蛋白表达,且其对HepG2细胞增殖的影响被AHR拮抗剂CH223191抑制。结论:ICA可能通过激活AHR信号抑制人肝癌HepG2细胞的增殖和诱导细胞周期阻滞于G0～G1期,并诱导细胞凋亡。     

反义寡核苷酸并超声微泡造影剂转染联合超声照射逆转肝癌多药耐药

目的探讨体内、体外mdr1、mrp、lrp反义寡核苷酸(AODNs)并超声微泡造影剂转染联合低强度超声照射逆转肝癌多药耐药的可行性,寻找逆转肿瘤多药耐药有效和靶向的方法。方法利用超声微泡造影剂包载肿瘤耐药基因mdr1、mrp、lrp的AODNs进行转染,联合低强度超声照射,以肝癌细胞多药耐药细胞模型(HepG2／ADM) 为研究对象,通过逆转录聚合酶链反应、western blot和四甲基偶氮唑盐法,从体外细胞培养及动物实验,研究 AODNs并超声微泡造影剂转染联合超声照射逆转癌细胞多药耐药及降低肿瘤恶性表型和成瘤能力的作用。结果 HepG2／AMD细胞增殖被抑制,其mdr1和mrp的mRNA、蛋白质表达水平明显降低;裸鼠皮下移植瘤生长受抑制。结论体外、体内AODNs并超声微泡造影剂转染联合低强度超声照射能有效逆转人肝癌细胞HepG2／ADM的多药耐药, 该技术可能为肝癌临床治疗提供新的思路。     

冬凌草甲素通过激活ATM蛋白诱导人肝癌HepG2细胞G_2/M细胞周期阻滞

目的研究冬凌草甲素诱导肝癌HepG2细胞G2/M细胞周期阻滞的机制。方法不同浓度的冬凌草甲素(16、32、64μmol/L)处理HepG2细胞48 h后,流式细胞仪检测冬凌草甲素诱导肝癌HepG2细胞的细胞周期。Western印迹检测不同浓度冬凌草甲素作用肝癌HepG2细胞后H2AX蛋白的磷酸化。免疫荧光实验检测Phos-S1981ATM和γ-H2AX焦点。结果彗星实验结果表明不同浓度的冬凌草甲素(16、32、64μmol/L)处理HepG2细胞48 h后,可发生G2/M细胞周期阻滞,并且随浓度增加细胞周期阻滞增加。Western印迹检测不同浓度冬凌草甲素作用肝癌HepG2细胞后,H2AX蛋白发生磷酸化,γ-H2AX随着浓度增加表达增大。免疫荧光实验发现Phos-S1981ATM和γ-H2AX焦点随着浓度增加表达量增加。结论冬凌草甲素可以诱导肝癌HepG2细胞G2/M细胞周期阻滞,H2AX蛋白发生磷酸化,诱导DNA损伤的发生。     

人肝癌多药耐药细胞株的建立及超声波诱导凋亡的研究

目的 建立人肝癌细胞系HepG2多药耐药模型并探讨低频脉冲式超声对其凋亡的影响及其机制。 方法 以人肝癌细胞株HepG2为研究对象,用阿霉素(ADM)浓度梯度递增诱导法,建立人肝癌细胞多药耐药模型(简称HepG2/ADM)。将研究对象分为HepG2/ADM、HepG2/ADM ADM、HepG2/ADM 超声波、HepG2/ADM ADM 超声波4组,以频率为0.8 MHz,声强为0.5 w/cm2,时间10 min的脉冲式超声波作用于研究对象。荧光显微镜观察细胞变化;DNA片段化分析检测染色体断裂情况;流式细胞仪检测细胞凋亡率。 结果 HepG2/ADM细胞对多种化疗药耐药,对阿霉素的耐药倍数为26,其耐药性与P-糖蛋白(P-GP)、多药耐药相关蛋白(MRP)、肺耐药蛋白(LRP)及谷胱甘肽转移酶(GST)的过表达相关。实验组经超声波作用10 min后,HepG2/ADM细胞死亡具有细胞凋亡的形态学特征;HepG2/ADM ADM和HepG2/ADM 超声波组细胞凋亡率分别为3.47％和12.23％;HepG2/ADM ADM 超声波联合治疗能显著增加细胞凋亡率,为18.81％,与对照组比较差异有显著性,t值分别为1.46、2.67、5.36,P<0.01。结论 人肝癌多药耐药细胞株HepG2/ADM具有多药耐药特性;低频脉冲式超声可诱导人肝癌多药耐药细胞株HepG2/ADM凋亡,联合化疗药物治疗,可显著增加细胞凋亡比例。     

没药甾酮对人肝癌细胞HepG2增殖和凋亡的影响

目的研究没药甾酮对人肝癌细胞HepG2增殖和凋亡的影响。方法以正常人肝细胞L-02作为对照,采用3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐法观察不同浓度没药甾酮（5～100μmol/L）对人肝癌细胞HepG2和L-02细胞增殖的影响并观察细胞形态的变化;应用流式细胞术检测细胞周期变化和凋亡发生。结果不同浓度没药甾酮均可显著抑制人肝癌细胞HepG2生长,并呈时间、剂量依赖性,最大抑制率可达81.9%±1.92%（100μmol/L）;没药甾酮可使G0/G1期细胞比例增多,G2/M期细胞比例下降,可将细胞阻滞于G0/G1期;没药甾酮诱导人肝癌细胞HepG2发生凋亡,50μmol/L和75μmol/L没药甾酮早期细胞凋亡率分别为24.91%±2.41%、53.03%±2.28%,与对照组相比,差异均具有统计学意义（P〈0.05）。结论没药甾酮可抑制人肝癌细胞HepG2增殖并诱导凋亡,其作用可能与干扰细胞周期有关。     

Molecular mechanisms of paclitaxel and NM-3 on human gastric cancer in a severe combined immune deficiency mice orthotopic implantation model

AIM： To explore the molecular mechanisms of action of paclitaxel and NM-3 on human gastric cancer in severe combined immune deficiency （SCID） mice.
METHODS： Human gastric cancer cells SGC-7901 were implanted into SCID mice and mice were treated with paclitaxel and NM-3. The effects of paclitaxel and NM-3 on apoptosis of human gastric cancer cells were analyzed using flow cytometry, TUNEL assays, and DNA fragment analyses.
RESULTS： Apoptosis of SGC-7901 cells was successfully induced by paclitaxel, NM-3, and the combination of paclitaxel and NM-3 24 h after injection as shown by the presence of apoptotic hypodiploid peaks on the flow cytometer before G1-S and a characteristic apoptotic band pattern in the DNA electrophoresis. The apoptotic rate detected by TUNEL assay was found to be significantly higher in the paclitaxel/NM-3 compared to the control group （38.5% ± 5.14% vs 13.2%± 1.75%, P 〈 0.01）.
CONCLUSION： Paclitaxel in combination with NM-3 is able to induce apoptosis of the human gastric cancer cells in SCID mice effectively and synergistically.     

丙型肝炎病毒核心区蛋白对 HepG2细胞周期、细胞凋亡和细胞端粒酶活性的影响

目的　研究丙型肝炎病毒核心区 (HCV C)蛋白对肝癌细胞HepG2细胞周期、细胞凋亡和细胞端粒酶活性的影响。方法　首先运用基因重组技术构建含有HCV C基因的真核表达质粒pcDNA3.1( ) ,然后利用脂质体介导将重组真核表达质粒转染HepG2 ,经G4 18筛选获得稳定转染HepG2细胞 (HCV C转染HepG2细胞 ) ,经逆转录 聚合酶链反应技术 (RT PCR)和间接免疫荧光法证实其中有HCV C蛋白表达。然后进行如下实验 :( 1)利用四甲基偶氮唑蓝比色 (MTT)法检测HCV C转染HepG2细胞、空白质粒转染HepG2细胞和未转染HepG2细胞的生长增殖率 ;经流式细胞术(FACS)检测 3组细胞的细胞周期 ;( 2 )经流式细胞术检测细胞凋亡率 ;( 3)经端粒重复扩增 酶联免疫吸附试验 (TRAP ELISA)法检测上述 3组细胞端粒酶活性表达情况。结果　 ( 1)HCV C转染HepG2细胞增殖率显著高于空白质粒转染HepG2和未转染HepG2细胞增殖率 ;HCV C转染HepG2细胞S期所占百分率高于未转染HepG2细胞S期所占百分率 ;( 2 )HCV C转染HepG2细胞凋亡率显著低于无HCV C转染细胞凋亡率 ;( 3)上述 3组细胞端粒酶活性之间差异无显著性。结论　 ( 1)HCV C蛋白具有抑制细胞凋亡的作用 ;( 2 )HCV C蛋白促进HepG2从G0 /1期进入S期 ,从而可能促进细胞生长增殖 ,抑制细胞凋亡 ;( 3)HCV     

Paclitaxel-induced apoptotic changes followed by time-lapse video microscopy in cell lines established from head and neck cancer

Paclitaxel (Taxol) is a potent chemotherapeutic drug for squamous-cell carcinoma (SCC) of the head and neckin vitro with microtubule-stabilizing activity that arrests cells in G2-M. To study the mechanism of its cytotoxic effect on SCCin vitro, we exposed five laryngeal SCC cell lines to 10 nM paclitaxel. The cell lines were studied by time-lapse video microscopy for 96 h, and by agarose gel electrophoresis. Paclitaxel blocked the cells in the premitotic phase for 6–24 h, after which the cells died morphologically by apoptosis. Mitotically arrested cells were seen within a few minutes after exposure to paclitaxel. No mitoses were seen in the paclitaxel-treated cells. A few apoptoses were also seen in the control cultures grown without paclitaxel, but they represented only 6%–20% of the frequency of apoptoses seen in the paclitaxel-treated group. In some paclitaxel-treated cultures the cells escaped the mitotic arrest without cytokinesis and formed multinucleated cells that eventually died. Agarose gel electrophoresis showed oligonucleosomal DNA fragmentation characteristic of apoptosis. We conclude that time-lapse video microscopy is an efficient method of observing drug-induced morphological changes in cell culture. Paclitaxel at a 10 nM concentration rapidly induces a premitotic block, which usually leads to apoptotic cell death. In some cases multinucleated cells are formed that morphologically also eventually die by apoptosis.Abbreviation SCC squamous-cell carcinoma     

雷公藤内酯醇联合紫杉醇对人卵巢癌耐顺铂细胞株体外活性的影响及机制

目的探讨雷公藤内酯醇（TP）联合紫杉醇对人卵巢癌耐顺铂细胞株（CoC1/DDP）体外活性的影响及其可能机制。方法将对数生长期CoC1/DDP细胞随机分为4组,TP组采用10 ng/ml TP作用于细胞,紫杉醇组采用3.13μg/ml紫杉醇,联合组采用10 ng/ml TP和3.13μg/ml紫杉醇,空白对照组不作任何处理（调零组）,采用MTT法检测各组细胞生长抑制率,透射电子显微镜下观察细胞超微结构变化,流式细胞仪检测细胞周期及细胞凋亡情况。结果联合组生长抑制率明显高于单药组,且呈时间依赖性（P〈0.05）;透射电子显微镜示TP组、紫杉醇组、联合组细胞均呈凋亡改变,联合组细胞凋亡率明显高于单药组,紫杉醇组与联合组细胞周期中G2/M期的比例明显增高（P均〈0.05）。结论 TP联合紫杉醇可协同抑制CoC1/DDP细胞生长,促进其凋亡,其机制可能为使细胞阻滞于G2/M期。     

Paclitaxel induces apoptosis in human gastric carcinoma cells

AIM: To investigate the apoptosis in gastric cancer cells induced by paclitaxel, and the relation between this apoptosis and expression of Bcl-2 and Bax. METHODS: In in vitro experiments, MTT assay was used to determine the cell growth inhibitory rate. Transmission electron microscope and TUNEL staining method were used to quantitatively and qualitively detect the apoptosis status of gastric cancer cell line SGC-7901 before and after the paclitaxel treatment. Immunohistochemical staining was used to detect the expression of apoptosis-regulated gene Bcl-2 and Bax. RESULTS: Paclitaxel inhibited the growth of gastric cancer cell line SGC-7901 in a dose-and time-dependent manner. Paclitaxel induced SGC-7901 cells to undergo apoptosis with typically apoptotic characteristics, including morphological changes of chromatin condensation, chromatin crescent formation, nucleus fragmentation and apoptotic body formation. Paclitaxel could reduce the expression of apoptosis-regulated gene Bcl-2, and improve the expression of apoptosis-regulated gene Bax. CONCLUSION: Paclitaxel is able to induce the apoptosis in gastric cancer. This apoptosis may be mediated by down-expression of apoptosis-regulated gene Bcl-2 and up-expression of apoptosis-regulated gene Bax.     

抗增殖蛋白过表达对HepG2细胞增殖和凋亡的影响*

目的 探讨抗增殖蛋白（PHB）过表达对人肝癌细胞系HepG₂细胞增殖和凋亡的影响。方法 在已构建的PHB真核表达质粒pEGFP-N1-PHB瞬时转染HepG₂细胞,采用四甲基偶氮唑盐比色法（MTT法）检测HepG₂细胞增殖;使用流式细胞仪检测HepG₂细胞周期和凋亡。结果 转染pEGFP-N1-PHB细胞增殖明显低于pEGFP-N1空载转染细胞或未转染细胞（P<0.05）;在转染后48 h,转染组G2/M期细胞比例为（27.84±0.47）%,显著高于空载转染组的（17.21±0.64）%或未转染组的（22.67±0.33）%（P<0.001）;转染组细胞凋亡率为（31.72±0.35）%,显著高于空载转染组的（18.66±0.56）%或未转染组的（13.47±0.94）%（P<0.001）。结论 PHB过表达可抑制人肝癌HepG₂细胞增殖,诱导细胞进入G2/M期后被阻滞,并诱导细胞凋亡。     

Effects of paclitaxel in combination with radiation on human head and neck cancer cells (ZMK-1), cervical squamous cell carcinoma (CaSki), and breast adenocarcinoma cells (MCF-7)

: The anticancer drug paclitaxel, a natural product from Taxus brevifolia, is a microtubule-stabilising agent, which has been shown to block different cells in the G2/M phase of the cell cycle and so modulate their radioresponsiveness. We investigated the radiosensitizing potential of paclitaxel in human head and neck cancer cells (ZMK-1), in cervical squamous cell carcinoma cells (CaSki) and in breast adenocarcinoma cells (MCF-7). Methods: ZMK-1 cells were incubated with paclitaxel for 3, 9, or 24 h before irradiation. ZMK-1-, CaSki- and MCF-7 cells were incubated with paclitaxel for 24 h after irradiation. The paclitaxel concentration (70 nM, 7 nM, 0.7 nM) was chosen to obtain equivalent toxicity at the different incubation times (3 h, 9 h, 24 h respectively). Radiation doses were from 0 to 8 Gy. Cell survival was measured by a standard clonogenic assay after a 9-day incubation. Flow cytometry was used to measure the capacity of paclitaxel to cause accumulation of cells in the G2/M phase of the cell cycle. Results: Paclitaxel alone was cytotoxic in a time- and concentration-dependent manner. Up to 36% of the ZMK-1 cells accumulated in G2/M after treatment for 24–36 h. If the cells were incubated with paclitaxel before irradiation the isoeffect enhancement ratios for ZMK-1 cells, determined at the 37% survival level, were 0.81, 1.48 and 1.15 for 3-h, 9-h, and 24-h pre-incubations respectively. For a paclitaxel incubation of 24 h after irradiation, the isoeffect enhancement ratios, determined at the 37% survival level, were 0.72, 0.76 and 1.2 for the ZMK-1, CaSki, and MCF-7 cells respectively. Conclusion: In the three cell lines no radiosensitizing effect of paclitaxel could be demonstrated unambiguously. The use of asynchronized cells or the support of cellular repair mechanisms while the cells are blocked in G2/M could partly explain the results. Received: 24 June 1998 / Accepted: 2 October 1998     

Gene therapy that inhibits NF-κB results in apoptosis of human hepatocarcinoma by recombinant adenovirus

AIM: To investigate whether the recombinant adenovirus induces the TNF-α-mediated apoptosis in vivo.METHODS: Human hepatocarcinoma cell line (HepG2)cells were transfected into BALB/c nude mice, and the tumor growth curve was drawn. We analyzed apoptosis in HepG2 cells by TUNEL, HE staining and electron microscopy.RESULTS: AdIκBαM was expressed stably and efficiently in HepG2 and could not be degraded by induction of TNF-α. Tumor growth in mice could be reduced remarkably if treated by AdIκBαM plus TNF-α. There was apoptosis of ＞ 70% of cells treated with AdIκBαM plus TNF-α and about 50% of cells treated with AdIκBαM. In contrast, there was few cell apoptosis in HepG2 cells treated with phosphate buffered saline and AdIκBα. HepG2 cells in mice also exhibited a high level of apoptosis after in vivo injection with AdIκBαM. The tumor growth curve indicated the tumor transfected with AdIκBαM could be restrained.CONCLUSION: AdIκBαM gene therapy greatly enhances apoptosis due to inhibition of an NF-κB-mediated antiapoptosis signaling pathway.