Human papillomavirus 16 E6 is associated with the nuclear matrix of esophagesl carcinoma cells

AIM: To explore the etiologic role of HPV infection in esophageal carcinoma, and the association of HPV-16 E6with the nuclear metrix of carcinoma cells. METHODS: Two esophageal carcinoma cell lines, EC/CUHK1 and EC/CUHK2, were tested for HPV-16 E6subgenetic fragment by polymerase chain reaction amplification of virus DNA associated nuclear matrix. RT-PCR and immunocytochemistry were also used to visualizethe expression of E6 subgene in the cells. RESULTS: The HPV-16 E6 subgenetic fragment wes found to be present in nuclear metrix-associeted DNA, E6oncoprotein localized in the nucleus where it is tightly associated with nuclear matrix after sequential extraction in EC/CUHK2 cells. It was not detected, however, in EC/CUHK1 cells. CONCLUSION: The interaction between HPV-16 E6 and nuclear matrix may contribute to the virus induced carcinogenesis in esophageal carcinoma.     

Human papillomavirus 16 E6 is associated with the nuclear matrix of esophageal carcinoma cells

AIM:To explore the etiologic role of HPV infection inesophageal carcinoma,and the association of HPV-16 E6with the nuclear matrix of carcinoma cells.METHODS:Two esophageal carcinoma cell lines,EC/CUHK1 and EC/CUHK2,were tested for HPV-16 E6subgenetic fragment by polymerase chain reactionarnplification of virus DNA associated nuclear matrix.RT-PCR and immunocytochemistry were also used to visualizethe expression of E6 subgene in the cells.RESULTS:The HPV-16 E6 subgenetic fragment was found tobe present in nuclear matrix-associated DNA,E6oncowprotein localized in the nucleus where it is tightlyassociated with nuclear matrix after sequential extraction inEC/CUHK2 cells.It was not detected,however,in EC/CUHK1 cells.CONCLUSION:The interaction between HPV-16 E6 andnuclear matrix may contribute to the virus inducedcarcinogenesis in esophageal carcinoma.     

北京地区妇女宫颈人乳头瘤病毒感染及亚型分布情况分析

目的探讨北京地区妇女宫颈人乳头瘤病毒(HPV)感染及其亚型分布情况。方法采用聚合酶链反应(PCR)体外扩增和脱氧核糖核酸(DNA)反向点杂交相结合的DNA芯片技术,对920例宫颈脱落细胞标本进行HPV基因分型检测。结果 920例标本共检出HPV感染508例,总感染率为55.22%。23种亚型共检出21种,高危亚型MM4及低危亚型44未检测出;感染率居前五位的基因亚型是HPV-16 238例(24.74%),HPV-11 100例(10.4%),HPV-6 95例(9.88%),HPV-58 84例(8.73%)和HPV-33 75例(7.8%)。单一基因型感染285例,占总感染数的56.1%;多重感染223例,占总感染数的43.9%。<20、20～29、30～39、40～49和≥50岁五个不同年龄组阳性感染构成比分别为1.97%、25.78%、37.60%、23.43%和11.22%。结论北京地区妇女宫颈HPV感染率较高,HPV感染高发年龄段为20～49岁性活跃阶段女性,HPV基因分型检测技术对宫颈癌预防有积极作用。     

Human papillomavirus 16 E7 protein is associated with the nuclear matrix.

The cellular localization of the human papillomavirus (HPV)-16 E7 gene product in the cell lines CaSki and SiHa has been determined by both biochemical and immunocytochemical methods. These measurements show E7 to be localized in the cell nucleus, specifically with the nonchromatin nuclear structure or nuclear matrix. This localization of E7 required an unambiguous fractionation of the nuclear constituents. This was achieved by using a gentle sequential fractionation procedure to prepare the scaffold consisting of the nuclear matrix and intermediate filaments (NM-IF). Chromatin was cleaved with nuclease and the resulting nucleosomes eluted with 0.25 M ammonium sulfate. Immunostaining of cells after this extraction procedure with monoclonal antibodies (mAbs) to E7 revealed a fine grained, punctate nuclear fluorescence in CaSki and SiHa, which was absent in normal cervical keratinocytes and the HPV-negative cell line C33.1. Western blots of cell fractions with these mAbs showed that E7 was localized in the NM-IF fraction in SiHa and CaSki but was not detected in HPV-negative cells. A second protein of slightly higher mobility is identified by these antisera in HPV-16-containing cells. The data suggest that the previous inability to directly visualize E7 by immunocytology is due to the masking of epitopes by cellular components and not to low levels of protein.     

p53 status and human papillomavirus infection in Thai women with cervical carcinoma

Loss of p53 function has been implicated in a wide variety of human malignacies. Many studies suggest that in cervical carcinoma p53 function is inactivated either by gene mutation or by complex formation with E6 oncoprotein product of high-risk human papillomavirus (HPV). The aim of this study was to determine the status of HPV infection and p53 gene mutation as well as their correlation in cervical carcinomas. Formalin-fixed paraffin-embedded tissues of 12 cervicitis, 21 cervical intraepithelial neoplasia grade 3 (CIN 3) and 17 squamous cell carcinomas were determined for the presence of HPV using polymerase chain reaction (PCR) amplification and dot blot hybridization. The status of p53 mutations in exons 5-8 was evaluated by polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) and confirmed by direct nucleotide sequencing. HPV infections were detected in all CIN 3 and squamous cell carcinomas (100%). Mutations of p53 were present in 3 of 38 HPV-positive samples: one with an ATG-->TTG transversion (Met-->Leu) in codon 237 of exon 7; and the others with a TGC-->TGG transversion (Cys-->Trp) in codon 242 of exon 7, and a CGT-->CCT transversion (Arg-->Pro) in codon 273 of exon 8, respectively. Our findings show that the frequency of p53 mutation is low in primary cervical carcinoma and that the p53 gene mutation and HPV infection are not mutually exclusive events in the development of cervical cancer. Thus, other genetic events independent of p53 inactivation may also significantly contribute to the carcinogenesis of the uterine cervix.     

Human papillomavirus genotypes in women with cervical cytological abnormalities from an area with high incidence of cervical cancer

It has been well demonstrated the relationship between the infection with high-risk human papillomavirus (HPVs) genotypes and cervical cancer. In Northeastern Argentina a high incidence of this pathology has been described and therefore a high prevalence of HPV infection is expected. In order to identify HPV genotypes associated with malignant and pre-malignant cervical lesions present in the area, 53 ecto-endo cervical cell specimens obtained from women with cytohistological alterations were studied by a PCR-RFLP technique. Out of 53 patients, 34 (64.2%) were positive for HPV infection, being HPV-16 (32.3%) the most frequently found genotype, followed by HPV-58 (14.7%), -6, -18 and -45 (5.9%), -33, -52, -53, -54, -56, -66, -MM4 and -LVX100 (2.9%). Also 5 cases of infection caused by multiple genotypes were found, which corresponded to 14.7% of the positive cases. Results indicate that besides HPV-16 and -18, the most prevalent high-risk HPV genotypes worldwide, others like -45 and -58 as well as co-infection cases are frequent between women of Northeastern Argentina, and a particular attention should be paid to this circumstance because it could be an epidemiological feature of regional importance and a useful information for a future vaccination program.     

Human papillomavirus type 16 molecular variants in Guarani Indian women from Misiones, Argentina.

OBJECTIVE: To identify human papillomavirus type 16 (HPV16) E6 and L1 molecular variants infecting Guarani Indian women settled in Misiones, Argentina, a region with a high prevalence of cervical cancer. Some intratypic molecular variants of HPV16 have been associated with greater oncogenic risk, but their implication in the etiology of cervical cancer is still uncertain. METHODS: Seventy HPV16 positive cervical samples from Guarani Indian women settled in two different areas of Misiones, Argentina, (34 from the northern area and 36 from the central area), were analyzed. Thirty-seven had normal cytology, 18 had a low-grade squamous intraepithelial lesion (LGSIL), and 15 a high-grade squamous intraepithelial lesion (HGSIL). HPV16 E6 and L1 molecular variants were identified by PCR, followed by dot blot hybridization with 23 and 12 biotinylated oligonucleotide probes, respectively. RESULTS: The frequency of HPV16 variants over the Guarani population was 51% EP (European prototype), 32% E-350G, 9% Af1-a (African 1), 4% E-6862C, 3% Af2-a, and 1% AA-a (Asian-American). The distribution of variants was not homogeneous in the two areas under analysis, with the northern area being more diverse showing 74% of European variants, while the central area presented exclusively E variants. No statistically significant association was found between any particular variant and grade of cervical lesion. CONCLUSION: This study reports for the first time HPV16 E6 and L1 molecular variants infecting women from an aboriginal community inhabiting a rainforest region of South America. The presence of E class variants could be attributed primarily to contacts with the Spanish conquerors, and Af variants from African slaves introduced later in the South American continent.     

Human papillomavirus type 16 nucleoprotein E7 is a tumor rejection antigen.

It has been speculated that immunological mechanisms play an important role in the control of carcinomas associated with human papillomavirus (HPV), such as cervical cancers. We have now demonstrated that immunization of C3H/HeN mice by syngeneic nontumorigenic fibroblast-like cells that contain the transfected HPV-16 E7 gene conferred protection against transplanted cells from a HPV-16 E7-positive syngeneic tumor. This protection was HPV-16 E7-specific and was mediated by CD8+ lymphocytes, which presumably were cytotoxic T lymphocytes. These results indicate that tumor cells containing HPV-16 E7, either as a result of transfection, as in our studies, or naturally, as occurs in many human carcinomas, can induce a tumor-specific rejection response and serve as targets for such a response. The system described here provides an animal model to further study immune responses to HPV-associated malignancies and to test the efficacy of anti-HPV vaccines toward the therapy and prevention of such tumors.     

Human papillomavirus and cervical cancer

Cervical cancer is the second most common cancer in women worldwide, and knowledge regarding its cause and pathogenesis is expanding rapidly. Persistent infection with one of about 15 genotypes of carcinogenic human papillomavirus (HPV) causes almost all cases. There are four major steps in cervical cancer development: infection of metaplastic epithelium at the cervical transformation zone, viral persistence, progression of persistently infected epithelium to cervical precancer, and invasion through the basement membrane of the epithelium. Infection is extremely common in young women in their first decade of sexual activity. Persistent infections and precancer are established, typically within 5-10 years, from less than 10% of new infections. Invasive cancer arises over many years, even decades, in a minority of women with precancer, with a peak or plateau in risk at about 35-55 years of age. Each genotype of HPV acts as an independent infection, with differing carcinogenic risks linked to evolutionary species. Our understanding has led to improved prevention and clinical management strategies, including improved screening tests and vaccines. The new HPV-oriented model of cervical carcinogenesis should gradually replace older morphological models based only on cytology and histology. If applied wisely, HPV-related technology can minimise the incidence of cervical cancer, and the morbidity and mortality it causes, even in low-resource settings.     

High HPV 16 viral load is associated with increased cervical dysplasia in Honduran women

Cervical cancer is believed to have a co-factorial etiology in which high-risk human papillomavirus (HPV) infections are considered an essential factor and other elements play an ancillary role. Besides the importance of specific HPV genotypes, other viral cofactors as viral load may influence the progression likelihood. In this study the relationship between HPV 16 viral load with respect to the grade of cervical disease in Honduran women was investigated. A real-time PCR allowing quantification of both HPV 16 genome and beta-globin gene to normalize the measuring HPV 16 load in cervical cells was used. The data in 87 women with cervical dysplasia or cervical cancer and in 23 women with a negative Pap smear were evaluated. The highest average of HPV 16 viral load was detected in women with High Squamous Intraepithelial Lesions (HSIL). An increasing amount of HPV in higher cervical lesions was found, which could indicate a dose-response association between viral load and precancerous lesion grade.     

Human papillomavirus type 16 intratypic variant infection and risk for cervical neoplasia in southern China

A mutation of the stromal cell-derived factor 1 gene (SDF-1 3'A) was shown to protect adults exposed to human immunodeficiency virus type 1 (HIV-1) from infection and to affect HIV disease progression in adults. The presence of this mutation in HIV-1-infected Kenyan children did not predict mother-to-child virus transmission. The SDF-1 3'A polymorphism was studied in 256 HIV-1-infected, 118 HIV-1-exposed but uninfected, and 170 unexposed and uninfected children of Italian origin, and the frequency of SDF-1 3'A heterozygosity and homozygosity in each of the 3 groups was similar. Of the 256 HIV-1-infected children, 194 were regularly followed up and were assigned to groups according to disease progression. The frequency of the SDF-1 3'A allele was substantially lower among children with long-term nonprogression than among children with rapid (P =.0329) or delayed (P =.0375) progression. We show that the presence of the SDF-1 3'A gene correlates with accelerated disease progression in HIV-1-infected children born to seropositive mothers but does not protect against mother-to-child HIV-1 transmission.     

人乳头瘤病毒16与胃癌相关性的研究

目的探讨人乳头瘤病毒１６（ＨＰＶ１６）与胃癌发生的关系。方法用聚合酶链式反应（ＰＣＲ）扩增出ＨＰＶ１６早期区Ｅ６的１２０ｂｐＤＮＡ片段，扩增产物与５＇末端３２Ｐ标记的特异性寡核苷酸探针进行斑点杂交及放射性自显影，用此方法对３４６份新鲜的及福尔马林固定石蜡包埋的胃组织标本中ＨＰＶ１６ＤＮＡ进行检测。结果胃腺癌、癌旁粘膜、胃局部淋巴结及正常胃粘膜组织中ＨＰＶ１６的检出率分别为：２２．７２％（３０／１３２）、５．８８％（４／６８）、０％（０／４２）、２．８８％（３／１０４），胃癌组ＨＰＶ１６的检出率高于其他各组，统计学上差异均有显著性（Ｐ＜０．０１）。结论ＨＰＶ１６可感染胃粘膜上皮细胞，可能是胃癌的致癌因素之一。     

广西地区宫颈癌患者HPV感染情况分析

目的观察基因芯片技术对宫颈癌人类乳头状瘤病毒（HPV）分型检测的可行性,探讨广西地区宫颈癌患者HPV感染情况及其亚型分布规律。方法采用基因芯片技术对163例宫颈癌组织标本进行HPV分型检测。结果HPV总感染率为95．1％,其中鳞癌131例,HPV阳性率为98．5％;腺癌分别为32例和81．3％（P〈0．05）。鳞癌最常见的感染亚型是HPV16（78．6％）,其次是HPV18（11．5％）、HPV59（5．3％）、HPV58（3．1％）、HPV33（3．1％）、HPV31（3．1％）;腺癌最常见的亚型是HPV18（59．4％）,其次是HPV16（21．9％）、HPV52（6．3％）、HPV35（3．1％）。鳞癌患者单一感染106例（82．2％）,双重感染27例（17．8％）;腺癌患者分别为22例（84．6％）、4例（15．4％）;均未见三重及以上多重感染。结论基因芯片技术检测宫颈癌组织中HPV分型简便、高通量。广西地区宫颈癌中HPV感染率极高,其中鳞癌中以HPV16最常见,腺癌中以HPV18最常见。     

Human papillomavirus (HPV) genotype distribution in women with abnormal cervical cytology in the Basque Country,Spain

Introduction

The aim of this study was to analyze the distribution of human papillomavirus (HPV) genotypes in cytologically abnormal cervical samples from 106 women living in a region of the north of Spain.

Methods

Cytological classification was reported according to the 2001 Bethesda System and HPV genotyping was performed by Roche Linear Array.

Results

The overall HPV prevalence was 69.8% with 30 different HPV genotypes detected. The prevalence of HR (high-risk) HPV types and pHR (probable high-risk) HPV types in positive samples was 94.3%, 78.1% and 100% in patients with ASCUS, LSIL and HSIL/CC, respectively, with no significant differences. The most frequent type was the HPV 16, present in 29.7% of all positive samples, followed by HPV 51 (17.5%), HPV 53 and 42 (16%), HPV 52 (12%), HPV 39 (10.8%), HPV 18 and 58 (9.4%) and HPV 66 (8.1%). No significant differences in the percentage of any HPV genotype with the grade of the cytological lesion were detected. The prevalence of HPV co-infection was 58.1% of HPV positive.

Conclusions

This study confirms the high prevalence of high-risk genotypes in women with abnormal cytology living in our geographical area. This information may be useful for the formulation of algorithms for patient management according to the different risks associated with specific high-risk genotypes.