人乳头状瘤病毒诱导人胚食管上皮永生化细胞恶性转化

为了证实ＨＰＶ１８Ｅ６Ｅ７基因诱导的人胚食管上皮永生化细胞（ＳＨＥＥ）６１代（ＳＨＥＥ６１）部份细胞（ＳＨＥＥ６１Ａ）已经恶性转化,以寻找监控细胞早期恶性转化的方法。对培养的ＳＨＥＥ第１０代（ＳＨＥＥ１０）和６１代（ＳＨＥＥ６１）细胞,用光学是为微镜和电子显微镜观察细胞形态及生长形式;用流工细胞仪分析细胞周期;用染色体Ｇ带核型分析和间期核染色体１、７、８号着丝粒探针荧光原位杂交９ＦＩＳＨ）检测细胞     

人乳头状瘤病毒协同60钴照射促进食管上皮细胞恶性转化

为探明人乳头状瘤病毒(HPV)和促癌剂对食管上皮致癌作用,人胚食管上皮细胞转染HPV协同60钴(60Co)放射观察其恶性转化.用HPV18E6E7AAV转染的人胚食管上皮(SHEE),培养至13代,分为4组,实验组分别用60Co2、4、8Gy照射,每周1次共4周;SHEE未经照射为对照组.细胞形态用相差显微镜观察;细胞DNA合成和定量用3H-TdR掺入和用流式细胞仪分析;染色体众数用常规方法分析;致瘤性用软琼脂培养和裸小鼠接种;HPVDNA用PCR检测.经60Co照射后细胞呈凋亡和坏死(危象期).8周后SHEE 4Gy组细胞增殖,增殖指数(34%)和3H-TdR摄入增高,软琼脂培养和裸鼠接种出现致瘤性.对照组SHEE组细胞增殖指数24%,伴有少数3H-TdR掺入,裸鼠未成瘤.染色体众数:对照组,58～62;4Gy组,63～65;两组HPV18E6E7 PCR呈阳性条带.此结果表明,用HPV18E6E7协同60Coγ射线可以使人胚食管上皮恶性转化,60Co γ射线有加速食管上皮细胞恶性转化作用.     

人乳头瘤病毒16型长控制区上YY1结合位点的破坏可增强病毒诱导细胞永生化能力

细胞转录调节因子 Ｙ Ｙ１ 可抑制人乳头瘤病毒１６ 型（ Ｈ Ｐ Ｖ １６） 癌基因启动子 Ｐ９７ 的活性, Ｙ Ｙ１ 位点的突变和缺失不仅可诱导 Ｐ９７ 活性增强而且可在全基因组内增强 Ｅ６ 癌基因转录,同时使病毒对啮齿类动物纤维细胞的转化能力增强。为了观测人乳头瘤病毒１６ 型长控制区（ Ｈ Ｐ Ｖ１６ Ｌ Ｃ Ｒ） 序列上 Ｙ Ｙ１ 蛋白特异性结合位点破坏在完整基因组范围内对人原代包皮角源细胞永生化能力的影响,将 Ｈ Ｐ Ｖ １６ Ｙ Ｙ１ 位点突变株和野毒株转染至人原代包皮角源细胞。筛选结果表明,突变株可诱导形成永生化细胞,永生化能力明显高于野毒株。对４ 株永生化细胞系 Ｄ Ｎ Ａ检测发现,均含有呈整合状态的 Ｈ Ｐ Ｖ １６ Ｄ Ｎ Ａ,其中３ 株的 Ｅ１／ Ｅ２ 区域有缺失。 Ｒ Ｎ Ａ 检测显示,４株细胞内均有 Ｅ６／ Ｅ７ ｍ Ｒ Ｎ Ａ 的转录。这表明, Ｈ Ｐ Ｖ １６ Ｌ Ｃ Ｒ 上 Ｙ Ｙ１ 蛋白特异性结合位点的破坏,可在完整基因组范围内增强病毒使人原代包皮角源细胞永生化的能力。     

宫颈上皮内瘤变治疗前后人乳头状瘤病毒载量的临床研究

目的:探讨宫颈上皮内瘤变(CIN)治疗前后人乳头状瘤病毒(HPV)载量与预后的意义.方法:从2006年6月～2009年9月间在新疆维吾尔自治区人民医院妇科门诊和妇科病房就诊的190例CIN患者,经宫颈环形电切术(LEEP)或宫颈冷刀锥切术治疗后进行1年随访,检测治疗前后HPV的载量,对病灶持续存在和复发进行分析.结果:CIN患者经LEEP或宫颈冷刀锥切术治疗后HPV平均载量较治疗前均显著降低(P＜0.01).随着HPV病毒载量持续时间越长,病变的持续存在率、复发率越高.结论:LEEP或宫颈冷刀锥切能显著降低CIN患者HPV载量,病毒载量影响疾病预后,其研究对随访和预后都有指导意义.     

人乳头瘤病毒与细胞凋亡

近来研究表明病毒感染与细胞凋亡有着密切的关系。在研究中发现,许多病毒参与细胞凋亡的诱导和抑制,在这些过程中相关病毒的基因的表达起着关键作用,而细胞凋亡相关因子直接或间接参与这一过程,对于这些问题有助于阐明病毒感染后病毒和细胞相互作用的分子机理。本文对人乳头瘤病毒的E6、E7、E2、和E5等基因及表达蛋白与细胞凋亡相关因子p53、pRB等相互作用,以阐述HPV的致癌机理。     

人乳头瘤病毒16型长控制区上YY1结合位点的破坏可增强病毒诱导细胞？…

细胞转当因子ＹＹ１可抑制人乳头瘤病毒１６型癌基因启动子Ｐ９７的活性,ＹＹ１位点的突变和缺失不仅可诱导Ｐ９７活性增强而且可在全基因组内增强Ｅ６癌基因转录,同时使病毒对啮齿类动物纤维细胞的转化能力增强。为了观测人乳头瘤病毒１６型长控制区序列上ＹＹ１蛋白特异性结合位点破坏在完整基因组范围内对人原代包皮角源细胞永生化能力的影响,将ＨＰＶ１６ ＹＹ１位点突变体和野毒株转染至人原代包皮角源细胞。     

PCR技术检测人乳头状瘤病毒DNA

本文用一对适合人乳头状瘤病毒DNA的通用PCR引物对临床阳性和正常组织进行了PCR扩增检测分析,阳性组织均得到一条特异性的DNA扩增片段,正常组织均没有任何扩增片段。阳性组织DNA扩增片段经克隆后进行DNA序列分析,证明该扩增片段确为目标DNA扩增片段。     

食管鳞癌人乳头状瘤病毒感染的原位杂交检测和观察

目的 :检测食管鳞癌中人乳头状瘤病毒 (HPV)的感染情况 ,探讨 HPV与食管癌发病的关系。方法 :用原位杂交技术及免疫组化方法对 33例食管鳞癌手术切除标本进行 HPV检测。结果 :用原位杂交方法检测食管鳞癌中 HPV DNA检出率为 4 5 .5 % (15 / 33)。HPV DNA阳性与食管鳞癌肿瘤细胞的分化程度无关 (P>0 .0 5 )。HPV衣壳蛋白的免疫组化检测均为阴性。结论 :HPV感染可能是引起食管上皮癌变的原因之一 ,与食管鳞癌的发生有关。即使在存在 HPV DNA的病例中 ,HPV衣壳蛋白亦可以不表达     

人B细胞永生化研究进展

人源单克隆抗体具有免疫原性低、半衰期长等优势,成为了体内应用中不可或缺的生物制剂.人类抗体库为人源单克隆抗体的制备提供了丰富的来源,人B细胞永生化是获得人类抗体库的潜在有效方法,可应用于人源单克隆抗体的制备.由于各平台均有亟待解决的问题,基于人B细胞永生化的抗体制备尚局限在实验室研究阶段,且目前尚缺乏一篇系统综述以明确...     

Generation of a human melanocyte cell line by introduction of HPV16 E6 and E7 genes

Summary Availability of a standard human melanocyte cell line with unlimited growth potential and otherwise normal melanocytic properties will greatly facilitate research in melanocyte biology and in vitro studies on the etiology of pigmentary disorders and melanoma. Using a retroviral vector, E6 and E7 open reading frames of human papilloma virus type 16 (HPV 16) have been introduced into cultured normal human melanocytes. Cells selected by increased resistance to geneticin conveyed by the vector and expressing E6E7 mRNA have been cloned to ensure genetic homogeneity. Since their establishment as primary cells, cloned PIG1 cells have undergone more than twice the amount of population doublings of senescent parental cells. Moreover, in passage numbers when parental cells had become senescent, proliferation of clonal cells was retained at levels exceeding those of normal human melanocytes in third passage by 100%. Further characterization has revealed that the cells remain dependent on tetradecanoyl phorbol 13-acetate (TPA) for growth and do not proliferate in soft agar nor form tumors in nude mice. The antigenic profile of the cells was slightly altered as compared to parental cells, but was incomparable to that of M14 melanoma cells. Importantly, PIG1 cells contain more melanin pigment than parental cells.     

Normal Human Fibroblasts Immortalized by Introduction of Human Papillomavirus Type 16 (HPV-16) E6-E7 Genes

This report demonstrates that normal human fibroblasts can be immortalized by the introduction of HPV-16 E6-E7 genes. We designed zinc-inducible expression plasmids with HPV-16 E6, E7 or both. Each plasmid was introduced into normal human fibroblasts (TIG-3 cells) using lipofection methods. Only trans-fectants with the HPV-16 E6-E7 zinc-inducible expression plasmid, which were cultured in medium supplemented with 100 μM ZnSO₄, overcame crisis and could be cultured over 200 population doubling levels (PDLs). These cell lines showed the reactivation of telomerase after crisis, and morphological alterations were also observed.     

腺伴随病毒载体介导HPV16 E6E7基因转化人胎食管上皮细胞

为了证实人乳头瘤病毒16型（HPV16）感染与食管鳞状细胞癌发生的关系,构建了包含HPV16E6E7基因的重组腺伴随病毒载体并包装重组病毒,重组病毒感染人胎食管粘膜组织,注射SCID小鼠皮下,在TPA协同下12周左右诱发肿瘤。PCR及打点杂交检测到瘤组织中HPV16E6E7基因的存在,HE染色表明为恶性鳞状上皮癌,培养形态及透射电镜观察证实了瘤组织的上皮来源。以上结果对于阐明食管癌发生的病毒病因、食管癌发生的分子机制以及为食管癌防治提供了理论和实践依据。     

Down-regulation of p21 contributes to apoptosis induced by HPV E6 in human mammary epithelial cells

Infection with human papillomaviruses (HPV) is strongly associated with the development of cervical cancer. The HPV E6 gene is essential for the oncogenic potential of HPV. E6 induces cell proliferation and apoptosis in cervical cancer precursor lesions and in cultured cells. Although induction of telomerase and inactivation of the tumor suppressor p53 play important roles for E6 to promote cell growth, the molecular basis of E6-induced apoptosis is poorly understood. While it is expected that inactivation of p53 by E6 should lead to a reduction in cellular apoptosis, numerous studies demonstrated that E6 could in fact sensitize cells to apoptosis. Understanding the mechanism of p53-independent apoptosis is of clinical significance. In the present study, we investigated the mechanism of apoptosis during E6-mediated immortalization of primary human mammary epithelial cell (HMEC). E6 by itself is sufficient to immortalize HMECs and is believed to do so at least in part by activation of telomerase. During the process of E6-mediated HMEC immortalization, an increased apoptosis was observed. Mutational analysis demonstrated that E6-induced apoptosis was distinct from its ability to promote cell proliferation, activate telomerase, or degrade p53. While the known pro-apoptotic E6 target proteins such as Bak or c-Myc did not appear to play an important role, down-regulation of the cyclin-dependent kinase inhibitor p21^Waf1/Cip1 (p21) by E6 correlated with its ability to induce apoptosis. Ectopic expression of p21 inhibited E6-induced apoptosis. Moreover, a p53 degradation defective E6 mutant was competent for p21 down-regulation and apoptosis induction. The anti-apoptotic function of p21 may not simply be the result of p21-induced growth arrest. These studies demonstrate an E6 activity to down-regulate p21 that is important for induction of apoptosis.     

Epithelium and fibroblast-like phenotypes derived from HPV16 E6/E7-immortalized human gingival keratinocytes following chronic ethanol treatment

Epithelial-mesenchymal transition (EMT) may be critical for neoplastic progression and its eventual tumorigenicity of epithelia. In this context, we investigated whether EMT and EMT-associated features occurred after chronic ethanol treatment of human gingival keratinocytes immortalized with the E6/E7 oncogenes of human papillomavirus (HPV) type 16. Following a nine-week treatment of cells with 30 mM ethanol in keratinocyte growth medium, they were cultured in normal DMEM with 10% serum. These cell populations were able to proliferate in this medium gradually exhibiting elongated morphology indicating that these cells underwent EMT. Control cells without ethanol treatment did not survive subcultures in DMEM. Upon long-term subcultures of ethanol-treated cells, two phenotypes were obtained exhibiting epithelium-like and spindle-shape fibroblast-like morphology (respectively, termed as EPI and FIB cells), the latter indicating EMT. In comparison to EPI cells, the phenotypic transition to FIB cells was concomitant with a decrease in the expression of keratins, desmoplakins and a complete loss of K14. Moreover, FIB cell transition strongly correlates with an increase in the expression of vimentin and simple epithelial keratin K18. These alterations in FIB cells were associated with the ability of these cells to exhibit anchorage-independent growth, while EPI cells exhibited anchorage-dependent growth. Concerning the transformation stage, FIB cells represent a progressively more advanced transformed phenotype which may reflect an early step during HPV- and ethanol-dependent multi-step carcinogenesis.     

人胚鼻咽上皮发育分化与c—erbB—2的表达变化

应用免疫组织化学方法对人胚鼻咽的ｃ－ｅｒｂＢ－２表达情况进行了研究．结果表明,人胚鼻咽上皮的ｃ－ｅｒｂＢ－２表达没有发育阶段性与鼻咽部位置的差异,而与鼻咽上皮的种类密切相关．在假复层纤毛柱状上皮中,以纤毛层的ｃ－ｅｒｂＢ－２表达阳性信号最强;在典型的过渡型上皮中,ｃ－ｅｒｂＢ－２阳性反应细胞主要分布于上皮的下五分之四左右的区域,表层细胞无阳性信号出现;而在复层鳞状上皮中,ｃ－ｅｒｂＢ－２阳性细胞的位置进一步下移,主要分布于上皮的下三分之二左右的区域．这些结果提示,ｃ－ｅｒｂＢ－２在人胚鼻咽上皮中的表达随细胞分化程度的增加而降低直至完全没有表达．     

HPV18 Utilizes Two Alternative Branch Sites for E6~*I Splicing to Produce E7 Protein

Human papillomavirus 18(HPV18) E6 and E7 oncogenes are transcribed as a single bicistronic E6 E7 pre-mRNA. The E6 ORF region in the bicistronic E6 E7 pre-mRNA contains an intron. Splicing of this intron disrupts the E6 ORF integrity and produces a spliced E6~*I RNA for efficient E7 translation. Here we report that the E6 intron has two overlapped branch point sequences(BPS) upstream of its 30 splice site, with an identical heptamer AACUA■C, for E6~*I splicing. One heptamer has a branch site adenosine(underlined) at nt 384 and the other at nt 388. E6~*I splicing efficiency correlates to the expression level of E6 and E7 proteins and depends on the selection of which branch site. In general, E6~*I splicing prefers the 30 ss-proximal branch site at nt 388 over the distal branch site at nt 384. Inactivation of the nt 388 branch site was found to activate a cryptic acceptor site at nt 636 for aberrant RNA splicing. Together, these data suggest that HPV18 modulates its production ratio of E6 and E7 proteins by alternative selection of the two mapped branch sites for the E6~*I splicing, which could be beneficial in its productive or oncogenic infection according to the host cell environment.