双启动子调控的条件复制腺病毒制备及其体外抑瘤作用

目的：构建并制备survivin及hTERT双启动子调控的条件复制腺病毒,探讨其特异性溶瘤作用。方法：PCR方法分别扩增肿瘤特异性survivin及hTERT启动子,分别克隆入腺病毒载体pXCl的两个复制必需基因E1A和E1B序列上游启动子区,构建出双肿瘤特异性启动子调控的条件复制腺病毒载体pXCl-SP—TP;脂质体法与pBHGE3骨架质粒共转染293E细胞进行重组腺病毒包装,稀释法测定腺病毒滴度;应用MTT、活细胞计数等方法观察其对肝癌细胞HepG2的特异性溶瘤作用并以正常人的血管内皮细胞ECV304作为对照。结果：测序及双酶切鉴定结果证实,成功构建了双肿瘤特异性启动子调控复制腺病毒载体;在293E细胞中获得了重组腺病毒Ad—sP—TP,滴度测定显示病毒滴度达到3．9×10^10TCID50／ml;MTT结果显示,Ad—sP—TP可有效抑制肝癌细胞增殖而对正常细胞无增殖抑制作用;活细胞计数及细胞形态观察结果显示,重组腺病毒在肝癌细胞中选择性复制并发挥溶细胞作用。结论：双启动子调控的腺病毒具有显著的溶瘤作用但对正常人血管内皮细胞不发挥溶细胞作用,实验结果为肝癌靶向治疗提供了更为良好的条件复制型病毒载体及新的治疗策略。     

双启动子调控的条件复制腺病毒制备及其体外抑瘤作用

目的:构建并制备survivin及hTERT双启动子调控的条件复制腺病毒,探讨其特异性溶瘤作用.方法:PCR方法分别扩增肿瘤特异性survivin及hTERT启动子,分别克隆入腺病毒载体pXC1的两个复制必需基因E1A和E1B序列上游启动子区,构建出双肿瘤特异性启动子调控的条件复制腺病毒载体pXC1-SP-TP;脂质体法与pBHGE3骨架质粒共转染293E细胞进行重组腺病毒包装,稀释法测定腺病毒滴度;应用MTT、活细胞计数等方法观察其对肝癌细胞HepG2的特异性溶瘤作用并以正常人的血管内皮细胞ECV304作为对照.结果:测序及双酶切鉴定结果证实,成功构建了双肿瘤特异性启动子调控复制腺病毒载体;在293E细胞中获得了重组腺病毒Ad-SP-TP,滴度测定显示病毒滴度达到3.9×1010TCID50/ml;MTT结果显示,Ad-SP-TP可有效抑制肝癌细胞增殖而对正常细胞无增殖抑制作用;活细胞计数及细胞形态观察结果显示,重组腺病毒在肝癌细胞中选择性复制并发挥溶细胞作用.结论:双启动子调控的腺病毒具有显著的溶瘤作用但对正常人血管内皮细胞不发挥溶细胞作用,实验结果为肝癌靶向治疗提供了更为良好的条件复制型病毒载体及新的治疗策略.     

肝癌选择性溶瘤腺病毒的构建及其体外抑瘤作用

目的: 构建由AFP基因增强子启动子调控,并携带自杀基因TK的新型条件复制型腺病毒载体,观察该载体的选择复制能力、溶瘤作用及其与前药GCV联合处理对肝癌细胞的杀伤作用。方法:以HepG2基因组DNA为模板,PCR扩增AFP基因启动子（AFPp）和增强子(AFPe),构建表达质粒pAFPpEGFPluc和pAFPepEGFPluc,再构建由AFPep调控E1A表达、并携带TK基因的穿梭质粒pDC311AFPepE1A/CMVTK,利用AdMax系统包装腺病毒Ad.AFPepE1A/CMVTK;利用Western blotting、病毒增殖测试、细胞病变效应实验、病毒联合前药GCV对肝癌细胞的杀伤实验等鉴定病毒的复制能力、溶瘤作用和对肝癌细胞的杀伤作用。结果：成功构建的腺病毒载体 Ad.AFPepE1A/CMVTK在AFP阳性细胞中选择性复制,病毒自身具有一定的溶瘤作用;该病毒载体联合GCV前药系统处理肝癌细胞后,AFP阳性肝癌HepG2细胞和Hep3B细胞的存活率分别为(10.35±1.07)%、(15.49±5.80)%,AFP阴性的张氏肝细胞和人肺癌NCIH460细胞的存活率分别为(73.55±436)%、(74.54±9.89)% (P<0.01)。结论:构建的新型溶瘤腺病毒载体具有选择性杀伤肝癌细胞的能力,在肝癌治疗方面有良好的应用前景。     

重组腺病毒Ad—hTERTp—HSV—TK载体的构建及抗肝癌实验研究

目的构建hTERT启动子调控的HSV—TK基因重组腺病毒载体系统,观察Ad—hTERTp—HSV-TK／GCV自杀基因系统对肝癌细胞的杀伤作用。方法将穿梭质粒pSU-Tp-TK与腺病毒骨架质粒pBHGE3共转导至HEK293细胞,利用细胞内同源重组法构建出hTERT启动子调控的携带TK基因的复制缺陷型腺病毒Ad—hTERTp—HSV—TK载体系统;将不同感染复数（MOI=1、10、100、1000）的重组腺病毒Ad—hTERTp—HSV—TK感染肝癌细胞HepG2及正常肝细胞L-02,加入不同浓度的GCV（0、1、10、100、1000ug／ml）,MTT、法检测细胞活性。结果HEK293细胞出现病毒空斑,提取病毒DNA,经PCR鉴定正确后扩增、纯化,滴度为1．5×10^10pfu／ml;MTT法检测到Ad—hTERTp—HSV-TK／GCV能靶向杀死肝癌细胞HepG2,且细胞存活率随着病毒滴度和GCV浓度的增加而降低。结论该实验构建的Ad—hTERTp—HSV—TK载体系统,可靶向抑制肝癌细胞HepG2,而对正常肝细胞L-02几乎无影响。     

装载mIFN-γ基因的溶瘤腺病毒CNHK200的抗肝癌活性

目的:研究鼠源γ-干扰素(mIFN-γ)基因插入溶瘤腺病毒CNHK200后,该病毒对不同的肝癌细胞系及其裸鼠移植瘤的增殖力及特异性杀伤作用。方法:用MTT法检测CNHK200-mIFN-γ在体外对人正常肝细胞L02、人肝癌细胞Hep3B、HepGⅡ的特异性杀伤作用;裸鼠体内试验观察CNHK200-mIFN-γ对肝癌Hep3B模型的抗肿瘤疗效。结果:CNHK200-mIFN-γ对正常人肝细胞L02无杀伤作用,但能特异性杀伤肝癌细胞,mIFN-γ的插入使病毒对肿瘤细胞的杀伤能力提高;动物体内,CNHK200-mIFN-γ具有明显的肿瘤生长抑制作用。结论:CNHK200-mIFN-γ可以高效率地杀死肝癌肿瘤细胞,而不杀伤正常细胞,可能具有良好的临床应用前景。     

VEGF启动子介导鼠α1，3半乳糖基转移酶表达及其对缺氧的人肝癌细胞HepG2的靶向杀伤效应

目的:利用血管内皮生长因子(VEGF)基因启动子介导鼠α1,3半乳糖基转移酶(α1,3 GT)在缺氧肝癌细胞HepG2中靶向表达并检测其诱导的人血清天然抗体对肝癌细胞的杀伤效应,为肝癌的靶向基因治疗方法提供新的思路.方法:利用PCR从Balb/c 小鼠肝组织中扩增出小鼠VEGF 基因启动子片段并插入到荧光素酶报告载体中;用所构建的荧光素酶报告载体瞬时转染 HepG2 细胞;经缺氧诱导后检测转染细胞中荧光素酶活性;进一步通过基因重组构建受VEGF 基因启动子调控的鼠α1,3GT重组逆转录病毒载体并稳定转染HepG2细胞;转染细胞在缺氧条件下培养后,通过CDCC试验检测人血清对转染细胞的杀伤效应.结果:在转染重组有VEGF 基因启动子的荧光素酶报告载体的HepG2中,荧光素酶的活性是对照组的2-3倍;通过CDCC实验发现转染有鼠α1,3GT重组逆转录病毒载体的HepG2细胞经缺氧培养后对人血清的杀伤效应更加敏感.结论:利用VEGF基因启动子介导鼠α1,3GT在缺氧肿瘤细胞中靶向表达并诱导人血清天然抗体对肿瘤细胞产生杀伤效应在肿瘤的靶向基因治疗中具有潜在的临床应用价值.     

6株NDV鄱阳株对肝癌细胞杀伤作用的初步研究

目的：研究从江西鄱阳湖野鸭分离的6株NDV对肝癌细胞的杀伤效应，进-步筛选NDV溶瘤毒株。方法：用MTT法研究6株NDV鄱阳株对两株传代肝癌细胞株Novikoff和HepG-2及一株正常肝细胞株HL-7702的杀伤效应。结果：6株NDV鄱阳株对肝癌细胞株Novikoff和HepG-2有湿著杀伤效应，而对人正常肝细胞HL-7702无明显影响；病毒对细胞的杀伤活性与病毒作用剂量和病毒作用时间成正比；病毒在肝癌细胞中有明显复制增殖现象；Novikoff肝癌细胞对NDV敏感性强于HepG-2肝癌细胞。结论：6株NDV鄱阳株对Novikoff及HepG-2肝癌细胞产生显著的杀伤作用，而对正常肝细胞HL-7702未见明显影响。     

表达嵌合性T细胞受体的肿瘤浸润淋巴细胞对KDR表达阳性细胞的选择性杀伤作用

目的 研究表达嵌合性T细胞受体VEGF 121-hinger-FcRγ的肿瘤浸润淋巴细胞(TIL)对血管内皮生长因子(VEGF)受体KDR(kinase-domain insert containing receptor)表达阳性细胞的选择性杀伤作用。方法 应用分子克隆技术重组VEGF 121-hinger-FcRy(Vhγ),构建重组逆转录病毒质粒pMSCVneo-Vhγ,经PT67包装后筛选高滴度的病毒,体外感染分离于肝癌组织的TIL,获得MSCVneo-Vhγ-TIL。以空病毒感染TIL获得的MSCVneo-TIL作为对照。以MTT比色法分析不同的TIL细胞对4种靶细胞(不表达VEGF受体KDR的成纤维细胞系NIH3T3和肝癌细胞系HepG2,以及表达VEGF、受体KDR的人脐静脉血管内皮细胞系ECV304和恶性黑色素瘤细胞系A375)的杀伤活性。结果 未转染的TIL和MSCVneo-TIL对NIH3T3和ECV304无明显的杀伤作用,对HepG2和A375有一定杀伤作用,对4种靶细胞杀伤活性的差异无显著性;MSCVneo-Vhγ-TIL对NIH3T3无明显杀伤活性,对ECV304有明显杀伤活性,对HepG2的杀伤与TIL、MSCVneo-TIL相比差异无显著性,而对A375的杀伤明显增强。结论 嵌合性T细胞受体Vhγ经逆转录病毒载体介导,可在TIL细胞表面稳定表达,并获得选择性识别和溶解KDR阳性血管内皮细胞和肿瘤细胞的新效应功能。     

双靶向组织特异性HSV-tk/GCV抗瘤系统构建及体外效应研究

目的 构建高靶向性基因转移及基因表达系统,并研究其介导HSV-tk/GCV自杀基因系统对人肝癌细胞的体外杀伤作用。 方法 通过重组DNA技术分别构建anti-TfR ScFv-GAL4融合蛋白表达载体ScFv-GAL4-pET28a及含AFP启动子、GAL4特异性识别序列(GAL4rec)的HSV-tk真核表达载体pEBAF/tk-GAL4rec。前者经IPTG诱导表达获取anti-TfR ScFv-GAL4融合蛋白作为非病毒转运载体,利用受体介导内吞作用介导pEBAF/tk-GAL4rec质粒转染表面均高表达TfR的人肝癌细胞株HepG2、SMMC7721及人肺癌细胞株A549,潮霉素筛选阳性细胞,扩大培养,分别命名为HepG2/tk、SMMC7721/tk及A549/tk,然后通过MTT法检测GCV对它们的杀伤作用。 结果 双酶切鉴定及SDS-PAGE电泳证明非病毒转移载体anti-TfR ScFv-GALA融合蛋白及重组pEBAF/tk-GAL4rec真核表达质粒构建成功。体外杀伤实验中,表面TfR阳性且高分泌AFP(845 ng/ml)的HepG2/tk细胞对GCV很敏感,且抑制率与GCV浓度及作用时间呈正相关;而低分泌AFP(2ng/ml)的SMMC7721/tk细胞对GCV低度敏感;表面TfR阳性但不分泌AFP的A549/tk细胞则对前药不敏感。 结论 双靶向组织特异性HSV-tk/GCV抗瘤系统构建成功,并显示出很好的靶向性。     

携带mda-7基因的复制缺陷型腺病毒通过促进线粒体释放促凋亡蛋白杀伤肝癌细胞

目的 探讨黑色素瘤分化相关基因7/白介素24(mda-7/IL-24)基因选择性杀伤肝癌细胞的机制.方法 应用携带mda-7基因的复制缺陷型腺病毒Ad.mda-7感染正常肝细胞L02和肝癌细胞HepG2.通过逆转录聚合酶链反应(RT-PCR)、酶联免疫吸附实验(ELISA)及Western blot方法,观察mda-7/IL-24基因的表达;应用Hoeehst染色和流式细胞仪观察mda-7/IL-24对肝癌细胞的杀伤作用;采用RT-PCR和Western blot方法,观察Bcl-2家族和caspase-9基因表达的变化,分离不同感染时点细胞内线粒体和胞浆蛋白,并检测线粒体释放促凋亡蛋白细胞色素C(Cyt-C)和Smac/DIABLO的变化过程.结果 Ad.mda-7能介导mda-7/IL-24在两种细胞株中的高效表达.能选择性杀伤肝癌细胞,感染24 h后,HepG2细胞凋亡率为24.0%±4.6%,而对正常的肝细胞没有影响.RT-PCR和亚细胞蛋白的分析结果显示,胞浆内Bel-2和Bcl-xL的表达在HepG2细胞中明显下降,而在L02细胞中的表达无变化,Bax在肝癌细胞中的表达明显增强,Bak的表达无变化;Ad.mda-7能促进细胞线粒体释放cyt-C和Smac/DIABLO蛋白,并促进caspase-9的表达.结论 Ad.mda-7能选择性杀伤肝癌细胞HepG2,通过促进线粒体促凋亡蛋白的释放而诱导肝癌细胞凋亡.     

双靶向组织特异性HSV-tk/GCV抗瘤系统的构建及体外效应研究

目的：构建高靶向性基因转移及表达系统，并研究其介导HSVtk/GCV自杀基因系统对肝癌细胞的体外杀伤作用。方法： 通过重组技术分别构建antiTfR ScFvGAL4融合蛋白表达载体ScFvGAL4pET28a及含AFP启动子、GAL4特异性识别序列（GAL4rec）的HSVtk真核表达载体pEBAF/tkGAL4rec。IPTG诱导后，利用受体介导内吞作用介导pEBAF/tkGAL4rec质粒转染表面均高表达TfR的人肿瘤细胞株HepG2，SMMC7721及A549。潮霉素筛选后，MTT法检测GCV对它们的杀伤作用。结果：双酶切鉴定、SDSPAGE电泳及测序分别证明antiTfR ScFvGAL4融合蛋白及重组pEBAF/tkGAL4rec真核表达质粒构建成功。体外杀伤实验中，高分泌AFP(845 ng/ml) 的HepG2/tk细胞对GCV很敏感，且抑制率与GCV浓度及作用时间呈正相关；而低分泌AFP(2 ng/ml)的SMMC7721/tk细胞对GCV低度敏感；不分泌AFP 的A549/tk细胞则不敏感。结论：双靶向组织特异性HSVtk/GCV抗瘤系统构建成功，并显示出很好的靶向性。     

Cell cycle arrest and apoptosis of melanoma cells by docosahexaenoic acid: association with decreased pRb phosphorylation

The incidence of cutaneous malignant melanoma is undergoing a dramatic increase in persons with light-color skin in all parts of the world. The prognosis for individuals with advanced disease is dismal due to the lack of effective treatment options. Thus, there is a need for new approaches to control tumor progression. Epidemiological, experimental, and mechanistic data implicate omega-6 polyunsaturated fatty acids (PUFAs) as stimulators and long-chain omega-3 PUFAs as inhibitors of development and progression of a range of human cancers, including melanoma. The aim of this study was to assess the mechanisms by which docosahexaenoic acid (DHA), an omega-3 PUFA, affects human melanoma cells. Exponentially growing melanoma cell lines were exposed in vitro to DHA and then assessed for (a) inhibition of cell growth; (b) expression of cyclins and cyclin-dependent kinase inhibitors in individual cells by flow cytometry and immunocytochemistry using specific monoclonal antibodies to cyclin D1, cyclin E, p21WAF1/CIP1, or p27(KIP1); and (c) expression of total pRb(T) independent of phosphorylation state and hypophosphorylated pRb(P-) in fixed cells by flow cytometry and immunocytochemistry using specific monoclonal antibodies to pRb(T) or pRb(P-), respectively. After treatment with increasing concentrations of DHA, cell growth in a majority of melanoma cell lines (7 of 12) was inhibited, whereas in 5 of 12 cell lines, cell growth was minimally affected. Two melanoma cell lines were examined in detail, one resistant (SK-Mel-29) and one sensitive (SK-Mel-110) to the inhibitory activity of DHA. SK-Mel-29 cells were unaffected by treatment with up to 2 microg/ml DHA whether grown in the absence or presence of 1% fetal bovine serum (FBS). No appreciable change was observed in cell growth, cell cycle distribution, the status of pRb phosphorylation, cyclin D1 expression, or the levels of the cyclin-dependent kinase inhibitors p21 and p27. In contrast, SK-Mel-110 cell growth was inhibited by DHA with the cells accumulating either in G1 or S phase: 0% in SK-Mel-29 versus 13.3 or 41.2% in SK-Mel-110 in the absence or presence of FBS, respectively. In the absence of serum, considerable death occurred by apoptosis. In addition, DHA treatment resulted in increasing numbers of SK-Mel-110 cells (from 12 to >40%) expressing hypophosphorylated pRb, whereas the levels of cyclin D1 and p21 changed little. Expression of p27 in these cells increased >2.5 times when grown in the absence of FBS but not in the presence of 1% FBS. Thus, we show for the first time that DHA inhibits the growth of cultured metastatic melanoma cells. Furthermore, growth inhibition correlates with a quantitative increase in hypophosphorylated pRb in the representative sensitive melanoma cell line SK-Mel-110. Although multiple factors influence pRb phosphorylation, it appears that both cyclin D1 and p21 expression do not change in the presence of DHA, although p27 was strikingly increased in SK-Mel-110 cells in the absence of FBS. The fact that pRb became hypophosphorylated after exposure to DHA suggests a cross-talk mechanism between fatty acid metabolism and the pRb pathway. Determining the mechanism by which PUFAs can inhibit melanoma growth will be an important first step in the rational use of PUFAs as antitumor agents.     

Novel oncolytic adenoviruses targeted to melanoma: specific viral replication and cytolysis by expression of E1A mutants from the tyrosinase enhancer/promoter

Malignant melanoma is characterized by growing incidence, early metastasis, and a lack of effective treatment for advanced disease, suggesting a pressing need for novel therapeutic approaches. Conditionally replicative adenoviruses (CRAds) constitute a new and promising strategy for cancer treatment that has been rapidly translated into clinical trials. We engineered novel melanoma-targeted CRAds, AdTyrdelta24 and AdTyrdelta2delta24, by replacing the adenoviral E1A promoter with a cassette containing a polyA sequence and a human tyrosinase enhancer/promoter construct (hTyr2E/P). The small size of this cassette allows retention of the E3 region within these CRAds, which was shown to enhance viral spread and oncolysis. In addition, we introduced mutations (delta24 and delta2delta24) into the viral E1A gene, which attenuate adenoviral replication in quiescent cells. The cell cycle pathways mediating this attenuation are defective in melanoma cells. By analysis of E1A expression, we prove fidelity of hTyr2E/P in the adenoviral genome and in the context of viral replication when an upstream polyA was included. We further show efficient cytotoxicity of AdTyrdelta24 and AdTyrdelta2delta24 in melanoma cell lines and a 100-1000-fold attenuation in cell lines derived from various nonmelanocytic tissues. Virus replication and progeny production of these viruses were similarly selective, resulting in 200-800-fold higher virus yields in melanoma cells versus control cells, thus establishing viral cytolysis and spread as the cause of the observed cell killing. Cytotoxicity of AdTyrdelta24 for normal fibroblasts and keratinocytes was strongly attenuated, and this virus caused selective killing of melanoma cells but not surrounding keratinocytes in a coculture system. Progeny production and cytotoxicity of AdTyrdelta24 in melanoma cells were similar to matching viruses containing the stronger cytomegalovirus enhancer/promoter instead of hTyr2E/P. Furthermore, AdTyrdelta24 showed a cytopathic effect similar to the wild-type E1A containing AdTyrwt and only minimally reduced compared with wild-type adenovirus. We conclude that the generated CRAds AdTyrdelta24 and AdTyrdelta2delta24 constitute novel targeted agents for gene therapy and viral oncolysis of metastatic melanoma.     

Acute extracellular acidification reduces intracellular pH, 42 degrees C-induction of heat shock proteins and clonal survival of human melanoma cells grown at pH 6.7.

Two human melanoma cell lines, SK-Mel-28 and DB-1, were used for in vitro studies of the mechanisms underlying heat resistance of human tumour cells adapted to growth in acidic environments. Adaptation to growth at low pH was characterized by resistance to 42 degrees C cytotoxicity and accompanied by an increase in endogenous levels of Hsp70 and/or Hsp27. Acute extracellular acidification to levels below pH 6.5 was required to sensitize the melanoma cells to 42 degrees C. Furthermore, cells grown at low pH were more resistant to sensitization by acute acidification than cells grown at pH 7.3. The intracellular pH (pHi) of cells grown at pH 6.7 was less than the pHi of cells grown at pH 7.3 both before and after acute acidification. A pHi threshold existed for melanoma cells growing at pH 7.3 below which they became sensitized to 42 degrees C. This pHi threshold differed between the SK-Mel-28 and DB-1 cells. In contrast, a pHi threshold for heat sensitization did not exist for cells growing at pH 6.7: any reduction in pHi before heating resulted in increased cell killing. Since cells grown at low pH lack a pHi threshold for heat sensitization, they are sensitized more to 42 degrees C per unit decrease in pHi than cells grown at pH 7.3. Acute acidification abrogated the 42 degrees C-induction of Hsp70 and Hsp27 in the melanoma cells. The pHi thresholds for abrogation of these HSPs are slightly higher than or comparable with the thresholds for cytoxicity for each cell line grown at pH 7.3, but abrogation occurred over a narrower range of pHi compared with cytotoxicity. Abrogation of heat-induced expression of these HSPs correlates with cytotoxicity in both cell lines with the exception of Hsp27 expression in SK-Mel-28 cells. In conclusion, strategies that reduce pHi in melanoma cells growing at low pH, such as in acidotic regions of tumours, could selectively sensitize them to hyperthermia because they lack a pHi threshold for heat sensitization.     

hTERT启动子调控的SEA-CD80基因共表达重组腺病毒载体的构建及在不同肿瘤细胞中的表达鉴定

目的：构建肿瘤靶向性葡萄球菌肠毒素 A 和 CD80基因共表达重组腺病毒载体。方法：采用 PCR 技术从质粒 pShuttle - AFP - CD80扩增人 CD80全长 cDNA 片段,克隆至已构建载体 pMD18- T - BIS,取代小鼠CD80 cDNA 片段。重组质粒命名为 pMD18- T - hBIS。经酶切,将 CWV 增强子修饰的人端粒酶反转录酶启动子从已构建载体 pGL3- CWVE - hTP,亚克隆至穿梭质粒 pShuttle2,然后经酶切将片段 hCD80- IRES - SEA从 pMD18- T - hBIS 质粒亚克隆至 CWV 增强子修饰的人端粒酶反转录酶启动子下游,构建质粒 pShuttle2-CE - hTP - hBIS。再与腺病毒骨架质粒 pAdEasy -1共转化 E. coli BJ5183,以获得的重组子（命名为 Ad - CE- hTP - BIS）转染 Ad293细胞制备病毒并纯化。将病毒分别感染人肝癌细胞 H7721、宫颈癌细胞株 Hela 细胞和原代培养的人牙龈成纤维细胞,经免疫荧光染色后,激光共聚焦显微镜观察 SEA 和 CD80在细胞膜的表达情况。结果：重组腺病毒能够使 CD80和 SEA 在人肝癌细胞 H7721、宫颈癌细胞株 Hela 细胞膜上共表达,而在人牙龈成纤维细胞中不表达。结论：成功地构建了多肿瘤靶向性 SEA 和 CD80基因共表达重组腺病毒载体。为应用 SEA 和 CD80基因对人多种肿瘤进行靶向基因治疗奠定了基础。     

In vitro antitumour activity of resveratrol in human melanoma cells sensitive or resistant to temozolomide

Resveratrol, a polyphenol present in many plant species, exhibits a wide range of biological and pharmacological activities both in vitro and in vivo. It has been shown to exert a potent chemopreventive effect in carcinogenesis models and to induce cell growth inhibition and apoptosis in human tumour cells, including melanoma cells. Malignant melanoma is considered to be a chemotherapy-refractory tumour, and the commonly used anticancer drugs do not seem to modify the prognosis of metastatic disease. To further evaluate the therapeutic potential of resveratrol in the treatment of melanoma, we selected three human melanoma cell lines with different levels of resistance to temozolomide (TMZ), an antitumour triazene compound. The cell lines were subjected to resveratrol treatment and analysed for cell growth inhibition, cell cycle perturbation and apoptosis induction. We found that resveratrol markedly impaired proliferation of both the TMZ-sensitive M14 and the TMZ-resistant SK-Mel-28 and PR-Mel cell lines. The latter cell line was two-fold more resistant to the drug than M14 and SK-Mel-28 cells. The sensitivity of normal human keratinocytes to resveratrol was found to be significantly higher than that of M14 and SK-Mel-28 cells and similar to that of the PR-Mel cell line. This suggests a possible good in vivo therapeutic index for resveratrol. Our results also show that the growth-inhibitory effect of resveratrol on melanoma cells is mainly due to its ability to induce S-phase arrest and apoptosis. Taken together, our data indicate that resveratrol is an interesting candidate for the treatment of advanced melanoma.     

CRISPR/CAS9靶向肝癌细胞Oct3/4增强化疗药物作用效果的研究

目的 探讨CRISPR/CAS9靶向敲除Oct3/4基因后化疗药物索拉菲尼(Sorafenib)对肝癌细胞的作用影响.方法 通过实时荧光定量PCR和免疫印迹检测人肝癌细胞Li-7、HepG2、Huh7、BEL-7405和人肝正常细胞LX-2中Oct3/4的表达水平.通过CRISPR设计工具(http://crispr....     

肿瘤选择性增殖腺病毒CNHK300联合紫杉醇对HER-2高表达乳腺癌细胞的杀伤作用

目的：观察肿瘤选择性增殖腺病毒CNHK300对HER-2高表达乳腺癌细胞株的杀伤作用。方法：用TRAP—ELISA方法检测乳腺癌细胞株（MDA—MB-453、SK—BR-3）和正常成纤维细胞株MRC-5的端粒酶活性；进行病毒增殖实验和细胞生长抑制实验，并与野生型腺病毒wtAd5进行对比，验证CNHK300选择性复制和选择性杀伤能力；用细胞生长抑制实验进一步考察CNHK300与化疗药物紫杉醇联合应用对乳腺癌细胞的杀伤作用；用Westernblot检测腺病毒E1A在细胞中的表达。结果：乳腺癌细胞株端粒酶均为阳性，而MRC-5正常成纤维细胞株端粒酶为阴性。CNHK300在乳腺癌细胞中的病毒增殖能力与野生型腺病毒相似。两者也具有相似的肿瘤细胞杀伤能力。在MRC-5正常成纤维细胞中，CNHK300病毒增殖能力较wtAd5明显减弱，同时对正常成纤维细胞的杀伤力明显减弱。CNHK300病毒和紫杉醇联合应用，较同样剂量的两者单独应用，细胞存活率明显下降。CNHK300病毒EIA可以选择性地在端粒酶阳性的乳腺癌细胞中表达，在端粒酶阴性的正常成纤维细胞中不表达。结论：肿瘤选择性增殖腺病毒CNHK300可选择性地在某些端粒酶阳性的乳腺癌细胞中复制，并产生溶瘤作用。与化疗药物紫杉醇联合应用可产生协同作用。