Protective effects of green tea extracts (polyphenon E and EGCG) on human cervical lesions

We investigated clinical efficacy of green tea extracts (polyphenon E; poly E and (-)-epigallocatechin-3-gallate [EGCG]) delivered in a form of ointment or capsule in patients with human papilloma virus (HPV) infected cervical lesions. Fifty-one patients with cervical lesions (chronic cervicitis, mild dysplasia, moderate dysplasia and severe dysplasia) were divided into four groups, as compared with 39 untreated patients as a control. Poly E ointment was applied locally to 27 patients twice a week. For oral delivery, a 200 mg of poly E or EGCG capsule was taken orally every day for eight to 12 weeks. In the study, 20 out of 27 patients (74%) under poly E ointment therapy showed a response. Six out of eight patients under poly E ointment plus poly E capsule therapy (75%) showed a response, and three out of six patients (50%) under poly E capsule therapy showed a response. Six out of 10 patients (60%) under EGCG capsule therapy showed a response. Overall, a 69% response rate (35/51) was noted for treatment with green tea extracts, as compared with a 10% response rate (4/39) in untreated controls (P<0.05). Thus, the data collected here demonstrated that green tea extracts in a form of ointment and capsule are effective for treating cervical lesions, suggesting that green tea extracts can be a potential therapy regimen for patients with HPV infected cervical lesions.

Seroreactivity to Human Papillomavirus (HPV) Types 16, 18, or 31 and Risk of Subsequent HPV Infection

Whether antibodies to human papillomavirus (HPV) capsids, elicited by natural infection, are protective is unknown. This question was addressed in a population-based cohort of 7046 women in Costa Rica by examining the association between baseline seroreactivity to HPV-16, HPV-18, or HPV-31 virus-like particles and the risk of subsequent HPV infection at a follow-up visit 5-7 years after enrollment. Seropositivity to HPV-16, HPV-18, or HPV-31 was not associated with a statistically significant decreased risk of infection with the homologous HPV type [relative risk (RR) and [95% confidence interval (CI)], 0.74 (0.45-1.2), 1.5 (0.83-2.7), and 0.94 (0.48-1.8), respectively]. Seropositivity to HPV-16 or HPV-31 was not associated with a decreased risk of infection with HPV-16 or its genetically related types [RR (95% CI), 0.82 (0.61-1.1) and 0.93 (0.68-1.2), respectively]. Seropositivity to HPV-18 was not associated with a decreased risk of infection with HPV-18 or its genetically related types (RR 1.3; 95% CI 1.0-1.8). Thus, we did not observe immunity, although a protective effect from natural infection cannot be excluded because of the limits of available assays and study designs.

Functional analysis of the human papillomavirus type 16 E1=E4 protein provides a mechanism for in vivo and in vitro keratin filament reorganization

High-risk human papillomaviruses, such as human papillomavirus type 16 (HPV16), are the primary cause of cervical cancer. The HPV16 E1=E4 protein associates with keratin intermediate filaments and causes network collapse when expressed in epithelial cells in vitro. Here, we show that keratin association and network reorganization also occur in vivo in low-grade cervical neoplasia caused by HPV16. The 16E1=E4 protein binds to keratins directly and interacts strongly with keratin 18, a member of the type I intermediate-filament family. By contrast, 16E1=E4 bound only weakly to keratin 8, a type II intermediate-filament protein, and showed no detectable affinity for the type III protein, vimentin. The N-terminal 16 amino acids of the 16E1=E4 protein, which contains the YPLLXLL motif that is conserved among supergroup A viruses, were sufficient to target green fluorescent protein to the keratin network. When expressed in the SiHa cervical epithelial cell line, the full-length 16E1=E4 protein caused an almost total inhibition of keratin dynamics, despite the phosphorylation of keratin 18 at serine 33, which normally leads to 14-3-3-mediated keratin solubilization. Mutant 16E1=E4 proteins which lack the LLKLL motif, or which have lost amino acids from their C termini, and which were compromised in the ability to associate with keratins did not disturb normal keratin dynamics. 16E1=E4 was found to exist as dimers and hexamers, whereas a C-terminal deletion mutant (16E1=E4Delta87-92) existed as monomers and formed multimeric structures only poorly. Considered together, our results suggest that by associating with keratins through its N terminus, and by associating with itself through its C terminus, 16E1=E4 may act as a keratin cross-linker and prevent the movement of keratins between the soluble and insoluble compartments. The increase in avidity associated with multimeric binding may contribute to the ability of 16E1=E4 to sequester its cellular targets in the cytoplasm.

Human papillomavirus vaccine as a new way of preventing cervical cancer: a dream or the future?

Cervical cancer is the major cause of death in women of reproductive age in parts of the developing world. Thanks to the effectiveness of national screening programs, the incidence and mortality rates for cervical cancer have declined dramatically in developed countries. According to many researchers, human papillomavirus (HPV) infection has an important role in the development of cervical neoplasm. The effects of HPV infection on the oncogenesis of cervical carcinoma can be explained to a large degree by the regulation and function of the two viral oncogenes, E6 and E7. About 25 of >80 types infect the genital tract. HPV types are stratified into low, intermediate- and high-risk categories. Today, vaccines are available against many serious human pathogens. It is accepted worldwide that cervical carcinoma is a consequence of infection with HPV viruses. Therefore it is reasonable to assume that vaccine that prevents infection will reduce the incidence of cervical cancer. Virus-like particles are empty viral capsids, and are the leading candidate vaccines for the treatment or prevention of cervical cancer in humans. The HPV type 16 (HPV16) L1 virus-like particle vaccines have been shown to be generally well tolerated and they generate high levels of antibodies against HPV16. Since approximately 50% of cervical cancers are associated with HPV16 infection, the administration of this type of vaccine to young women could reduce the incidence of HPV16 infection, which is related to cervical dysplasia and cervical neoplasm. Vaccination against HPV infection could reduce the risk of infection and, most importantly, decrease the incidence of cervical cancer. A vaccine for cervical cancer is not a dream in the far future, it is happening today.

Human papillomavirus type 16 and 18 DNA in oral squamous cell carcinoma and normal mucosa

The aim of this study was to ascertain the prevalence of HPV 16/18 DNA in oral squamous cell carcinoma (OSCC) vs. normal oral mucosa, and to correlate the virologic data with other factors obtained from the patients' records. One hundred and thirteen paraffin embedded tissue samples (73 OSCC and 40 normal oral mucosa) were studied using HPV type specific primer-mediated polymerase chain reaction (PCR). Seventy-four per cent (54/73) of OSCC and 55% (22/44) of normal oral mucosa were positive for HPV 16/18 DNA. Statistical analysis indicated there was a significant difference between HPV16/18 positive OSCC vs. normal oral mucosa (P=0.040), and that age (<60 years) and gender (male) were correlated with the presence of HPV16/18 in the tumour. No significant association was found between the presence of HPV and other risk factors, including tobacco use, alcohol use, tumour location, histologic grade or TNM staging. We found a significant association of HPV16/18 with oral squamous cell carcinoma. Also, HPV16/18 is a co-factor in oral carcinogenesis, particularly in male patients and patients under the sixth decade. In addition, we found that HPV infection is a common event in the normal oral mucosa.

Kinetics of in vitro adsorption and entry of papillomavirus virions

There has been much incongruence in reports addressing the rate at which papillomaviruses enter cultured cells. We used a recently developed QRT-PCR assay (J. Virol. Methods 111 (2003) 135) to analyze the expression, adsorption, and entry kinetics of human papillomavirus type 11 (HPV-11) in multiple cell lines. Parallel experiments with HPV-40 and cottontail rabbit papillomavirus (CRPV) were also performed with biologically relevant lines. Infection was determined by the expression of early transcripts containing the E1 E4 splice junction. Results support previous observations that papillomaviruses may enter cultured cells much more slowly than rates reported for similarly structured viruses (Virology 207 (1995) 136; Virology 307 (2003) 1; J. Virol. 75 (2001) 1565). Additionally, our data suggest that, following adsorption to the cell surface, capsomeric structure remains largely unchanged for many hours as HPV-11 virions remain equally susceptible to neutralization by a nonspecific microbicide and by L1-specific monoclonal antibodies (MAb) targeting both linear and conformationally sensitive epitopes.

Recapitulation of the effects of the human papillomavirus type 16 E7 oncogene on mouse epithelium by somatic Rb deletion and detection of pRb-independent effects of E7 in vivo

Although the human papillomavirus (HPV) E7 oncogene is known to contribute to the development of human cervical cancer, the mechanisms of its carcinogenesis are poorly understood. The first identified and most recognized function of E7 is its binding to and inactivation of the retinoblastoma tumor suppressor (pRb), but at least 18 other biological activities have also been reported for E7. Thus, it remains unclear which of these many activities contribute to the oncogenic potential of E7. We used a Cre-lox system to abolish pRb expression in the epidermis of transgenic mice and compared the outcome with the effects of E7 expression in the same tissue at early ages. Mice lacking pRb in epidermis showed epithelial hyperplasia, aberrant DNA synthesis, and improper differentiation. In addition, Rb-deleted epidermis (i.e., epidermis composed of cells with Rb deleted) exhibited centrosomal abnormalities and failed to arrest the cell cycle in response to ionizing radiation. Transgenic mice expressing E7 in skin display the same range of phenotypes. In sum, few differences were detected between Rb-deleted epidermis and E7-expressing epidermis in young mice. However, when both E7 was expressed and Rb was deleted in the same tissue, increased hyperplasia and dysplasia were observed. These findings indicate that inactivation of the Rb pathway can largely account for E7's phenotypes at an early age, but that pRb-independent activities of E7 are detectable in vivo.

Signals that dictate nuclear localization of human papillomavirus type 16 oncoprotein E6 in living cells

Human papillomavirus (HPV) type 16 E6 (16E6) is an oncogenic, multifunctional nuclear protein that induces p53 degradation and perturbs normal cell cycle control, leading to immortalization and transformation of infected keratinocytes and epithelial cells. Although it is unclear how 16E6 disrupts the epigenetic profile of host genes, its presence in the nucleus is a key feature. The present report describes intrinsic properties of 16E6 that influence its nuclear import in living cells. When the coding region of full-length 16E6 was inserted in frame into the C terminus of green fluorescent protein (GFP), it effectively prevented the 16E6 pre-mRNA from being spliced and led to the expression of a GFP-E6 fusion which localized predominantly to the nucleus. Further studies identified three novel nuclear localization signals (NLSs) in 16E6 that drive the protein to accumulate in the nucleus. We found that all three NLS sequences are rich in positively charged basic residues and that point mutations in these key residues could abolish the retention of 16E6 in the nucleus as well as the p53 degradation and cell immortalization activities of the protein. When inserted into corresponding regions of low-risk HPV type 6 E6, the three NLS sequences described for 16E6 functioned actively in converting the normally cytoplasmic HPV type 6 E6 into a nuclear protein. The separate NLS sequences, however, appear to play different roles in nuclear import and retention of HPV E6. The discovery of three unique NLS sequences in 16E6 provides new insights into the nuclear association of 16E6 which may reveal other novel activities of this important oncogenic protein.

Further evidence that papillomavirus capsids exist in two distinct conformations

Cell surface heparan sulfate proteoglycans (HSPGs) serve as primary attachment receptors for human papillomaviruses (HPVs). To demonstrate that a biologically functional HPV-receptor interaction is restricted to a specific subset of HSPGs, we first explored the role of HSPG glucosaminoglycan side chain modifications. We demonstrate that HSPG O sulfation is essential for HPV binding and infection, whereas de-N-sulfated heparin interfered with VLP binding but not with HPV pseudoinfection. This points to differences in VLP-HSPG and pseudovirion-HSPG interactions. Interestingly, internalization kinetics of VLPs and pseudovirions, as measured by fluorescence-activated cell sorting analysis, also differ significantly with approximate half times of 3.5 and 7.5 h, respectively. These data suggest that differences in HSPG binding significantly influence postbinding events. We also present evidence that pseudovirions undergo a conformational change after cell attachment. A monoclonal antibody (H33.J3), which displays negligible effectiveness in preattachment neutralization assays, efficiently neutralizes cell-bound virions. However, no difference in H33.J3 binding to pseudovirions and VLPs was observed in enzyme-linked immunosorbent assay and virus capture assays. In contrast to antibody H33.B6, which displays equal efficiencies in pre- and postattachment neutralization assays, H33.J3 does not block VLP binding to heparin, demonstrating that it interferes with steps subsequent to virus binding. Our data strongly suggest that H33.J3 recognizes a conformation-dependent epitope in capsid protein L1, which undergoes a structural change after cell attachment.

Different heparan sulfate proteoglycans serve as cellular receptors for human papillomaviruses

Papillomaviruses replicate in stratified epithelia of skin and mucosa. Infection with certain human papillomavirus (HPV) types is the main cause of anogenital neoplasia, in particular cervical cancer. Early events of papillomavirus infectivity are poorly understood. While heparan sulfate proteoglycans (HSPGs) mediate initial binding to the cell surface, the class of proteins carrying heparan sulfates has not been defined. Here we examined two processes of papillomavirus infection, attachment of virus-like particles (VLP) to cells and infection with authentic HPV type 11 (HPV11) virions. Of the HSPGs, syndecan-1 is the major epithelial form and is strongly upregulated in wound edge keratinocytes. We employed K562 cells, which lack HSPGs except minor amounts of endogenous betaglycan, and stable clones that express cDNAs of syndecan-1, syndecan-4, or glypican-1. Binding of VLP correlated with levels of heparan sulfate on the cell surface. Parental K562 bound HPV16 VLP weakly, whereas all three K562 transfectants demonstrated enhanced binding, with the highest binding capacity observed for syndecan-1-transfected cells, which also expressed the most HSPG. For HPV11 infectivity assays, a high virion inoculum was required to infect K562 cells, whereas ectopic expression of syndecan-1 increased permissiveness eightfold and expression of syndecan-4 or glypican-1 fourfold. Infection of keratinocytes was eliminated by treatment with heparitinase, but not phospholipase C, further implicating the syndecan family of integral membrane proteins as receptor proteins. Human keratinocytes with a homozygous deletion of alpha6 integrin are permissive for HPV11 infection. These results indicate that several HSPGs can serve as HPV receptors and support a putative role for syndecan-1, rather than alpha6 integrin, as a primary receptor protein in natural HPV infection of keratinocytes.

Extended duration of the detectable stage by adding HPV test in cervical cancer screening

The human papillomavirus test (HPV) test could improve the (cost−) effectiveness of cervical screening by selecting women with a very low risk for cervical cancer during a long period. An analysis of a longitudinal study suggests that women with a negative Pap smear and a negative HPV test have a strongly reduced risk of developing cervical abnormalities in the years following the test, and that HPV testing lengthens the detectable stage by 2–5 years, compared to Pap smear detection alone.

Human papillomavirus detection: verification with cervical cytology

OBJECTIVE

Thirteen specific types of human papillomavirus (HPV), classified as high-risk for the development of cervical cancer, have been reported in 99.7% of all cervical cancers. For this reason, and because of the reported lack of sensitivity of the Papanicolaou (Pap) smear for detecting HPV, some experts believe that the use of papillomavirus DNA testing may replace cytology for routine gynecological screening. Our goal was to validate a commercial assay, the Digene Hybrid Capture-2 for the detection of human papillomavirus by comparing the results to cytological detection of cervical abnormalities.

DESIGN

Cytology results of concurrent liquid-based Papanicolaou smears were compared to the Hybrid Capture-2 results. Correlation was assessed and discordant cytology results were reviewed.

SETTING

Louisiana State University Health Sciences Center at Shreveport, Department of Pathology, HPV Diagnostic Laboratory.

PATIENTS

All liquid cytology specimens submitted for HPV testing between November 1, 2000 and April 1, 2001.

RESULTS

Of the 291 cases tested by Hybrid Capture-2, 12% and 28% were positive with the low-risk and high-risk probes, respectively, and 265 had concurrent cytology results. Fourteen specimens testing positive only with the low-risk probe were not included in this comparison. Thus, the results for 251 of the 291 (86%) specimens tested for human papillomavirus DNA were compared to the original cytology report. Overall concordance between Hybrid Capture-2 and the original smear cytology result was 78%. Slide review reduced the number of discordant specimens from 22% to 12%.

CONCLUSION

Based upon these data, we find the HPV assay to be useful as a routine screen for Human papillomavirus.

Human papillomavirus type 59 immortalized keratinocytes express late viral proteins and infectious virus after calcium stimulation

Human papillomavirus type 59 (HPV 59) is an oncogenic type related to HPV 18. HPV 59 was recently propagated in the athymic mouse xenograft system. A continuous keratinocyte cell line infected with HPV 59 was created from a foreskin xenograft grown in an athymic mouse. Cells were cultured beyond passage 50. The cells were highly pleomorphic, containing numerous abnormally shaped nuclei and mitotic figures. HPV 59 sequences were detected in the cells by DNA in situ hybridization in a diffuse nuclear distribution. Southern blots were consistent with an episomal state of HPV 59 DNA at approximately 50 copies per cell. Analysis of the cells using a PCR/reverse blot strip assay, which amplifies a portion of the L1 open reading frame, was strongly positive. Differentiation of cells in monolayers was induced by growth in F medium containing 2 mM calcium chloride for 10 days. Cells were harvested as a single tissue-like sheet, and histologic analysis revealed a four-to-six cell-thick layer. Transcripts encoding involucrin, a cornified envelope protein, and the E1/E4 and E1/E4/L1 viral transcripts were detected after several days of growth in F medium containing 2 mM calcium chloride. The E1/E4 and L1 proteins were detected by immunohistochemical analysis, and virus particles were seen in electron micrographs in a subset of differentiated cells. An extract of differentiated cells was prepared by vigorous sonication and was used to infect foreskin fragments. These fragments were implanted into athymic mice. HPV 59 was detected in the foreskin xenografts removed 4 months later by DNA in situ hybridization and PCR/reverse blot assay. Thus, the complete viral growth cycle, including production on infectious virus, was demonstrated in the HPV 59 immortalized cells grown in a simple culture system.

Selective suppression of monocyte chemoattractant protein-1 expression by human papillomavirus E6 and E7 oncoproteins in human cervical epithelial and epidermal cells

Infection of cervical keratinocytes by high-risk HPV is involved in the etiology of cervical carcinoma. Since viral products are immunogenic, development of cancer may require suppression of immune responses directed against infected epithelial cells. Many markers of host immune effector responses decrease as cervical intraepithelial neoplasia progresses. Among these is epithelial cell expression of the chemokine MCP-1, though the mechanism for its suppression is unclear. Here, we show that the E6 and E7 viral oncogenes from high-risk HPV, individually and together, suppress MCP-1 expression in primary epithelial cells derived from the female genital tract. This is not a consequence of global suppression of chemokine expression since other chemokines, including IP-10, IL-8 and RANTES, were less affected. Furthermore, 4 of 6 HPV-positive cervical carcinoma cell lines did not express MCP-1. Our data indicate that suppression of MCP-1 expression is part of the program of high-risk HPV E6/E7-induced transformation of primary epithelial cells. These observations are consistent with a model in which MCP-1 expression by infected keratinocytes, which would stimulate an immune attack on HPV-transformed cells, is suppressed for invasive cervical cancer to appear.

The effect of codon 98 of the FHIT gene on cervical cancer in Korean women

The Fragile Histadine Triad (FHIT) is a putative tumor suppressor gene involved in different tumors. The objective of this study was to examine the effect of codon 98 of FHIT on cervical carcinogenesis. The study subjects were patients who were pathologically diagnosed with cervical neoplasia and who had a positive result for human papillomavirus (n = 567) compared to normal healthy women as normal controls (n = 506). The FHIT-specific sequences of DNA from peripheral blood samples from study subjects were determined by PCR using allele-specific primers and were compared with those of the controls. The genetic susceptibility of codon 98 of the FHIT gene (3p14.2) in cervical carcinogenesis was determined by examining the effect of the gene and environmental factors vs. the different stages of cervical intraepithelial lesions and the different histopathologic types of invasive cervical cancers. On assessing FHIT polymorphisms, the percentages of individuals homozygous for the T allele, homozygous for the C allele, and heterozygous for these two alleles were 42.1%, 11.3, and 46.6% in the control group. The corresponding figures were 39.5%, 14.8%, and 45.7% among in women with cervical cancer. Compared with FHIT T/ T, odds ratio (95% confidence interval) for FHIT C/C was 1.4 (0.8-2.5) for invasive cervical cancer and 1.7 (0.9-3.1) for cervical intraepithelial neoplasia (CIN) II or III. The risks for invasive cervical cancer were higher with early onset cervical carcinogenesis (2.3, 1.0-5.5, P = 0.0438), than with late onset (1.0, 0.5-2.1, P = 0.9306). The risks of FHIT C/C or C/ T also increased for ever smokers or women with two or more children compared with FHIT T/ T. Polymorphisms of FHIT are associated with a higher risk of developing cervical cancer, in particular early onset cervical carcinogenesis.

Diet and premalignant lesions of the cervix: evidence of a protective role for folate, riboflavin, thiamin, and vitamin B12

OBJECTIVE

A case-control study was conducted among a population of multiethnic women identified from clinics on Oahu, Hawaii between 1992 and 1996 to explore the relationship between diet and cervical dysplasia.

METHODS

Two-hundred and fourteen women with biopsy-confirmed high and low grade squamous intraepithelial lesions of the cervix (SIL) and 271 controls were identified. Exfoliated cervical cells were collected for HPV DNA testing. Surveys were administered to assess non-dietary risk factors and intake of nutrients from over 250 specific food items as well as nutritional supplements.

RESULTS

Riboflavin and thiamin from food sources, vitamin B12 supplements, and total (food and supplements) folate displayed inverse, dose-responsive associations with high-grade SIL (HSIL). Riboflavin from food sources and total folate also demonstrated inverse, dose-responsive associations with low-grade SIL (LSIL). The odds ratios for LSIL and HSIL were reduced by 50-90% for the highest compared to the lowest levels of intake of these nutrients. A number of major food sources of these vitamins, including all types of breads, bran cereal, and fruit juice, also demonstrated inverse associations with HSIL. There was some evidence that the increased risk of HSIL associated with low nutrient intake was most pronounced among drinkers and smokers.

CONCLUSIONS

This investigation provides evidence that thiamin, riboflavin, folate, and vitamin B12 may play a protective role in cervical carcinogenesis.

The interaction between steroid hormones, human papillomavirus type 16, E6 oncogene expression, and cervical cancer

Various risk factors have been implicated in the causation of cervical cancer including human papillomavirus (HPV), the early genes (E6 and E7 ) of which encode the main transforming proteins. Studies have suggested that steroid hormones may enhance the expression of these genes leading to loss of p53 gene-mediated cell apoptosis. A total of 120 cervical tissue samples were obtained from patients with proven cervical cancer. Patients who used depo-medroxyprogesterone acetate steroid contraception were recruited as part of the steroid arm. Only HPV DNA type 16 samples were used for the study. Controls included three cell lines (CaSki, SiHa, & C33A) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an internal housekeeping gene. Of 120 patients, there were 111 patients with HPV type 16 identified. Of this number, RNA was present in 63 samples. There were 30 women (30/63) who used steroid contraception. In relation to patients who used contraception, HPV 16 E6 gene expression was present in 79% (n = 23) and 88% (n = 30) of steroid users compared to nonusers, respectively. In total there were 25 patients (40%) with expression of the HPV 16 E6*I gene and 30 patients with expression of the E6*II gene. There were 57% of steroid users (n = 17) who had expression of the E6*I/E6*II gene, compared to 52% (n = 17) of nonusers (P = 0.800). From a molecular level, this study does not confirm the role of injectable progesterones in cervical carcinogenesis.

Shanxi Province cervical cancer screening study II: Self-sampling for high-risk human papillomavirus compared to direct sampling for human papillomavirus and liquid based cervical cytology

The objective of this study was to compare the sensitivity and specificity of a new method for self-sampling for high risk human papillomavirus (HPV) with direct sampling and liquid based cervical cytology. In Shanxi Province, China, 8,497 women (ages 27-56) underwent a self-sample for HPV using a conical-shaped brush placed into the upper vagina and rotated. Three to sixteen months later the women were screened with liquid-based cytology and direct HPV tests. Subjects with any abnormal test underwent colposcopy and multiple biopsies. Mean age was 40.9 years. 4.4 percent of subjects had >or=CIN II, 26% a positive self-sample and 24% a positive direct test for HPV. The sensitivity for detection of >or=CIN II was 87.5% for self-sampling, and 96.8% for the direct test (P < 0.001). The specificity was 77.2% for the self-sample and 79.7% for the direct test. With an abnormal Pap defined as ASCUS or greater the sensitivity of the Pap for the detection of >CIN II was 88.3% and the specificity was 81.2%. We conclude that self-sampling for HPV is less sensitive for >CIN II than the direct test, but similar to liquid based cytology.

Moderate variation of the oncogenic potential among high-risk human papillomavirus types in gynecologic patients with cervical abnormalities

The oncogenic potential of human papillomavirus (HPV) infection was assessed by following the disease course in 455 patients who had had a routine diagnostic Hybrid Capture HPV test due to squamous cell abnormalities of the uterine cervix as detected by cytology and/or colposcopy. At entry, 308 patients had cytologic atypia classified as P3 by the Papanicolau classification, 168 had a positive high-risk HPV test, and 23 were infected only with low-risk HPV. The patients were followed-up using the patient registry until the endpoint of histologically diagnosed cervical intraepithelial neoplasia (CIN). High-grade CIN was diagnosed in 75 surgical biopsies. High-risk HPV infection (relative risk: 76.8 CI(95): 23.7-249.5), cytologic atypia (RR: 16.2 CI(95): 3.9-66.6), and age above 35 (RR: 1.99 CI(95): 1.26-3.16) were independent risk factors for high-grade CIN, while the viral load did not predict oncogenic progression (P = 0.47). After PCR-RFLP typing, the high-risk types were classified into groups as follows: (1) types 16 and 18, (2) types 45, 52, and 56, (3) types 31, 33, 35, 51, and 58. The relative risks of high-grade CIN were 119.1 (CI(95): 36.2-390.9) for group 1, 44.4 (CI(95): 9.8-201) for group 2, and 39.7 (CI(95): 10.9-144.8) for group 3, respectively. The risk ratios between the groups of high-risk types were found to differ at most by a factor of 2.98 (corrected P value: 0.007) indicating that the oncogenic potential varies moderately within the high-risk group of HPVs.

Buccal exposure to human papillomavirus type 16 is a common yet transitory event of childhood

High-risk human papillomaviruses, such as type 16 (HPV-16), are established etiological agents for cervical carcinoma. In most cases, this virus is transmitted sexually, though can also be spread from mother to infant at delivery. We have demonstrated previously a high prevalence ( approximately 52%) of HPV-16 DNA in the mouths of prepubertal children, albeit with low levels of transcription [Rice et al., 2000]. We investigated whether childhood buccal infections with HPV-16 are persistent or transient and whether children became infected through contact with their immediate family members. Two groups of children were selected: one group were all initially HPV-16 E5 DNA-positive in sensitive polymerase chain reaction tests of swabs from their buccal mucosa (n = 20), and the other group consisted of children who were all HPV-16 E5-negative (n = 19). Thirty months later, a second oral swab was collected from each child and tested for HPV DNA. At this second visit, 40% of the HPV-16-positive group had no detectable HPV-16 DNA; conversely, 63% of children who were originally HPV-16-negative had now acquired the virus. Three months later, a third sample was collected from eight children and their immediate families (seven were HPV-16 E5 DNA-positive at the second visit). Amongst the family samples tested, in two families a single previously untested child was HPV-16 DNA-positive. It is concluded that HPV-16 DNA in the oral cavities of children is a transient event and is most probably acquired from their peers.