The Roles of Four Multi-drug Resistance Proteins in Hepatocellular Carcinoma Multidrug Resistance

The roles of multi-drug resistance protein 1 (MDR1), multi-drug resistance related pro- tein 1 (MRP1), lung resistance protein (LRP) and breast cancer resistance protein (BCRP) in the multi-drug resistance (MDR) of hepatocellular carcinoma (HCC) were studied. By exposing HepG2 cell line to progressively increased concentrations of adriamycin (ADM), HepG2 multi-drug resistant subline (HepG2/ADM) was induced. The MDR index of HepG2/ADM was detected by using MTT. The expressions of the four MDR proteins in the three cell lines (L02, HepG2, HepG2/ADM) were investigated at mRNA and protein levels by real-time RT-PCR and Western blot respectively. Our re- sults showed that when the ADM concentration was under 100 μg/L, HepG2 could easily be induced to be drug-resistant. The IC50 of the HepG2/ADM to ADM was 282 times that of HepG2. The expres- sion of MDR1 and BCRP mRNA in HepG2/ADM cells were 400 and 9 times that of HepG2 cells re- spectively while there was no difference in the mRNA expressions of MRP1 and LRP. There was no difference between HepG2 and L02 cells in the mRNA expressions of the four genes. At the protein level, the expressions of MDR1, BCRP and LRP but MRP1 in HepG2/ADM were significantly higher than those of HepG2 and L02. Between HepG2 and L02, there was no difference in the ex- pressions of four genes at the protein level. HepG2/ADM is a good model for the study of MDR. The four genes are probably the normally expressed gene in liver. The expressions of MDR1 and BCRP could be up-regulated by anti-cancer agents in vitro. The MDR of HCC was mainly due to the up-regulation of MDR1 and BCRP but MRP1 and LRP. These findings suggest they may serve as targets for the reversal of MDR of HCC.     

肝硬化中肝脏祖细胞的激活与扩增

目的证实肝硬化组织中存在人肝脏祖细胞（HPCs），探讨HPCs分布及激活的强度与肝脏炎症程度的关系，提供HPCs向肝细胞分化的依据。方法对30例肝硬化及3份正常组织标本进行常规组织学观察，对门静脉炎症程度进行评分，并用胆管上皮标志物（细胞角蛋白7）和肝星状细胞激活标志物（a平滑肌肌动蛋白）进行免疫组织化学染色，对符合HPCs、中间型肝细胞以及小管样反应的细胞进行计数和半定量评分。结果在正常肝组织中无门静脉周围HPCs和小管样反应增殖。在肝硬化组织中，增殖的HPCs起源于肝门静脉区域，随着门静脉炎症程度加重，HPCs及小管样反应从肝硬化结节周围向肝实质扩散并出现中间型肝细胞增殖，其周围有显著的肝星状细胞激活。HPCs及小管样反应增殖程度随着门静脉炎症程度的加重而增加。HPCs数目与中间型肝细胞数目之间存在直线正相关。丙氨酸氨基转移酶和天冬氨酸氨基转移酶与HPCs及中间型肝细胞数目存在直线正相关。结论在人肝硬化中存在祖细胞的激活，炎症反应是HPCs激活的触发因素，HPCs向肝实质内迁移并向肝细胞方向分化是肝再生的重要途径。     

PPAR对小鼠肝细胞增殖的影响研究

过氧化物酶体增殖子 (Ｐｅｒｏｘｉｓｏｍｅｐｒｏｌｉｆｅｒａｔｏｒ ,ＰＰｓ)是一类化学结构不相关的非基因毒性的致癌化合物 ,它的致癌确切机制还不是很清楚 ,但研究发现ＰＰＡＲａｌｐｈａ(Ｐｅｒｏｘｉｓｏｍｅｐｒｏｌｉｆｅｒａｔｏｒｓ ａｃｔｉｖａｔｅｄｒｅ ｃｅｐｔｏｒａｌｐｈａ)是哺乳类动物尤其是啮齿类动物肝脏致癌生物学行为不可或缺的因素[1] 。以ｗｙ 14 6 43喂养小鼠 ,发现其肝脏都有不同程度的增生变大 ,并伴有调节细胞增殖活性的酶的异常[2 ] 。而细胞的持续异常增殖是肿瘤的生物学特性之一。因此 ,对细胞异常增殖…     

裸鼠原位肝细胞癌多药耐药模型的建立

目的建立裸鼠原位肝癌多药耐药模型。方法分别在开腹直视下将人肝癌细胞系 HepG2和多药耐药细胞系HepG2／ADM两种细胞种植于裸鼠的肝包膜下建立原位肝细胞癌多药耐药动物模型。用B超、剖腹探查检测两组肝脏肿瘤生长情况。利用长链PCR技术对耐药细胞系 HepG2／ADM和相应种植瘤组织MDR1基因全长进行扩增并测序,再分别用RT—PCR、免疫组化、 Western blotting方法检测两组肿瘤耐药基因MDR1mRNA和P—gp蛋白的表达。结果原位肝脏种植肿瘤成瘤率均为100％(30／30),耐药诱导成功率为95％(19／20);用长链PCR技术对耐药细胞系 HepG2／ADM和相应种植瘤组织进行MDR1基因扩增,均能扩增出全长为3．8 Kb的基因条带,双向 DNA测序结果均与Genebank报道一致。耐药组MDR1mRNA和P-gp蛋白的表达均明显高于对照组 (t1=3．72,t2=2．98,P<0．01)。耐药组P-gp蛋白表达为(42．6±1．7)％远高于对照组(2．6± 0．1)％,差异有统计学意义(t=6．43,P<0．01)。结论成功建立肝癌多药耐药动物模型并且为研究肝癌多药耐药逆转提供基础。     

An Antisense Plasmid Targeting Survivin Expression Induces Apoptosis and Sensitizes Hepatocarcinoma Cells to Chemotherapy

Regulationofapoptosis (programmedcelldeath)iscriticalfornormalembryonicdevelopmentandforhomeostasisinadulttissues[1] .Dysregulationofthisprocesswithincreasedresistancetocelldeathisacommonfeatureofmalignantcells[2 ] andrepresentsasignificantobstacletotherapyofhumancancer[3] .Theinhibitorofapoptosis (IAP) protein survivinisabsentfrommostadulttissuesbutnotableforitsex pressioninmosthumancancers.Survivinisastruc turallyuniquememberoftheinhibitorofapoptosisfamilyofproteinsthatispotentiallyinvolved…     

腹腔镜肝癌根治术的难点与争议

随腹腔镜肝切除经验的积累和设备的改进,腹腔镜肝切除的手术指征与开放手术已基本相同。但由于肝癌肝切除本身就面临手术指征和切除范围等主要问题的争议,加上腹腔镜肝切除固有的较难控制出血、显露困难等问题,使腹腔镜这项技术应用在肝癌根治性切除中存在更多值得磋商的事项。本文就腹腔镜肝切除的手术适应证、切除范围及困难部位的肝切除等问题做一述评,以期对上述问题引起重视,使腹腔镜肝切除在临床应用中更加合理。     

双"U"形贯穿缝合法行胰腺-空肠端端套入式吻合

胰十二指肠切除术应用于临床已有半个多世纪，由于其切除器官多、创伤大，术后并发症发生率和病死率高，严重影响其推广应用。近20年来，尽管外科学者们为了简化手术操作、减少术后并发症特别是术后胰瘘的发生率做出了许多努力，但术后胰瘘的发生率依然高达5％～25％。而一旦发生胰瘘，手术死亡率高达20％～50％。显然，建立一种安全、简便的胰肠吻合方法非常重要。     

核转录因子-κB对肝癌细胞Hep3B COX-2表达的调节

目的 探讨核转录因子(NF)-κB对肝细胞癌细胞Hep3B中COX-2表达的调控作用。方法 以体外合成的NF-κB亚单位p50反义寡聚脱氧核苷酸(ASODN)处理Hep3B细胞72h，利用Western blot方法检测ASODN处理的Hep3B细胞p50和COX-2蛋白表达水平。利用电泳凝胶迁移法测定经ASODN处理的Hep3B细胞核内NF-κB水平。对照组为p50正义寡聚脱氧核苷酸(SODN)和未经处理的Hep3细胞。结果(1)Western blot分析显示，与以SODN处理和对照组的Hep3B细胞相比，以AS ODN处理的Hep3B细胞其NF-κB亚单位p50蛋白的水平明显降低，Hep3B细胞核抽提物NF-κB水平也相应减低。(2)以ASODN处理的Hep3B细胞其COX-2蛋白水平低于以SODN处理的Hep3B细胞和对照组细胞。结论 在肝细胞癌细胞Hep3B中，NF-κB亚单位p50反义寡聚脱氧核苷酸(ASODN)可抑制NF-κB活性，导致COX-2的表达下调。由此反过来推测．活化的NF-κB对COX-2具有激活和诱导作用，提示COX-2在肝细胞中作用与NF-κB通道有关．在肝细胞癌的形成和以NSAIDs预防性或治疗性用于肝细胞癌时，NF-κB有了新的作用。