腺病毒伴随病毒表达载体表达人乳头状瘤病毒16型E6/E7基因的构建及应用

目的　为了了解人乳头状瘤病毒 (Humanpapillomavirus ,HPV) 1 6型的E6 /E7基因在细胞恶性转化中所起的作用 ,利用腺病毒伴随病毒载体 (AAVHelper -FreeSystem)构建和表达人乳头状瘤病毒 1 6型E6 /E7基因。方法　在pLXSN1 6E6E7质粒中经PCR扩增回收HPV 1 6E6E7基因片段 ,连接于T载体上进行测序 ,将正确的HPV 1 6E6E7插入pAAV -IRES -hrGFP质粒 ,协同pAAV -RC质粒和pHelper质粒共转染HEK 2 93细胞 ,包装表达HPV 1 6E6E7基因的重组腺病毒伴随病毒 ,收获病毒 ,并检测病毒的感染效率。结果　在包装细胞系HEK 2 93细胞中能形成较高感染效率的腺病毒伴随病毒 ,激光共聚焦检测可发现HEK 2 93细胞内有绿色荧光蛋白表达 ,HEK 2 93细胞经PCR可扩增出特异性的HPV 1 6E6E7基因片段 ,经流式细胞仪检测重组病毒的感染效率为71 3%。结论　携带人乳头状瘤病毒 1 6型E6E7基因的腺病毒伴随病毒可感染细胞 ,并在细胞内表达 ,可望用于宫颈癌病因学的研究     

Immunotherapy of human cervical high-grade cervical intraepithelial neoplasia with microparticle-delivered human papillomavirus 16 E7 plasmid DNA

OBJECTIVE: The purpose of this study was to evaluate the safety of the administration of a bacterial expression plasmid encoding a 13 amino acid sequence that is highly homologous with human papillomavirus E7 within poly (lactide-co-glycolide) microparticles (ZYC101) in women with HLA A2+ antigen and persistent cervical intraepithelial neoplasia grade 2/3 and human papillomavirus 16. STUDY DESIGN: Fifteen women entered an institutional review board-approved dose-escalating phase I study with the use of three levels of blood monitoring and urine studies, Papanicolaou tests, and colposcopy. Escalation required no serious adverse events. Immunologic responses were evaluated in peripheral blood with the use of human papillomavirus peptide-stimulated interferon gamma enzyme-linked immunosorbent assay for T-cell reactivity. In cervical secretions, immunoglobulin A anti-human papillomavirus 16 E2 concentrations were measured. Three doses every 3 weeks were followed 4 weeks later by surgical excision. RESULTS: No serious adverse events occurred. Five women had complete histologic responses; 11 women had human papillomavirus-specific T-cell responses. Four of five complete histologic responses developed immunoglobulin A anti-E2-specific antibody. CONCLUSION: ZYC101 warrants further investigation because of a 33% complete histologic responses, a 73% immunologic response, and no serious adverse events.     

A DNA vaccine constructed with human papillomavirus type 16 (HPV16) E7 and E6 genes induced specific immune responses

OBJECTIVE: Cervical cancer is found highly associated with human papillomaviruses type 16 (HPV16). HPV16 E6 and E7 oncogenes are important transforming genes which have become the main focus of anti-cervical cancer therapy. In this study, a recombinant DNA vaccine candidate, termed HPV16-DNA-E6E7, constructed with HPV16 E7 and E6 genes was generated and used to against HPV16-induced tumors. METHODS: We inserted an E7 DNA fragment into E6 gene to produce a recombinant gene (E6E7-DNA). The E6E7-DNA gene was inserted into a mammalian expression vector, pcDNA 3.1+, to construct the DNA vaccine candidate. Animals (C57BL/6 mice) were immunized with the vaccine candidate with various concentrations (50 microg, 100 microg or 200 microg, respectively), and cytotoxicity measurement and tumor protection assay were carried out to examine the immunological effects of the vaccine candidate. RESULTS: Immunization of with HPV16-E6E7-DNA induced HPV16-specific immune response and also conveyed protection against TC-1 induced tumor in vivo. A survival rate (90%) after 45 days of tumor challenge was observed. The animals injected with a higher dosage of the vaccine (200 microg) exhibited prolonged survival duration of more than 55 days. No transforming activity of the vaccine candidate was detected, as determined by focus formation and degradation of endogenous p53. CONCLUSION: Our results demonstrated that the HPV16-E6E7-DNA compound might become a candidate for HPV16 precautionary and immunotherapy.     

反义HPV16 E6/E7-EGFP重组质粒的构建及其对宫颈癌SiHa细胞的促凋亡作用

目的:构建HPV16早期基因E6/E7的反义重组质粒,探讨其对SiHa细胞的促凋亡作用。方法:将HPV16E6/E7基因片段反向克隆于真核表达载体pEGFP-C1并转染SiHa细胞,用RT-PCR方法检测转染后SiHa细胞E6、E7基因mRNA的表达,West-ernblot方法检测转染后E6/E7蛋白的表达,流式细胞仪检测转染后细胞的凋亡率。结果:成功构建携带HPV16E6/E7基因反义片段的真核表达载体,转染该质粒后,SiHa细胞E6、E7基因的mRNA和蛋白均明显下调;转染后细胞凋亡率为(59.3±11.3)%,明显高于转染空载体组[(9.4±1.8)%]和未转染组[(2.1±0.4)%](P<0.05)。结论:反义HPV16E6/E7基因可下调宫颈癌细胞中E6/E7癌基因的表达,诱导宫颈癌细胞凋亡,为宫颈癌的基因治疗提供了实验依据。     

人乳头状瘤病毒16型多肽疫苗的制备及体内外效应观察

目的 探讨人乳头状瘤病毒(HPV)16型多肽疫苗的制备,并观察HPV16多肽疫苗的体内外效应.方法 (1)针对抗原加工相关转运子(TAP)设计HPV16 E7蛋白的主要组织相容性复合物Ⅰ类分子(MHC-I)的抗原结合表位,利用生物信息学分析平台筛选出一致性较高、特异性及亲和力较强的HPV16 E7多肽作为研究对象制备HPV16多肽疫苗用于以下研究,本研究共筛选出3段多肽,分别命名为E7Pa、E7Pb、E7Pc.(2)C57BL/6小鼠注射鼠肺上皮细胞株TC-1细胞(为鼠源性的HPV16阳性的肿瘤细胞株)后,采用等额抽取的随机方法分为5组,ETPa+二核苷胞嘧啶(CpG)、E7Pb+CpG、E7Pc+CpG[均为实验组,分别加入终浓度为50μg/ml的E7Pa、E7Pb、E7Pc和终浓度为12 mg/L的刀豆蛋白(ConA)]、CpG(为阳性对照,加入终浓度为12 mg/L 的Con A)和空白对照组(不做任何处理).采用四甲基偶氮唑蓝(MTT)比色法检测各组作用不同时间后小鼠脾T淋巴细胞的体外增殖效应,乳酸脱氢酶(LDH)释放法检测小鼠脾T淋巴细胞在不同效靶比下的体外细胞毒T淋巴细胞(CTL)活性,实时荧光定量RT-PER技术检测小鼠肿瘤组织中γ干扰素(IFN-γ)、白细胞介素2(IL-2)mRNA的表达水平,酶联免疫吸附试验(ELISA)检测小鼠外周血中IFN-γ、IL-2的表达水平,通过定期测量比较各组小鼠接种HPV16多肽疫苗后体内肿瘤体积的变化.结果 (1)本研究筛选出了一致性较高、特异性及亲和力较强的3段HPV16 E7多肽作为研究对象制备HPV16多肽疫苗,分别命名为E7Pa、E7Pb、E7Pc.(2)MTT比色法检测显示,在接种疫苗24、48、72、96 h后,以E7Pa+CpG组的增殖效应最明显,其细胞增殖率分别为(131±32)%、(302±15)%、(552±28)%、(731±24)%,明显高于空白对照组的(72±15)%、(120±57)%、(176±41)%、(288±29)%(P<0.01);E7Pb+CpG、ETPc+CpG、CpG组的细胞增殖率也均明显高于空白对照组(P<0.05);但E7Pb+CpG、E7Pc+CpG、CpG组间比较,差异则无统计学意义(P>0.05).LDH释放法榆测显示,效靶比为100:1时,E7Pa+CpG、E7Pb+CpG、E7Pc+CpG、CpG和空白对照组CTL 活性分别为(85.9±3.0)%、(55.9±2.5)%、(60.2±1.5)%、(41.0±1.7)%和(4.1±1.0)%,E7Pa+CpG组与空白对照组比较,差异有统计学意义(P<0.01);E7Pb+CpG、E7Pc+CpG、CpG组分别与空白对照组比较,差异也有统计学意义(P<0.05);但E7Pb+CpG、E7Pc+CpG、CpG组间比较,差异则无统计学意义(P>0.05).在肿瘤组织及外周血中,小鼠IFN-γ、IL-2的表达水平,E7Pa+CpG组与空白对照组比较,差异均有统计学意义(P<0.01);E7Pb+CpG、E7Pc+CpG和CpG组分别与空白对照组比较,差异也均有统计学意义(P<0.05);但E7Pb+CpG、E7Pc+CpG、CpG组问比较,差异则无统计学意义(P>0.05).小鼠体内的肿瘤体积,各实验组肿瘤生长均明显被抑制,接种后第60大,E7Pa+CpG组与空白对照组比较,差异有统计学意义(P<0.01);E7Pb+CpG、E7Pc+CpG和CpG组分别与空白对照组比较,差异也均有统计学意义(P<0.05);但 E7Pb+CpG、E7Pc+CpG、CpG组间比较,差异则无统计学意义(P>0.05).结论 在动物模型中,针对TAP筛选的HPV16 E7多肽联合CpG制备的HPV16多肽疫苗,可以有效治疗HPV16 E7阳性的肿瘤.     

Human papillomavirus type 16 E7 peptide(38-61) linked with an immunoglobulin G fragment provides protective immunity in mice

OBJECTIVE: To explore whether the recombinant protein (Human papillomavirus (HPV) type16 E7 peptide(38-61) linked with an immunoglobulin G fragment) will generate protective immunity in mouse model. METHODS: In our study, we combined the HPV16 E7 peptide(38-61) with a murine IgG heavy chain constant region to construct a chimeric protein compound, which was highly expressed as inclusion bodies in a bacterial expression system with Escherichia coli. The purified chimeric protein was injected into C57BL/6 mice and the efficiency of the chimeric vaccine candidate was evaluated by antibody response assay, T cell proliferation assay, CTL assay, tumor challenge assay and therapeutic experiment. RESULTS: The chimeric vaccine candidate was able to induce anti-HPV antibodies as well as to elicit HPV16 E7-specific CTLs and T cell proliferation in a pre-clinical mouse model. It was also able to effectively protect mice against the challenge of HPV16-positive tumor cells, and to eradicate HPV16-expressing tumors in mice. CONCLUSIONS: The chimeric protein vaccine can induce E7-specific immune responses and protect mice against challenge of HPV16-positive tumor, even eradicate developed tumor. The results indicated a possibility to use the chimeric protein vaccine to protect human against HPV infection.     

IgG antibodies against human papillomavirus type 16 E7 proteins in cervicovaginal washing fluid from patients with cervical neoplasia

Abstract. Tjiong MY, ter Schegget J, Tjong-a-Hung SP, Out TA, van der Vange N, Burger MPM, Struyk L. IgG antibodies against human papillomavirus type 16 E7 proteins in cervicovaginal washing fluid from patients with cervical neoplasia.
Little information is available about the cervicovaginal mucosal antibodies against human papillomavirus (HPV) proteins. In this study specific IgG antibodies against HPV 16 E7 protein were determined in paired samples of cervicovaginal washing fluid and serum from patients with cervical cancer ( n = 22), cervical intraepithelial neoplasia (CIN) ( n = 38), healthy individuals ( n = 22), and serum from children ( n = 41) by a radioactive immunoprecipitation assay (RIPA). HPV 16 E7 specific IgG antibodies were found in cervicovaginal washings ( n = 8) and in sera ( n = 8) of the patients with cervical cancer. About 60% of the patients with HPV 16 positive cervical cancer had HPV 16 E7 specific IgG antibodies. Titration studies showed that the IgG antibody reactivity in cervicovaginal washings was higher than in the paired serum samples of six patients with cervical cancer ( P < 0.001). In the CIN group we found no IgG reactivity in the serum, but in five patients we found a low IgG reactivity in the cervicovaginal washings. No IgG reactivity was found in cervicovaginal washings and sera from healthy individuals and sera from children. HPV 16 E7 specific IgG antibodies seem to be locally produced in a number of patients with HPV 16 positive (pre)malignant cervical lesions. For more definitive evidence for the local production of these antibodies immunostaining should be performed to demonstrate the presence of specific anti-HPV 16 E7 IgG producing plasma cells in the cervical epithelium.     

Protein profiling and identification of modulators regulated by human papillomavirus 16 E7 oncogene in HaCaT keratinocytes by proteomics

OBJECTIVES: Viral oncogenes E6 and E7 are selectively retained and expressed in carcinoma cells infected with human papillomavirus type 16 and cooperated with each other in immortalization and transformation of primary keratinocytes. This study was performed to identify proteins to be bound or modulated by high risk HPV E7 oncogene by using a proteomics. METHODS: HaCaT normal keratinocyte was prepared to establish a stable cell line expressing E7. The E7-affinity column was also prepared to obtain E7-interacting proteins. In order to search the target molecules modulated by E7 expression, we used 2-dimensional electrophoresis and matrix-assisted laser desorption/ionization time of flight (MALDI/TOF) mass spectrometry. Pull down assay was also performed in order to confirm the E7-interacting proteins. RESULTS: We identified 28 spots that are modulated by E7 in HaCaT/E7 using 2-dimensional electrophoresis (2-DE) and MALDI/TOF mass spectrometry. Proteomics analyses showed that actin and leukocyte elastase inhibitor were down-regulated, whereas stress-induced phosphoprotein 1, CD2 binding protein 1, catalase, T-complex protein 1, Ku70-binding protein, heat shock 60 kDa protein 1, G1/S-specific cyclin E1 and peroxiredoxin 2 were up-regulated. Western blot revealed that heat shock 60 kDa protein, catalase and peroxiredoxin 2 were also up-regulated. Pull down assay also showed that leukocyte elastase inhibitor (LEI) and Ku70-binding protein were bound to the E7 oncoprotein. By using E7-affinity column and 2-DE/MALDI-TOF, 22 spots were found to interact with E7 recombinant protein. MG11-like proteins, livin inhibitor-of-apoptosis, protein serine kinase c17, CD2 binding protein 1, cyclin E1, TATA box binding protein-associated factor and uridine-cytidine kinase 2 were up-regulated by E7 oncogene and also bound to E7 oncoprotein. CONCLUSIONS: It is presumed that E7 can influence cell status by modulating the factors related to cell signaling, apoptosis and cell cycle regulation.     

Absence of human papillomavirus E6-E7 transforming genes from HPV 16 and 18 in malignant ovarian carcinoma

Ovarian carcinoma is one of the frequent causes of death from malignancies in the United States. A report excited the scientific community when human papillomavirus were identified in advanced epithelial ovarian carcinoma tissues in 10 of 12 patients. A few studies also identified HPV DNA in ovarian carcinoma tissues. However, several researchers employing polymerase chain reaction techniques and using different oligonucleotide probes did not detect HPV DNA in ovarian carcinoma tissues. The objective was to determine the presence of the E6-E7 genes of HPV types 16 and 18 in archived paraffin-embedded malignant ovarian carcinoma using primers targeting. Archived human malignant ovarian cancer tissues (N = 20 cases) embedded in paraffin blocks were processed, and DNA was extracted and the presence of DNA verified by p53 amplifications. PCR analyses were performed on the extracted DNA together with appropriate controls. The results showed an absence of E6-E7 genes of HPV types 16 and 18 in ovarian carcinoma. However, the presence of other HPV types or gene regions is not ruled out and more studies are needed to resolve the question of HPV involvement in ovarian carcinogenesis.     

Cancerous inhibitor of protein phosphatase 2A is overexpressed in cervical cancer and upregulated by human papillomavirus 16 E7 oncoprotein

Objectives

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified oncoprotein stabilizing c-Myc and promoting cell proliferation and transformation. Here we investigated the role of CIP2A in cervical cancer in vivo and in vitro.

Methods

CIP2A expression was assessed in normal cervical, cervical intraepithelial neoplasia (CIN) I to III and cervical cancer tissues by immunohistochemistry and RT-PCR. Cell growth was explored by cell proliferation assay, colony formation assay and anchorage-independent growth in soft agar after inhibition of CIP2A by siRNA in HeLa, SiHa and Caski cells. Crosstalk of CIP2A and HPV16 E7 was investigated by immunohistochemistry in cervical cancer tissues and by real-time PCR and western blot analysis after HPV16 E7 inhibition by siRNA in SiHa cells.

Results

CIP2A was transcribed in 73.3% of cervical cancer tissues (n = 15) but not in normal cervical tissues (n = 8). CIP2A protein was detected in 52.8% of cervical cancer (n = 72) and 12.5% of CIN III tissues (n = 24) but not in normal (n = 15), CIN I (n = 21) or CIN II samples (n = 25). CIP2A protein level was positively associated with HPV16 E7 level in cervical cancer tissues. CIP2A expression was markedly reduced after E7 depletion. Moreover, CIP2A depletion reduced c-Myc protein level and impaired proliferation and growth of cervical cancer cells.

Conclusions

CIP2A is overexpressed in cervical cancer and promotes the malignant growth of cervical cancer cells. Its expression is upregulated by HPV16 E7. Therefore, CIP2A plays an important role in carcinogenisis of cervical cancer and shows promise for the diagnosis and treatment of cervical cancer.     

外源性人乳头状瘤病毒16型E7基因对子宫颈癌细胞周期的影响

目的了解外源性人乳头状瘤病毒16型(HPV16)E7基因对子宫颈癌细胞周期的影响。方法从宫颈癌标本中经 PCR 扩增回收 HPV16 E7基因片段,将正确的 E7基因片段插入到穿梭质粒 pAdrTrack-CMV 中,与骨架质粒 pAdEasy-1在大肠埃希菌 Bj5183中同源重组,重组腺病毒质粒转染人胚肾细胞株 HEK-293细胞,包装表达 E7基因的腺病毒,然后转染 HPV18阳性的宫颈癌细胞株HeLa 细胞,四甲基偶氮唑蓝(MTT)比色法检测转染后 HeLa 细胞的增殖情况,以吸光度(A)值表示;流式细胞仪检测转染前后 HeLa 细胞的细胞周期和细胞周期蛋白 D1表达的变化。结果在 HEK-293细胞中,可以收获高转染效率的腺病毒。在荧光显微镜下,可以观察到 HEK-293细胞和 HeLa 细胞中均有绿色荧光蛋白的表达。提取 HEK-293细胞 RNA,RT-PCR 技术可以检测到 E7基因的表达。MTT 比色法检测结果显示,转染后 HeLa 细胞的 A 值最低为0.38±0.02,最高为0.96±0.01,分别与转染前的0.27±0.03比较,差异均有统计学意义(P<0.01)。流式细胞仪检测结果显示,转染12h后,S 期细胞占(36.0±2.0)%,转染24h 后为(49.9±4.2)%,分别与转染前的(26.0±0.4)%比较,差异均有统计学意义(P<0.05);转染前、后细胞周期蛋白 D1阳性表达率分别为22.4%、55.2%,两者比较,差异有统计学意义(P<0.01)。结论携带 HPV16 E7基因的腺病毒可转染子宫颈癌 HeLa细胞,并在 HeLa 细胞内表达,HPV16 E7基因的表达进一步影响 HeLa 细胞的细胞周期蛋白的表达,促进 HeLa 细胞增殖,可望用于治疗宫颈癌。     

Effects of human papillomavirus type 16 E7 protein on the growth of cervical carcinoma cells and immuno-escape through the TGF-beta1 signaling pathway

OBJECTIVE: E7 is regarded as one of the main oncoproteins of high-risk human papillomaviruses (HPVs). It may affect the transforming growth factor beta 1 (TGF-beta1) signaling pathway. In this study, the relationship between HPV-16 infection and the functions of three critical factors of the TGF-beta1/Smads pathway was explored to assess the possible role of E7 in the development of cervical cancer. METHODS: The expression of E7, TGF-beta1, TbetaR-II and Smad4 was detected by immunohistochemistry in paraffin-embedded cervical samples, and by RT-PCR and Western blotting in cervical cancer cell lines. The effect of TGF-beta1 on the growth of cervical cancer cells were tested by methyl thiazolyl tetrazolium (MTT), and the effects of HPV-16 E7 protein on normal and malignant cervical cells were investigated by flow cytometry. RESULTS: During the progression from benign to malignant lesions, the expression levels of TGF-beta1 and Smad4 increased significantly in cervical carcinoma tissues. The expression of TGF-beta1 was positively correlated with E7 expression. In vitro experiments showed that TGF-beta1 could not inhibit the proliferation of several cervical carcinoma cell lines in long-term regulation, but could inhibit immunologic reactions of peripheral blood mononuclear cells (PBMCs). Blocking E7 expression could lower the expression level of TGF-beta1 and induce cells to enter apoptosis. CONCLUSIONS: Our data indicate that HPV-16 E7 protein plays an important role during the development of cervical cancer by immuno-inhibition and stimulation of tumor cell proliferation through the TGF-beta1/Smads signaling pathway.     

子宫颈癌组织中人乳头状瘤病毒16 E6 mRNA表达与survivin蛋白表达的相关性

目的探讨宫颈癌组织中人乳头状瘤病毒(HPV)16E6mRNA表达与survivin蛋白表达的相关性。方法采用半定量PCR技术和免疫组化链霉菌抗生物素蛋白-过氧化物酶连接法,检测慢性宫颈炎、宫颈上皮内瘤变(CIN)及宫颈癌共148例患者宫颈组织中HPV16E6mRNA及survivin蛋白的表达。结果148例患者中,HPV16阳性共37例,其中慢性宫颈炎5例、CINⅠ6例、CINⅡ～Ⅲ11例及宫颈癌15例。慢性宫颈炎、CINⅠ、CINⅡ～Ⅲ及宫颈癌组织中,HPV16E6mRNA的表达水平分别为0.3±0.4、0.6±0.4、1.8±0.6及2.4±0.6;survivin蛋白阳性表达率分别为7%、31%、63%及84%。CINⅡ～Ⅲ及宫颈癌组织中,HPV16E6mRNA的表达水平及survivin蛋白阳性表达率均显著高于慢性宫颈炎及CINⅠ组织,两者比较,差异均有统计学意义(P<0.01)。宫颈癌组织中,HPV16E6mRNA的表达水平与survivin蛋白阳性表达率呈显著正相关关系(γs=0.62,P<0.05)。结论HPV16E6mRNA的表达水平与宫颈病变的进展有关,survivin蛋白阳性表达率升高可能与宫颈癌的发生、发展密切相关。