分泌性内皮抑制素真核质粒治疗小鼠肝癌的初步研究

目的 构建并表达分泌性内皮抑制素真核表达质粒,以此对肝癌进行基因治疗。方法 人工合成Ig κ信号肽序列,和内皮抑制素编码序列一起克隆入pcDNA3.1质粒。重组质粒转染上清液作用于ECV304内皮细胞,MTT法检测内皮细胞的增殖。局部注射重组质粒治疗接种在小鼠腿部肌肉内的H_(22)肝癌瘤株,疗程结束后解剖称取瘤重。结果 构建的内皮抑制素真核表达质粒转染上清液可以抑制内皮细胞的增殖抑制率为29.2％。经质粒裸DNA注射治疗后,治疗组瘤重[(1.34±0.96)g]比空载体组[(2.70±0.82)g]和生理盐水组[(3.73±1.41)g]明显减小(P<0.05)。结论 分泌性内皮抑制素真核表达质粒用于H_(22)肝癌的基因治疗有一定效果。     

Potential roles of EZH2, Bmi-1 and mi R-203 in cell proliferation and invasion in hepatocellular carcinoma cell line Hep3B

AIM: To investigate the potential roles of enhancer of zeste homolog2(EZH2), Bmi-1 and mi R-203 in cell proliferation and invasion in hepatocellular carcinoma(HCC) cell line Hep3 B.METHODS: A total of 73 patients who underwent surgical resection at Fuzong Clinical Medical College of Fujian Medical University were enrolled in this study. Hep3 B cells were cultivated in RPMI 1640 medium supplemented with 10% fetal bovine serum at 37?℃. Vectors that containing c DNA of the EZH2 gene or mi R-203 targeted sh RNA plasmid were constructed, and then transfected into Hep3 B cells. The m RNA expression of mi R-203, EZH2, and Bmi-1 was analyzed using quantitative real-time polymerase chain reaction analysis, and the protein levels of EZH2 and Bmi-1 were detected by Western blot analysis. Effect of EZH2 or mi R-203 on cell proliferation was observed by methyl thiazolyl tetrazolium assay, and cell apoptosis was assessed using flow cytometry. Besides, effect of EZH2 or mi R-203 on tumor cell invasion was detected using Transwell assay.RESULTS: The m RNA levels of EZH2 and Bmi-1 in HCC tissues and in Hep3 B cells were significantly higher compared with those in normal samples(P 0.01), while mi R-203 level was significantly lower in HCC tissues(P 0.01). Hep3 B cells transfected with EZH2-sh RNA or mi R-203-sh RNA showed lower expression levels of EZH2 and Bmi-1(P 0.05). Compared with controls, Hep3 B cells transfected with EZH2-sh RNA had relative slow cell proliferation, indicating that low expression of EZH2 and Bmi-1 and overexpression of mi R-203 could inhibit Hep3 B cell proliferation(P 0.05). The average apoptosis rate of Hep3 B cells transfected with EZH2-sh RNA vector was about 18.631%, while that of Hep3 B cells transfected with sh RNA vector was about 5.33%, suggesting that EZH2 was down-regulated by transfecting with EZH2-sh RNA, and the down-regulated EZH2 contributed to the cell apoptosis. Low expression of EZH2 and Bmi-1 and overexpression of mi R-203 could reduce Hep3 B cell invasion(P 0.05).CONCLUSION: Our study suggests that EZH2 and Bmi-1 are up-regulated while mi R-203 is downregulated in Hep3 B cells. Mi R-203 may contribute to the metastasis and enhance apoptosis of HCC cells by regulating EZH2 and Bmi-1. Our study may provide a theoretical basis for metastasis of HCC and targeted therapy of HCC.     

载体肝干细胞分泌表达的Endostatin对血管内皮细胞增殖和凋亡的影响

目的观察携带内皮抑素基因的载体肝干细胞分泌表达的内皮抑素蛋白（Endostatin，ES）对血管内皮细胞体外增殖和凋亡的影响。方法体外扩增培养本室构建的携带内皮抑素基因的载体肝干细胞WB-ES，收集合有分泌型Endostatin的上清液。将人脐静脉内皮细胞ECV304体外增殖培养，加入不同浓度的含倍比稀释Endostatin的上清液，在不同的作用时间（24、48、72h），通过四甲基偶氮唑蓝比色法（MTT）检测细胞生长抑制率。采用流式细胞仪检测细胞周期和凋亡率，分析载体肝干细胞WB—ES分泌表达的Endostatin对ECV304的增殖和凋亡的影响。结果载体肝干细胞胞外表达的Endostatin对人脐静脉内皮细胞ECV304生长有显著抑制作用，48h作用达到高峰，随浓度增加抑制作用增强；Endostatin作用的实验组，G1期细胞比例增加，s期细胞数下降，抑制细胞生长的机制可能主要是通过对细胞增殖的影响（P〈0．05）；实验组细胞存在细胞凋亡增加现象，但与对照组比较凋亡率差异无统计学意义。结论携带内皮抑素基因的载体肝干细胞WB-ES胞外表达的Endostatin在体外可有效抑制血管内皮细胞增殖，载体肝干细胞WB-ES有望成为靶向抗肿瘤血管生成的肝癌基因治疗载体细胞。     

Rab23 is a potential biological target for treating hepatocellula carcinoma

AIM:To elucidate the role of Rab23 in hepatocellular carcinoma(HCC)by assessing the expression of Rab23 in HCC tissue and in HCC cell lines.METHODS:Primary tumors(n = 100)were stained with Rab23 antibodies using immunohistochemistry and in situ hybridization in tissue microarrays.Relationships between gene expression and pathology parameters were analysed.The biological significance of Rab23 in Hep-3B cells was examined by knocking down Rab23 gene expression.We designed a pair of doublestranded RNAs against human rab23 and transfected siRNA into Hep-3B cells.Rab23 expression in these cells was examined using RT-PCR and Western blots.We investigated cell growth by MTT assays and fluorescenceactivated cell sorting.RESULTS:High cytoplasmic and nuclear expression of Rab23 was found in 38 of 71(53.5%)and in 49 of 68 HCC patients(72%)respectively,which correlated with tumor size.HCC cell lines expressed Rab23.In Hep3B cells,siRNA for Rab23 decreased Rab23 mRNA by 4.5-fold and protein expression by 2-fold.Survival rates at 24 and 48 h for Hep-3B cells transfected with siRNA were lower and about 30% Hep-3B cells were apoptotic.Knocking down rab23 suppressed Hep3B cell growth,suggesting that rab23 could play an important role in Hep3B cell growth.CONCLUSION:Rab23 is overexpressed and/or activated in HCC.Rab23 may be both a HCC predictor and a target for treating HCC.     

VEGF基因治疗靶向载体的构建及其特异性表达分析

目的 :构建KDR启动子介导的VEGF逆转录病毒载体pLXSN D2 99 KDRp VEGF1 6 5,并对其内皮细胞特异性表达作用进行分析。方法 :将逆转录病毒载体 3’LTR的U3区缺失 2 99个碱基使其自身启动子失活 ,然后重组pLXSN D2 99 KDRp VEGF1 6 5载体。经PA317细胞包装 ,NIH3T3细胞测定其病毒滴度。用高病毒滴度细胞株产生的病毒上清分别感染ECV30 4人脐静脉血管内皮细胞和NIH3T3细胞 ,收集细胞培养上清经ELISA和westernBlot分析。结果 :VEGF1 6 5在内皮细胞ECV30 4中的表达量明显高于NIH3T3细胞。结论 :构建的pLXSN D2 99 KDRp VEGF载体 ,可在内皮组织细胞中特异性地表达VEGF。     

Rab23 is a potential biological target for treating hepatocellular carcinoma

AIMTo elucidate the role of Rab23 in hepatocellular carcinoma(HCC)by assessing the expression of Rab23 in HCC tissue and in HCC cell lines.METHODSPrimary tumors(n = 100)were stained with Rab23 antibodies using immunohistochemistry and in situ hybridization in tissue microarrays.Relationships between gene expression and pathology parameters were analysed.The biological significance of Rab23 in Hep-3B cells was examined by knocking down Rab23 gene expression.We designed a pair of doublestranded RNAs against human rab23 and transfected siRNA into Hep-3B cells.Rab23 expression in these cells was examined using RT-PCR and Western blots.We investigated cell growth by MTT assays and fluorescenceactivated cell sorting.RESULTSHigh cytoplasmic and nuclear expression of Rab23 was found in 38 of 71(53.5%)and in 49 of 68 HCC patients(72%)respectively,which correlated with tumor size.HCC cell lines expressed Rab23.In Hep3B cells,siRNA for Rab23 decreased Rab23 mRNA by 4.5-fold and protein expression by 2-fold.Survival rates at 24 and 48 h for Hep-3B cells transfected with siRNA were lower and about 30% Hep-3B cells were apoptotic.Knocking down rab23 suppressed Hep3B cell growth,suggesting that rab23 could play an important role in Hep3B cell growth.CONCLUSIONRab23 is overexpressed and/or activated in HCC.Rab23 may be both a HCC predictor and a target for treating HCC.     

腺病毒介导MDA-7/IL-24选择性促进肝癌细胞的凋亡和增殖阻滞

目的 观察MDA-7／IL-24基因对不同p53状态人肝癌细胞HepG2、MHCC97L以及Hep3B和正常的肝细胞L02的选择性杀伤作用，为肝癌的基因治疗提供理论基础。方法 将携带人MDA-7／IL-24基因的腺病毒Ad．mda-7感染人正常肝细胞L02和不同p53状态的肝癌细胞HepG2，MHCC97L、Hep3B。通过逆转录聚合酶链反应方法观察MDA7／IL24基因的表达，酶联免疫吸附法检测细胞培养上清液中MDA-7／IL-24蛋白的浓度，通过四甲基偶氮唑盐染色法及Hoechst染色观察MDA-7／IL-24对肝癌细胞的生长抑制和杀伤作用，Annexin-V和碘化丙啶双染后流式细胞仪检测细胞的凋亡，应用流式细胞仪检测细胞周期。结果 复制缺陷型腺病毒能介导外源基因MDA-7／IL-24在肝癌细胞株HepG2，MHCC97L和Hep3B以及正常细胞L02中高效表达。细胞培养上清液中有MDA-7／IL-24蛋白表达。MDA-7／IL-24能明显抑制各种肝癌细胞的生长，Hoechst染色提示MDA-7／IL-24促进肝癌细胞的凋亡，流式细胞仪提示MDA-7能选择性杀伤肝癌细胞而对正常的肝细胞无影响，细胞周期分析提示MDA-7／IL-24阻滞肝癌细胞在G2／M期，同时对正常的肝细胞没有促凋亡作用和增殖阻滞作用。结论 复制缺陷型重组腺病毒载体Ad．mda-7能介导MDA-7／IL-24基因在人肝癌细胞中高效表达，选择性地杀伤肝癌细胞HepG2、MHCC97L和Hep3B，促进细胞增殖阻滞及诱导肿瘤细胞凋亡而与肿瘤细胞的P53基因的状态无关，同时对正常的肝细胞L02无任何毒性作用。     

血管内皮生长因子反义寡核苷酸抑制甲状腺癌血管生成的效应

目的探讨反义寡核苷酸(ASODN)抑制甲状腺癌细胞血管内皮生长因子(VEGF)表达及内皮细胞生长的效应。方法设计合成靶向VEGF的ASODN转染人髓状甲状腺癌细胞系(TT)细胞,并制备相应条件培养基作用内皮细胞ECV304,设正义寡核苷酸(SODN)和空白对照组进行比较。观察细胞生长状态,RT PCR、免疫细胞化学法检测TT细胞VEGFmRNA和蛋白表达,四氮唑蓝法检测TT和ECV304细胞生长抑制率(IR),流式细胞仪、吖啶橙/溴化乙锭染色法检测ECV304细胞凋亡状态。结果ASODN组TT细胞VEGFmRNA和蛋白表达显著低于SODN和对照组(P<0.01),但IR差异无统计学意义(P>0.05);各转染组ECV304细胞IR差异亦无统计学意义(P>0.05);而经各ASODN组TT细胞条件培养基作用的ECV304细胞生长明显受抑,IR(分别为0.21±0.03、0.31±0.01、0.42±0.22)显著高于SODN组(0.05±0.03,P<0.01),并伴明显细胞凋亡,上述效应呈浓度依赖性。结论ASODN可通过特异性封闭甲状腺癌细胞VEGF表达,抑制内皮细胞生长,干扰肿瘤血管生成。     

特异性寡聚脱氧核苷酸对Hep3B肝癌细胞恶性表型的作用

目的研究一段序列和胰岛素样生长因子2(IGF-2)基因第四启动子互补的特异性寡聚脱氧核苷酸(SODN)对Hep3B肝癌细胞株的抑制效应。方法根据IGF-2基因第四启动子序列人工合成一段与之互补的特异性脱氧核苷酸,并制备其长效的硫代衍生物,通过转染试剂将其导入高表达IGF-2的Hep3B 肝癌细胞株后,采用逆转录聚合酶链反应法和western blot技术分析SODN对IGF-2基因转录和蛋白表达的抑制效应,并通过四甲基偶氮唑盐法、流式细胞术、细胞克隆形成实验以及细胞侵袭和运动实验进一步观察SODN对Hep3B细胞的生长、细胞周期、体外克隆形成能力及侵袭和运动能力所产生的影响。结果空白对照组和导入非特异性寡聚脱氧核苷酸(CODN)对照组相比,导入SODN的Hep3B细胞,其IGF-2 mRNA 和蛋白的表达有明显降低;SODN对Hep3B细胞的增殖及运动能力不产生效应,但可以抑制其在培养板上的克隆形成数和穿透Matrigel的细胞数,抑制率分别为90.2%、95.5%。结论SODN具有"分子开关"作用,可以抑制和下调Hep3B肝癌细胞的IGF-2基因表达,并可逆转其部分恶性表型。     

血红素加氧酶-1基因转染对内毒素诱导的ECV304细胞氧化损伤的影响

目的 探讨血红素加氧酶-1( HO-1)基因转染对脂多糖诱导的ECV304细胞氧化损伤的影响.方法 利用逆转录病毒介导的基因转染技术将HO-1基因转染人人脐静脉内皮细胞(ECV304),应用RT-PCR和Western印迹技术检测转染细胞HO-1 mRNA和蛋白表达水平.未转染和转染HO-1基因的ECV304细胞分别培养于含或不含脂多糖(5 mg/L)的DMEM培养基24h后,检测细胞脂质过氧化产物丙二醛(MDA)含量和乳酸脱氢酶(LDH)释放率.结果 HO-1基因和蛋白在转染的ECV304细胞的表达量显著升高.与ECV304细胞相比,转染HO-1基因的ECV304细胞MDA含量和LDH释放率均下降(P＜0.05);应用HO-1抑制剂锌原卟啉共孵育后,转染细胞的MDA含量和LDH释放率增高.结论 HO-1的基因转染可增强ECV304细胞对抗脂多糖氧化损伤的能力.     

Effect of fragile histidine triad gene transduction on proliferation and apoptosis of human hepatocellular carcinoma cells

AIM： To evaluate the inhibitory effects of human fragile histidine triad （FHIT） gene on cell proliferation and apoptosis in human hepatocellular carcinoma line Hep3B in vitro.
METHODS： A recombinant pcDNA3.1 （＋）/FHIT including the functional region of FHIT gene was constructed and transferred into human hepatocellular carcinoma cells in vitro, mRNA and protein expression of the FHIT gene in the transfected cells was detected by RT-PCR and Western blot, respectively. The effect of FHIT on proliferation was detected by MTT assay. Changes in cell cycle and apoptosis were assayed by flow cytometry. Five mice received subcutaneous transplantation of Hep3B-FHIT; 5 mice received subcutaneous transplantation of normal Hep3B and Hep3B-C as controls. The body weight of nude mice and tumor growth were measured.
RESULTS： RT-PCR and Western blot analysis showed that the expression level of FHIT-mRNA and FHIT protein was higher in Hep3B cells after infection with pcDNA3.1 （＋）/FHIT. The growth of Hep3B cells treated with pcDNA3.1 （＋）/FHIT was significantly inhibited. The pcDNA3.1 （＋）/FHIT-transfected Hep3B cells showed a significantly higher cell rate at G0-G1 phase and increased apoptosis in comparison with controls （P 〈 0.05）. The growth of transplanted tumor was inhibited markedly by FHIT. Tumors arising from the Hep3B-FHIT cells occurred much later than those arising from the Hep3B and Hep3B-C cells. The growth of Hep3B-FHIT cells was slow and the tumor volume was low.
CONCLUSION： Transduction of FHIT gene inhibits the growth of human hepatocellular carcinoma cells and induces cell apoptosis in vivo and in vitro.     

溶血磷脂酰胆碱诱导内皮细胞表达血管内皮生长因子及丹酚酸B的抑制作用

研究溶血磷脂酰胆碱对内皮细胞中血管内皮生长因子表达的影响以及丹酚酸B的保护作用。在人脐静脉内皮细胞株ECV30 4培养基中加入溶血磷脂酰胆碱或溶血磷脂酰胆碱 +丹酚酸B ,用酶联免疫吸附试验检测各组内皮细胞培养上清液中血管内皮生长因子蛋白含量 ;用原位杂交检测血管内皮生长因子mRNA的表达。结果显示 ,培养的ECV30 4中未见血管内皮生长因子mRNA的表达 ,溶血磷脂酰胆碱刺激后可见血管内皮生长因子mRNA的高表达 ,加入丹酚酸B后阳性反应明显低于溶血磷脂酰胆碱组。酶联免疫吸附试验结果显示 ,溶血磷脂酰胆碱可使ECV30 4细胞条件培养基中血管内皮生长因子蛋白表达明显增加 ,丹酚酸B可明显降低其含量。以上结果提示 ,溶血磷脂酰胆碱能诱导ECV30 4表达高水平的血管内皮生长因子 ,丹酚酸B可明显降低其含量     

重组人内皮抑素腺病毒抑制肝癌裸鼠移植瘤生长

目的 观察重组人内皮抑素腺病毒(Ad/hEndo)对人肝癌裸鼠移植瘤生长的影响。方法 人脐静脉内皮细胞ECV-304经Ad/hEndo感染后,western印迹检测人内皮抑素的表达。人肝癌BEL-7402细胞移植到裸鼠背脊部后,检测Ad/hEndo对肝癌移植瘤生长的抑制作用。逆转录聚合酶链反应(RT-PCR)检测肿瘤组织中内皮抑素mRNA的表达。分析人内皮抑素在裸鼠体内的表达分布。结果 Western印迹检测到人内皮抑素基因在ECV-304细胞内高效表达。Ad/hEndo明显抑制人肝癌BEL-7402裸鼠移植瘤生长(F=4.061,P<0.05)。Ad/hEndo组血管密度计数为6.88±1.08,DMEM组为13.60±1.71(t=9.216,P<0.01)。瘤内注射Ad/hEndo后3d,RT-PCR在肿瘤组织检测到内皮抑素mRNA的表达,7d后表达不明显。人内皮抑素蛋白主要分布在肿瘤组织。结论 腺病毒介导的人内皮抑素基因在体内、体外获得高效表达,并明显抑制肝癌裸鼠移植瘤的生长与血管生成。     

Treatment of pancreatic carcinoma by adenoviral mediated gene transfer of vasostatin in mice

BACKGROUND: Tumour growth is angiogenesis dependent and antiangiogenesis therapy may represent a promising therapeutic option. AIMS: To evaluate the inhibitory effect of vasostatin gene mediated by a replication deficient recombinant adenovirus (Ad) on human pancreatic cancer in vivo and to investigate the mechanism of action of vasostatin. METHODS: Human umbilical vein endothelium derived ECV304 cells were infected with Ad-vasostatin and Ad-lacZ, and compared with phosphate buffered saline (PBS). MTT (3,-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was used to estimate the proliferation of ECV304 cells; tube formation assay and choriallantoic membrane assay were used to evaluate angiogenesis in vivo and in vitro. Xenografted nude mice with pancreatic cancer were established to observe in vivo tumour growth suppression. Microvessel density revealed by CD31 immunohistochemical staining was measured. RESULTS: Growth and tube formation of ECV304 cells infected with Ad-vasostatin were suppressed significantly compared with cells infected with Ad-lacZ or cells treated with PBS. Neovascularisation in the Ad-vasostatin group was less than that in the PBS and Ad-lacZ groups, based on chorioallantoic membrane results. Volumes of pancreatic tumours in the Ad-vasostatin group were significantly smaller than those in the PBS and Ad-lacZ groups at the end of the treatment period. Microvessel density in the Ad-vasostatin group was significantly lower than that in the Ad-lacZ and PBS groups. CONCLUSION: The vasostatin gene mediated by adenovirus is efficient for gene therapy for pancreatic carcinoma. Suppression of vasostatin on proliferation of vascular endothelium cells and angiogenesis may account for its effect.     

Retrovirus—mediated gene transfer of human endostatin inhibits growth of human liver carcinoma cells SMMC7721 in nude mice

AIM: To study the effect of human endostatin mediated by retroviral gene transfer on the growth of human hepatocarcinoma cell line SMMC7721 in nude mice. METHODS: Human endostatin gene together with rat serum albumin signal peptide was transferred into human liver carcinoma SMMC7721 cells by retroviral vector pLncx to build a stable transfectant (SMMC-endo). PCR and Western blot analysis were used to verify the transfection and secretion of human endostatin gene in SMMC7721 cells. The endothelial cell proliferation assay in vitro was conducted to test the biological activity of the expressed human endostatin. The inhibitory effect of endostatin expressed by transfected SMMC7721 on the growth rates of tumor cells in vivo was observed. The mean microvessel density in the specimen was also counted. RESULTS: PCR amplification proved that the genome of SMMC-endo cells contained a 550bp specific fragment of endostatin gene. Western blot analysis confirmed the secretion of human endostatin gene in the conditioned medium of transfected SMMC-endo cells. The endothelial proliferation assay showed that the conditioned medium of SMMC-endo cells significantly inhibited the proliferation of human umbilical vein endothelial cells by 48 %, significantly higher than that of SMMC-pLncx (10.2 %, P<0.01). In vitro experiments revealed that only in 3 out of 5 mice tumors were formed and the mean size of flank tumors from SMMC-endo cells was 94.5 % smaller than that from the control SMMC-pLncx cells 22 days after tumor inoculation (P<0.001). The mean microvessel density in tumor samples from SMMC-endo cells was only 8.6+/-1.1, much fewer than that of 22.6+/-4.5 from SMMC-pLncx cells (P<0.01). CONCLUSION: Human endostatin mediated by retroviral gene transfer can inhibit human liver carcinoma cell SMMC7721 growth in nude mice.     

Enhanced cell survival of Hep3B cells by the hepatitis B x antigen effector, URG11, is associated with upregulation of beta-catenin

Intrahepatic expression of hepatitis B x antigen (HBxAg) is associated with the development of hepatocellular carcinoma (HCC), perhaps through trans-activation of selected cellular genes. When this was examined by PowerBlot analysis, upregulated levels of beta-catenin and several known beta-catenin effectors were observed in HBxAg-positive compared with HBxAg-negative HepG2 cells. When HBxAg was introduced into Hep3B cells, upregulated expression of wild-type beta-catenin was observed. This was also observed in Hep3B cells overexpressing the HBxAg upregulated gene, URG11. Upregulated expression of URG11 and beta-catenin correlated with HBxAg trans-activation function. Transient transfection assays with fragments of the beta-catenin promoter showed that it was activated by both HBxAg and URG11 and inhibited by URG11-specific small inhibitory RNA. The latter also inhibited the growth of Hep3BX cells in a serum-free medium, which correlated with depressed levels of beta-catenin. Activation of beta-catenin effector genes was observed in cells stably expressing HBxAg or overexpressing URG11 compared with control cells transfected with the pTOPFLASH reporter plasmid. Extensive costaining between HBxAg, URG11, and beta-catenin was observed in infected liver and HCC nodules, suggesting a close relationship in vivo. In conclusion, wild-type beta-catenin is activated by HBxAg, in part, through the upregulated expression of the HBxAg effector URG11. URG11 stimulates the beta-catenin promoter and hepatocellular growth and survival. These observations also suggest that URG11 may be a regulatory element in the beta-catenin signaling pathway and may be a target for chemoprevention of HCC.     

尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4过表达对人脐静脉内皮细胞凋亡和活性氧水平的影响

目的研究尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4表达水平的改变对内皮细胞活性氧生成和凋亡的影响。方法转染尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4表达质粒或GFP质粒到人脐静脉内皮细胞和ECV304中,用逆转录聚合酶链反应检测转染后尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4mRNA的水平,用流式细胞仪检测细胞内活性氧水平和细胞凋亡率,用Hoechst染色和TUNEL法观察细胞凋亡。结果转染后的人脐静脉内皮细胞中尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4mRNA水平明显高于GFP质粒组和对照组,不表达尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶的ECV304细胞系经转染后亦表达尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4mRNA;流式细胞仪检测发现,与GFP质粒组(ECV304和人脐静脉内皮细胞的凋亡率分别为1.56%±0.33%和4.56%±0.62%)和对照组(ECV304和人脐静脉内皮细胞的凋亡率分别为1.05%±0.25%和2.28±0.37%)相比,转染尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4质粒组内皮细胞的活性氧生成和凋亡率(ECV304和人脐静脉内皮细胞的凋亡率分别为9.60%±0.92%和12.41%±1.12%)明显增加(P<0.05,n=3);Hoechst和TUNEL染色发现,转染尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4质粒后有部分内皮细胞胞核出现凋亡特征性改变。结论尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4表达质粒可有效地转染人脐静脉内皮细胞,引起尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4mRNA水平升高;尼克酰胺腺嘌呤二核苷酸磷酸盐氧化酶4过表达可诱导人脐静脉内皮细胞凋亡。     

Cyclooxygenase-2 promotes hepatocellular carcinoma cell growth through Akt activation: evidence for Akt inhibition in celecoxib-induced apoptosis

Cyclooxygenase-2 (COX-2)-controlled prostaglandin (PG) metabolism recently has been implicated in the pathogenesis of hepatocellular carcinoma (HCC). However, the biologic role and molecular mechanism of COX-2-mediated PGs in the control of liver cancer growth have not been established. This study was designed to examine the direct effect of COX-2 and its inhibitor celecoxib on the growth control of liver cancer cells. Human HCC cell lines Hep3B and HepG2 transfected with COX-2 expression vector showed increased cell growth and enhanced phosphorylation of serine/threonine protein kinase B (Akt). The level of COX-2 expression and Akt phosphorylation is correlated positively in cultured HCC cells and human liver cancer tissues. Inhibition of Akt activation by phosphatidylinositol 3-kinase (PI3-kinase) inhibitor LY294002 significantly decreased the viability of Hep3B and HepG2 cells (P <.01). These results reveal a novel role of Akt activation in COX-2-induced HCC cell survival. Furthermore, HCC cells treated with the COX-2 inhibitor celecoxib showed significant reduction of Akt phosphorylation and marked morphologic and biochemical characteristics of apoptosis. Overexpression of COX-2 or addition of exogenous PGE(2) partially prevented celecoxib-induced apoptosis (P <.01). In conclusion, our results suggest the involvement of COX-2-dependent and -independent mechanisms in celecoxib-mediated HCC cell apoptosis.