人肝癌细胞中原癌基因Pokemon上调Shp2的表达

目的研究人肝癌细胞中Pokemon对Shp2表达的影响。方法通过RT-PCR、Real time PCR和Western blot方法检测人肝癌细胞系QGY-7703和人正常肝细胞系HL-7702中Pokemon和Shp2的mRNA和蛋白表达水平差异;并通过瞬时转染si-Pokemon RNA沉默QGY-7703细胞中Pokemon使其低表达,再检测Shp2的mRNA和蛋白水平变化。结果 Pokemon在人肝癌细胞系QGY-7703中的表达水平高于人正常肝细胞系HL-7702,Shp2的表达水平高低与Pokemon表达一致;在QGY-7703细胞中沉默Pokemon表达之后,Shp2的表达也相应降低。结论原癌基因Pokemon作为一种转录因子,可能调控Shp2的表达。     

Effect of TM208 on QGY-7703 xenograft tumor growth

A newly synthesized dithiocarbamate derivative, 4-methylpiperazine-1-carbodithioc-acid-3-cyano-3,3-diphenylpropyl ester hydrochloride (TM208), has demonstrated anticancer effects with low toxicity in earlier studies; however, the mechanism has yet to be identified. We explored antitumor effects of TM208 and the possible mechanisms by which it inhibited the growth of human hepatocellular carcinoma cell line QGY-7703 xenograft tumors. Cell proliferation was evaluated with the sulforhodamine B assay in vitro. The results suggested that TM208 had slightly antiproliferative activity on QGY-7703 cells. The antitumor effect of TM208 was assessed in nude mice xenografted with QGY-7703 tumors. We found that TM208 significantly inhibited tumor growth but did not cause loss of body weight or leukocytopenia. Western blotting was used to detect the expression of protein kinase C alpha, mitogen-activated protein kinase signal pathways, and cell cycle-related proteins. The results showed that TM208 decreased the expression of protein kinase C alpha, phospho-extracellular signal-regulated kinase-1/2, phospho-p38, cyclin B1, cell division cycle 2 (cdc2), and phospho-cdc2 (Thr161) and increased the expression of phospho-cdc2 (Tyr15). Taken together, our data show that TM208 has little antiproliferative effect on QGY-7703 cells in vitro, whereas it significantly inhibits the growth of QGY-7703 xenograft tumors with low toxicity in vivo. The inhibition of mitogen-activated protein kinase signal pathways and the regulation of the G2/M phase may be responsible for its antitumor effects.     

木姜子乙醇提取物对肝癌细胞侵袭和迁移能力的影响及机制初探

目的：探讨木姜子乙醇提取物（Litsea pungens ethanol extract,LPEE）对肝癌细胞侵袭转移能力的影响及其相关机制。方法：MTT法测定LPEE对肝癌细胞株HepG2和QGY-7703的IC50;transwell迁移实验和matrigel侵袭实验检测LPEE对HepG2和QGY-7703细胞迁移和侵袭能力的影响;qRT-PCR和Western blot检测LPEE对各组细胞中E-cadherin和VEGF基因和蛋白水平的表达变化。结果：LPEE可显著抑制HepG2和QGY-7703细胞穿过transwell小室和matrigel基质胶的细胞数（P<0.05）;50和100 μg·mL^-1 LPEE作用组与0组相比,可明显降低VEGF mRNA和蛋白水平的表达（P<0.05）,而促进E-cadherin mRNA和蛋白水平的表达（P<0.05）。结论：LPEE可抑制肝癌细胞的侵袭和迁移能力,其机制可能与抑制VEGF表达和促进E-cadherin表达有关。     

miR-506 对肝癌细胞恶性表型的影响

摘要:目的 探讨微 RNA-506（microRNA-506,miR-506）对肝癌细胞活性、 增殖和侵袭等恶性表型的调控作 用。方法 以肝癌细胞系 HepG2 和 QGY-7703 为模型, 依处理方式不同分别分为细胞常规培养 （细胞对照） 组、 pcD⁃ NA3 空载体对照组、 转染 pcDNA3/pri-506 过表达 miR-506 （过表达 miR-506） 组、 pSIH1 空载体对照组及转染 pSIH1/ TuD-506 抑制 miR-506 （抑制 miR-506） 组。实时定量逆转录 PCR 检测细胞内 miR-506 的表达水平。分别用 CCK- 8 实验、 体外集落形成实验和 Transwell 侵袭实验检测各组细胞的活性、 集落形成能力和侵袭能力。结果 在肝癌细 胞系 HepG2 和 QGY-7703 中, 与对应的空载体对照组相比, 过表达 miR-506 组的细胞内 miR-506 表达水平升高, 而 抑制 miR-506 组的细胞内 miR-506 表达水平降低（P＜0.05）; 过表达 miR-506 组细胞活性降低且形成集落的数量 和穿过 Transwell 微孔的细胞数量均减少, 而抑制 miR-506 组细胞活性升高且形成集落的数量和穿过 Transwell 微孔 的细胞数量均明显增加（P＜0.05）。与细胞对照组相比, pcDNA3 空载体对照组和 pSIH1 空载体对照组均不影响以 上各指标 （P＞0.05）。结论 miR-506 抑制肝癌细胞的活性、 集落形成能力和侵袭能力等恶性表型, 在肝癌细胞中发 挥抑癌基因的作用。     

大叶香茶菜辛素的结构

从大叶香茶菜Rabdosia macrophylla(Migo)C.W.Wu et H.W.Li干叶中提取、分离得十五种成分,其中数种为具有抗肿瘤或细胞毒活性的二萜。本文报道另一种新二萜成分大叶香茶菜辛素(rabdophyllin H)的结构,并由X线单晶衍射方法证实。大叶香茶菜辛素对QGY-7703肝癌细胞具有抑制作用。     

Molecular modes of action of cephalotaxine and homoharringtonine from the coniferous tree <Emphasis Type="Italic">Cephalotaxus hainanensis</Emphasis> in human tumor cell lines

Homoharringtonine (HHT) is an ester of cephalotaxine (CET), both of which derive from the Chinese coniferous tree Cephalotaxus hainanensis. HHT inhibited tumor cell growth at molar ranges comparable to established cytostatic drugs, whereas CET was 3-4 orders of magnitude less active. Inhibition concentration 50% (IC50) values of CET and HHT were significantly correlated to doxorubicin, vincristine, methotrexate, cisplatin, or camptothecin in 55 cell lines of the Developmental Therapeutics Program of the National Cancer Institute (NCI, Bethesda, Md., USA). We tested both drugs for resistance of cell lines which selectively overexpress the multidrug resistance (MDR)-conferring genes P-glycoprotein/ MDR1 (CEM/ADR5000), MDR-related protein 1 MRP1 (HL60/AR), and breast cancer resistance protein BCRP (MDA-MB-231-BCRP). A threefold and ninefold resistance to HHT and CET, respectively, was found in CEM/ADR5000 cells, while the other MDR cell lines did not show cross-resistance compared to their drug-sensitive counterparts. As the tumor suppressor p53 is another important factor of chemoresistance, we also analyzed the possibility that p53 affects the response of tumor cells to CET and HHT. Comparing the p53 mutational status of the 55 NCI cell lines (http://dtp.nci.nih.gov) with the IC50 values showed a significant correlation. Thus, CET and HHT were more active in cell lines without p53 mutation. We correlated the IC50 values of CET and HHT with the cell doubling times of the 55 NCI cell lines as proliferation parameter and observed that rapidly growing cells were more susceptible than slowly growing cell lines. We conducted a search mining the NCI's database for the mRNA expression of 465 genes in 55 cell lines and correlated the data with the IC50 values for CET and HHT. Of these genes 61 (=13%) correlated with the IC50 values for CET and 122 (=26%) with the IC50 values for HHT indicating the multifactorial mode of action of these drugs in cancer cells. We have chosen one example from these genes to test a causative role for drug response. U-87MG.DeltaEGFR cells transfected with an epidermal growth factor receptor ( EGFR) gene truncated in its extracellular domain through a deletion of exons 2-7 (Delta EGFR) were 14-fold more resistant to HHT than control cells transfected with mock expression vector or non-transfected cells. The present investigation presents a starting point to dissect the genes and molecular pathways involved in the tumor cells' response to CET and HHT in greater detail.     

Anti-inflammatory and anti-tumour effects of Abies georgei extracts

Chloroform (AGC), ethyl acetate (AGE) and n-butanol (AGB) extracts of Abies georgei were investigated for anti-tumour and anti-inflammatory activities in-vitro and in-vivo. AGC exhibited potent antiproliferative effects against A549, LOVO, QGY-7703 and 6T-CEM tumour cells, with EC50 values of 77.5, 7.8, 11.1 and 32.8 microg mL(-1), respectively. It also inhibited the growth of S180 sarcoma implanted into mice; tumour growth inhibition ratios were 46.7, 53.1 and 31.0% of controls at doses of 100, 200 and 400 mgkg(-1), respectively. AGE showed significant anti-inflammatory activities in the carrageenin-induced acute pedal oedema model in rats and dimethylbenzene-induced ear oedema in mice at doses of 140 mgkg(-1) and 200 mgkg(-1) p.o., respectively. Primary mechanism studies in-vitro showed that AGE inhibited platelet aggregation induced in rabbits by arachidonic acid (AA), with an IC50 of 14.4 microg mL(-1). Its effect on AA metabolism was also studied in mouse peritoneal macrophages stimulated by A23187. Formation of prostaglandin E(2), leukotriene B(4) and 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE) was significantly inhibited in a concentration-dependent manner. In addition, AGE inhibited lipopolysaccharide-induced nitric oxide production in RAW246.7 macrophages and nuclear factor kappaB activation induced in 293 cells by tumour necrosis factor alpha.     

高三尖杉酯碱对鼻咽癌CNE-2Z细胞的增殖抑制和凋亡诱导作用

目的　探讨高三尖杉酯碱 (homoharringtonine,HHT)对鼻咽癌细胞CNE 2Z的增殖抑制和凋亡诱导作用。方法　采用MTT法检测增殖抑制率和IC50 ,流式细胞术、琼脂糖凝胶电泳和Hoechst 3 3 2 5 8/PI荧光染色分析细胞凋亡。结果　不同浓度的HHT分别处理CNE 2Z细胞 2 4、48和 72h ,抑制率随浓度的增加和时间的延长而增高 ,其IC50 分别为(0 62 9± 0 0 3 9)、(0 483± 0 0 2 7)、(0 3 89± 0 0 2 7)mg·L-1,各IC50 间差异有统计学意义 (P <0 0 1)。 1、0 5mg·L-1HHT处理细胞 8h ,流式细胞术观察到凋亡峰 ,荧光染色可见凋亡形态学改变 ,流式细胞术和荧光染色检出的凋亡率均高于对照组 (P <0 0 1) ;1mg·L-1HHT处理细胞 8h ,琼脂糖凝胶电泳可见DNA梯带。结论　HHT对CNE 2Z细胞具有增殖抑制作用 ,此抑制作用具有剂量和时间依赖性 ;HHT可诱导CNE 2Z细胞凋亡     

三尖杉酯碱和高三尖杉酯碱诱导人早幼粒白血病细胞的程序性死亡

体外实验证明2×1O^-7 mol·L^-1 三尖杉酯碱和 1O^-7 mol·L^-1高三尖杉酯碱与HL-60细胞作用 4 h，可诱导该细胞产生程序性死亡。提取细胞DNA进行琼脂糖凝胶电泳呈现典型的DNA 梯，同时出现细胞核染色体断裂、核固缩及细胞空泡样变等形态变化。并且在一定范围内具有作用时间和浓度依赖性，二者诱导HL-60细胞程序性死亡作用的强弱与其细胞毒作用平行。     

Endoglin and alk1 as therapeutic targets for hereditary hemorrhagic telangiectasia

Introduction: Hereditary Haemorrhagic Telangiectasia (HHT) is as an autosomal dominant trait characterized by frequent nose bleeds, mucocutaneous telangiectases, arteriovenous malformations (AVMs) of the lung, liver and brain, and gastrointestinal bleedings due to telangiectases. HHT is originated by mutations in genes whose encoded proteins are involved in the transforming growth factor β (TGF-β) family signalling of vascular endothelial cells. In spite of the great advances in the diagnosis as well as in the molecular, cellular and animal models of HHT, the current treatments remain just at the palliative level.

Areas covered: Pathogenic mutations in genes coding for the TGF-β receptors endoglin (ENG) (HHT1) or the activin receptor-like kinase-1 (ACVRL1 or ALK1) (HHT2), are responsible for more than 80% of patients with HHT. Therefore, ENG and ALK1 are the main potential therapeutic targets for HHT and the focus of this review. The current status of the preclinical and clinical studies, including the anti-angiogenic strategy, have been addressed.

Expert opinion: Endoglin and ALK1 are attractive therapeutic targets in HHT. Because haploinsufficiency is the pathogenic mechanism in HHT, several therapeutic approaches able to enhance protein expression and/or function of endoglin and ALK1 are keys to find novel and efficient treatments for the disease.     

阿糖胞苷、高三尖杉酯碱诱导急性非淋巴细胞白血病细胞凋亡的临床研究

运用吖啶橙（AO）／溴乙锭（EB）染色法检测阿糖胞苷（Ara－c）、高三尖杉酯碱（HHT）体外诱导临床初发及复发／难治急性非淋巴细胞白血病（ANLL）患者的白血病细胞凋亡,观察细胞凋亡指数与临床疗效的关系。结果显示初治ANLL药物诱导组凋亡率明显高于复发／难治组,初治组完全缓解（CR）者凋亡指数明显高于未缓解（NR）者。说期凋亡与耐药、凋亡与临床疗效有一定的关系。     

紫杉醇诱导人乳腺癌MCF-7细胞周期阻断及凋亡的基因表达谱分析

目的研究紫杉醇诱导人MCF-7细胞周期阻断及凋亡的分子机制。方法用流式细胞仪分析紫杉醇对MCF-7细胞周期变化的影响，用自制的含9 984个已知基因和EST的高密度基因芯片检测MCF-7细胞在不同浓度紫杉醇作用下的基因表达变化。结果MCF-7细胞在100 nmol·L^-1紫杉醇作用24 h，流式细胞仪结果显示77.8%细胞阻断在G₂/M期和1.3%细胞发生凋亡；基因表达谱分析发现：在12.5 nmol·L^-1 (IC₅₀)及100 nmol·L^-1紫杉醇作用下，分别有27及77个基因差异表达。结论紫杉醇可诱导MCF-7细胞周期阻断在G₂/M期并引起部分细胞凋亡，该作用与药物浓度有关。基因表达谱分析显示部分差异表达基因参与细胞微管及骨架结构、细胞周期调控、以及DNA损伤修复和凋亡过程。     

高三尖杉酯碱激活ATM/p53通路抑制人肝癌细胞PLC5增殖

目的探讨高三尖杉酯碱(homoharringtonine,HHT)对肝癌细胞PLC5增殖的影响及其可能的机制。方法采用CCK-8以及EdU检测HHT对PLC5细胞增殖的影响;流式细胞术检测HHT对PLC5细胞周期的影响;Western blot检测周期相关蛋白CyclinA、CDK2、p21以及p53、ATM的表达。结果CCK-8结果显示,HHT(0、5、10、20、40、80μg·L^-1)分别作用PLC5细胞24、48、72 h后,HHT对PLC5细胞的抑制率明显升高,且呈现浓度和时间依赖性;EdU结果显示,经HHT作用后,PLC5细胞增殖能力明显减弱;流式细胞结果显示,HHT可将PLC5细胞阻滞在S期;Western blot结果显示,HHT可上调PLC5细胞中p21、p53以及ATM的蛋白水平,并下调PLC5细胞中CyclinA、CDK2的蛋白水平。结论HHT可诱导PLC5细胞发生DNA损伤,激活DNA损伤修复信号通路,阻滞细胞周期,从而抑制细胞增殖。     

异三尖杉酯碱诱导HL-60细胞凋亡

用透射电镜观察、DNA凝胶电泳及流式细胞术研究了异三尖杉酯碱(IHT)诱导HL-60细胞凋亡的作用。结果证明异三尖杉酯碱能快速、显著地诱导HL-60细胞发生凋亡,其作用呈明显的浓度-效应关系和时间依赖性。IHT处理的细胞出现凋亡相关的特征性变化。在电镜观测中发现细胞核内染色质浓缩边集、核碎裂及凋亡小体形成;琼脂糖凝胶电泳可见明显的DNA梯;流式细胞光度术出现显著的G1亚峰。经10^-7mol·L^-1IHT处理120min,可使43.8%HL-60细胞发生凋亡。IHT有明显诱导HL-60细胞凋亡的作用,并与其细胞杀伤活性相平行,提示IHT的抗癌活性与诱导肿瘤细胞凋亡相关。这些实验结果对进一步研究、开发IHT有重要实用价值。     

星形孢菌素诱导NG108—15细胞凋亡

目的：研究星形孢菌素是否能引起NG108—15细胞的凋亡及它对数种与凋亡相关基因蛋白表达水平的影响．方法：用相差显微镜、荧光显微镜和透射电镜观察形态学变化;琼脂糖凝胶电泳检测DNA梯带;免疫印迹法检测凋亡相关基因蛋白的表达水平．结果：经星形孢菌素0．1μmol／L处理后NG108—15细胞呈典型的凋亡形态学变化．星形孢菌素处理后6h即出现DNA凋亡梯带,可持续至24h．Bax蛋白表达在星形孢菌素处理后6h开始上升,12h至最高峰,24h后下降．Bcl-2蛋白表达在星形孢菌素处理后3h明显上升,随后逐渐下降．星形孢菌素处理后6h可见caspase-3切割产物出现,但Cdk5蛋白的表达水平未见明显变化．p53蛋白表达在星形孢菌素处理12h后下降．结论：星形孢菌素诱导了NG108—15细胞的凋亡,可能与Bax蛋白表达的增加及caspase-3切割有关,而与p53和Cdk5无明显相关性．