Regulation of human papillomavirus type 18 in vivo: effects of estrogen and progesterone in transgenic mice

Small DNA tumor viruses and human cancer: Preclinical models of virus infection and disease

Human tumor viruses cause various human cancers that account for at least 15% of the global cancer burden. Among the currently identified human tumor viruses, two are small DNA tumor viruses: human papillomaviruses (HPVs) and Merkel cell polyomavirus (MCPyV). The study of small DNA tumor viruses (adenoviruses, polyomaviruses, and papillomaviruses) has facilitated several significant biological discoveries and established some of the first animal models of virus-associated cancers. The development and use of preclinical in vivo models to study HPVs and MCPyV and their role in human cancer is the focus of this review. Important considerations in the design of animal models of small DNA tumor virus infection and disease, including host range, cell tropism, choice of virus isolates, and the ability to recapitulate human disease, are presented. The types of infection-based and transgenic model strategies that are used to study HPVs and MCPyV, including their strengths and limitations, are also discussed. An overview of the current models that exist to study HPV and MCPyV infection and neoplastic disease are highlighted. These comparative models provide valuable platforms to study various aspects of virus-associated human disease and will continue to expand knowledge of human tumor viruses and their relationship with their hosts.

Effect of human papilloma virus infection on in-vitro fertilization outcome: systematic review and meta-analysis

OBJECTIVES

To identify, appraise and summarize the available data concerning the impact of human papilloma virus (HPV) infection on reproductive outcome following in-vitro fertilization (IVF).

METHODS

We searched for studies in PubMed, EMBASE, Scopus, Lilacs and the Cochrane Central Register of Controlled Trials from inception to March 2017. Any type of HPV infection assessed through polymerase chain reaction, subfertility factors and IVF indications and protocols were considered. Our primary outcomes were live birth/ongoing pregnancy and miscarriage, while secondary outcomes included clinical and laboratory parameters. We planned subgroup analyses according to the status of cervical cytology and presence of infection in the male partner. We assessed the relative risk (RR), using a random-effects model; heterogeneity was assessed using the I² statistic. Quality of the evidence was evaluated using the recommendations of the GRADE Working Group.

RESULTS

From the 14 studies eligible for inclusion, quantitative data from 10, evaluating 299 women with HPV infection and 2049 women without HPV infection, were included in the analysis. The pooled results showed no significant difference between HPV-infected and non-infected women in rates of live birth/ongoing pregnancy (RR, 1.16 (95% CI, 0.88-1.53); I²  = 0%; six studies, 983 women), clinical pregnancy (RR, 1.06 (95% CI, 0.74-1.54); I²  = 61%; eight studies, 1173 women) or miscarriage (RR, 1.58 (95% CI, 0.93-2.69); I²  = 8%; six studies, 290 clinical pregnancies). The overall quality of the evidence was very low, downgraded two levels because of serious limitations of the included studies (observational studies) and imprecision. In contrast, pooled results in the subgroup analysis based on the presence of infection in the male partner showed significant differences in rates of live birth/ongoing pregnancy (RR, 0.43 (95% CI, 0.23-0.82); I²  = 0%; three studies, 429 participants; P = 0.01) and miscarriage (RR, 3.70 (95% CI, 1.94-7.05); I²  = 0%; two studies, 90 participants; P < 0.0001).

CONCLUSIONS

The available evidence is still inadequate to enable us to draw firm conclusions regarding the effect of HPV infection in women on the most important reproductive outcomes following IVF; however, it suggests that the effect is not large for rates of live birth/ongoing pregnancy and clinical pregnancy. When infection is present in the male partner, it seems that there is a negative effect on live birth/ongoing pregnancy rate and an increase in miscarriage rate, a finding that should be interpreted with caution, owing to the very low quality of evidence supporting it. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Reproductive and genital health and risk of cervical human papillomavirus infection: results from the Ludwig-McGill cohort study

Background

There are inconsistencies in the literature on reproductive and genital health determinants of human papillomavirus (HPV) infection, the primary cause of cervical cancer. We examined these factors in the Ludwig-McGill Cohort Study, a longitudinal, repeated-measurements investigation on the natural history of HPV infection.

Methods

We analyzed a cohort subset of 1867 women with one complete year of follow-up. We calculated odds ratios (OR) and 95 % confidence intervals (CI) for reproductive and genital health characteristics from questionnaire and laboratory data in relation to 1-year period prevalence of HPV infection. Two outcomes were measured; the first based on phylogenetic grouping of HPV types based on tissue tropism and oncogenicity (Alphapapillomavirus Subgenus 1: species 1, 8, 10 and 13; Subgenus 2: species 5, 6, 7, 9, 11; Subgenus 3: species 3, 4 and 14) and the second based on transient or persistent HPV infections.

Results

Lifetime (Subgenus 3 OR = 2.00, CI: 1.23–3.24) and current (Subgenus 3 OR = 2.00, CI: 1.15–3.47) condom use and use of contraceptive injections (Subgenus 1 OR = 1.96, CI: 1.22–3.16, Subgenus 2 OR = 1.34, CI: 1.00–1.79) were associated with increased risk of HPV infection. Intrauterine device use was protective (Subgenus 1 OR = 0.48, CI: 0.30–0.75, Subgenus 2 OR = 0.78, CI: 0.62–0.98). These factors were not associated with persistence of HPV infection. Tampon use, previous gynecologic infections and cervical inflammation were associated with an overall increased risk of HPV infection.

Conclusions

Cervical HPV infection was associated with reproductive and genital health factors. Further studies are necessary to confirm the low to moderate associations observed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1446-x) contains supplementary material, which is available to authorized users.

Role of nuclear progesterone receptor isoforms in uterine pathophysiology

BACKGROUND

Progesterone is a key hormonal regulator of the female reproductive system. It plays a major role to prepare the uterus for implantation and in the establishment and maintenance of pregnancy. Actions of progesterone on the uterine tissues (endometrium, myometrium and cervix) are mediated by the combined effects of two progesterone receptor (PR) isoforms, designated PR-A and PR-B. Both receptors function primarily as ligand-activated transcription factors. Progesterone action on the uterine tissues is qualitatively and quantitatively determined by the relative levels and transcriptional activities of PR-A and PR-B. The transcriptional activity of the PR isoforms is affected by specific transcriptional coregulators and by PR post-translational modifications that affect gene promoter targeting. In this context, appropriate temporal and cell-specific expression and function of PR-A and PR-B are critical for normal uterine function.

METHODS

Relevant studies describing the role of PRs in uterine physiology and pathology (endometriosis, uterine leiomyoma, endometrial cancer, cervical cancer and recurrent pregnancy loss) were comprehensively searched using PubMed, Cochrane Library, Web of Science, and Google Scholar and critically reviewed.

RESULTS

Progesterone, acting through PR-A and PR-B, regulates the development and function of the endometrium and induces changes in cells essential for implantation and the establishment and maintenance of pregnancy. During pregnancy, progesterone via the PRs promotes myometrial relaxation and cervical closure. Withdrawal of PR-mediated progesterone signaling triggers menstruation and parturition. PR-mediated progesterone signaling is anti-mitogenic in endometrial epithelial cells, and as such, mitigates the tropic effects of estrogen on eutopic normal endometrium, and on ectopic implants in endometriosis. Similarly, ligand-activated PRs function as tumor suppressors in endometrial cancer cells through inhibition of key cellular signaling pathways required for growth. In contrast, progesterone via PR activation appears to increase leiomyoma growth. The exact role of PRs in cervical cancer is unclear. PRs regulate implantation and therefore aberrant PR function may be implicated in recurrent pregnancy loss (RPL). PRs likely regulate key immunogenic factors involved in RPL. However, the exact role of PRs in the pathophysiology of RPL and the use of progesterone for therapeutic benefit remains uncertain.

CONCLUSIONS

PRs are key mediators of progesterone action in uterine tissues and are essential for normal uterine function. Aberrant PR function (due to abnormal expression and/or function) is a major cause of uterine pathophysiology. Further investigation of the underlying mechanisms of PR isoform action in the uterus is required, as this knowledge will afford the opportunity to create progestin/PR-based therapeutics to treat various uterine pathologies.

The role of retinoid deficiency and estrogens as cofactors in cervical cancer

Persistent infection with high-risk human papillomaviruses (HR-HPVs) is involved in cervical cancer (CC), a major cause of cancer mortality worldwide. Infection occurs primarily at the transformation zone (TZ), the most estrogen- and retinoid-sensitive region of the cervix. Development of CC affects a small percentage of HR-HPV-infected women and often takes decades after infection, suggesting that HR-HPV is a necessary but not sufficient cause of CC. Thus, other cofactors are necessary for progression from cervical HR-HPV infection to cancer such as long-term use of hormonal contraceptives, multiparity, smoking, as well as micronutrient depletion and in particular retinoid deficiency, which alters epithelial differentiation, cellular growth and apoptosis of malignant cells. Therefore, early detection of HR-HPV and management of precancerous lesions together with a profound understanding of additional risk factors could be a strategy to avoid this disease. In this review we focus on the synergic effect of estrogens, retinoid deficiency and HR-HPVs in the development of CC. These risk factors may act in concert to induce neoplastic transformation in squamous epithelium of the cervix, setting the stage for secondary genetic or epigenetic events leading to cervical cancer.

Transplacental transmission of Human Papillomavirus

This paper aimed at studying the transplacental transmission of HPV and looking at the epidemiological factors involved in maternal viral infection. The following sampling methods were used: (1) in the pregnant woman, (a) genital; (b) peripheral blood; (2) in the newborn, (a) oral cavity, axillary and inguinal regions; (b) nasopharyngeal aspirate, and (c) cord blood; (3) in the placenta. The HPV DNA was identified using two methods: multiplex PCR of human β-globin and of HPV using the PGMY09 and PGMY11 primers; and nested-PCR, which combines degenerated primers of the E6/E7 regions of the HPV virus, that allowed the identification of genotypes 6/11, 16, 18, 31, 33, 42, 52 and 58. Transplacental transmission was considered when type-specific HPV concordance was found between the mother, the placenta and the newborn or the mother and cord blood. The study included 49 HPV DNA-positive pregnant women at delivery. Twelve placentas (24.5%, n = 12/49) had a positive result for HPV DNA. Eleven newborn were HPV DNA positive in samples from the nasopharyngeal or buccal and body or cord blood. In 5 cases (10.2%, n = 5/49) there was HPV type-specific agreement between genital/placenta/newborn samples. In one case (2%, n = 1/49) there was type specific HPV concordance between genital/cord blood and also suggested transplacental transmission. A positive and significant correlation was observed between transplacental transmission of HPV infection and the maternal variables of immunodepression history (HIV, p = 0.011). In conclusion the study suggests placental infection in 23.3% of the cases studied and transplacental transmission in 12.2%. It is suggested that in future HPV DNA be researched in the normal endometrium of women of reproductive age. The possible consequence of fetal exposure to HPV should be observed.

Relationship of cytopathology and cervical infection to outcome of in-vitro fertilization and embryo transfer

OBJECTIVE

To determine whether a relationship exists between in-vitro fertilization and embryo transfer (IVF-ET) outcome and cervical infection or presence of human papillomavirus (HPV).

METHOD

Cervical scrapes, digital colposcopies, and cervical biopsies were performed in 1044 Chinese women undergoing IVF for tubal infertility or, in their partners, abnormal semen. The pregnant (n=415) and nonpregnant (n=629) groups differed neither in clinical signs of cervical inflammation nor in rate of HPV detection.

RESULTS

There were no associations between IVF-ET outcome and infection rate, degree of cytopathologic abnormality, detection of HPV, or results of digital colposcopy and cervical biopsy. Cytologic results did not correlate with any of the clinical parameters of IVF-ET.

CONCLUSIONS

No association was found between IVF-ET outcome and cervical infection, cytopathologic result, HPV detection, or result from the colposcopy or biopsy. Extensive testing and treatment for cervical infection do not appear necessary in IVF-ET candidates.

Relationship of Pregnancy to Human Papillomavirus Among Human Immunodeficiency Virus–Infected Women

OBJECTIVE

Because parity is a reported risk factor for cervical cancer, we sought to estimate the effects of pregnancy on the prevalence, incident detection, and copy number of human papillomavirus (HPV) among human immunodeficiency virus (HIV)-infected women, patients at high risk for cervical cancer.

METHODS

Human immunodeficiency virus-infected women who had a pregnancy in the Women's Interagency HIV Study (n = 178) and the Women and Infants Transmission Study (n = 450) underwent serial type-specific HPV DNA testing using MY09/MY11 polymerase chain reaction. During pregnancy and during the prepregnancy and postpregnancy periods, we assessed HPV prevalence, incident detection, and HPV copy number (estimated using hybridization signal strength) of both oncogenic and nononcogenic HPV. All binary-regression analyses incorporated generalized estimating equations to address the repeated observations of the same women over time, and were further adjusted for parity, gestational age, smoking, antiretroviral use, number of lifetime sexual partners, and oral contraceptive use.

RESULTS

The prevalence and copy number of oncogenic and nononcogenic HPV did not significantly differ between pregnancy and either the prepregnancy or postpregnancy periods. Incident HPV detection was significantly lower for both oncogenic and nononcogenic HPV during pregnancy compared with the postpregnancy period (relative risk 0.534, 95% confidence interval 0.390-0.732, P < .001 and relative risk 0.577, 95% confidence interval 0.428-0.779, P < .001, respectively), but not compared with the prepregnancy period

CONCLUSION

Among HIV-infected women, the incident detection of HPV is lower during pregnancy compared with postpregnancy, while prevalence and copy number do no differ between pregnancy and either prepregnancy or postpregnancy.

LEVEL OF EVIDENCE

II-3.

Incidence of Cervical Cytological Abnormalities With Aging in the Women’s Health Initiative

OBJECTIVE

To estimate the incidence of cytological abnormalities and cervical cancer and to determine the effect of oral estrogen and progestin on cervical cytology among postmenopausal women participating in a multi-institution clinical trial.

METHODS

The study was a longitudinal analysis of a prospective cohort of 16,608 postmenopausal women (aged 50-79 years) participating in the Women's Health Initiative (WHI) clinical trial of estrogen plus progestin. Eligible participants had a cervical smear within 1 year before randomization and at 3- and 6-year follow-ups. Outcomes measured were low-grade and high-grade squamous intraepithelial lesions (LSIL, HSIL) and cervical cancer at follow-up years 3 and 6.

RESULTS

Of 15,733 eligible participants with a uterus, 7,663 were assigned to placebo and 8,070 to estrogen plus progestin. At baseline, 318 women (2%) had low-grade abnormalities on cervical cytology. The annual incidence rate of any new cytological abnormality in the estrogen plus progestin group was significantly higher than that in the placebo group (hazard ratio 1.4, 95% confidence interval [CI] 1.2-1.6). Independent risk factors for HSIL and cervical cancer over a 6-year follow-up (after stratifying for baseline cytologic abnormalities) included sexual activity in the past year while not being married or living as married (hazard ratio 3.5, 95% CI 1.5-8.3). Risk factors did not include age or use of estrogen plus progestin.

CONCLUSION

Use of estrogen plus progestin was associated with increased incidence of any cytologic abnormality, although it had no impact on the incidence of HSIL or cervical cancer. Sexually active older women who are not married or living as married may benefit from continued cervical cancer screening.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, www.clinicaltrials.gov, NCT00000611.

Organization of human papillomavirus productive cycle during neoplastic progression provides a basis for selection of diagnostic markers

The productive cycle of human papillomaviruses (HPVs) can be divided into discrete phases. Cell proliferation and episomal maintenance in the lower epithelial layers are followed by genome amplification and the expression of capsid proteins. These events, which occur in all productive infections, can be distinguished by using antibodies to viral gene products or to surrogate markers of their expression. Here we have compared precancerous lesions caused by HPV type 16 (HPV16) with lesions caused by HPV types that are not generally associated with human cancer. These include HPV2 and HPV11, which are related to HPV16 (supergroup A), as well as HPV1 and HPV65, which are evolutionarily divergent (supergroups E and B). HPV16-induced low-grade squamous intraepithelial lesions (CIN1) are productive infections which resemble those caused by other HPV types. During progression to cancer, however, the activation of late events is delayed, and the thickness of the proliferative compartment is progressively increased. In many HPV16-induced high-grade squamous intraepithelial lesions (CIN3), late events are restricted to small areas close to the epithelial surface. Such heterogeneity in the organization of the productive cycle was seen only in lesions caused by HPV16 and was not apparent when lesions caused by other HPV types were compared. By contrast, the order in which events in the productive cycle were initiated was invariant and did not depend on the infecting HPV type or the severity of disease. The distribution of viral gene products in the infected cervix depends on the extent to which the virus can complete its productive cycle, which in turn reflects the severity of cervical neoplasia. It appears from our work that the presence of such proteins in cells at the epithelial surface allows the severity of the underlying disease to be predicted and that markers of viral gene expression may improve cervical screening.

Neoplastic change of squamo-columnar junction in uterine cervix and vaginal epithelium by exogenous estrogen in hpv-18 URR E6/E7 transgenic mice

OBJECTIVE

The goal of this study was to study whether estrogen could induce progression of cervical neoplasia by the influence of direct hormonal transactivation of the viral genes.

METHODS

We examined the in vivo effect of estrogen on HPV-18 URR E6/E7 transgenic mice. We analyzed the growth stimulation of epithelial cells at squamo-columnar junction and vagina and the expression of HPV E6/E7 in transgenic mice. The promoter activity of HPV-18 URR after treatment of estrogen was also evaluated by in vitro transient transfection assay.

RESULTS

The dysplastic lesions of lower genital tract were more frequently seen in the HPV-18 URR E6/E7 transgenic mice and estrogen-treated mice, when compared to those of control group (P < 0.05). The majority of cells in whole epithelial layer of cervix and vagina were proliferating cell nuclear antigen-positive (PCNA) by immunohistochemical staining in the estrogen-treated transgenic mice. Hyperplastic glandular lesions were also identified in estrogen-treated HPV-18 URR E6/E7 transgenic mice (5 of 21) and estrogen-treated nontransgenic mice (2 of 10). The level of E6/E7 transcripts in transgenic mouse was increased in the presence of estradiol. Treatment with 0.5 x 10(-6) M estradiol in the presence of cotransfection with the estrogen receptor expression vector and URR-CAT showed an additive effect of CAT activity (4.8-fold increase).

CONCLUSION

The HPV E6 and E7 oncogenes implicated in cervical cancer are indeed capable of potentiating tumor formation in animal model. Continual estrogen-induced proliferation might be viewed by in vivo and in vitro mechanisms by which squamous cells as well as glandular cells in cervix and vagina became permissive for neoplastic progression in HPV-18 URR E6/E7 transgenic mice and their molecular systems.

Prevalence and genotype distribution of cervical human papillomavirus infection: Comparison between pregnant women and non-pregnant controls

Controversies exist on the effect of pregnancy on human papillomavirus (HPV) infection. A cross-sectional section study was conducted to compare the prevalence and genotype distribution of cervical HPV infection between pregnant and non-pregnant women in Hong Kong. Cervical samples were collected from 308 pregnant women and from the same number of age-matched controls recruited from a cervical cancer screening center located at the same hospital. HPV was detected by the polymerase chain reaction, followed by genotype identification by restriction fragment length polymorphism and direct sequencing analyses. The prevalence of HPV for pregnant women was 10.1%, without significant variation with age, gestation, gravidity and parity. The prevalence of HPV for non-pregnant group was 11.4% and did not show significant difference when compared to the pregnant group either by overall or age-stratified subgroup analyses. When the analysis was stratified according to the risk-type of HPV infection, still no significant difference between pregnant and non-pregnant groups was observed (all types: 10.1 vs. 11.4%, P = 0.602; high-risk types: 5.8 vs. 7.8%, P = 0.338; low-risk types: 1.0 vs. 2.9%, P = 0.080; unknown-risk types: 3.2% vs. 1.3%, P = 0.105). The results of this study show no evidence for an influence of pregnancy on HPV prevalence, and a majority of HPV-infected pregnant women had normal cervical cytology. HPV positive results in pregnant women per se should be managed conservatively.

High-risk human papillomavirus clearance in pregnant women: trends for lower clearance during pregnancy with a catch-up postpartum

We followed 353 women referred with abnormal cervical cytology in a non-intervention cohort study. In 91 pregnant women we compared high-risk human papilloma virus rates in the subsequent trimesters and postpartum in comparison to 262 non-pregnant women. High-risk human papilloma virus clearance was compared with 179 high-risk human papilloma virus positive non-pregnant women. Our main questions were: (1) do high-risk human papilloma virus rates change during pregnancy?; and (2) is there any difference between high-risk human papilloma virus clearance in pregnant and non-pregnant women? Women were monitored 3-4 monthly by cytology, colposcopy, and high-risk human papilloma virus testing. The median follow-up time was 33 months (range 3-74). Non-pregnant women showed prevalence rates of high-risk human papilloma virus of 64, 57, 53, and 50%, respectively, in four subsequent 3-months periods since the start of the study. These high-risk human papilloma virus rates were higher than in the three trimesters of pregnancy, and during the first 3 months postpartum, i.e. 50, 44, 45, and 31%, respectively. Postpartum only, this difference was statistically significant (P=0.004). Paired comparisons of high-risk human papilloma virus prevalence rates of the different trimesters with the postpartum rate showed (McNemar test) decreased rates: first trimester: 18% (P=0.02), second trimester: 13% (P=0.02) and third trimester: 23% (P<0.005). Such a phenomenon was not found in non-pregnant women. Pregnant women showed a trend for increased high-risk human papilloma virus clearance during the third trimester and postpartum compared to non-pregnant women (hazard ratios 3.3 (0.8-13.7) and 4.6 (1.6-12.8), respectively). These results suggest a lowered immune-response against human papilloma virus during the first two trimesters of pregnancy with a catch-up postpartum.

Oestrogen receptor transcripts associated with cervical human papillomavirus infection

OBJECTIVE

Studies have been inconsistent in establishing sex steroids as a risk factor for human papillomavirus (HPV) infections. This study was designed to determine whether cervical oestrogen receptors (as measured by oestrogen receptor transcripts) at the cervix would be associated with cervical HPV infections.

METHODS

In 175 women, ages 14-44, we tested for the presence of HPV DNA and oestrogen receptors transcripts at the cervix during routine pelvic examinations. All subjects completed a self administered questionnaire regarding sexual and menstrual histories.

RESULTS

40% of the women (n=70) tested positive for HPV at the cervix. Of those women testing positive for HPV, 99% had detectable levels of Oestrogen receptors transcripts (n=69/70). HPV cervical infections were independently associated with presence of Oestrogen receptors transcripts (OR=39.8, CI=4.4, 361.1) and greater numbers of sexual partners (OR=1.1, CI=1.01, 1.18).

CONCLUSION

Women who expressed higher levels of oestrogen receptors transcripts were significantly more likely to have cervical HPV infection. These results demonstrate that Oestrogen receptors may play an important part in cervical HPV infections.

In vivo tissue-specific regulation of the human papillomavirus type 18 early promoter by estrogen, progesterone, and their antagonists

Human papillomavirus type 18 is a causative agent of epithelial cancers in the uterine cervix. We show here that estrogen and progesterone activate beta-galactosidase expression from the early promoter of this virus in the genital epithelia of transgenic mice. Ovariectomy caused suppression of transgene expression exclusively in vagina and cervix epithelia. Beta-galactosidase expression could be restored in ovariectomized females by administration of estrogen, alone or in combination with progesterone. Further, rescue of transgene expression was inhibited by the estrogen antagonist tamoxifen and the anti-progesterone RU486, suggesting that this was a specific effect.

Adenoassociated virus type 2-induced inhibition of the human papillomavirus type 18 promoter in transgenic mice

The epithelium of the cervix uteri has been reported to be frequently coinfected with both human papillomaviruses (HPV) and helper virus-dependent adenoassociated viruses (AAV). Seroepidemiological data suggest that AAV infection could inhibit cervical cancer that is caused by specific ("high-risk") types of papillomaviruses. In vitro, infection with AAV type 2 (AAV-2) or transfection of AAV-2 early (rep) genes has been shown to inhibit transformation by papillomaviruses. To analyze the effects of AAV on HPV in vivo, we studied the influence of AAV-2 infection on the promoter activity of high-risk HPV type 18 (HPV-18) in mice, transgenic for sequences of the upstream regulatory region (URR) of HPV-18 controlling transcription of the reporter gene, lacZ. Transgenic animals (or tongue cells thereof, explanted and grown in culture) were treated with dexamethasone to induce the HPV-18 promoter. Simultaneously they were (i) infected with AAV, (ii) inoculated with AAV virus-like particles (VLPs; empty capsids), or (iii) mock infected. Inoculation with AAV-2 or VLPs inhibited activation of the HPV-18 promoter. In vitro, in baby hamster kidney cells transfected with the HPV-18-lacZ construct, tissue extracts from AAV-infected animals suppressed the HPV-18 URR to a similar extent as AAV infection did. Down-regulation of the HPV-18 promoter was less efficient with extracts from animals inoculated with VLPs and was not observed with extracts from uninfected or dexamethasone-treated animals. This indicates that AAV induces cellular factor(s) in vivo capable of mediating down-regulation of the HPV-18 promoter also in cells in vitro. In contrast, promoters of the low-risk HPV types (HPV-6, HPV-11) were not influenced by AAV infection as opposed to promoters of the high-risk types (HPV-18 and HPV-16).

Advancing age and cervical cancer screening and prognosis

OBJECTIVES

To determine associations between advancing age and screening behavior and prognosis in long-term members of a prepaid health plan diagnosed with invasive cervical cancer (ICC).

DESIGN

Case series.

SETTING

Prepaid health plan.

PARTICIPANTS

All women diagnosed with ICC at Kaiser Permanente Medical Care Program-Northern California health plan from 1988 to 1994.

MEASUREMENTS

From medical records, we recorded participants' age, stage at diagnosis, tumor histology, and results of and reasons for all previous cervical smears. We limited our analysis to women who had been members of the health plan for at least 30 of the 36 months preceding diagnosis (n = 455).

RESULTS

Women in older age groups were less likely than younger women to have been screened within the 3 years before diagnosis (P = .005 for trend). Nonadherence to follow-up of abnormal cervical smears was uncommon (17/455, 3.7%) and not age related (P = .932 for trend). The proportions of ICC that were interval cancers, defined as ICC diagnosed within 3 years of a negative screening smear, were highest in women under age 30 (P = .004 for trend). In multivariate analyses controlling for stage at diagnosis, women age 60 and older were not more likely to die of ICC within 3 years of diagnosis than were women younger than age 60 (odds ratio 1.30, 95% confidence interval 0.75-2.28).

CONCLUSION

The disproportionate burden of cervical cancer observed in older women appears to be largely attributable to lack of screening within the 3 years before diagnosis.

Oestrogen and progesterone increase the levels of apoptosis induced by the human papillomavirus type 16 E2 and E7 proteins

Human papillomavirus (HPV) type 16 infects the genital tract and is generally acknowledged to be a causative agent of cervical cancer. HPV infection alone is not sufficient to induce cervical cancer and other factors such as steroid hormones are thought to play a role in the establishment and/or progression of this disease. The HPV-16 E2 protein is required for virus replication and modulates viral gene expression whereas the HPV-16 E7 protein is required for cell transformation. We and others have shown that both the E2 and E7 proteins can induce apoptotic cell death in HPV-transformed and non-HPV transformed cell lines. Here we show that the steroid hormones oestrogen and progesterone can both increase the levels of E2- and E7-induced apoptosis. The oestrogen metabolite 16 alpha-hydroxyoestrone also increases E2- and E7-induced cell death and the dietary component indole-3-carbinol, which reduces the formation of 16alpha-hydroxyoestrone from oestrogen, blocks the effects of oestrogen. Thus the metabolism of oestrogen to 16 alpha-hydroxyoestrone appears to be required for the effects of this hormone on E2- and E7-induced cell death. We also show that the oestrogen receptor antagonist 3-hydroxytamoxifen blocks the effects of oestrogen on E2- and E7-induced cell death, whereas the anti-progesterone RU486 blocks the effects of both progesterone and oestrogen. We discuss these results in terms of the origin and progression of cervical cancer.

Contraceptive and reproductive risk factors for cervical intraepithelial neoplasia in American Indian women

OBJECTIVES

To evaluate contraceptive and reproductive risk factors for cervical intraepithelial neoplasia (CIN) in southwestern American Indian women.

METHODS

We conducted a clinic-based case-control study. Cases were American Indian women with biopsy-proven CIN I, CIN II or CIN III. Controls were from the same clinics and had normal cervical epithelium. All subjects underwent structured interviews focused on contraceptive and reproductive factors. Laboratory assays included polymerase chain reaction (PCR)-based tests for cervical human papillomavirus (HPV) infection.

RESULTS

We enrolled 628 women in the study. The strongest risk factors for CIN II/III included HPV infection (adjusted odds ratio [OR] = 7.9, 95% CI : 4.7-13.2), and low income (OR = 3.1, 95% CI : 1.7-5.7). The use of an intrauterine device (IUD) ever (OR = 3.0, 95% CI : 1.4-6.1) and currently (OR = 4.1, 95% CI : 1.1-14.6), and > or = 3 vaginal deliveries (OR = 5.2, 95% CI : 2.4-11.1) were associated with CIN II/III. History of infertility was also associated with CIN II/III (OR = 2.1, 95% CI : 1.0-4.2).

CONCLUSIONS

The data suggest that history of infertility, IUD use and vaginal deliveries were associated with CIN among American Indian women.

Prevalence of 'high risk' human papillomavirus in the lower genital tract of Brazilian gravidas

The presence of high-risk human Papillomavirus types 16, 18 and 33 was examined in 125 pregnant patients with abnormal Papanicolau smears. Specimens of cervicovaginal cells were analyzed by a simplified method of slot-blot hybridization. The overall prevalence of those viral sequences was 48%, being: 22.4% of HPV16, 17.6% of HPV18, 4.0% for double HPV16 and 18 infestation and 4.0% of HPV33. Their prevalence in HPV positive cervical sample was alone respectively 46.6%, 36.6%, 8.3% and 8.3%. Besides the high incidence of those carcinogenic types and intense viral proliferation, a rapid progression from CIN to carcinoma was clinically observed in four pregnant patients. Our data may reinforce the idea that progesterone has a positive role to the persistence and transformation of 'high risk' HPV, particularly of HPV16. The enhanced detection of potentially malignant types during pregnancy should warn on the importance of early diagnosis and treatment of papillomatosis.

The human papillomavirus type 11 upstream regulatory region triggers hair-follicle-specific gene expression in transgenic mice

We have generated transgenic mice carrying the URR of the human papillomavirus type 11 ligated in front of the Escherichia coli beta-galactosidase coding region sequence. Using X-Gal staining to demonstrate beta-galactosidase production, we observed a hair-specific transcription of the reporter gene. This transcription was limited to the epithelial cells of the hair bulge region. The transgene was developmentally regulated, as no LacZ staining was demonstrated during embryogenesis and specific staining was first observed after birth. Surprisingly, dexamethasone and ultraviolet B, but not phorbol myristate acetate or progesterone treatment of the animals resulted in an increase in number and intensity of hair follicles expressing the reporter gene.

Influence of ovarian stimulation on the detection of human papillomavirus DNA in cervical scrapes obtained from patients undergoing assisted reproductive techniques

OBJECTIVE

To determine whether gonadotropin stimulation influences the detection of human papillomavirus (HPV) DNA in cervical scrapes.

DESIGN

Prospective, controlled study.

SETTING

Tertiary care infertility clinic.

PATIENT(S)

Two hundred ninety-four patients enrolled in an IVF or IUI program. Two thousand two hundred sixty-two women from an ongoing screening study who were of similar age served as a control group.

INTERVENTION(S)

Cervical scrapes were obtained with a cytobrush before and after ovarian stimulation with gonadotropins.

MAIN OUTCOME MEASURE(S)

Human papillomavirus status was assessed with a general primer (GP) polymerase chain reaction (PCR) using the GP5+/GP6+ system. In GP-PCR-positive samples, high-risk HPV types were identified with a cocktail of digoxigenin-labeled oligonucleotides. Viral load was evaluated by semiquantitative analysis of the PCR products.

RESULT(S)

The prevalence of high-risk HPVs was 7.8% before stimulation and 6.8% after stimulation and, thus, was similar to the prevalence in controls (8.4%). Twenty-nine patients were positive for high-risk HPVs: 14 were positive before and after stimulation, 6 were negative before and positive after stimulation, and 9 were positive before and negative after stimulation. Positivity for high-risk HPVs and viral load did not correlate directly with serum estrogen levels.

CONCLUSION(S)

Ovarian stimulation has no significant effect on the prevalence of HPV DNA in cervical scrapes obtained from patients undergoing assisted reproductive techniques.