The natural history of human papillomavirus infections of the mucosal epithelia

Short half-life of HPV16 E6 and E7 mRNAs sensitizes HPV16-positive tonsillar cancer cell line HN26 to DNA-damaging drugs

Here we show that treatment of the HPV16-positive tonsillar cancer cell line HN26 with DNA alkylating cancer drug melphalan-induced p53 and activated apoptosis. Melphalan reduced the levels of RNA polymerase II and cellular transcription factor Sp1 that were associated with HPV16 DNA. The resulting inhibition of transcription caused a rapid loss of the HPV16 early mRNAs encoding E6 and E7 as a result of their inherent instability. As a consequence of HPV16 E6 and E7 down-regulation, the DNA damage inflicted on the cells by melphalan caused induction of p53 and activation of apoptosis in the HN26 cells. The BARD1-negative phenotype of the HN26 cells may have contributed to the failure to repair DNA damage caused by melphalan, as well as to the efficient apoptosis induction. Finally, nude mice carrying the HPV16 positive tonsillar cancer cells responded better to melphalan than to cisplatin, the chemotherapeutic drug of choice for tonsillar cancer. We concluded that the short half-life of the HPV16 E6 and E7 mRNAs renders HPV16-driven tonsillar cancer cells particularly sensitive to DNA damaging agents such as melphalan since melphalan both inhibits transcription and causes DNA damage.

Human Papillomavirus Infection and Cervical Cancer in HIV+ Women

Human papillomavirus (HPV) is the first identified necessary cause of human cancers and is associated with nearly 100% of all cervical cancers. Compared to the general female populations, HIV+ women have higher prevalence and incidence of cervical HPV infections, higher risks of persistent HPV infections and subsequent cervical intraepithelial lesions, and a higher incidence of cervical cancer. Although the wide use of combined antiretroviral therapy (cART) has improved the immune function and the longevity of HIV+ women, the incidence of cervical cancer in HIV+ women has not declined. For HIV+ women who follow routine cervical cancer screenings, their incidence of cervical cancer is comparable to that in HIV-negative women. Thus, adherence to the recommended cervical cancer screening is still critical for HIV+ women to prevent cervical cancer. Prophylactic HPV vaccines may also benefit HIV+ women, but prospective studies are needed to determine the effectiveness of HPV vaccination on reducing cervical cancer incidence in HIV+ women.

Tobacco Exposure Enhances Human Papillomavirus 16 Oncogene Expression via EGFR/PI3K/Akt/c-Jun Signaling Pathway in Cervical Cancer Cells

High-risk human papillomavirus (HR-HPV) infection is not a sufficient condition for cervical cancer development because most infections are benign and naturally cleared. Epidemiological studies revealed that tobacco smoking is a cofactor with HR-HPV for cervical cancer initiation and progression, even though the mechanism by which tobacco smoke cooperates with HR-HPV in this malignancy is poorly understood. As HR-HPV E6/E7 oncoproteins overexpressed in cervical carcinomas colocalize with cigarette smoke components (CSC), in this study we addressed the signaling pathways involved in a potential interaction between both carcinogenic agents. Cervical cancer-derived cell lines, CaSki (HPV16; 500 copies per cell) and SiHa (HPV16; 2 copies per cell), were acutely exposed to CSC at various non-toxic concentrations and we found that E6 and E7 levels were significantly increased in a dose-dependent manner. Using a reporter construct containing the luciferase gene under the control of the full HPV16 long control region (LCR), we also found that p97 promoter activity is dependent on CSC. Non-synonymous mutations in the LCR-resident TPA (12-O-tetradecanoylphorbol 13-acetate)-response elements (TRE) had significantly decreased p97 promoter activation. Phosphoproteomic arrays and specific inhibitors revealed that CSC-mediated E6/E7 overexpression is at least in part reliant on EGFR phosphorylation. In addition, we showed that the PI3K/Akt pathway is crucial for CSC-induced E6/E7 overexpression. Finally, we demonstrated that HPV16 E6/E7 overexpression is mediated by JUN. overexpression, c-Jun phosphorylation and recruitment of this transcription factor to TRE sites in the HPV16 LCR. We conclude that acute exposure to tobacco smoke activates the transcription of HPV16 E6 and E7 oncogenes through p97 promoter activation, which involves the EGFR/PI3K/Akt/C-Jun signaling pathway activation in cervical cancer cells.

Role of the DNA Damage Response in Human Papillomavirus RNA Splicing and Polyadenylation

Human papillomaviruses (HPVs) have evolved to use the DNA repair machinery to replicate its DNA genome in differentiated cells. HPV activates the DNA damage response (DDR) in infected cells. Cellular DDR factors are recruited to the HPV DNA genome and position the cellular DNA polymerase on the HPV DNA and progeny genomes are synthesized. Following HPV DNA replication, HPV late gene expression is activated. Recent research has shown that the DDR factors also interact with RNA binding proteins and affects RNA processing. DDR factors activated by DNA damage and that associate with HPV DNA can recruit splicing factors and RNA binding proteins to the HPV DNA and induce HPV late gene expression. This induction is the result of altered alternative polyadenylation and splicing of HPV messenger RNA (mRNA). HPV uses the DDR machinery to replicate its DNA genome and to activate HPV late gene expression at the level of RNA processing.

Adenosine causes read-through into the late region of the HPV16 genome in a guanosine-dependent manner

Adenosine plays an important role in cell death and differentiation as well as in tumorigenesis and the intra- and extra-cellular levels range from nanomolar to millimolar levels under various physiological or pathophysiological conditions. Here we report that adenosine can activate HPV16 late gene expression in a dose- and time-dependent manner, but only in the presence of guanosine. This activation occurred within hours after addition of the nucleosides and was primarily dependent on the ENT1 nucleoside transporter protein. Induction of HPV16 late gene expression was mainly the result of increased read-through at the early HPV16 polyadenylation signal into the late region of the HPV16 genome, thereby producing HPV16 late L2 mRNAs. The effect of guanosine and adenosine on HPV16 late gene expression was mediated by the increased binding to HPV16 mRNAs and nuclear export of the cellular HuR protein. Our results demonstrate that nucleosides can affect HPV16 gene expression.

The DNA damage response activates HPV16 late gene expression at the level of RNA processing

We show that the alkylating cancer drug melphalan activated the DNA damage response and induced human papillomavirus type 16 (HPV16) late gene expression in an ATM- and Chk1/2-dependent manner. Activation of HPV16 late gene expression included inhibition of the HPV16 early polyadenylation signal that resulted in read-through into the late region of HPV16. This was followed by activation of the exclusively late, HPV16 splice sites SD3632 and SA5639 and production of spliced late L1 mRNAs. Altered HPV16 mRNA processing was paralleled by increased association of phosphorylated BRCA1, BARD1, BCLAF1 and TRAP150 with HPV16 DNA, and increased association of RNA processing factors U2AF65 and hnRNP C with HPV16 mRNAs. These RNA processing factors inhibited HPV16 early polyadenylation and enhanced HPV16 late mRNA splicing, thereby activating HPV16 late gene expression.

Periodontitis and oral human papillomavirus infection among Hispanic adults

INTRODUCTION

Research on the association between periodontitis and oral human papilloma virus (HPV) infection is inconsistent. The cross-sectional association of severe periodontitis with oral HPV infection was investigated in a sample of Hispanic adults.

METHODS

Data from the 2014-2016 San Juan Overweight Adults Longitudinal Study (n = 740) was analyzed. Periodontitis assessment and self-collection of oral HPV samples followed the National Health and Nutrition Examination Survey methodology. Periodontitis was defined using the Centers of Disease Control and Prevention/American Academy of Periodontology definition. HPV typing was performed using polymerase chain reaction. Multivariate logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

5.7% of participants had oral HPV infection and 20.3% had severe periodontitis. Adults with severe periodontitis had higher odds of oral HPV infection than those with none/mild disease (OR=2.9, 95% CI: 1.0-8.4, p < 0.05) in multivariable analysis. Adults with clinical attachment loss≥ 7 mm and pocket depth PD≥ 6 mm had 2- to 3-fold higher odds of HPV infection.

CONCLUSIONS

Severe periodontitis was positively associated to oral HPV infection. Longitudinal evaluation of periodontal inflammation's role in acquisition and persistence of oral HPV infection is needed, as periodontitis screening could identify individuals at increased risk of HPV-related oral malignancies.

Stem Cell Properties of Normal Human Keratinocytes Determine Transformation Responses to Human Papillomavirus 16 DNA

Human papillomavirus (HPV) infection of the genital tract is common; however, only about 10 to 15% of infections persist, and approximately 10 to 15% of these persistent infections result in cancer. Basal epidermal stem cells are the presumed target cells for HPV infection, providing a reservoir of latently infected cells that persist over time and initiate lesions. However, it is not known whether stem cell density has any influence on transformation of human keratinocytes by HPV. We explored the relationship between stem cell properties of normal human keratinocytes and their susceptibility to transformation by HPV16 DNA. Normal human keratinocyte isolates (NHKc) derived from different donors were cultured in three-dimensional anchorage-free suspension to assess their spheroid-forming ability. NHKc spheroids were then plated back into plastic monolayer culture and transfected with full-length HPV16 DNA, which we have previously shown to integrate into the host cell genome upon transfection. Spheroid-derived NHKc (SD-NHKc) and fluorescence-activated cell sorting-purified populations of basal stem-like keratinocytes, expressing low levels of epidermal growth factor receptor and high levels of integrin alpha 6 (EGFR^lo/ITGα6^hi), responded to transfection with HPV16 DNA with more vigorous proliferation, greater immortalization efficiency, and faster progression to differentiation resistance than autologous mass-cultured cells. Conversely, cells committed to terminal differentiation (EGFR^hi/ITGα6^lo) grew slowly after transfection with HPV16 and failed to generate immortalized or DR clones. HPV16 DNA induced stem cell properties in mass-cultured NHKc. We conclude that HPV16 preferentially immortalizes basal keratinocytes with stem cell properties and that these cells readily achieve a differentiation-resistant phenotype upon immortalization by HPV16.IMPORTANCE This paper explores the relationship between the stem cell properties of normal human epidermal cells in culture and these cells' susceptibility to transformation by HPV16 DNA, the HPV type present in about 50% of cervical cancers. We report variable susceptibilities to HPV16-mediated transformation among different keratinocyte isolates derived from neonatal foreskin. Our findings provide strong experimental evidence that HPV16 preferentially transforms basal keratinocytes with stem cell properties. Insights gained from these studies increase our understanding of the host cell-specific factors influencing individual susceptibility to HPV-driven transformation and the contributing factors leading to preneoplastic and neoplastic progression of HPV-positive lesions.

hnRNP G prevents inclusion on the HPV16 L1 mRNAs of the central exon between splice sites SA3358 and SD3632

HPV16 late L1 mRNAs encode a short central exon that is located between HPV16 3'-splice site SA3358 and HPV16 5'-splice site SD3632. While SA3358 is used to produce both HPV16 early mRNAs encoding the E6 and E7 oncogenes, and late mRNAs encoding E4, L1 and L2, SD3632 is used exclusively to produce late L1 mRNA. We have previously identified an 8-nucleotide regulatory RNA element that is required for inclusion of the exon between SA3358 and SD3632 to produce L1 mRNAs at the expense of mRNAs polyadenylated at the HPV16 early polyadenylation signal pAE. Here we show that this HPV16 8-nucleotide splicing enhancer interacts with hnRNP G. Binding of hnRNP G to this element prevents inclusion of the exon between SA3358 and SD3632 on the HPV16 late L1 mRNAs. We concluded that hnRNP G has a splicing inhibitory role and that hnRNP G can control HPV16 mRNA splicing.

Folate Deficiency Facilitates Genomic Integration of Human Papillomavirus Type 16 DNA In Vivo in a Novel Mouse Model for Rapid Oncogenic Transformation of Human Keratinocytes

Background

Epidemiologic and in vitro studies suggest independent linkages between poor folate and/or vitamin B-12 nutrition, genomic human papillomavirus (HPV) type 16 viral integration, and cancer. However, there is no direct evidence in vivo to support the causative role of poor folate nutrition in HPV16 integration into the cellular genome.

Objective

We tested the hypothesis that folate deficiency enables the integration of HPV16 into the genome of HPV16-harboring keratinocytes, and could thereby influence earlier transformation of these cells to cancer in an animal model.

Methods

HPV16-harboring human keratinocytes [(HPV16)BC-1-Ep/SL] were differentiated into 3-dimensional HPV16-organotypic rafts under either folate-replete or folate-deficient conditions in vitro. These were then subcutaneously implanted in severely immunocompromised female Beige Nude XID (Hsd: NIHS-LystbgFoxn1nuBtkxid) mice (4-6 wk old, 16-18 g) fed either a folate-replete diet (1200 nmol folate/kg diet) or a progressively folate-deficient diet (600 or 400 nmol folate/kg diet) for 2 mo prior to raft-implantation surgery, and indefinitely thereafter. The tumors that subsequently developed were characterized for onset, pattern of growth, morphology, HPV16 oncogene expression, and HPV16-genomic integration.

Results

All HPV16-organotypic rafts developed in either folate-replete or physiologic low-folate media in vitro and subsequently implanted in folate-replete mice eventually transformed into aggressive malignancies within weeks. When compared to HPV16-high folate-organotypic raft-derived tumors from mice fed either a 1200 or 600 nmol folate/kg diet, those raft-derived cancers that developed in mice fed a 400 nmol folate/kg diet expressed significantly more HPV16 E6 (1.8-fold more) and E7 (2.8-fold more) oncogenic proteins (P = 0.001), and revealed significantly more HPV16-integration sites in genomic DNA (2-fold more), either directly into, or in the vicinity of, cellular genes (P < 0.05).

Conclusions

This unprecedented animal model for the consistent rapid transformation of differentiated (HPV16)BC-1-Ep/SL-derived organotypic raft-keratinocytes to cancer in Beige Nude XID mice confirms that dietary folate deficiency can profoundly influence and modulate events leading to HPV16-induced carcinogenesis, and facilitates genomic integration of HPV16 DNA in vivo.

Characteristics of human papillomaviruses infection in men with genital warts in Shanghai

Human papillomaviruses (HPV) infected men causes continued transmission of HPV to women. The prevalence of 15 high-risk HPV strains (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68) and 6 low-risk HPV strains (HPV6, 11, 42, 43, 44 and CP8304) were evaluated in 935 males with genital warts. Of the 447 (447/935, 47.8%) HPV DNA positive subjects, 230 (24.6%), 356 (38.1%) and 139 (14.9%) were infected by high-risk, low-risk and both high and low-risk HPV respectively. Of the 356 low-risk HPV infected subjects, 333(93.5%) were infected by single HPV strain; 203 (57.0%), 147 (41.3%), 24 (6.7%) and 5 (1.4%) were infected with HPV genotype 6, 11, CP8304 and 44 respectively; population with age ≤ 20 showed the highest infection rate. High-risk HPV are also highly prevalent in our patients, genotype 16, 58, 51, 39, 52 and 53 are the top five prevalent genotypes with infection rates of 27.4%, 18.7%, 14.3%, 13.9%, 12.6% and 12.6% respectively; only 68.3% subjects were sole infection; subjects with 41 ≤ age ≤ 50 showed the highest infection rate. Both high and low-risk HPV are highly prevalent in men with genital warts, its impact on women HPV control and prevention need further evaluation.

Current and future management of recurrent respiratory papillomatosis

Objectives

Recurrent respiratory papillomatosis (RRP) is a chronic disease of the respiratory tract that occurs in both children and adults. It is caused by the human papillomavirus (HPV), in particular low‐risk HPV6 and HPV11, and aggressiveness varies among patients. RRP remains a chronic disease that is difficult to manage. This review provides perspectives on current and future management of RRP.

Results

The current standard of care is surgical excision, with adjuvant therapies as needed. Surgical management of RRP has evolved with the introduction of microdebriders and photoangiolytic lasers; the latter can now be used in the office setting. Numerous adjuvant pharmacologic therapies have been utilized with some success. Also, exciting preliminary data show that HPV vaccines may prolong the time to recurrence in the RRP population. There is also optimism that wide‐spread HPV vaccination could reduce RRP incidence indirectly by preventing vertical HPV transmission to newborns.

Conclusion

To date, the biology of RRP is not well understood, although it has been noted to become more aggressive in the setting of immune suppression. Additional research is needed to better understand immune system dysfunction in RRP such that immunomodulatory approaches may be developed for RRP management.

Level of Evidence

4

Integrity of a HPV11 infection cell model and identification of (-)-Epigallocatechin-3-gallate as a potential HPV11 inhibitor

Background

Condyloma acuminatum (CA) is one of the most common sexually transmitted diseases and induced by low-risk human papillomaviruses (HPVs), mainly HPV type 6 and 11. Here, we report the identification of (-)-Epigallocatechin-3-gallate (EGCG) by an HPV11 infection cell model.

Results

The recombined HPV11.HaCaT cells had stable HPV 11 early genes expression. The introducing of HPV11 genome significantly increased the proliferation of HPV11.HaCaT cells, as well as the proportion of cells in S and G2/M phases. After treated with rhIFN-α 2a, IFN signaling pathway was activated in both HaCaT and HPV11.HaCaT cells, while HPV11 decreased the activation level. In addition, rhIFN-α 2a, could inhibit expression of HPV 11 E6 and E7 mRNA significantly (P<0.05). However, cell growth and cell cycle did not show statistical difference (P>0.05). Nevertheless, EGCG, a major active constituent in tea polyphenol, showed strong anti-HPV11 effect, which inhibited HPV11 E6 and E7 mRNA.

Methods

Gene transfection technique was used to introduce HPV11 genome into HaCaT cells, named HPV11.HaCaT cells. With the established cell model, we explore the anti-HPV11 effect of (-)-Epigallocatechin-3-gallate (EGCG) on cell growth, viability and affection on expression HPV11 E6 and E7 mRNA.

Conclusion

Our data collectively demonstrated that the recombinant HPV11.HaCaT cells were integral and practical to be a cell model to test anti-HPV11 agents and explore the interaction between HPV11 genes and host cells. And EGCG inhibits expression of HPV11 E6 and E7 mRNA in the recombinant HPV11.HaCaT cells.

Eradicating HPV-Associated Cancer Through Immunization: A Glass Half Full…

The human papillomavirus (HPV) is an important causal agent of premalignant cervical epithelial changes and cervical cancers. These cancers account for ∼5% of all cancers globally and kill more than a quarter million women annually. HPV infections also associate with certain anogenital and oropharyngeal cancers. Events leading to the development of HPV vaccines to prevent associated cancers are described, with a further discussion of goals that must be met to achieve full virus eradication.

hnRNP L controls HPV16 RNA polyadenylation and splicing in an Akt kinase-dependent manner

Inhibition of the Akt kinase activates HPV16 late gene expression by reducing HPV16 early polyadenylation and by activating HPV16 late L1 mRNA splicing. We identified ‘hot spots’ for RNA binding proteins at the early polyA signal and at splice sites on HPV16 late mRNAs. We observed that hnRNP L was associated with sequences at all HPV16 late splice sites and at the early polyA signal. Akt kinase inhibition resulted in hnRNP L dephosphorylation and reduced association of hnRNP L with HPV16 mRNAs. This was accompanied by an increased binding of U2AF65 and Sam68 to HPV16 mRNAs. Furthermore, siRNA knock-down of hnRNP L or Akt induced HPV16 gene expression. Treatment of HPV16 immortalized keratinocytes with Akt kinase inhibitor reduced hnRNP L binding to HPV16 mRNAs and induced HPV16 L1 mRNA production. Finally, deletion of the hnRNP L binding sites in HPV16 subgenomic expression plasmids resulted in activation of HPV16 late gene expression. In conclusion, the Akt kinase inhibits HPV16 late gene expression at the level of RNA processing by controlling the RNA-binding protein hnRNP L. We speculate that Akt kinase activity upholds an intracellular milieu that favours HPV16 early gene expression and suppresses HPV16 late gene expression.

Mouse papillomavirus infections spread to cutaneous sites with progression to malignancy

We report secondary cutaneous infections in the mouse papillomavirus (MmuPV1)/mouse model. Our previous study demonstrated that cutaneous MmuPV1 infection could spread to mucosal sites. Recently, we observed that mucosal infections could also spread to various cutaneous sites including the back, tail, muzzle and mammary tissues. The secondary site lesions were positive for viral DNA, viral capsid protein and viral particles as determined by in situ hybridization, immunohistochemistry and transmission electron microscopy analyses, respectively. We also demonstrated differential viral production and tumour growth at different secondarily infected skin sites. For example, fewer viral particles were detected in the least susceptible back tissues when compared with those in the infected muzzle and tail, although similar amounts of viral DNA were detected. Follow-up studies demonstrated that significantly lower amounts of viral DNA were packaged in the back lesions. Lavages harvested from the oral cavity and lower genital tracts were equally infectious at both cutaneous and mucosal sites, supporting the broad tissue tropism of this papillomavirus. Importantly, two secondary skin lesions on the forearms of two mice displayed a malignant phenotype at about 9.5 months post-primary infection. Therefore, MmuPV1 induces not only dysplasia at mucosal sites such as the vagina, anus and oral cavity but also skin carcinoma at cutaneous sites. These findings demonstrate that MmuPV1 mucosal infection can be spread to cutaneous sites and suggest that the model could serve a useful role in the study of the viral life cycle and pathogenesis of papillomavirus.

Genital HPV infection among heterosexual and homosexual male attendees of sexually transmitted diseases clinic in Beijing, China

Human papillomavirus (HPV) has been identified as etiologic agent of various cancers for both men and women. However, HPV vaccine has not been recommended for men in China by far. To provide more evidences to promote HPV vaccination among males at high-risk of infection, this study investigated genital HPV genotypes among male attendees of sexually transmitted disease (STD) clinic. Male attendees (⩾18 years old) were recruited from STD clinic of Beijing Ditan Hospital. Data on sociodemographic characteristics and self-reported sexual behaviors were collected based on questionnaire. Genital swab specimens were collected for HPV genotypes. Finally, a total of 198 eligible participants were included in the study. Nearly half of them were infected with at least one type of HPV. The prevalence of genital infection among participants with only heterosexual behaviors (50·91%, 56/110) was significantly higher than those with only homosexual behaviors (36·36%, 32/88) (P < 0·001). However, the distribution pattern of the most frequently observed HPV subtypes were found to be similar between these two subgroups. HPV31, HPV18, HPV16 and HPV58 were the most frequently identified high-risk types and HPV11, HPV6, HPV81 and HPV61 were the most frequently observed low-risk types. Our results, although need further verification by larger sample size, suggested that currently available HPV vaccines covered most prevalent HPV types observed in Chinese men. As HPV vaccine has been approved for application in females in China, molecular epidemiological studies and intervention studies among high-risk males should be promoted as well.

A Mathematical Model of Cell Cycle Dysregulation Due to Human Papillomavirus Infection

Human papillomaviruses (HPVs) that infect mucosal epithelium can be classified as high risk or low risk based on their propensity to cause lesions that can undergo malignant progression. HPVs produce the E7 protein that binds to cell cycle regulatory proteins including the retinoblastoma tumor suppressor protein (RB) to modulate cell cycle control. Generally, high-risk HPV E7 proteins bind to RB with a higher affinity than low-risk HPV E7s, but both are able to deactivate RB and trigger S phase progression. In uninfected cells, RB inactivation is a tightly controlled process that must coincide with growth factor stimulation to commit cells to division. High-risk HPV E7 proteins short-circuit this control by decreasing growth factor requirement for cell division. We develop a mathematical model to examine the role that RB binding affinity, growth factor concentration, and E7 concentration have on cell cycle progression. Our model predicts that high RB binding affinity and E7 concentration accelerate the [Formula: see text] to S phase transition and weaken the dependence on growth factor. This model thus captures a key step in high-risk HPV oncogenesis.

Comparative analysis of HPV16 gene expression profiles in cervical and in oropharyngeal squamous cell carcinoma

Human papillomavirus type 16 (HPV16) is the major cause of cervical cancer and of a fraction of oropharyngeal carcinoma. Few studies compared the viral expression profiles in the two types of tumor. We analyzed HPV genotypes and viral load as well as early (E2/E4, E5, E6, E6*I, E6*II, E7) and late (L1 and L2) gene expression of HPV16 in cervical and oropharyngeal cancer biopsies. The study included 28 cervical squamous cell carcinoma (SCC) and ten oropharyngeal SCC, along with pair-matched non-tumor tissues, as well as four oropharynx dysplastic tissues and 112 cervical intraepithelial neoplasia biopsies. Viral load was found higher in cervical SCC (<1 to 694 copies/cell) and CIN (<1 to 43 copies/cell) compared to oropharyngeal SCC (<1 to 4 copies/cell). HPV16 E2/E4 and E5 as well as L1 and L2 mRNA levels were low in cervical SCC and CIN and undetectable in oropharynx cases. The HPV16 E6 and E7 mRNAs were consistently high in cervical SCC and low in oropharyngeal SCC. The analysis of HPV16 E6 mRNA expression pattern showed statistically significant higher levels of E6*I versus E6*II isoform in cervical SCC (p = 0.002) and a slightly higher expression of E6*I versus E6*II in oropharyngeal cases. In conclusion, the HPV16 E5, E6, E6*I, E6*II and E7 mRNA levels were more abundant in cervical SCC compared to oropharyngeal SCC suggesting different carcinogenic mechanisms in the two types of HPV-related cancers.

Splicing and Polyadenylation of Human Papillomavirus Type 16 mRNAs

The human papillomavirus type 16 (HPV16) life cycle can be divided into an early stage in which the HPV16 genomic DNA is replicated, and a late stage in which the HPV16 structural proteins are synthesized and virions are produced. A strong coupling between the viral life cycle and the differentiation state of the infected cell is highly characteristic of all HPVs. The switch from the HPV16 early gene expression program to the late requires a promoter switch, a polyadenylation signal switch and a shift in alternative splicing. A number of cis-acting RNA elements on the HPV16 mRNAs and cellular and viral factors interacting with these elements are involved in the control of HPV16 gene expression. This review summarizes our knowledge of HPV16 cis-acting RNA elements and cellular and viral trans-acting factors that regulate HPV16 gene expression at the level of splicing and polyadenylation.

Cytokeratin 7 in Oropharyngeal Squamous Cell Carcinoma: A Junctional Biomarker for Human Papillomavirus-Related Tumors

Background: Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (SCC) represents a distinct subgroup of head and neck tumors. We analyze the expression of cytokeratin 7, a junctional biomarker with a SEQIKA fragment, which stabilizes HPV-16 E7 transcripts, in oropharyngeal SCCs.Methods: Archived tumor specimens and epidemiologic data were collected from patients with oropharyngeal SCCs over 10 years. Briefly, DNA was extracted from tissue blocks, and HPV testing was carried out using SPF10 HPV PCR and INNO-LiPA HPV Genotyping. Immunohistochemical staining for CK7 and p16ink4a was performed on the Ventana BenchMark Ultra Immunostainer. Analysis was by light microscopy using the H-score. CK7 expression was correlated with epidemiologic data, p16ink4a positivity, and HPV status using SPSS.Results: CK7 expression was observed specifically and uniformly in the tonsillar crypt epithelium of normal tonsils and tumor specimens. There were 226 cases of oropharyngeal SCCs, with 70 demonstrating both HPV and p16 positivity. Of 216 cases evaluated for CK7, 106 demonstrated some positivity, whereas H-score > 60 was seen in 55 of these. CK7 H-score > 60 was significantly associated with tonsillar subsite and HPV and p16 positivity.Conclusions: An association between CK7 and HPV has been demonstrated. CK7-expressing tonsillar crypt cells potentially represent an oropharyngeal subsite susceptible to HPV-related SCC.Impact: Along with the cervix and anorectum, specific oropharyngeal expression of CK7 in a site predisposed to HPV-related tumors may suggest a role for CK7 in the pathogenesis of this subgroup of tumors. Further research is warranted to characterize the association between CK7 and HPV-related head and neck SCC. Cancer Epidemiol Biomarkers Prev; 26(5); 702-10. ©2017 AACR.

Human Papillomavirus Infection Among 2460 Men in Denmark: Prevalence in Relation to Age Using 2 Human Papillomavirus DNA Testing Methods

BACKGROUND

It is crucial to understand the epidemiology and natural history of human papillomavirus (HPV) infection in both men and women, to prevent the increasing HPV-related disease burden in men. Data on HPV prevalence among men in the general population are limited. In this cross-sectional population-based study, we aimed to estimate genital HPV infection prevalence in Danish men using 2 different test methods.

METHODS

Penile swab samples from 2460 male employees and conscripts at military barracks in Denmark were tested for HPV DNA with the hybrid capture 2 (HC2) method, and a polymerase chain reaction (PCR) assay, Inno-LiPA. The overall and age- and type-specific prevalence of HPV infection with 95% confidence intervals (CIs) were estimated, and the correlation between the 2 assays was assessed.

RESULTS

The overall HPV prevalence was 22.2% (95% CI, 20.6-23.9) in the HC2 test and 41.8% (95% CI, 39.9-43.8) with PCR. Of the PCR-positive samples, 50.9% were negative in the HC2 test. Of 183 PCR-positive samples that could not be genotyped (HPVX), 88.0% (95% CI, 83.2-92.7) were HC2 negative. The most prevalent types were HPV-51, HPV-16, HPV-66, HPV-53, and HPV-6. The prevalence of high-risk and low-risk HPV peaked among men aged 20 to 29 years, whereas the HPVX prevalence increased with age.

CONCLUSIONS

Human papillomavirus is highly prevalent in the general male population of Denmark, with HPV-16 and HPV-51 being the most prevalent. Polymerase chain reaction detects twice as many positive samples as HC2 but includes HPVX, possibly representing cutaneous HPV types found on normal genital skin.

Characterization of serum antibodies from women immunized with Gardasil: A study of HPV-18 infection of primary human keratinocytes

The prevalent human papillomaviruses (HPVs) infect human epithelial tissues. Infections by the mucosotropic HPV genotypes cause hyperproliferative ano-genital lesions. Persistent infections by high-risk (HR) HPVs such as HPV-16, HPV-18 and related types can progress to high grade intraepithelial neoplasias and cancers. Prophylactic HPV vaccines are based on DNA-free virus-like particles (VLPs) composed of the major capsid protein L1 of HPV-16, -18, -6 and -11 (Gardasil) or HPV-16 and -18 (Cervarix). Sera from vaccinated animals effectively prevent HPV pseudovirions to infect cell lines and mouse cervical epithelia. Both vaccines have proven to be highly protective in people. HPV pseudovirions are assembled in HEK293TT cells from matched L1 and L2 capsid proteins to encapsidate a reporter gene. Pseudovirions and genuine virions have structural differences and they infect cell lines or primary human keratinocytes (PHKs) with different efficiencies. In this study, we show that sera and isolated IgG from women immunized with Gardasil prevent authentic HPV-18 virions from infecting PHKs, whereas non-immune sera and purified IgG thereof are uniformly ineffective. Using early passage PHKs, neutralization is achieved only if immune sera are added within 2-4h of infection. We attribute the timing effect to a conformational change in HPV virions, thought to occur upon initial binding to heparan sulfate proteoglycans (HSPG) on the cell surface. This interpretation is consistent with the inability of immune IgG bound to or taken up by PHKs to neutralize the virus. Interestingly, the window of neutralization increases to 12-16h in slow growing, late passage PHKs, suggestive of altered cell surface molecules. In vivo, this window might be further lengthened by the time required to activate the normally quiescent basal cells to become susceptible to infection. Our observations help explain the high efficacy of HPV vaccines.

Anal Neoplasia in Inflammatory Bowel Disease Is Associated With HPV and Perianal Disease

OBJECTIVES:

Literature describing the risk factors predisposing inflammatory bowel disease (IBD) patients to anal squamous neoplasia is very scarce. Case reports and small case series have implicated perianal Crohn's disease (CD), long-standing IBD, human papillomavirus (HPV) infection, and immunosuppressive treatment. In this study, we retrospectively examined the association between HPV infection and anal squamous neoplastic lesions among IBD patients from our center.

METHODS:

We reviewed the pathology records and slides of IBD patients diagnosed with anal squamous cell carcinomas (SCCs), high-grade squamous intraepithelial lesions (HSILs), and low-grade squamous intraepithelial lesions (LSILs) who presented at our center between 1 March 1994 and 9 September 2014. The HPV status of the neoplasms was assessed histologically, by immunohistochemical staining for p16 overexpression, and by global and type-specific HPV PCR.

RESULTS:

SCCs, HSILs, LSILs, and small cell carcinoma were identified, respectively, in six, nine, two, and one IBD patients. All six patients with SCC had CD with perianal involvement. HPV-related neoplasia was identified in 3/6 cases of SCC (all HPV-16), 1/1 small cell carcinoma (HPV-18), and 9/9 HSIL (7 HPV-16, 2 not typed); 2/2 LSILs were negative for high-risk HPV.

CONCLUSIONS:

In our experience, anal squamous neoplastic lesions in IBD are associated with HPV infection and SCC seem to be associated with perianal CD. Prospective studies are needed to confirm these results.

Simultaneous detection of human papillomavirus integration and c-MYC gene amplification in cervical lesions: an emerging marker for the risk to progression

PURPOSE

The persistence of high-risk oncogenic human papillomavirus (HR-HPV) infection and its integration into the host genome are key steps in the induction of malignant alterations. c-MYC chromosome region is a frequent localization for HPV insertion that has been observed in chromosome band 8q24 by fluorescence in situ hybridization (FISH). We report the HPV viral integration and amplification patterns of the c-MYC gene in cytological smears with FISH as a potential biomarker for the progression of squamous intraepithelial lesions (SIL).

METHODS

HPV detection and genotyping by polymerase chain reaction (PCR) and FISH analysis by "Vysis Cervical FISH Probe" kit (ABBOTT Molecular Inc.) were performed in 37 cervical samples including 8 NILM, 7 ASC-US, 7 LSIL, 3 ASC-H, 7 HSIL and 5 SCC.

RESULTS

The results show concordance between FISH and PCR techniques for HPV detection. The majority of the samples contained HR-HPV, the majority being -16 and -18 genotypes. HPV integration as determined by FISH was most frequent in high-risk lesions. The c-MYC gene amplification was found only in HPV-positive samples and was detected primarily in high-risk lesions and in cells with an integrated form of HPV.

CONCLUSIONS

HPV integration and c-MYC gene amplification detected by FISH could be an important biomarker for use in clinical practice to determine SIL with a risk of progression.

RNA Binding Proteins that Control Human Papillomavirus Gene Expression

The human papillomavirus (HPV) life cycle is strictly linked to the differentiation program of the infected mucosal epithelial cell. In the basal and lower levels of the epithelium, early genes coding for pro-mitotic proteins and viral replication factors are expressed, while terminal cell differentiation is required for activation of late gene expression and production of viral particles at the very top of the epithelium. Such productive infections are normally cleared within 18–24 months. In rare cases, the HPV infection is stuck in the early stage of the infection. Such infections may give rise to cervical lesions that can progress to cancer, primarily cancer of the uterine cervix. Since cancer progression is strictly linked to HPV gene expression, it is of interest to understand how HPV gene expression is regulated. Cis-acting HPV RNA elements and cellular RNA-binding proteins control HPV mRNA splicing and polyadenylation. These interactions are believed to play a particularly important role in the switch from early to late gene expression, thereby contributing to the pathogenesis of HPV. Indeed, it has been shown that the levels of various RNA binding proteins change in response to differentiation and in response to HPV induced cervical lesions and cancer. Here we have compiled published data on RNA binding proteins involved in the regulation of HPV gene expression.

Heterogeneous Nuclear Ribonucleoprotein C Proteins Interact with the Human Papillomavirus Type 16 (HPV16) Early 3'-Untranslated Region and Alleviate Suppression of HPV16 Late L1 mRNA Splicing

In order to identify cellular factors that regulate human papillomavirus type 16 (HPV16) gene expression, cervical cancer cells permissive for HPV16 late gene expression were identified and characterized. These cells either contained a novel spliced variant of the L1 mRNAs that bypassed the suppressed HPV16 late, 5'-splice site SD3632; produced elevated levels of RNA-binding proteins SRSF1 (ASF/SF2), SRSF9 (SRp30c), and HuR that are known to regulate HPV16 late gene expression; or were shown by a gene expression array analysis to overexpress the RALYL RNA-binding protein of the heterogeneous nuclear ribonucleoprotein C (hnRNP C) family. Overexpression of RALYL or hnRNP C1 induced HPV16 late gene expression from HPV16 subgenomic plasmids and from episomal forms of the full-length HPV16 genome. This induction was dependent on the HPV16 early untranslated region. Binding of hnRNP C1 to the HPV16 early, untranslated region activated HPV16 late 5'-splice site SD3632 and resulted in production of HPV16 L1 mRNAs. Our results suggested that hnRNP C1 controls HPV16 late gene expression.

Barrett's oesophagus: can meaningful screening and surveillance guidelines be formulated based on new data and rejigging the old paradigm?

Gastro-oesophageal reflux disease (GORD) and Barrett's oesophagus (BO) have been considered to be the most important known risk factors for oesophageal adenocarcinoma (OAC). It has been the fastest growing cancer in the Western World and has occurred against a backdrop of progressive reduction in the risk estimate of malignancy associated with BO and no reduction in mortality from OAC using the prevailing screening and surveillance guidelines. The recently published link between high risk HPV and Barrett's dysplasia/cancer may be the 'missing' strong risk factor responsible for the significant rise of OAC since the 1970's, as has been the case with head and neck tumours, another viral associated cancer. P53 immunohistochemistry has been proposed as a good molecular marker for predicting disease progression in BD. Nevertheless, significant negative staining for this mutation in BD remains a major hurdle to widespread routine clinical use as a sole molecular marker. Recent data raises the distinct possibility of at least 2 (probably more) carcinogenic pathways operating in OAC. One is HPV mediated devoid largely of p53 mutations and the other p53 dependent. The joint use of both these markers as part of a molecular panel may represent the best bet yet of detecting the high risk group of progressors to OAC. Patients who are positive for either or both biomarkers i.e p53 or/and transcriptional markers of HPV may warrant more intensive screening. In future, genome wide technology may provide molecular signatures to aid diagnosis and risk stratification in BO.

Pathogenesis of human papillomavirus-associated mucosal disease

Human papillomaviruses (HPVs) are a necessary cause of carcinoma of the cervix and other mucosal epithelia. Key events in high-risk HPV (HRHPV)-associated neoplastic progression include persistent infection, deregulated expression of virus early genes in basal epithelial cells and genomic instability causing secondary host genomic imbalances. There are multiple mechanisms by which deregulated virus early gene expression may be achieved. Integration of virus DNA into host chromosomes is observed in the majority of cervical squamous cell carcinomas (SCCs), although in ∼15% of cases the virus remains extrachromosomal (episomal). Interestingly, not all integration events provide a growth advantage to basal cervical epithelial cells or lead to increased levels of the virus oncogenes E6 and E7, when compared with episome-containing basal cells. The factors that provide a competitive advantage to some integrants, but not others, are complex and include virus and host contributions. Gene expression from integrated and episomal HRHPV is regulated through host epigenetic mechanisms affecting the virus long control region (LCR), which appear to be of functional importance. New approaches to treating HRHPV-associated mucosal neoplasia include knockout of integrated HRHPV DNA, depletion of virus transcripts and inhibition of virus early gene transcription through targeting or use of epigenetic modifiers. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Extracellular calcium regulates keratinocyte proliferation and HPV 16 E6 RNA expression in vitro

Human papillomaviruses (HPV) are known to immortalize oral keratinocytes in vitro, but the underlying mechanisms causing the following resistance to differentiation remain unclear. We investigated the effect of extracellular calcium on the proliferation of HPV16-positive keratinocytes and on the mRNA expression of the viral E6-oncogene. HPV16-positive hypopharyngeal carcinoma cells (UD-SCC-2), spontaneously immortalized- (HMK) and HPV16 E6/E7-immortalized human gingival keratinocytes (IHGK) were grown for 3, 6 and 9 days in Keratinocyte Serum-free Medium with calcium concentrations ranging from 0 mM to 6 mM. Calcium concentrations up to 0.09 mM increased cellular proliferation, which decreased at higher concentrations. A shift of calcium concentration from 0 to 4 mM increased E6 expression in UD-SCC-2 cells 2.4-fold by day 9. Simultaneously, E2 expression increased. The most significant upregulation of E6 and E2 expressions was observed at day 9, grown in high-calcium media and the increase in E6 expression coincided with an increase in involucrin expression, likely indicating cell differentiation. Despite this, HPV-positive cells continued to proliferate even at high-calcium media in contrast to HPV-negative cells. Overexpression of E6 mRNA may be an important feature of HPV16-positive cells to resist the natural calcium gradient in differentiating keratinocytes allowing cell proliferation.

Comparison of five protocols to extract DNA from paraffin-embedded tissues for the detection of human papillomavirus

Formalin-fixed paraffin-embedded (FFPE) tissues are a valuable source of DNA with which to perform large retrospective studies on the epidemiology of HPV infection. Five different DNA extraction protocols were carried out to evaluate the DNA obtained from FFPE samples with polymerase chain reaction (PCR) using two primer sets to amplify a constitutive human gene, β-globin, and two primer sets to detect the L1 and E6 HPV genes. From the five DNA extraction protocols evaluated, the best results were obtained with protocol A, corresponding to a crude extract from the sample. With the procedures described herein, we were able to amplify DNA extracted from archival paraffin blocks stored for six years. However, the amplification products were more efficiently obtained with primers that amplified shorter fragments. This result indicates that a major factor limiting the extraction process in these samples is DNA fragmentation, a factor that will naturally vary between the different specimens evaluated. Also, depending upon the extraction method, PCR amplification of a human gene does not necessarily guarantee the successful extraction of viral DNA. In conclusion, different DNA and HPV detection methods can significantly influence the results. Therefore, the DNA extraction methods and primers used for DNA amplification in fixed tissues need to be chosen carefully, depending on the specific requirements of the study being carried out.

Insights into the mechanism of action of cidofovir and other acyclic nucleoside phosphonates against polyoma- and papillomaviruses and non-viral induced neoplasia

Acyclic nucleoside phosphonates (ANPs) are well-known for their antiviral properties, three of them being approved for the treatment of human immunodeficiency virus infection (tenofovir), chronic hepatitis B (tenofovir and adefovir) or human cytomegalovirus retinitis (cidofovir). In addition, cidofovir is mostly used off-label for the treatment of infections caused by several DNA viruses other than cytomegalovirus, including papilloma- and polyomaviruses, which do not encode their own DNA polymerases. There is considerable interest in understanding why cidofovir is effective against these small DNA tumor viruses. Considering that papilloma- and polyomaviruses cause diseases associated either with productive infection (characterized by high production of infectious virus) or transformation (where only a limited number of viral proteins are expressed without synthesis of viral particles), it can be envisaged that cidofovir may act as antiviral and/or antiproliferative agent. The aim of this review is to discuss the advances in recent years in understanding the mode of action of ANPs as antiproliferative agents, given the fact that current data suggest that their use can be extended to the treatment of non-viral related malignancies.

Regulation of HPV16 E6 and MCL1 by SF3B1 inhibitor in head and neck cancer cells

ABT-737 inhibits the anti-apoptotic proteins B-cell lymphoma 2 (BCL-2) and BCL-X_L. Meayamycin B switches the splicing pattern of myeloid cell leukemia factor 1 (MCL1) pre-mRNA. Specifically, inhibition of splicing factor 3B subunit 1 (SF3B1) with meayamycin B promotes the generation of the proapoptotic, short splicing variant (MCL1-S) and diminishes the antiapoptotic, long variant (MCL1-L). This action was previously associated with the cytotoxicity of meayamycin B in non-small cell lung carcinoma cell lines. ABT-737 induced apoptosis in response to an ablation of MCL1-L by meayamycin B. In this study, we further exploited this synergistic combination in head and neck squamous cell carcinoma (HNSCC), up to 90% of which overexpress MCL1 and BCL-X_L. In a panel of seven HNSCC cell lines, the combination of meayamycin B and ABT-737 rapidly triggered a Bax/Bak-mediated apoptosis that overcame the resistance from HPV16-positive HNSCC against each agent alone. Both RT-PCR and Western blotting showed that meayamycin B up-regulated MCL1-S and down-regulated MCL1-L. Significantly, we discovered that SF3B1 was involved in the splicing of oncogenic HPV16 E6 to produce non-oncogenic HPV16 E6*, indicating that SF3B1 may inhibit HPV16-induced tumorigenesis.

Xenograft model for therapeutic drug testing in recurrent respiratory papillomatosis

OBJECTIVE

Identifying effective treatment for papillomatosis is limited by a lack of animal models, and there is currently no preclinical model for testing potential therapeutic agents. We hypothesized that xenografting of papilloma may facilitate in vivo drug testing to identify novel treatment options.

METHODS

A biopsy of fresh tracheal papilloma was xenografted into a NOD-scid-IL2Rgamma(null) (NSG) mouse.

RESULTS

The xenograft began growing after 5 weeks and was serially passaged over multiple generations. Each generation showed a consistent log-growth pattern, and in all xenografts, the presence of the human papillomavirus (HPV) genome was confirmed by polymerase chain reaction (PCR). Histopathologic analysis demonstrated that the squamous architecture of the original papilloma was maintained in each generation. In vivo drug testing with bevacizumab (5 mg/kg i.p. twice weekly for 3 weeks) showed a dramatic therapeutic response compared to saline control.

CONCLUSION

We report here the first successful case of serial xenografting of a tracheal papilloma in vivo with a therapeutic response observed with drug testing. In severely immunocompromised mice, the HPV genome and squamous differentiation of the papilloma can be maintained for multiple generations. This is a feasible approach to identify therapeutic agents in the treatment of recurrent respiratory papillomatosis.

Prevalence of genital human papillomavirus among men in Europe: systematic review and meta-analysis

INTRODUCTION

Human papillomavirus (HPV) is the commonest sexually transmitted infection worldwide and causes substantial morbidity in both sexes. Most European countries offer HPV vaccination for girls, but vaccine recommendations for boys are warranted.

AIMS

The aims of this study were to investigate the prevalence of genital HPV, identify parameters that affect the prevalence, and describe the type-specific prevalence among men in Europe.

METHODS

A systematic review and meta-analysis of the published literature in PubMed and Embase.

MAIN OUTCOME MEASURES

Genital HPV prevalence and factors influencing prevalence in general and high-risk male populations in Europe.

RESULTS

We included 31 articles that gave the prevalence of genital HPV DNA among men in northern, southern and western Europe; no studies from eastern Europe were identified. The pooled HPV prevalence among 1,863 men representing the general population (nine studies) was 12.4%, with large heterogeneity between studies (I(2)  = 96.3%, P < 0.0001). The pooled HPV prevalence among 6,428 men in the high-risk population (22 studies) was 30.9%, also with substantial heterogeneity (I(2)  = 95.6%, P < 0.0001). In unadjusted meta-regression analysis, the HPV prevalence in the general population was significantly higher in studies published after 2000 (28.5%) than in earlier studies (8.8%) (P = 0.0179). In the meta-regression analysis adjusted by publication year, the heterogeneity in the two population groups could not be explained by geographical region, anatomical sampling site, or HPV detection method. HPV16 was the most prevalent high-risk type in both populations.

CONCLUSIONS

HPV prevalence differs in male general and high-risk populations, but HPV16 and HPV18 are among the most common HPV types detected in both groups. Our findings contribute knowledge that may be useful as a baseline measure before the introduction of HPV vaccination for boys in Europe, and add to understanding of the epidemiology of HPV infection in men.

Kissing and hpv: honest popular visions, the human papilloma virus, and cancers

Kissing is among the multitude of functions of the lips [...]

Clinical implications of (epi)genetic changes in HPV-induced cervical precancerous lesions

Infection of cervical epithelium with high-risk human papilloma virus (hrHPV) might result in productive or transforming cervical intraepithelial neoplasia (CIN) lesions, the morphology of which can overlap. In transforming CIN lesions, aberrations in host cell genes accumulate over time, which is necessary for the ultimate progression to cancer. On the basis of (epi)genetic changes, early and advanced transforming CIN lesions can be distinguished. This paves the way for new molecular tools for cervical screening, diagnosis and management of cervical cancer precursor lesions.

High HPV infection prevalence in men from infertile couples and lack of relationship between seminal HPV infection and sperm quality

Human papillomaviruses (HPV) are the most frequently sexually transmitted viruses and etiological agents of several human cancers. Controversial results of the role of HPV in infertile population on sperm parameters have been published. The aim of this study was to estimate the type-specific prevalence of HPV DNA infection of the external genitalia and semen in 340 Slovenian men from infertile couples and to establish the relationship between seminal HPV DNA infection and abnormal sperm parameters. Self-taken swabs of the entire penile surface and semen samples were collected, and HPV detection and genotyping were performed. HPV DNA was detected in 37.12% of external genitalia and in 13.61% of semen samples with high HPV type concordance of both sampling sites. The most prevalent HPV types in the male external genitalia were HPV-CP6108 and HPV-84. The most prevalent HPV types in semen were HPV-53 and HPV-CP6108. The prevalence of HPV infection between normozoospermic men and men with abnormal sperm parameters did not differ significantly. Sperm quality did not differ significantly between men with seminal HPV infection and uninfected men. In conclusion, the men from infertile couples are equally susceptible to HPV infection regardless of their fertile potential; seminal HPV infection does not impair sperm quality.

Review of the clinical and biologic aspects of human papillomavirus-positive squamous cell carcinomas of the head and neck

Human papillomavirus (HPV), a known etiology of a subset of head-and-neck squamous cell carcinomas (HNCs), causes numerous alterations in normal cellular functions. This article reviews the biology, detection, and treatment of HPV-positive HNC. The role of HPV oncoproteins in tumor development, the natural history of HPV infection, and risk factors for and prevention of transmission of oral HPV are considered. Commonly used methods for detecting HPV infection, including limitations of these methods, are discussed to aid the practicing clinician in using these tests in their clinical practice. Clinical characteristics of HPV-positive HNC, including potential explanations for the improved outcomes seen in patients with HPV-positive HNC, are assessed. Ongoing clinical trials specific for patients with HPV-positive HNC are described, and areas in need of additional research are summarized. Until the results of ongoing trials are known, treatment of HPV-positive HNC should not differ in clinical practice from treatment of similar non-HPV related cancers.

Diagnostic algorithm to reflect regressive changes of human papilloma virus in tissue biopsies

PURPOSE

Landmark indicators have not yet to be developed to detect the regression of cervical intraepithelial neoplasia (CIN). We propose that quantitative viral load and indicative histological criteria can be used to differentiate between atypical squamous cells of undetermined significance (ASCUS) and a CIN of grade 1.

MATERIALS AND METHODS

We collected 115 tissue biopsies from women who tested positive for the human papilloma virus (HPV). Nine morphological parameters including nuclear size, perinuclear halo, hyperchromasia, typical koilocyte (TK), abortive koilocyte (AK), bi-/multi-nucleation, keratohyaline granules, inflammation, and dyskeratosis were examined for each case. Correlation analyses, cumulative logistic regression, and binary logistic regression were used to determine optimal cut-off values of HPV copy numbers. The parameters TK, perinuclear halo, multi-nucleation, and nuclear size were significantly correlated quantitatively to HPV copy number.

RESULTS

An HPV loading number of 58.9 and AK number of 20 were optimal to discriminate between negative and subtle findings in biopsies. An HPV loading number of 271.49 and AK of 20 were optimal for discriminating between equivocal changes and obvious koilocytosis.

CONCLUSION

We propose that a squamous epithelial lesion with AK of >20 and quantitative HPV copy number between 58.9-271.49 represents a new spectrum of subtle pathological findings, characterized by AK in ASCUS. This can be described as a distinct entity and called "regressing koilocytosis".

Epidemiology of ocular surface squamous neoplasia in Africa

OBJECTIVES

To describe the epidemiology and an aetiological model of ocular surface squamous neoplasia (OSSN) in Africa.

METHODS

Systematic and non-systematic review methods were used. Incidence was obtained from the International Agency for Research on Cancer. We searched PubMed, EMBASE, Web of Science and the reference lists of articles retrieved. Meta-analyses were conducted using a fixed-effects model for HIV and cigarette smoking and random effects for human papilloma virus (HPV).

RESULTS

The incidence of OSSN is highest in the Southern Hemisphere (16° South), with the highest age-standardised rate (ASR) reported from Zimbabwe (3.4 and 3.0 cases/year/100 000 population for males and females, respectively). The mean ASR worldwide is 0.18 and 0.08 cases/year/100 000 among males and females, respectively. The risk increases with exposure to direct daylight (2-4 h, OR = 1.7, 95% CI: 1.2-2.4 and ≥5 h OR = 1.8, 95% CI: 1.1-3.1) and outdoor occupations (OR = 1.7, 95% CI: 1.1-2.6). Meta-analysis also shows a strong association with HIV (6 studies: OR = 6.17, 95% CI: 4.83-7.89) and HPV (7 studies: OR = 2.64, 95% CI: 1.27-5.49) but not cigarette smoking (2 studies: OR = 1.40, 95% CI: 0.94-2.09). The effect of atopy, xeroderma pigmentosa and vitamin A deficiency is unclear.

CONCLUSIONS

Africa has the highest incidence of OSSN in the world, where males and females are equally affected, unlike other continents where male disease predominates. African women probably have increased risk due to their higher prevalence of HIV and HPV infections. As the survival of HIV-infected people increases, and given no evidence that anti-retroviral therapy (ART) reduces the risk of OSSN, the incidence of OSSN may increase in coming years.

Human papillomavirus infection and vaginal tape exposure after midurethral sling: a case report

Midurethral tape placement is the gold standard procedure for stress urinary incontinence (SUI). Among reported complications, tape erosion is uncommon. Several risk factors have been postulated as causes of vaginal erosion, but none have been demonstrated. Cases of vaginal erosion caused by tape infections have been described, but none has been associated with human papillomavirus (HPV) infection. We report the first case of vaginal exposure in a woman who underwent a midurethral sling procedure for SUI after HPV colonization.

Eight nucleotide substitutions inhibit splicing to HPV-16 3'-splice site SA3358 and reduce the efficiency by which HPV-16 increases the life span of primary human keratinocytes

The most commonly used 3'-splice site on the human papillomavirus type 16 (HPV-16) genome named SA3358 is used to produce HPV-16 early mRNAs encoding E4, E5, E6 and E7, and late mRNAs encoding L1 and L2. We have previously shown that SA3358 is suboptimal and is totally dependent on a downstream splicing enhancer containingmultiple potential ASF/SF2 binding sites. Here weshow that only one of the predicted ASF/SF2 sites accounts for the majority of the enhancer activity. We demonstrate that single nucleotide substitutions in this predicted ASF/SF2 site impair enhancer function and that this correlates with less efficient binding to ASF/SF2 in vitro. We provide evidence that HPV-16 mRNAs that arespliced to SA3358 interact with ASF/SF2 in living cells. In addition,mutational inactivation of the ASF/SF2 site weakened the enhancer at SA3358 in episomal forms of the HPV-16 genome, indicating that the enhancer is active in the context of the full HPV-16 genome.This resulted in induction of HPV-16 late gene expression as a result of competition from late splice site SA5639. Furthermore, inactivation of the ASF/SF2 site of the SA3358 splicing enhancer reduced the ability of E6- and E7-encoding HPV-16 plasmids to increase the life span of primary keratinocytes in vitro, demonstrating arequirement for an intact splicing enhancer of SA3358 forefficient production of the E6 and E7 mRNAs. These results link the strength of the HPV-16 SA3358 splicing enhancer to expression of E6 and E7 and to the pathogenic properties of HPV-16.

Suppression of HPV-16 late L1 5'-splice site SD3632 by binding of hnRNP D proteins and hnRNP A2/B1 to upstream AUAGUA RNA motifs

Human papillomavirus type 16 (HPV-16) 5′-splice site SD3632 is used exclusively to produce late L1 mRNAs. We identified a 34-nt splicing inhibitory element located immediately upstream of HPV-16 late 5′-splice site SD3632. Two AUAGUA motifs located in these 34 nt inhibited SD3632. Two nucleotide substitutions in each of the HPV-16 specific AUAGUA motifs alleviated splicing inhibition and induced late L1 mRNA production from episomal forms of the HPV-16 genome in primary human keratinocytes. The AUAGUA motifs bind specifically not only to the heterogeneous nuclear RNP (hnRNP) D family of RNA-binding proteins including hnRNP D/AUF, hnRNP DL and hnRNP AB but also to hnRNP A2/B1. Knock-down of these proteins induced HPV-16 late L1 mRNA expression, and overexpression of hnRNP A2/B1, hnRNP AB, hnRNP DL and the two hnRNP D isoforms hnRNP D37 and hnRNP D40 further suppressed L1 mRNA expression. This inhibition may allow HPV-16 to hide from the immune system and establish long-term persistent infections with enhanced risk at progressing to cancer. There is an inverse correlation between expression of hnRNP D proteins and hnRNP A2/B1 and HPV-16 L1 production in the cervical epithelium, as well as in cervical cancer, supporting the conclusion that hnRNP D proteins and A2/B1 inhibit HPV-16 L1 mRNA production.

Association of Chlamydia trachomatis infection with redetection of human papillomavirus after apparent clearance

BACKGROUND

Persistent infection with oncogenic human papillomavirus (HPV) is associated with an increased risk of cervical malignancy. Redetection of type-specific HPV after a period of nondetection may be caused by reactivation of a low-level persistent infection. Little is known about factors associated with type-specific HPV redetection.

METHODS

For a longitudinal cohort of adolescent women with frequent behavioral and sexually transmitted infection (STI) information (every 3 months), Cox proportional hazard models were used to assess the influence of sexual behaviors and STIs on the redetection of oncogenic or high-risk HPV infections.

RESULTS

A total of 210 type-specific high-risk HPV detection episode periods were identified in this longitudinal cohort; 71 (33.8%) were characterized by a period of nondetection followed by redetection. Chlamydia trachomatis (hazard ratio [HR], 3.14; 95% confidence interval [CI], 1.44-6.86) was associated with redetection; redetection was >2 times more likely with each additional self-reported sex partner in the past 3 months (HR, 2.26; 95% CI, 1.35-3.78).

CONCLUSIONS

This study demonstrates the role of C. trachomatis and number of recent sexual partners in type-specific HPV redetection. Given that persistent oncogenic HPV infections are associated with cancer-related outcomes, understanding the potential role of such factors in the pathogenesis of HPV-related outcomes is important.