TLR4通路对polyI:C诱导肝癌细胞凋亡的影响

目的:研究TLR4信号通路活化对polyI:C诱导人肝癌细胞系H7402凋亡的影响,并分析其可能的作用机制。方法:用TLR4激动剂LPS处理H7402细胞24 h后,转染polyI:C刺激24 h,然后利用流式细胞术检测细胞凋亡,荧光定量PCR检测凋亡基因及胞内RNA模式识别受体TLR3、MDA5、RIG-I和LGP2的表达,Western blot检测识别受体的蛋白表达水平。结果:LPS预处理,减弱了polyI:C诱导H7402细胞凋亡的作用。同时,促凋亡基因Noxa的表达水平降低。在此过程中polyI:C的胞内识别受体RIG-I、MDA5的基因和蛋白水平表达下调。结论:LPS可能通过降低H7402细胞内dsRNA识别受体的表达,抑制了polyI:C诱导H7402细胞凋亡的作用。     

赖氨大黄酸与顺铂联合对人肺癌A549细胞系增殖和凋亡的影响

目的研究赖氨大黄酸(RHL)、顺铂和两者联合对人肺癌A549细胞增殖和凋亡的影响及其作用机制,为RHL联合顺铂抗肺癌的临床实验研究提供理论依据。方法肺癌细胞系A549随机分为对照组、顺铂组、RHL组和顺铂联合RHL组,用MTT法和流式细胞术分别检测细胞48 h增殖和凋亡。Western blot法检测细胞48 h后凋亡相关蛋白和MEK/ERK蛋白的表达。结果细胞培养48 h后,顺铂组和RHL组的细胞增殖受到一定的抑制并有细胞凋亡发生,但两药联合后的增殖抑制作用和凋亡诱导作用显著高于单用顺铂和RHL组(P0.05)。顺铂和RHL均能上调caspase-3、caspase-7和poly ADP-ribose polymerase(PARP)的切割片断蛋白表达,但两药联合后caspase-3、caspase-7和PARP的切割片断蛋白表达进一步增高(P0.05),并显著下调Bcl-2蛋白的表达水平,上调Bax蛋白的表达水平,同时RHL还能降低顺铂上调的ERK蛋白磷酸化。结论 RHL能够通过抑制顺铂对ERK的激活、上调caspase-3、caspase-7和PARP的切割片断蛋白表达,增强顺铂对肺癌细胞增殖和凋亡诱导作用。     

LPS刺激诱导人卵巢癌细胞株Toll样受体4表达及细胞免疫调节

目的 探讨脂多糖(LPS)刺激对体外培养的人卵巢癌细胞株SKOV3的生长、Toll样受体4(TLR4)的表达、细胞活性氧(ROS)表达及6种炎性细胞因子分泌水平变化的影响.方法 用流式细胞仪测定不同浓度LPS刺激SKOV3 4 h后TLR4的表达水平;用LPS分别刺激SKOV3细胞不同时间后,MTT法检测细胞增殖情况,流式细胞仪分析TLR4表达、细胞周期分布、ROS表达水平以及细胞因子分泌水平.结果 TLR4表达与LPS作用浓度之间存在浓度依赖性和最大量效曲线关系;LPS刺激组与正常组的细胞增殖、细胞周期PrI值(细胞增殖指数,S+G_2/M)、ROS表达水平、细胞因子分泌水平均有显著性差异.结论 LPS具有诱导卵巢癌细胞TLR4表达、活性氧表达、炎症因子分泌以及细胞增殖和抑制的作用.     

MR1 siRNA抑制人肝癌细胞BEL-7402的增殖

目的 研究MR1基因对肝癌细胞增殖的影响及机制。 方法 化学合成MR1 siRNA,用脂质体lipofectamine 2000转染肝癌细胞系BEL-7402细胞,RT-PCR检测MR1 siRNA基因沉默效果。用SRB法、集落形成法和生长曲线法检测MR1 siRNA对BEL-7402细胞增殖的影响。流式细胞术检测BEL-7402细胞周期,用细胞同步化的方法,即与G2期阻滞药物噻氨酯哒唑（nocodazole）联合应用,以间接反映MR1 siRNA对肿瘤细胞周期的影响。Western blot法检测Cyclin D1蛋白。结果（1）300nmol/L MR1 siRNA处理BEL-7402细胞24h后,MR1基因的mRNA水平明显降低。（2）经siRNA处理后,BEL-7402细胞存活细胞数明显下降,细胞生长速度明显减慢,集落形成率显著下降,Cyclin D1表达水平明显降低。（3）MR1 siRNA与nocodazole联合处理BEL-7402细胞后,G2期细胞比例显著减少,而G1期细胞明显增多。结论 MR1基因与人肝癌BEL-7402细胞增殖相关,抑制MR1表达,能够引起细胞的增殖抑制,其作用机制与诱导细胞的G1期阻滞有关。     

lncRNA PCGEM1通过靶向miR-155-5p抑制LPS诱导的气管平滑肌细胞增殖及炎症反应北大核心CSCD

目的研究lncRNA PCGEM1/miR-155-5p轴对LPS诱导的气管平滑肌细胞增殖和凋亡及炎症反应的影响。方法采用100μg/ml LPS刺激支气管平滑肌细胞BSMC 12 h以诱导细胞损伤。实时荧光定量PCR(RT-qPCR)检测细胞lncRNA PCGEM1和miR-155-5p表达水平;细胞计数试剂盒(CCK-8)法检测细胞增殖;流式细胞术检测细胞凋亡;蛋白质印迹(Western blot)法检测细胞CyclinD1、Cleaved-caspase-3蛋白表达;双荧光素酶报告实验检测lncRNA PCGEM1和miR-155-5p靶向关系。结果与NC组比较,LPS组细胞lncRNA PCGEM1表达水平显著降低,miR-155-5p表达水平显著升高(P<0.05)。与pcDNA+LPS组比较,pcDNA-lncRNA PCGEM1+LPS组lncRNA PCGEM1表达水平显著升高,吸光度值、CyclinD1蛋白表达显著降低,细胞凋亡率、Cleaved-caspase-3蛋白表达显著升高,TNF-α、IL-6、IL-33水平显著降低(P<0.05)。与anti-miR-NC+LPS组比较,antimiR-155-5p+LPS组miR-155-5p表达水平显著降低,吸光度值、CyclinD1蛋白表达显著降低,细胞凋亡率、Cleaved-caspase-3蛋白表达显著升高,TNF-α、IL-6、IL-33水平显著降低(P<0.05)。与miR-NC+pcDNA-lncRNA PCGEM1+LPS组比较,miR-155-5p+pcDNA-lncRNA PCGEM1+LPS组细胞miR-155-5p表达水平显著升高,吸光度值、CyclinD1蛋白表达显著升高,细胞凋亡率、Cleaved-caspase-3蛋白表达显著降低,TNF-α、IL-6、IL-33水平显著升高(P<0.05)。结论lncRNA PCGEM1下调miR-155-5p降低LPS诱导的气管平滑肌细胞凋亡及炎症反应,抑制增殖。     

赖氨大黄酸与顺铂联合对人肺癌A549细胞系增殖和凋亡的影响简

 目的 研究赖氨大黄酸（RHL）、顺铂和两者联合对人肺癌A549细胞增殖和凋亡的影响及其作用机制,为RHL联合顺铂抗肺癌的临床实验研究提供理论依据。方法 肺癌细胞株A549随机分为对照组、顺铂组、RHL组和顺铂联合RHL组,用MTT法和流式细胞术分别检测细胞48 h增殖和凋亡。Western blot 法检测细胞48h后凋亡相关蛋白和MEK/ERK蛋白的表达。结果 细胞培养48 h后,顺铂组和RHL组的细胞增殖受到一定的抑制并有细胞凋亡发生,但两药联合后的增殖抑制作用和凋亡诱导作用显著高于单用顺铂和RHL组(P<0.05)。顺铂和RHL均能上调caspase-3、caspase-7和poly ADP-ribose polymerase (PARP)的切割片断蛋白表达,但两药联合后caspase-3、caspase-7和PARP的切割片断蛋白表达进一步增高(P<0.05),并显著下调Bcl-2蛋白的表达水平,上调Bax蛋白的表达水平,同时RHL还能降低顺铂上调的ERK蛋白磷酸化。结论 RHL能够通过抑制顺铂对ERK的激活、上调caspase-3、caspase-7和PARP的切割片断蛋白表达,增强顺铂对肺癌细胞增殖和凋亡诱导作用。     

肝癌耐药细胞株Bel-7402/ADM的建立以及家蝇幼虫抗菌肽对其耐药性逆转作用的研究

本研究通过建立人肝癌多药耐药细胞系,研究家蝇抗菌肽对该耐药细胞耐药性的逆转作用。采用阿霉素浓度梯度递增体外诱导法建立人肝癌耐药细胞株Bel-7402/ADM;采用MTT法检测阿霉素、顺铂、吉西他滨以及抗菌肽对细胞的毒性作用,并计算Bel-7402/ADM细胞对阿霉素、顺铂、吉西他滨耐药指数(RI);荧光显微镜观察细胞内阿霉素的荧光强度;采用流式细胞术检测细胞周期及细胞表面P-糖蛋白的含量。细胞毒性检测结果显示Bel-7402/ADM对阿霉素、顺铂和吉西他滨耐药指数分别为10.96、1.74和8.14,周期分析结果显示Bel-7402/ADM细胞的细胞周期较Bel-7402细胞发生改变:G0/G1期细胞比例明显升高,S期的细胞比例下降,荧光显微镜观察Bel-7402/ADM细胞内阿霉素量明显低于Bel-7402细胞,流式细胞术检测结果显示,Bel-7402/ADM细胞表面P-gp含量明显高于Bel-7402细胞,表明建成的Bel-7402/ADM细胞对多种药物耐药。抗菌肽对细胞的毒性作用检测显示,抗菌肽对Bel-7402/ADM细胞抑制作用呈剂量依赖性,但耐药细胞对抗菌肽并无耐药性。小剂量(100 mg/m L)的抗菌肽作用后,Bel-7402/ADM细胞的耐药指数减小至7.1,荧显微镜观察Bel-7402/ADM细胞内阿霉素荧光强度增强,流式细胞术检测Bel-7402/ADM细胞表面P-gp表达降低。结果表明,抗菌肽有可能通过降低细胞表面P-gp的表达起到逆转Bel-7402/ADM细胞耐药性的作用。     

葆盛口服液对人肝癌HepG-2细胞株生长和凋亡的影响

目的研究观察复方中药提取物(葆盛口服液)在体外对肝癌HepG-2细胞株生长和凋亡的作用及机制。方法以人肝癌HepG-2细胞株为研究对象,用MTT法检测葆盛口服液对肿瘤细胞增殖的影响,流式细胞仪检测细胞调亡以及凋亡基因Fas的表达情况,以顺铂为对照组,比较葆盛口服液与顺铂的疗效。结果葆盛口服液对Hela细胞有较强的体外增殖抑制作用,流式细胞术发现葆盛口服液能促进Fas表达,诱导HepG-2细胞凋亡。结论葆盛口服液通过阻滞肿瘤细胞的生长及诱导细胞凋亡等机制,对肝癌细胞增殖有一定的抑制作用。     

Annexin A3抑制顺铂诱导人卵巢上皮癌细胞凋亡

目的 进一步探讨annexin A3能否通过凋亡途径调节卵巢癌细胞对顺铂敏感性.方法 运用反转录病毒载体构建及目的细胞感染技术,获得annexin A3稳定上调和稳定下调卵巢癌细胞系,运用annexin V/碘化丙啶分析方法和免疫印迹法检测细胞凋亡率、细胞内caspase蛋白裂解水平和annexin A3表达水平.结果 顺铂敏感细胞annexin A3表达水平上调后,60μg/mL顺铂诱导细胞凋亡率由68.72%±1.01%下调至29.13%±2.61%(P<0.05);高浓度顺铂诱导caspase和PARP蛋白裂解.相反,顺铂耐药细胞内mumxin A3水平下调后,凋亡率由35.05%±3.06%上升至76.73%±6.42%(P<0.05),低浓度顺铂诱导caspase和PARP蛋白裂解.此外,annexin A3还能够显著抑制卵巢癌细胞内P38 MAPK磷酸化.结论 Annexin A3能通过抑制细胞凋亡调节卵巢癌细胞对顺铂的敏感性.     

雷帕霉素介导丝裂原活化蛋白激酶信号通路对肝癌细胞的影响

目的： 探讨雷帕霉素介导丝裂原活化蛋白激酶（MAPK）信号通路对肝癌细胞Bcl-2、Bcl-xl 及Bax 蛋白表 达的影响。方法：将人肝癌细胞BEL-7402 细胞分为对照组和雷帕霉素处理组（20、50、100 ng/mL）,观察各组 BEL-7402 细胞的形态变化、细胞增殖抑制率、凋亡及蛋白（MAPK、Bcl-2、Bcl-xl 及Bax）表达。结果：随着 雷帕霉素浓度的升高,BEL-7402 细胞呈现崩解和坏死;对照组BEL-7402 细胞增殖抑制率最低,雷帕霉素干预组 BEL-7402 细胞增殖抑制率高于对照组,随着时间及雷帕霉素浓度的升高,细胞生长抑制率逐渐升高;雷帕霉素 处理组与对照组相比差异有统计学意义;随着浓度的升高,BEL-7402 细胞凋亡率升高;对照组BEL-7402 细胞中 MAPK阳性表达率高于雷帕霉素处理组,雷帕霉素处理组随着浓度升高,MAPK阳性表达率不断降低;对照组 BEL-7402 细胞中Bcl-2、Bcl-xl 蛋白升高,与雷帕霉素处理组比较存在显著差异,雷帕霉素处理组Bcl-2、Bcl-xl 蛋白水平随着雷帕霉素的浓度升高而降低,Bax 表达水平随着雷帕霉素的浓度升高而增加。结论：雷帕霉素能 够抑制肝癌细胞增殖,加快坏死及破裂,随着雷帕霉素的浓度升高,凋亡程度增大,其作用机制可能与抑制 MAPK、Bcl-2、Bcl-xl 表达,促进Bax 水平升高有关。     

miR-634 在肝癌中的表达及对肝癌细胞生物学行为的影响

目的:检测microRNA-634(miR-634)在肝癌中的表达水平及其对肝癌细胞常见生物学行为的调控作用。方法:采用实时荧光定量PCR(RT鄄qPCR)法检测肝癌细胞系(HepG2、SMMC7721、Bel7402、Bel7404、SNU739)、69 例肝癌组织及匹配癌旁组织中miR-634 的相对定量,分析miR-634 表达与肝癌患者性别、年龄、肿瘤直径、分化程度、Child-Pugh 分级、BCLC 分期、门静脉癌栓及肝外转移的关系,同时构建miR-634 的真核表达载体并转染肝癌细胞系,采用活细胞计数试剂盒CCK-8、流式细胞仪Annexin V/ PI 双染法和Transwell 侵袭实验检测转染miR鄄634 对细胞增殖、凋亡和侵袭能力的影响。结果:与正常人肝细胞系L-02 相比,肝癌细胞的miR-634 水平均降低(P <0.05),表达量依次为HepG2 >SNU739 >Bel7402 > Bel7404 >SMMC7721;69 例肝癌组织的miR鄄634 水平为(0.253±0.019),低于匹配癌旁组织(P<0.05),且与肿瘤直径、分化程度、BCLC分期、门静脉癌栓及肝外转移均有关(P<0.05)。过表达组转染24 ~96 h 后的miR鄄634 水平持续升高,与对照组和空转染组的差异有统计学意义(P<0.05);与对照组和空转染组相比,转染组的增殖抑制率、凋亡率均升高,但穿膜细胞数降低,差异有统计学意义(P<0.05)。结论:miR-634 在肝癌组织和细胞中均为低表达,且与临床病理参数有关,上调其水平可抑制肝癌细胞增殖及侵袭并诱导凋亡,对于肝癌防治有重要借鉴价值。     

Annonaceous acetogenins reverses drug resistance of human hepatocellular carcinoma BEL-7402/5-FU and HepG2/ADM cell lines

Hepatocellular carcinoma (HCC) is the most common tumor in worldwide and chemotherapy resistant is a severe obstacle in HCC treatment. Annonaceous acetogenins was a nature compound from Uvaria accuminata and it has show the anti-tumor proliferation activity in many types cancer. In this study, we showed that annonaceous acetogenins is correlated with the drug resistance reversal in human hepatocellular carcinoma BEL-7402/5-FU and HepG2/ADM cell lines. We found that cell apoptosis was improved and cell cycle was arrested, further, multidrug-resistance proteins such as MDR1, MRP1, Topo-IIα, GST-π, cyclin D1, Survivin and bcl-2 are down-regulated, however, intracellular Rh-123 and caspase-3/8 was up-regulated by Annonaceous acetogenins treatment. We also found that there was a decreased activity of NF-κB and Akt in Annonaceous acetogenins treatment groups. Therefore, we demonstrate that Akt/NF-κB pathway was involved in Annonaceous acetogenins reverses drug resistance of human hepatocellular carcinoma cells.     

Proliferation and migration mediated by Dkk-1/Wnt/beta-catenin cascade in a model of hepatocellular carcinoma cells

Beta-catenin is a multifunctional protein acting as a key factor in the cadherin-mediated cell-cell adhesion system and in the Wnt signaling pathway. To demonstrate the molecular mechanisms of metastasis of hepatocellular carcinoma (HCC) cells, we established a metastatic subclone of human HCC H7402 cells, termed M-H7402, by isolating from transplantation of H7402 cells into severe combined immunodeficient (SCID) mice. Based on the 2 parallel cell lines, we investigated the roles of dickkopf-1 (Dkk-1) and Wnt/beta-catenin pathway in proliferation and migration of HCC cells. cDNA microarray showed that 24 genes were related to tumor metastasis differentially expressed between H7402 and M-H7402 cells. Western blot analysis revealed that the expression levels of beta-catenin, c-Myc, and cyclin D1 were upregulated, but Dkk-1 and nm23 were dramatically downregulated in M-H7402 cells, which suggests that the 2 cell lines were remarkably different in molecular events associated with metastasis. Furthermore, we found that overexpression of Dkk-1 by transfection was able to downregulate the expression of c-Myc and cyclin D1, and it also inhibited the growth and migration in M-H7402 cells. Although reduction of Dkk-1 expression by RNA interference was able to upregulate the expression of beta-catenin, c-Myc, and cyclin D1 in H7402 cells, it also promoted beta-catenin translocation from cytoplasm into nuclei and increased the migration of the cells. Therefore, we conclude that Dkk-1/Wnt/beta-catenin cascade may mediate the proliferation and migration of HCC cells during the metastasis process.     

阻断Sonic Hedgehog信号对不同人肝癌细胞生长的影响

 目的: 研究阻断Sonic Hedgehog (Shh)信号对不同人肝癌细胞生长的影响,探讨阻断Shh信号抑制肝癌细胞生长的机制。方法: RT-PCR法检测Shh信号分子在3株人肝癌细胞(BEL-7402、Huh7和HepG2)中的表达,并检测Shh阻断抗体作用后BEL-7402细胞Shh信号效应分子表达变化;MTT法检测人肝癌细胞增殖活性;流式细胞术检测人肝癌细胞凋亡;Western blot 检测凋亡相关蛋白表达。结果: Shh信号分子在3株人肝癌细胞中均有表达,Shh阻断抗体可以下调Shh信号效应分子patched (Ptch)、Gli1和Gli2的表达;Shh阻断抗体可以抑制3株肝癌细胞生长,增加G₀/G₁期细胞,并诱导细胞凋亡;Shh阻断抗体作用后,BEL-7402细胞pro-caspase-3、pro-caspase-8和pro-caspase-9蛋白表达水平下降,cleaved caspase-3、cleaved caspase-8和cleaved caspase-9蛋白表达水平升高。结论: 阻断Shh信号可抑制Shh高表达的人肝癌细胞生长,阻滞细胞周期于G₀/G₁期,并诱导肝癌细胞凋亡。     

Docosahexaenoic acid (DHA) induces apoptosis in human hepatocellular carcinoma cells

The docosahexaenoic (DHA), a ω-3 fatty acid, could play a beneficial inhibition of the incidence and progress of a series of human diseases including cancer. It has been report that DHA is involved in cell apoptosis. Recent studies show that the signal transduction pathway links with bcl-2, bax, caspase-3 and MMP-9 molecules. Therefore, we tested the relationship between DHA and cell apoptosis in human hepatocellular carcinoma cells (Bel-7402 cells). We show here that DHA induces Bel-7402 cells apoptosis after pre-treating cells with DHA. DHA down-regulates the protein expression of Bcl-2 and Bim mRNA level, and up-regulates caspase-3 activity and Bax expression level. We also found that DHA inhibits Bel-7402 cells migration. Basic on our studies, DHA may play a role in tumor invasion and survival.     

脂多糖对人正常肝细胞株L02损伤的实验研究

目的探讨脂多糖(lipopolysaccharide,LPS)对人正常肝细胞株L02的损伤作用及其机制。方法采用流式细胞术分别检测LPS诱导L02细胞凋亡和线粒体膜电位变化的作用,测定L02细胞膜上CD14、Toll样受体4(TLR4)、Toll样受体2(TLR2)的表达水平;采用酶联免疫吸附法(ELISA)测定细胞培养上清液中肿瘤坏死因子α(TNF-α)含量;生化法测定细胞培养上清液中丙氨酸转氨酶(ALT)、门冬氨酸转氨酶(AST)及乳酸脱氢酶(LDH)含量。结果10、20、40、80mg/L剂量的LPS作用于L02细胞后0、6、12、24和36h,细胞的凋亡率和线粒体膜电位无显著性差异(P>0.05),各组上清液中ALT、AST、LDH和TNF-α含量亦无明显变化(P>0.05),L02细胞膜上LPS受体CD14、TLR4、TLR2表达分别为(2.28±0.60)%,(1.04±0.80)%,(2.07±0.50)%。结论L02细胞膜上LPS受体CD14、TLR4、TLR2表达水平低,致使LPS不能直接引起L02细胞损伤。     

层粘连蛋白与佛波醇酯对人肝癌细胞粘连和增殖特性的影响

目的:探讨层粘连蛋白(Ln)与佛波醇酯(PMA)对人肝癌细胞粘连和增殖特性的影响及其相关机制,提供肝癌治疗的新线索。方法:体外以人肝癌细胞系(BEL-7402)为靶细胞,在揭示靶细胞是否存在内源性Ln(enLn)表达的同时,利用促癌剂PMA(phorbol-12-myristate-13-acetate)与外源性Ln(exLn)的作用来比较研究enLn及细胞蛋白激酶C-α(cPKC-α)活性表达变化与细胞粘连和增殖特性的关系。结果:靶细胞呈现enLn的阳性表达,exLn能加强其细胞粘连及增殖能力;当PMA作用时,其细胞呈现enLn的更高程度表达,其细胞粘连性亦得到更明显地加强;而仅PMA的单独作用却能使其细胞呈现明显的增殖抑制,但PMA与exLn的共同作用,其细胞增殖力呈现在exLn单独作用得到加强的基础上获得更进一步的加强,显示出了协同效应。并且,PMA的单独作用能下调其细胞cPKC-α的表达,而外源性Ln的作用则能加强其细胞cPKC-α的表达。结论:内、外源性Ln的作用与人肝癌细胞的粘连、增殖密切相关,其与癌细胞的cPKC-α的活性密切关联。抗Ln抗体及PKC的抑制剂的联合应用可提供一条肝癌治疗的可探索新途径。     

Expression of apoptosis related proteins during malignant progression in chronic ulcerative colitis

BACKGROUND: Chronic ulcerative colitis (CUC) is associated with increased risk of developing colon cancer through a dysplasia (intraepithelial neoplasia)-carcinoma sequence. AIMS: To investigate the expression of apoptosis and inflammatory related proteins in CUC. METHODS: The expression of proteins involved in apoptosis and inflammation (inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), Bcl-xl, Fas, and active caspase 3) was investigated and compared with that seen in sporadic colon carcinoma. RESULTS: COX-2 was negative in the epithelium of all samples. iNOS was clearly present in inflammatory areas in CUC epithelium, weakly expressed in dysplasia, and absent or weakly expressed in tumour cells. Bcl-xl was absent in CUC, increased in dysplasia, and highly expressed in most carcinomas. Fas expression was positive in the surface epithelium of CUC, dysplasia, and most tumour cells. Activated caspase 3 was weakly positive in all samples, indicating limited apoptosis. Compared with CUC associated carcinoma, iNOS was consistently expressed in sporadic colon carcinoma cells, whereas Bcl-xl was almost absent in these tumour cells and Fas was only weakly expressed. Activated caspase 3 was present in normal mucosal samples and some tumour cells. CONCLUSION: Apoptosis related proteins--particularly iNOS, Bcl-xl, and Fas-show a distinct pattern of expression in the CUC to carcinoma sequence, which differs from that seen in sporadic carcinoma, but bears a striking resemblance to that seen during neoplastic progression in Barrett's oesophagus. These results support a causal role for chronic inflammation in cancer development in CUC, and treatment of ulcerative colitis should aim to minimise inflammation.     

蛋白激酶C的活性变化对人肝癌细胞增殖及端粒酶表达的影响

目的:揭示蛋白激酶C(PKC)活性变化对人肝癌细胞增殖及端粒酶表达的影响。方法: 体外以PKC激活剂PMA(phorbol-12-myristate-13-acetate)及其抑制剂星形孢菌素(staurosporine,SP)作用于人肝癌细胞系(BEL-7402)48 h后,运用TRAP-银染(telomeric repeat amplification protocol silver staining)与计算机图像凝胶扫描记录技术结合的方法来揭示细胞端粒酶活性、PKC变化与细胞增殖的关系。结果:PMA与SP的作用,促进其细胞增殖抑制的同时,抑制其细胞端粒酶活性表达。结论:PKC的活性变化与人肝癌细胞增殖相关,并可能与端粒酶的活性表达关联。