人乳头状瘤病毒16型与促癌物TPA协同作用诱发人胚口腔细胞恶性转化研究

目的 研究人乳头状瘤病毒16型(HPVl6)与TPA(12-O-tetradecanog 1phorbo1-13-acetate)协同作用在scid小鼠体内诱发人胚口腔细胞的恶性转化。方法 制备包装含有HPV 16 E6／E7基因的逆转录病毒，用此病毒感染人胚口腔粘膜，将组织块接种于scid小鼠右侧肩部皮下，共分为4组：实验组为感染病毒的口腔粘膜和TPA，共接种8只小鼠；病毒组为感染病毒的口腔粘膜，共接种6只小鼠；促癌组为正常口腔粘膜和TPA，共接种6只小鼠；对照组为正常口腔粘膜，共接种5只小鼠。于接种第3日起在左侧肩部皮下注射TPA，每周一次。观察16周后处死动物，对瘤组织进行病理诊断，并作聚合酶链反应(PCR)检测HPV 16 E6／E7基因。结果 实验组成瘤率为7／8，其他3组成瘤率皆为0／6、0／6、0／5,，实验组肿瘤组织的病理学检查结果证实为生长活跃的纤维组织细胞瘤，在肿瘤组织中用PCR检测到HPV 16 E6／E7基因。结论 口腔细胞在感染含有HPV 16 E6／E7基因的逆转录病毒后，在TPA作用下可以发生恶性转化。     

特异siRNA抑制宫颈癌细胞中人乳头状瘤病毒16型E6表达的研究

目的 优化HPV-16 E6癌基因特异的U6质粒表达的siRNA，抑制HPV癌基因表达及其对子宫颈癌细胞生长繁殖的影响。方法 选择4个分别针对HPV-16 E6 mRNA外显子和内含子序列为靶序列，合成DNA链，构建表达HPV-16 E6短发卡样dsRNA的重组pSilencer1．0-U6载体，导入HPV-16DNA阳性的宫颈癌细胞株CaSki中，观察该细胞中HPV-16 E6、E7基因表达水平及其蛋白含量的变化，并观察细胞生长被抑制的情况。结果 4种HPV-16 E6 siRNA均能降低宫颈癌细胞CaSki的生长速率。通过细胞生长曲线观察到HPV-16 E6 shRNA表达质粒导入细胞0-96h内，可降低细胞生长速度。荧光定量RT-PCR检测HPV-16 E6 siRNA可使宫颈癌细胞株CaSki中HPV-16 E6、E7基因转录的mRNA水平降低，其中针对E6 mRNA内含子的重组shRNA只抑制E6基因的表达水平。Western blot分析表明，4个HPV-16 E6 siRNA作用72h后，未能检测到宫颈癌细胞中HPV-16 E6蛋白。结论 HPV-16 E6 siRNA能使宫颈癌细胞CaSki生长缓慢；选择针对E6内含子的siRNA作用位点，特异性抑制E6表达；而针对E6外显子的siRNA作用位点，可抑制E6和E7基因的表达，是用于治疗HPV阳性宫颈癌细胞的理想靶位。     

逆转录病毒载体介导HPV16 E6E7基因转化人胚食管纤维细胞的研究

目的 研究HPV16型病毒感染与食管癌发生的关系。方法 包装含有HPVl6E6E7基因重组逆转录病毒，以重组病毒感染人胚食管纤维细胞，在TPA协同下诱导SCID小鼠成瘤。结果 重组病毒感染人胚食管纤维细胞可以诱导SCID小鼠形成肉瘤，可以检测到E6E7基因的存在及表达，流式细胞仪检测从瘤组织培养出来的纤维细胞，确定为异倍体；但未能诱导人胚食管组织成瘤。结论 建立的重组逆转录病毒系统可以成功介导HPV16E6E7基因的转移，可以应用于HPV致瘤性研究。     

腺病毒伴随病毒表达载体表达人乳头瘤病毒18型E6E7基因构建及其转化作用的鉴定

目的：探讨人乳头瘤病毒（HPV）的E6E7基因在细胞恶性转化中所起的作用。方法：将人乳头瘤病毒（HPV）的E6E7基因克隆至腺病毒伴随病毒表达载体中，通过包装的重组病毒感染，将E6E7基因导入并整合到永生293细胞的基因组中。结果：本研究成功地构建了HPV18 E6E7 AAV病毒并感染了永生293细胞，PCR／Southern杂交分析表明E6E7基因在转化细胞293TL中确有表达，转化细胞293TC和293TL具有明显的转化表型，和亲本293细胞相比，生长速度快，接触抑制消失，集落形成率提高20倍，且集落明显增大，形成时间短。结论：成功地构建了HPV18 E6E7 AAV病毒，HPV18 E6E7基因引起永生化人上皮细胞293的恶性转化。此病毒可用于感染正常上皮细胞，研究其致癌机制。     

肺癌基因治疗研究进展

1　抑癌基因　　肿瘤的形成是“癌基因”与“抑癌基因”这对矛盾的平衡被打破的结果 ,如癌基因放大或过度表达 ,抑癌基因失活都会导致癌变发生。抑癌基因有很多如ＴＰ5 3、ＲＢ、Ｐ1 6、Ｂａｘ等 ,其中ＴＰ5 3是最重要的抑癌基因 ,ＴＰ5 3功能的失活 ,引起抑癌活性丧失 ,促进细胞恶性转化。目前认为ＴＰ5 3基因抑制肿瘤除它直接诱导细胞凋亡外 ,还能诱导肿瘤局部产生ＴＮＦα、ＩＬ-6等炎性细胞因子 ,增强瘤细胞对放、化疗的敏感性。晚近还认为它能抑制肿瘤内ＶＥＧＦ表达 ,抑制肿瘤血管生成。ＴＰ5 3基因在大多恶性肿瘤中表现为突变或缺失 …     

HPV对细胞周期调控影响的研究进展

人乳头瘤病毒 (HPV)通过其基因产物干扰正常的细胞周期调节 ,延长宿主细胞终末分化时间 ,使病毒易于自身复制。HPVE5 ,E6 ,E7蛋白不仅在细胞转化过程中起重要作用 ,而且是干扰细胞周期调控的重要蛋白。E5主要通过提高丝裂原激活蛋白激酶 (MAP)活性发挥转化作用 ,HPVE6和E7蛋白主要通过与关键细胞周期调节物 (p5 3,pRb)作用 ,使受累细胞绕过细胞周期负性调控因子的调控 ,导致细胞连续增殖及恶性转化。     

HPV与宫颈癌关系及疫苗研究进展

流行病学和病原学研究表明,人乳头瘤病毒（HV）感染是妇女发生宫颈癌重要的原因之一.HPV是无包膜的小型双链环状DNA病毒,不同基因型病毒对细胞的转化能力不同,其中HPV-16、18与子宫颈癌关系最密切.HPV诱发官颈癌的主要机制,是其E6和E7蛋白基因在宫颈细胞中的表达增加,产生的E6和E7蛋白两个癌蛋白分别与抑癌蛋白p53和pRb结合而诱导后两者降解.HPV疫苗包括预防性疫苗和治疗性疫苗两大类.本文对HPV感染与宫颈癌发生的关系、疫苗研究进展进行了系统的阐述.     

人乳头瘤病毒16型E6和E7基因特征分析

目的 对北京15例宫颈癌病变组织中的人乳头瘤病毒(HPV)16型E6和E7基因进行扩增及序列测定,分析E6和E7基因突变特征,并探讨宫颈癌病变中HPV16的感染情况.方法 自行设计HPVl6型E6和E7基因扩增引物,采用PCR法扩增15例宫颈癌组织中HPV16 E6和E7片段,将PCR产物克隆到TA载体,进行序列测定.通过Sequencer、Bioedit、Mega等生物学软件对E6和E7基因进行核苷酸和氨基酸序列分析.结果 15例宫颈癌中8例鳞癌检出E6和E7基因,检出率为8/15.2例腺癌、1例腺鳞癌和其他4例鳞癌中均未检出HPV16 E6E7 DNA.8例鳞癌中的4例检出的HPVl6为亚洲类似株,在E6基因178位(T→G,D25E)和E7基因647位(A→G,N29S)发生突变;另外4例为欧洲类似株,其中1例(BJ16)的HPV16在E6基因335位点发生突变(C→T,H78Y).结论 HPV16是致宫颈癌的重要因素;宫颈鳞状细胞癌HPV16感染的发生频率较腺癌和腺鳞癌高;E6基因178位点可能是区分亚洲株和欧洲株的重要位点;E6基因178位点和E7基因647位点是突变频率较高的位点,可能导致HPV16致癌能力发生改变.     

HPV与宫颈癌关系及疫苗研究进展

流行病学和病原学研究表明,人乳头瘤病毒(HV)感染是妇女发生宫颈癌重要的原因之一.HPV是无包膜的小型双链环状DNA病毒,不同基因型病毒对细胞的转化能力不同,其中HPV-16、18与子宫颈癌关系最密切.HPV诱发官颈癌的主要机制,是其E6和E7蛋白基因在宫颈细胞中的表达增加,产生的E6和E7蛋白两个癌蛋白分别与抑癌蛋白p53和pRb结合而诱导后两者降解.HPV疫苗包括预防性疫苗和治疗性疫苗两大类.本文对HPV感染与宫颈癌发生的关系、疫苗研究进展进行了系统的阐述.     

共表达HPV16型E6和E7突变基因重组痘苗病毒的构建及其抗肿瘤免疫效果的观察

目的：构建用于子宫颈癌治疗的HPV16型E6和E7重组痘苗病毒实验性疫苗株，并对其抗肿瘤免疫效果进行初步评价。方法：以痘苗病毒为载体、利用同源重组技术构建共表达HPV16 E6和E7基因的重组痘苗病毒。该病毒免疫C57BL／6小鼠后，检测其免疫原性和抗移植瘤生长情况。结果：PCR结果显示，重组病毒VmE6E7的TK基因内插入了分别由痘苗病毒早晚期启动子H6和7．5K表达的ME6和ME7－1基因。动物实验结果表明，rVmE6E7在C57BL／6小鼠体内可诱发E6和E7特异性抗体产生，被免疫小鼠能够抵抗HPV16 E6E7转化的同系肿瘤细胞的攻击。结论：获得1株用于宫颈癌治疗的HPV16型实验疫苗株，为进一步研制人用HPV16型疫苗株奠定了基础。     

Enhanced human papillomavirus type 8 oncogene expression levels are crucial for skin tumorigenesis in transgenic mice

Human papillomavirus 8 (HPV8) is involved in skin cancer development in epidermodysplasia verruciformis patients. Transgenic mice expressing HPV8 early genes (HPV8-CER) developed papillomas, dysplasias and squamous cell carcinomas. UVA/B-irradiation and mechanical wounding of HPV8-CER mouse skin led to prompt papilloma induction in about 3 weeks. The aim of this study was to analyze the kinetics and level of transgene expression in response to skin irritations. Transgene expression was already enhanced 1 to 2 days after UVA/B-irradiation or tape-stripping and maintained during papilloma development. The enhanced transgene expression could be assigned to UVB and not to UVA. Papilloma development was thus always paralleled by an increased transgene expression irrespective of the type of skin irritation. A knock-down of E6 mRNA by tattooing HPV8-E6-specific siRNA led to a delay and a lower incidence of papilloma development. This indicates that the early increase of viral oncogene expression is crucial for induction of papillomatosis.     

Dual expression of Epstein-Barr virus,latent membrane protein-1 and human papillomavirus-16 E6 transform primary mouse embryonic fibroblasts through NF-κB signaling

The prevalence of Epstein-Barr virus (EBV) and high-risk human papilloma virus (HPV) infections in patients with oral cancer in Okinawa, southwest islands of Japan, has led to the hypothesis that carcinogenesis is related to EBV and HPV co-infection. To explore the mechanisms of transformation induced by EBV and HPV co-infection, we analyzed the transformation of primary mouse embryonic fibroblasts (MEFs) expressing EBV and HPV-16 genes, alone or in combination. Expression of EBV latent membrane protein-1 (LMP-1) alone or in combination with HPV-16 E6 increased cell proliferation and decreased apoptosis, whereas single expression of EBV nuclear antigen-1 (EBNA-1), or HPV-16 E6 did not. Co-expression of LMP-1 and E6 induced anchorage-independent growth and tumor formation in nude mice, whereas expression of LMP-1 alone did not. Although the singular expression of these viral genes showed increased DNA damage and DNA damage response (DDR), co-expression of LMP-1 and E6 did not induce DDR, which is frequently seen in cancer cells. Furthermore, co-expression of LMP-1 with E6 increased NF-κB signaling, and the knockdown of LMP-1 or E6 in co-expressing cells decreased cell proliferation, anchorage independent growth, and NF-κB activation. These data suggested that expression of individual viral genes is insufficient for inducing transformation and that co-expression of LMP-1 and E6, which is associated with suppression of DDR and increased NF-κB activity, lead to transformation. Our findings demonstrate the synergistic effect by the interaction of oncogenes from different viruses on the transformation of primary MEFs.     

Effects of 12-o-tetradecanoyl-phorbol-13-acetate (TPA) on the colony growth of human T lymphocytes

The T colony promoting activity of 12-o-tetradecanoyl-phorbol-13-acetate (TPA) was assessed in a double layer culture assay which is dependent on the simultaneous presence of phytohaemagglutinin (PHA) and a leucocyte rich underlayer. TPA (10(-8) M) incorporated in the overlayer in place of PHA was capable of promoting T cell growth in the form of clusters in all 37 experiments performed and in the form of colonies in more than 50% of the samples tested. However, the T colony promoting activity of TPA alone was markedly less evident and consistent than that of PHA (mean 13 +/- 19.9 s.d. colonies vs 168 +/- 78.6). TPA concentrations of 10(-6) M, 10(-9) M and 10(-10) M were practically ineffective. On the other hand, the number of colonies obtained when both TPA 10(8) M and PHA were incorporated in the overlayer was significantly higher (P less than 0.01) than that observed with PHA alone (mean 250 +/- 108.2 vs 178 +/- 84.5 colonies). When TPA concentrations of 10(-9) M and 10(-10) M were used in addition to PHA, the enhancing effect was less evident, while an inhibition of T colony growth was observed with TPA 10(-6) M + PHA. TPA 10(-8) M was also capable of enhancing T colony growth when incorporated in the leucocyte rich underlayer (222 +/- 98.6 vs 172 +/- 80.9 colonies). In all cultures with TPA the peak of growth was delayed compared with that of control experiments with PHA. These findings demonstrate that TPA, particularly when co-cultured with PHA, is an effective T colony promoting agent. The observation that the number of colonies formed in the presence of TPA plus PHA is higher than the sum of those observed with the two stimulators independently, suggests that their synergistic effect may be mediated via the production of colony stimulating soluble factors.     

亚硝基吡啶对人乳头状瘤病毒诱导的食管上皮永生化细胞的促癌作用

目的 观察亚硝基吡啶在细胞恶性转化过程中的促癌作用.方法 用HPV18E6E7诱导食管上皮细胞永生化细胞系SHEE,第17代细胞培养在50 ml培养瓶.加入亚硝基吡啶（Nnitrosopiperidine,NPIP）0,2,4,8 mmol/L作用3周.用相差显微镜检查细胞形态,流式细胞仪检测细胞增殖和凋亡;染色体常规制样,检查染色体众数;细胞软琼脂集落形成及接种裸小鼠检查成瘤性;用Western blot检测HPV18表达.结果 当细胞暴露在8 mmol/L NPIP时细胞死亡增加,只剩少量活细胞.换正常培基代替NPIP,经4周后细胞进入增殖状态,细胞出现增生和异型增生.第8周末细胞软琼脂培养有大集落形成,接种裸小鼠成瘤.2,4 mmol/L组细胞倍增时间延长,细胞未能成瘤.8 mmol/L NPIP组染色体众数61～65,对照组56～61.实验组和对照组HPV阳性.结论 NPIP促进人乳头状瘤病毒诱导人胚食管永生化上皮恶性转化,HPV18E6E7和NPIP能协同作用加速食管上皮恶性转化.     

Proteomic analysis reveals the actin cytoskeleton as cellular target for the human papillomavirus type 8

Recent studies strongly support a role of human papillomavirus type 8 (HPV8) in non-melanoma skin cancer development. In this study, a quantitative two-dimensional (2D) differential gene expression (DiGE) gel approach combined with mass spectrometry has been used to identify proteins that are abundantly deregulated in primary human epidermal keratinocytes expressing HPV8 sequences. Twenty six protein spots showed significant changes in the level of expression between keratinocytes expressing E7 or the complete early region (CER) of HPV8 compared to extracts from cells lacking HPV8 gene expression. No differences between HPV8 E7 alone and HPV8 CER expressing cells were observed. The 26 protein spots that were differentially expressed corresponded to 20 different proteins, of which 14 actin-associated proteins were downregulated except for calponin-2, which was the only actin-binding protein that was overexpressed. Besides changes in actin modulating proteins, an upregulation of cytokeratins (CK) 5, 6 and 14 was also noted. This study suggests that the actin and keratin cytoskeleton modulating proteins are targets for HPV8.     

Human papillomavirus 8 E6 disrupts terminal skin differentiation and prevents pro-Caspase-14 cleavage

Expression of the betapapillomavirus (betaPV) E6/E7 genes has been shown to impair both keratinocyte differentiation and apoptosis. Especially late-terminal keratinocyte differentiation shares certain aspects with apoptosis, such as fragmentation of DNA and activation of caspases. Here we investigated the disruption of keratinocyte differentiation in organotypic skin (raft) cultures of primary (PHK) and immortalized (N/TERT) human keratinocytes, in particular by human papillomavirus (HPV)8.Immunohistochemical analysis of HPV5 and HPV8 E6/E7-expressing PHK revealed thickening of the rafts and complete absence of stratum corneum formation, even after 18 days of culture. This phenotype was confirmed in N/TERT raft cultures. When expressed separately, the aberrant morphology was observed only in rafts expressing E6, not E7. Immunofluorescence analysis of HPV8 E6 PHK rafts showed an increase in number and size of Filaggrin- and Caspase-14-positive cells in the granular layer. In raft lysates analyzed by western-blot, the presence of pro-Caspase-14 in the differentiated keratinocytes was confirmed, but in the HPV8 E6 rafts none of the Caspase-14 subunits were detected.In conclusion, in the raft system, HPV8 E6 prevented late-terminal keratinocyte differentiation resulting in an accumulation of Filaggrin and pro-Caspase-14-positive cells in the absence of stratification. This differentiation arrest was accompanied by the failure to express Caspase-14 subunits, suggesting absence of Caspase-14 activation and probable abrogation of Filaggrin maturation in HPV8 E6-expressing keratinocytes.     

Analysis of CD3 and antigen receptor expression on T cell subpopulations of aged athymic mice

The expression of the T cell antigen receptor on subpopulations of extrathymically generated T cells from athymic mice was investigated and compared to antigen receptor expression in normal mice. To this end, spleen and lymph node cells from 18 individual athymic BALB/c nu/nu mice between 6 and 12 months of age and from normal controls were enriched for T cells by nylon wool filtration. Expression of the following cell surface markers was analyzed by two-color flow cytometry: Thy-1, CD4, CD8, V beta 8 and CD3. The distribution of subpopulations as defined by these markers varied much more among athymic than among normal mice. Some recurrent patterns did, however, occur that may be characteristic of the extrathymic pathway of T cell differentiation in nu/nu mice. Among Thy-1.2+ cells, CD8+ cells predominated over CD4+ cells. No CD4+8+ "double positive" cells were found, but CD4-8- "double negative" cell constituted 16% on average. All nu/nu nylon wool-nonadherent cells expressing Thy-1 at a normal level also expressed CD3, whereas Thy-1low and Thy-1- cells were CD3-. The fraction of V beta 8 T cells among the CD4+ and CD8+ subsets was near to normal in the majority of these animals. Most interestingly, the density of V beta 8 and CD3 expression was lower in athymic than in euthymic animals. This level of T cell antigen receptor expression was, however, higher than on immature CD4+8+ thymocytes. A fraction of the nude T cells presently characterized responded with proliferation to both anti-T cell receptor V beta 8 monoclonal antibody and to concanavalin A. Despite their apparently normal phenotype (with the exception of reduced T cell receptor expression), this response was, however, 4 to 10 times smaller than that of normal control cells. The presently described Thy-1+ T cell receptor intermediate cells may either be a(n) aberrant lineage(s) only generated extrathymically, or represent the accumulation of an immature intermediate stage of normal (i.e. thymic) T cell differentiation.     

佛波酯处理人胃癌MGC80-3细胞过程中磷酯酶C-γ2的意义

目的 探讨佛波酯(TPA)处理人胃癌MGC80-3细胞过程中磷酯酶C-γ2(PLC-γ2)的意义.方法 通过DAPI染色,荧光显微镜观察分析TPA对胃癌MGC80-3细胞的影响;借助核浆分离手段获得胃癌细胞核浆蛋白,并通过免疫印迹(Western blotting)检测TPA对PLC-γ2蛋白表达水平影响;通过免疫荧光技术处理,激光扫描共焦显微镜观察胃癌细胞内PLC-γ2蛋白的定位和转运;用PLC-γ2的抑制剂(U73122)预处理细胞,免疫印迹和激光扫描共焦显微镜分别检测其对TPA作用胃癌细胞内PLC-γ2的影响;以及荧光显微镜下观察分析U73122是否影响TPA对胃癌细胞的作用.结果 TPA诱导胃癌MGC80-3细胞凋亡;同时TPA提高PLC-γ2蛋白表达水平,并诱导其发生核浆转运;其抑制剂(U73122)可以降低TPA对PLC-γ2蛋白表达水平的作用,但并不能影响TPA诱导胃癌细胞凋亡;而TPA诱导的PLC-γ2核浆转运却没有被PLC-γ2抑制剂(U73122)阻止.结论 尽管TPA提高了胃癌MGC80-3细胞中PLC-γ2表达水平,但PLC-γ2表达水平和TPA诱导的胃癌MGC80-3凋亡没有直接关系,而其核浆转运可能与TPA诱导的胃癌细胞凋亡相关.