Roots and perspectives of contemporary papillomavirus research

Global burden of oropharyngeal cancer attributable to human papillomavirus by anatomical subsite and geographic region

BACKGROUND

Oropharynx is the anatomical site with the highest human papillomavirus (HPV) infection in head and neck. Many studies on HPV prevalence and p16^INK4a positivity in oropharyngeal cancer have been published in recent years. We aimed to update the global burden estimates of oropharyngeal cancer attributable to HPV with the latest data and estimate global burden of tonsillar cancer and base of tongue cancer attributable to HPV by region and country.

METHODS

We calculated the number of new cancer cases using the Cancer Incidence in Five Continents Volume XI (CI5XI) and country-specific population in 2012 issued by the United Nations. Estimates of HPV prevalence and p16^INK4a positivity were obtained from literature search and pooled analyses where necessary.

RESULTS

Globally the number of oropharyngeal cancer and tonsillar cancer attributable to HPV were 42,000 and 20,000 in 2012, corresponding to AFs of 42.7% and 52.7%. The number of cancer cases attributable to HPV among males was about 4-fold greater than that among females. For both oropharyngeal cancer and tonsillar cancer, AFs were higher in more developed countries. Among HPV positive oropharyngeal cancer cases, 86.7%, 87.8%, and 92.5% could have been prevented by bivalent (2v), quadrivalent (4v), and nonavalent (9v) HPV vaccines.

CONCLUSIONS

It is worth considering the inclusion of HPV immunization in males, especially in the regions where oropharyngeal cancer is highly prevalent.

Prevalence, genotypes and phylogenetic analysis of human papillomaviruses (HPV) in northeast Iran

OBJECTIVES

Human papillomaviruses (HPV) are the main etiology of invasive cervical cancer. Together HPV and viral hepatitis account for the cause of 25% of cancers in developing countries. To evaluate the association between population movements and the spread of HPV, this study looked at prevalence, genotypes, and phylogenetic assessment of HPV in Great Khorasan, a pilgrimage-tourism province in northeast Iran.

METHODS

From March 2013 to July 2018, 567 samples were collected from three groups in Khorasan: Razavi and North Khorasan provinces (highly mobile population); South Khorasan province (conservative and desert); and diverse group (tourists).

RESULTS

HPV prevalence was 48.4% in Razavi and North Khorasan (first group); 19.9% in South Khorasan (second group); and 33.6% in the diverse group. The four most common HPV genotypes were HPV-6, 11, 51 and 16, in the first group; HPV-6, 11, 16 and 58 in the second group; and HPV-6, 11, 16 and 53/89 in the diverse group. The most frequent genotypes that are known as high risk for cervical cancer were HPV-51 in the first group, HPV-16 in the second group and the diverse group. Among low-risk genotypes, HPV-6, and HPV-11 were more frequent in all groups. DNA sequencing and phylogenetic analysis of 20 HPV-positive samples showed that the distributions of the HPV genotypes were HPV-6 (50%), 11 (10%), 67 (5%), 16 (15%), 31 (10%), 54 (5%), and 89 (5%).

CONCLUSIONS

The findings show that areas associated with population movement should be frequently monitored for infectious diseases, while conservative and less populated areas have less risk for virus spread and endemicity. Health authorities should focus more on the establishment of HPV diagnostic facilities, screening, vaccination, and enhancement of public knowledge in these regions.

Nanomedicinal strategies as efficient therapeutic interventions for delivery of cancer vaccines

The applications of gene therapy-based treatment of cancers were started almost two decades back as a boon over the chemotherapeutic treatment strategies. Gene therapy helps in correcting the genetic sequences for treatment of cancers, thus also acts like a vaccine to induce the cellular and humoral immunity. However, the cancer vaccines typically suffer from a series of biopharmaceutical challenges due to poor solubility, low systemic availability and lack of targeting ability. Owing to these challenges, the physicians and pharmaceutical scientists have explored the applications of nanocarriers as quite promising systems for effective treatment against the tumors. A series of nanotherapeutic systems are available to date for diverse drug therapy applications. Systematic understanding on the preparation, evaluation and application of nanomedicines as a carrier system for delivering the cancer vaccines is highly important. The present review article provides an in-depth understanding on the challenges associated with cancer vaccine delivery and current opportunities with diverse nanomedicinal carriers being available for treatment of cancers.

Historical review of the causes of cancer

In the early 1900s, numerous seminal publications reported that high rates of cancer occurred in certain occupations. During this period, work with infectious agents produced only meager results which seemed irrelevant to humans. Then in the 1980s ground breaking evidence began to emerge that a variety of viruses also cause cancer in humans. There is now sufficient evidence of carcinogenicity in humans for human T-cell lymphotrophic virus, human immunodeficiency virus, hepatitis B virus, hepatitis C virus, human papillomavirus, Epstein-Barr virus, and human herpes virus 8 according to the International Agency for Research on Cancer (IARC). Many other causes of cancer have also been identified by the IARC, which include: Sunlight, tobacco, pharmaceuticals, hormones, alcohol, parasites, fungi, bacteria, salted fish, wood dust, and herbs. The World Cancer Research Fund and the American Institute for Cancer Research have determined additional causes of cancer, which include beta carotene, red meat, processed meats, low fibre diets, not breast feeding, obesity, increased adult height and sedentary lifestyles. In brief, a historical review of the discoveries of the causes of human cancer is presented with extended discussions of the difficulties encountered in identifying viral causes of cancer.

Detection of major HPVs by a new multiplex real-time PCR assay using type-specific primers

In this study, we aimed to develop a cost-effective, practical, and sensitive method to be used for the diagnosis of HPV infections. The presence of HPV-DNA was investigated in cervical smear samples using three different methods: MY09/11 consensus PCR, TaqMan-based type-specific real-time PCR, and SYBR Green-based multiplex PCR. Of the 315 samples, 21.6% (68/315) were HPV-DNA positive by using at least one of the three methods. The relative sensitivities of MY09/11 PCR, type-specific PCR, and multiplex PCR were found to be 86.8% (59/68), 91.2% (62/68), and 91.2% (62/68), respectively. Genotyping analyses were successfully carried out in 62 of 68 HPV-DNA positive samples, and 77 isolates (8 low-risk and 69 high-risk HPV) were identified, while six samples were determined to be positive by consensus PCR only and could not be genotyped. The type distribution of the 69 high-risk HPV strains was as follows: 37.7% HPV 16, 13.0% HPV 52, 11.6% HPV 58, 7.2% HPV 18, 7.2% HPV 31, 7.2% HPV 68, 4.3% HPV 35, 4.3% HPV 39, 4.3% HPV 82, 1.4% HPV 33, and 1.4% HPV 45. Our data suggests that the diagnosis of HPV infections using only consensus PCR may lead to epidemiologically significant data loss, and that our multiplex PCR is more sensitive than consensus PCR and lower in cost than the type-specific PCR. We believe that the SYBR Green-based multiplex PCR may be useful and cost-effective for other microbiological fields. In addition, type-specific screening of HPV-DNA gives more reliable results, but it may also be used in combination with consensus PCR if the type spectrum of the test is not large enough.

The patient-consumer-advocate nexus: the marketing and dissemination of gardasil, the human papillomavirus vaccine, in the United States

The 2006 availability of Merck's human papillomavirus (HPV) vaccine, Gardasil, in the United States provides an opportunity to examine the pharmaceutical company's creation of patient awareness for one of the most common sexually transmitted infections and its related cancer. In spite of the ubiquity of gynecological screening, prior to the vaccine's dissemination, most U.S. women were not familiar with either the infection or its association with cancer. Merck's role in encouraging a patient advocacy community mimics existing breast cancer patient advocacy culture in the United States while also demonstrating marked popular culture differences between the two women's health concerns and their respective advocacy groups. This article draws on ethnographic fieldwork with an HPV/cervical cancer advocacy organization to demonstrate how the group and its members engaged in an activism of awareness that disavows larger political aims.

Diversity and uncommon HPV types in HIV seropositive and seronegative women attending an STI clinic

Given the causal relationship between specific types of HPV with cervical cancer and precursor lesions, it is important to identify the viral type involved. The aim of this study is to access the prevalence of HPV types in HIV seropositive and seronegative women. Accordingly, 77 HPV positive cervical samples were obtained from 284 women (seropositive (n=112) and seronegative (n=172) for HIV) who attended a Sexually Transmitted Infection clinic, in Vitoria, Southeastern Brazil. Viral DNA was amplified by PCR using MY09/MY11 degenerated primers and the genotyping was performed by Restriction Fragment Length Polymorphism. Seventy five out of the 77 HPV samples were genotyped: 6, 11, 13, 16, 18, 26, 31, 31b, 32, 33, 34, 35, 52, 53, 55, 56, 58, 59, 61, 62, 64, 66, 71, 81, 83, 84. The most prevalent type was HPV16 followed by HPV types 6, 11 and 53. Fifty five percent and 45% belonged to high and low risk types, respectively. High risk types corresponded to 59% and 54.5% of the HPV detected in HIV seronegative and seropositive women, respectively. The uncommon HPV 13 type in cervical samples was also observed in this study. The oncogenic types were more common in the HIV seronegative samples and the number of cases with multiple infections was similar for the two groups. HPV typing is not only important clinically for the establishment of monitoring and treatment of a patient, it also provides knowledge of the viral types circulating in a population, which is of interest in the development of prevention and treatment programs for this disease.

Anal HPV infection in Slovenian men who have sex with men

Anal human papillomavirus (HPV) infection commonly affects men who have sex with men (MSM) and is associated with the development of anal cancer, with the highest prevalence in MSM who are positive for human immunodeficiency virus (HIV). The purpose of this study was to determine the prevalence of anal HPV infection and genotype distribution in Slovenian MSM and its correlation with behavioral patterns in order to predict the possible impact of quadrivalent HPV vaccine in this population. To our knowledge, this is the first study of prevalence and genotype distribution of anal HPV infection in MSM from any of the Eastern European countries. The study included 136 MSM who visited two outpatient offices from January 2007 through December 2008. All participants were clinically examined and tested for HIV, and anal swabs were taken for HPV testing. The results showed a high prevalence of anal HPV infection in both HIV-negative (75%) and HIV-positive (95%) MSM. Promiscuity and use of “poppers” (alkyl nitrites taken for recreational purposes through direct inhalation) were clearly associated with a higher prevalence of anal HPV infection. The four most common HPV genotypes were 6, 11, 16, and 18. The prevalence of anal HPV infection in Slovenian MSM is higher in comparison with other studies. Quadrivalent HPV vaccine could have great potential in this population.

A generally applicable cost-effectiveness model for the evaluation of vaccines against cervical cancer

Objective

This study aimed at evaluating the cost-effectiveness of human papillomavirus virus (HPV) vaccination in France, using a generally applicable succinct cohort model.

Methods

A lifetime Markov cohort model, adapted to the French setting, simulate the natural history of oncogenic HPV infection towards cervical cancer (CC). Additional modules account for the effects of screening and vaccination. The girls’ cohort is vaccinated at age 12 and follows current screening. Costs and outcomes (discounted at 3 and 1.5%, respectively) were compared with a cohort receiving screening alone.

Results

The model results agreed well with real-life data. Vaccination in addition to screening would substantially reduce the incidence of and mortality from CC, compared with screening alone, at an estimated cost-effectiveness of €9,706 per quality-adjusted-life-year. Sensitivity analysis showed that the discount rate and the parameters related to the disease history have the largest impact on the results.

Conclusion

This succinct cohort model indicated that HPV vaccination would be a cost-effective policy option in France. It uses readily available data and should be generally applicable to the evaluation of HPV vaccination in a variety of countries and settings.

Treatment of genital warts in males by pulsed dye laser

OBJECTIVE

To determine the safety and efficacy of the flashlamp-pumped pulsed dye laser for the treatment of uncomplicated genital warts in adult males.

METHODS

This was a prospective observational study set in the outpatient clinics of the Department of Andrology and Sexually Transmitted Diseases, National Institute of Laser Enhanced Sciences, the Dermatology Clinic, Cairo University, and the Department of Dermatology and Venereology, Suez Canal University. A total of 174 adult male patients with 550 uncomplicated anogenital warts were included. Selective photothermolysis and photocoagulation of the lesions with the flashlamp-pumped pulsed dye laser was carried out. A pulsed dye laser (wavelength 585 nm, 450 s pulse duration; Cynosure, USA) was used with the following settings: spot size 5-7 mm; fluence 9-10 J/cm2.

RESULTS

Complete resolution of treated warts was achieved in 96% of lesions. Side effects were limited, transient and infrequent. Lesion recurrence rate was 5%.

CONCLUSION

The pulsed dye laser has been found to be safe, effective and satisfactory for the treatment of anogenital warts in males. It could be used to selectively destroy warts without damaging the surrounding skin.

Prevalence of human papillomavirus genotypes in women from a rural region of Puebla, Mexico

OBJECTIVE

To determine the prevalence of human papillomavirus (HPV) genotypes 6, 11, 16, 18, and 31 in Mexican women living in rural areas of Puebla, Mexico and to evaluate risk factors associated with cervical neoplasm in this population.

METHODS

A cross-sectional study was conducted in 326 women at the General Hospital of Metepec, Puebla. Cervical samples were obtained using a cytobrush and tested for HPV genotypes by PCR assays using type-specific primers. A questionnaire was completed regarding gynecological, obstetric, and sexual behavior of the patients.

RESULTS

The overall prevalence of HPV infection was 25.4%, with two peaks of higher HPV prevalence in those aged 18-24 and 55-64 years. The individual genotype prevalences were: 9.6% HPV6, 4.8% HPV11, 54.2% HPV16, 37.3% HPV18, and 9.6% HPV31. Number of pregnancies was the most important risk factor associated with cervical cancer.

CONCLUSIONS

HPV16 was the most common type found in all cervical lesions. Genotype 16 or 18 was detected in patients with a diagnosis of cervical cancer. We found two peaks of age-specific HPV prevalence similar to findings reported worldwide.

Significance of SHP-1 and SHP-2 expression in human papillomavirus infected Condyloma acuminatum and cervical cancer

Human papillomaviruses (HPVs) are a group of DNA viruses that infect the skin and mucous membranes. Type HPV6/11 is closely related to Condyloma acuminatum, while HPV16/18 is the principal cause of cervical cancer. In this study, we examined the expression of protein tyrosine phosphatases SHP-1 and SHP-2 in Condyloma acuminatum, cervical cancer and the relationship between SHP-1/SHP2 expression and HPV infection. Forty Condyloma acuminatum cases, 20 cervical cancer cases and 20 normal human foreskins were examined for HPV infection by in situ hybridization and the expression of SHP-1 and SHP-2 were examined by immunohistochemistry. Results demonstrated that positive expression rates of HPV6/11, HPV16/18, and HPV31/33 were 98%, 10%, and 7.5% in Condyloma acuminatum, 10%, 85%, and 25% in cervical cancer. Only one normal foreskin demonstrated positive staining for HPV16/18. Positive expression rates of SHP-1 and SHP-2 were 80% and 85% in Condyloma acuminatum, 85% and 90% in cervical cancer. The SHP-1 and SHP-2 expressions were mainly distributed in the prickle layer of Condyloma acuminatum and were diffusely distributed in cervical cancer cells. Only 35% and 30% of foreskins demonstrated weak staining in the basal layer cells. There were statistically significant correlations among the infection of HPV and the expression of SHP-1 and SHP-2 in both Condyloma acuminatum and cervical cancer (P < 0.05). SHP-1 expression has a positive correlation with SHP-2 expression. Our results demonstrate putative roles of SHP-1 and SHP-2 in the progression of both Condyloma acuminatum and cervical cancer after HPV infection.

Detection of human papillomavirus type 56 in Bowen's disease involving the nail matrix

BACKGROUND

As Bowen's disease of the nail apparatus is quite rare, there have been only a few reports on the prevalence of human papillomavirus (HPV) infection in this condition.

OBJECTIVES

The purpose of this study was to clarify the association of HPV with this disease involving the nail apparatus.

METHODS

Five patients with Bowen's disease of the nail apparatus were investigated clinically, virologically and histologically. Total DNAs extracted from excised skin lesions were analysed using polymerase chain reaction (PCR) for the presence of HPV DNA and the amplified products were subjected to DNA sequence analyses. Histological localization of HPV DNA was examined by in situ hybridization.

RESULTS

In three of five patients, HPV was detected by PCR amplification, and subsequent sequence analyses of the PCR products showed the sequences of HPV type 56. A common clinical feature of the three HPV-positive patients was longitudinal melanonychia. In contrast, the two HPV-negative patients presented with a convex nail deformity and a periungual ulcerative lesion. In two of three positive cases, there was a silent point mutation in the L1 gene of each HPV. In the remaining one case, the nucleotide sequence was consistent with the consensus sequence of HPV 56. Sequence analyses of the E6 gene revealed the infection of different variants of HPV 56 among the three cases. The viral genomes were located in keratinocyte nuclei upon in situ hybridization.

CONCLUSIONS

HPV 56 may be involved in the carcinogenesis of Bowen's disease affecting the nail matrix with longitudinal pigmentation.

Viral infections affecting the skin in organ transplant recipients: epidemiology and current management strategies

Viral skin infections are common findings in organ transplant recipients. The most important etiological agents are the group of human herpesviruses (HHV), human papillomaviruses (HPV), and molluscum contagiosum virus. HHV that are important in this group of patients are herpes simplex virus (HSV) types 1 and 2, varicella-zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), HHV-6 and -7, and HHV-8, which causes Kaposi sarcoma (KS). HSV infections are characterized by their ability to establish latency and then reactivate at a later date. The most common manifestations of HSV infection in organ transplant recipients are mucocutaneous lesions of the oropharynx or genital regions. Treatment is usually with acyclovir, valaciclovir, or famciclovir. Acyclovir resistance may arise although the majority of acyclovir-resistant strains have been isolated from AIDS patients and not organ transplant recipients. In such cases, alternatives such as foscarnet, cidofovir, or trifluridine may have to be considered. VZV causes chickenpox as well as herpes zoster. In organ transplant recipients, recurrent herpes zoster can occur. Acute chickenpox in organ transplant patients should be treated with intravenous acyclovir. CMV infection occurs in 20-60% of all transplant recipients. Cutaneous manifestations, which include nonspecific macular rashes, ulcers, purpuric eruptions, and vesiculobullous lesions, are seen in 10-20% of patients with systemic infection and signify a poor prognosis. The present gold standard for treatment is ganciclovir, but newer drugs such as valganciclovir appear promising. EBV is responsible for some cases of post-transplant lymphoproliferative disorder, which represents the greatest risk of serious EBV disease in transplant recipients. HHV-6 and HHV-7 are two relatively newly discovered viruses and, at present, the body of information concerning these two agents is still fairly limited. KS is caused by HHV-8, which is the most recently discovered lymphotrophic HHV. Iatrogenic KS is seen in solid-organ transplant recipients, with a prevalence of 0.5-5% depending on the patient's country of origin. HPV is ubiquitous, and organ transplant recipients may never totally clear HPV infections, which are the most frequently recurring infections in renal transplant recipients. HPV infection in transplant recipients is important because of its link to the development of certain skin cancers, in particular, squamous cell carcinoma. Regular surveillance, sun avoidance, and patient education are important aspects of the management strategy.

Human Papillomaviruses and Genital Disease

Human papillomavirus (HPV) infection is causally related to several benign and malignant diseases of the anogenital tract. In this article the authors detail the epidemiology, methods of transmission and risk factors, pathogenesis, and oncogenesis of HPV, and describe clinical manifestations and current treatments. Special attention is given to condyloma acuminatum and non-cervical anogenital intraepithelial neoplasia. The authors conclude with the latest information on prophylactic vaccine development and prospects for future control of HPV-related disease.

comparison of two commercial assays for detection of human papillomavirus (HPV) in cervical scrape specimens: validation of the Roche AMPLICOR HPV test as a means to screen for HPV genotypes associated with a higher risk of cervical disorders

Certain high-risk (HR) human papillomavirus (HPV) types are a necessary cause for the development of cervical disorders. Women with persistent HR HPV infections have an increased risk of developing high-grade cervical lesions, compared with those who have no or low-risk HPV infections. Therefore, implementation of HPV detection into cervical screening programs might identify women at risk of cervical cancer. Several HPV detection methods with different sensitivities and specificities are available. Recently, a new PCR-based technique, the Roche AMPLICOR HPV Test, was developed. This test recognizes a group of 13 HR HPV types simultaneously. This study was undertaken to validate and compare HPV detection in 573 cervical scrape specimens by the AMPLICOR HPV Test and the INNO-LiPA HPV detection/genotyping assay (SPF10-LiPA system version 1). Human beta-globin was not detected in nine specimens, which were therefore excluded from the comparison. Eleven scrape specimens containing HPV type 53 or 66 were also excluded from the comparison because these (probably) HR HPV types cannot be detected by the AMPLICOR HPV Test. The results of HPV detection by the Roche AMPLICOR HPV Test were confirmed by INNO-LiPA HPV detection/genotyping assay in 539/553 cases, showing an absolute agreement of 97.5% with a Cohen's kappa of 0.9327, indicating almost complete similarity of the two tests. Like the INNO-LiPA HPV detection/genotyping assay, the AMPLICOR HPV Test was sensitive, specific, feasible, and easy to handle. The value of the Roche AMPLICOR HPV Test with a broad-spectrum HR HPV detection has to be determined in prospective clinical studies.

The epidemiology of human papillomavirus infections

Infection with oncogenic human papillomavirus (HPV) types is a necessary cause of cervical cancer, the second most frequently occurring cancer in women worldwide. Rates of acquisition of HPV are high, particularly among sexually active young adults. Reported estimates of incident HPV infection among initially negative women have reached as high as 60% over a 5-year follow-up period. In this article, we review the epidemiology of HPV infection. In addition to estimates of disease frequency, we highlight risk factors for HPV infection, including the number of lifetime sex partners, which is the most salient risk factor. We discuss significant issues surrounding the natural history of HPV infection, including viral persistence versus clearance, immune response, development of lesions and development of cancer. Finally, we discuss strategies for preventing HPV infection.

Ectopic chromosome around centrosome in metaphase cells as a marker of high-risk human papillomavirus-associated cervical intraepithelial neoplasias

This report describes the appearance of ectopic chromosome around centrosome (ECAC) in metaphase cell nuclei of high-risk HPV-associated cervical neoplasms. ECAC are clearly visible on HE-stained sections as a tiny (approx. 0.7 micro), round, dark structure or an aggregate of filamentous chromosome, often symmetrical at bilateral centrosomes. They appear in CINs from an early stage (CIN I), with the highest incidence in HPV16-associated CIN II-III (75%), and are less common in HPV-related invasive carcinomas (21%) and in lesions associated with high-risk HPV types other than 16. Rates for ECAC-positive nuclei in metaphase preparations (ECAC rate) for each lesion ranged 3.6-30%, the average being 14.5%. ECAC appeared very rarely in CINs associated with intermediate-risk HPVs and was never encountered in HPV6/11-induced condylomas or HPV-unrelated neoplasms in other organs. ECAC may be morphologic evidence of HPV-induced chromosomal instability working as a background mechanism in cervical carcinogenesis and also a useful marker for the histopathologic differentiation of high-risk CINs.

Human papillomaviruses and non-melanoma skin cancer

Epidemiological and experimental studies have overwhelmingly confirmed human papillomaviruses as important causal agents in anogenital carcinogenesis. A role for human papillomaviruses has also been proposed in a diverse range of other malignancies, and particular interest has focused on non-melanoma skin cancer, the commonest malignancy in fair-skinned populations worldwide. Although the evidence for this is considerably less convincing than for anogenital cancer, important epidemiological and functional data have emerged over the past year that have furthered our understanding of the possible contribution of human papillomaviruses to skin cancer. Epidemiological human papillomavirus DNA detection studies have shown associations with non-melanoma skin cancer, but have also emphasized the ubiquity of epidermodysplasia verruciformis human papillomavirus types in normal skin, hair follicles and benign hyperproliferative disorders, as have seroepidemiological approaches. Functional investigations have demonstrated mechanistically relevant interactions between the virus and ultraviolet radiation, host cytokines and cellular proteins including p53 and the pro-apoptotic protein Bak. Taken together, these data have advanced our understanding of the contribution of human papillomaviruses to malignant transformation in cutaneous keratinocytes, but further research is required before a causal association between human papillomaviruses and skin cancer is reliably confirmed.

The causal relation between human papillomavirus and cervical cancer

The causal role of human papillomavirus infections in cervical cancer has been documented beyond reasonable doubt. The association is present in virtually all cervical cancer cases worldwide. It is the right time for medical societies and public health regulators to consider this evidence and to define its preventive and clinical implications. A comprehensive review of key studies and results is presented.

Cervical cancer screening from Pap smear to human papillomavirus DNA testing

Human papillomavirus (HPV) types 16 and 18 are strongly associated with cervical cancer. Testing of HPV DNA in cervical specimens offers an useful option in triaging women with equivocal Pap smear diagnosis such as atypical squamous cells of undetermined significance.

In vivo detection of human papilloma virus-induced lesions of anogenital area after application of acetic acid: a novel and accurate approach to a trivial method

Human papilloma virus infection is increasing at an alarming rate. The ability of the virus to establish a subclinical infection and its association with malignancy of the lower genital tract make the statistics even more worrisome. Topical application of acetic acid solution provokes temporal alterations of the light-scattering properties of human papilloma virus-induced lesions of anogenital area. For the in vivo study of the phenomenon, an imaging system has been employed, which performs time-lapse imaging and enables the calculation and display of the kinetics of the provoked alterations in any point within the examined area. Confirmation of diagnosis has been established with conventional histology and polymerase chain reaction. It has been shown that the method provides early detection and staging of skin alteration or transformation due to human papilloma virus infection and enables mapping of the infected area.

Expression of endothelin 1 and endothelin A receptor in HPV-associated cervical carcinoma: new potential targets for anticancer therapy

Human papillomaviruses (HPV) are associated with cervical cancer and interact with growth factors that may enhance malignant transformation of cervical carcinoma cells. Endothelin-1 (ET-1) is released from HPV transfected keratinocytes and induces increased growth response in these cell lines in comparison with normal cells. In the present study several cervical carcinoma cell lines have been analyzed to investigate the expression of ET-1 and its receptors as well as their involvement in tumor growth. All HPV-positive cancer cells secreted ET-1 and expressed mRNA for ET-1 and its receptors, whereas a HPV-negative carcinoma cell line expressed only the ETBR mRNA and didn't secrete ET-1. Binding studies showed that HPV-associated cells expressed an increased number of functional ETAR. ET-1 stimulated a marked dose-dependent increase in [3H]-thymidine incorporation with respect to the normal cells whereas ET-3 and ETBR agonists had no effect. In HPV-positive cancer cells, a specific antagonist of ETAR inhibited the proliferation induced by ET-1 and substantially reduced the basal growth rate of unstimulated cervical tumor cells, whereas the ETBR antagonist had no effect. These results demonstrate that ET-1 participates in the progression of neoplastic growth in HPV-associated carcinoma, in which ETAR are increased and could be targeted for antitumor therapy.

Verrucas. Guidelines for management

Most people will experience infection with human papilloma virus (HPV) at some point in their life. Diagnosis, based on clinical examination, is usually straight forward. Treatment can, however, be challenging. Indications for treatment include pain, interference with function, cosmetic embarrassment, and risk of malignancy. Clearance rates are highest in young, healthy individuals with short duration of infection. Treatment may be with destructive agents (keratolytics, cryotherapy, curettage and cautery, laser, photodynamic therapy), with antimitotic agents (podophyllin, bleomycin, retinoids), with immune stimulants (topical sensitizers, cimetidine), or with topical virucidal agents [formaldehyde (formalin), glutaral (gluteraldehyde)]. As yet, there is no single totally effective treatment for viral warts. Some patients may choose to leave their warts untreated until spontaneous resolution. In those who seek intervention, simple, well tolerated therapies should be chosen initially in preference to more complicated, potentially harmful agents. It is likely that future research will be directed to developing an antiviral agent specific for HPV which would be safe, effective and not prohibitively expensive.

Infection, immunity, and cancer

A significant percentage of human cancers worldwide are associated with infections due to known viruses, including human papillomaviruses (cervical cancer and other skin cancers), human T-lymphotropic viruses (adult T-cell leukemias and lymphomas in endemic areas), hepatitis B virus (liver cancer), and Epstein-Barr virus (Burkitt lymphoma and nasopharyngeal carcinoma). The fraction of human cancers attributable to infection may now need to be revised in light of the fact that new viral associations have been discovered and other nonviral associations have been identified. This article addresses the increasingly recognized role of infectious agents as precipitants of human neoplasia and the possibility that novel diagnostic, therapeutic, and chemopreventive strategies may emanate directly from research directed at identifying and understanding these agents.

New concepts on the role of human papillomavirus in cell cycle regulation

Human papillomaviruses (HPVs) are strictly host-specific and also show a distinct tropism to squamous epithelial cells. Upon HPV infection, only a portion of the virus reaching the nucleus seems to undergo replication, suggesting that HPV replication remains confined to a small number of cells. HPVs critically depend on the cellular machinery for the replication of their genome. Viral replication is restricted to differentiated keratinocytes that are normally growth arrested. Hence, HPVs have developed strategies to subvert cellular growth regulatory pathways and are able to uncouple cellular proliferation and differentiation. Endogenous growth factors and cellular oncogenes modify HPV E (early) and L (late) gene expression and influence on the pathogenesis of HPV infections. HPV oncoproteins (E5, E6, E7) are important proteins not only in cell transformation but also in the regulation of the mitotic cycle of the cell, thus allowing the continuous proliferation of the host cells. Cyclins are important regulators of cell cycle transitions through their ability to bind cyclin-dependent kinases (cdks). Cdks have no kinase activity unless they are associated with a cyclin. Several classes of cyclins exist which are thought to coordinate the timing of different events necessary for cell cycle progression. Each cdk catalytic subunit can associate with different cyclins, and the associated cyclin determines which proteins are phosphorylated by the cdk-cyclin complex. The effects of HPVs on the cell cycle are mediated through the inhibition of antioncogens (mostly p53 and retinoblastoma) and through interference with the cyclins and cdks, resulting in target cell proliferation, their delayed differentiation, and as a side-effect, in malignant transformation.

Overview of viruses, cancer, and vaccines in concept and in reality

Cancer is a consequence of malfunction of the replicative cell cycle caused by acquisition of independence from proliferative and restrictive controls in the process. Such alteration may be driven by unrepaired mutations in proto-oncogenes and anti-oncogenes or by genetic insults of environmental, infectious, or spontaneous origin. The consequence of mutations may be reflected at any of a number of locations in the transductive pathways from receptor to nucleus which upset normal homeostatic balance between the opposing forces for promotion or restraint of cell proliferation. About 15% of human cancers are caused primarily by viruses that bring about aberrations in gene structure and function or that express proteins that bind to cell regulatory proteins. The means for achieving immunoprophylaxis of viral cancers, such as hepatitis B or Marek's disease, are based on prior specific perturbation of the immune system, causing it to respond rapidly and effectively in preventing infection on subsequent contact with the corresponding agent. Existing cancers of viral origin and those of nonviral causation come together in attempted immunotherapy. Cure is far more difficult to achieve than prevention and relies on the principle that tumor cells can display abnormal markers on the cell surface that are capable of being detected and engaged by an effective immune response. Efforts to prevent and cure cancer of viral, spontaneous, or environmental origin are a worthy pursuit and must take account of the most advanced information relating to the chemistry of the cell cycle and to the function of the immune system.

The E5 oncoprotein of human papillomavirus type 16 enhances endothelin-1-induced keratinocyte growth

Human keratinocytes express ETA receptors and produce endothelin-1 (ET-1), which stimulates growth response. Previously, we reported that a twofold increase in ETA receptors is present in human papillomavirus type 16 (HPV16) immortalized keratinocytes and that ET-1 induces enhanced proliferative response in these cell lines compared to normal cells. The present studies examine whether the E5 gene of HPV16 is responsible for the enhanced activity of ET-1 in HPV-transfected keratinocytes. The presence of the E5 gene in growth factor-starved keratinocytes induced the DNA synthesis and enhanced the mitogenic activity of ET-1 or epidermal growth factor. The selection of primary keratinocytes in growth factor-free medium with the addition of ET-1 as a growth factor showed that E5-transfected keratinocytes were able to grow and to form a higher number of larger colonies with respect to untransfected cells. This effect seems to be related to the interaction of E5 with the mitogenic signaling pathway of ET-1 rather than to an increase in the expression of the receptors for ET-1. In conclusion, our data demonstrate that E5 enhances ligand signaling in keratinocytes outside the EGF pathway by the amplification of the proliferative effect of ET-1/ETA receptor signaling.

Cytokine expression in squamous intraepithelial lesions of the uterine cervix: implications for the generation of local immunosuppression

We have addressed the notion that the progression of cancer of the uterine cervix is associated with a preferential constraint on the development of a type 1 cellular mediated response, which is necessary to efficiently eliminate (pre)neoplastic cells. Based on the importance of cytokines in the regulation of an appropriate immune response, we have evaluated the expression of IL-12p40, IL-10 and transforming growth factor-beta 1 (TGF-beta1). Using reverse transcriptase-polymerase chain reaction (RT-PCR), the expression of these three cytokines was evaluated in both low-grade (LG) and high-grade (HG) cervical squamous intraepithelial lesions (SIL) and in normal exocervix and transformation zone biopsies. Our results show that the average level of IL-12 increases within both the LG and HG SIL, compared with both control groups. Interestingly, the percentage of HG SIL expressing IL-12p40 was lower compared with LG SIL. In contrast, the expression of IL-10 increased in parallel with the severity of the lesion to a maximal level in HG SIL. Using immunohistochemistry, we ascertained the presence of IL-12 protein in SIL and IL-10 protein in the transformation zone and SIL biopsies. Both IL-12- and IL-10-producing cells were localized in the stroma, not within the SIL. Furthermore, in this study we also observed that the region of the cervix the most sensitive to lesion development, the transformation zone, was associated with higher average levels of the immunosuppressive cytokines IL-10 and TGF-beta1.

A novel method to culture laryngeal human papillomavirus-positive epithelial cells produces papilloma-type cytology on collagen rafts

A novel method to culture human papillomavirus (HPV) positive laryngeal epithelial cells is described. Biopsies of laryngeal papillomas and of HPV-positive laryngeal mucosa were first cultured as a monolayer in which irradiated laryngeal fibroblasts originally derived from a papilloma (PPLF-XR) patient served as feeder cells. When these fourth or fifth passage epithelial cells were transferred to allow growth on an organotypic growth base (collagen raft containing unirradiated PPLF), they grew as a multilayer. This layer showed features typical of HPV infection with koilocytosis, parakeratosis, and isolated dyskeratotic cells. Based on in situ hybridisation, the original tumour sections and epithelial cells from each monolayer passage, as well as the collagen raft sections, contained HPV DNA. Our results show that HPV-infected epithelial cells can be maintained during passages in monolayer culture and that PPLF can support the growth of these cells well. The monolayer cell culture and the collagen raft, the latter providing differentiation-promoting effects, appears to facilitate maintenance of the infected cells and of the viral genome.

Presence of human papillomavirus DNA and expression of L-fucose moiety in some vulvar intraepithelial lesions and vulvar squamous cell carcinoma

BACKGROUND

Human papillomavirus could reside and play an etiological role in some vulvar epithelial lesions. Human papillomavirus-infected keratinocytes might have certain biochemical changes that could be of significance in helping clinical diagnosis or elucidating the pathogenesis of some vulvar epithelial diseases.

OBJECTIVE

To detect the presence of human papillomavirus DNA and observe the expression pattern of L-fucose moiety in some vulvar intraepithelial lesions and vulvar squamous cell carcinoma.

METHODS

Nineteen cases of vulvar intraepithelial lesions and 13 cases of vulvar squamous cell carcinoma from the inner aspect of labia majora or the outer aspect of labia minora were selected. Polymerase chain reaction was employed to detect the presence of human papillomavirus DNA in lesional skin. Ulex europeaus agglutinin-1 histochemistry was used to observe the L-fucose expression pattern.

RESULTS

A large proportion of vulvar intraepithelial lesions had the presence of human papillomavirus DNA, but the positive rate was low in vulvar squamous cell carcinoma and squamous cell hyperplasia. L-Fucose expression was much more pronounced in human papillomavirus DNA-positive lesions than those negative ones.

CONCLUSIONS

Human papillomavirus had an important impact on some vulvar intraepithelial lesions in this Oriental population. The expression pattern of L-fucose may be used as an indicator for vulvar keratinocyte transformation by human papillomavirus.

Molecular analysis of episomal human papillomavirus type 16 DNA in a cervical carcinoma cell line

Integration of human papillomavirus type 16 DNA sequences into host DNA is a frequent event in cervical carcinogenesis. However, recent studies showing that HPV16 is present exclusively in an episomal form in many primary cervical cancers suggest that HPV16 can transform target cells by mechanisms that do not require viral integration. We have established a cervical carcinoma cell line that harbors episomal copies of HPV16 DNA of approximately 10 kb. Restriction enzyme and two-dimensional gel analysis confirmed that HPV16 DNA was extrachromosomal with both monomeric and multimeric forms present. HPV16 was maintained as episomes with passage both in culture and after subcutaneous growth in nude mice. The 10 kb viral genome, consisting of a full-length copy of HPV16 and a partial duplication of the long control region and the L1 open reading frame, exhibited transforming activity comparable to prototype HPV16. This cell line should provide a useful model system for studying the biological significance of the physical state of the HPV16 genome in cervical carcinoma cells.

The autonomous growth of human papillomavirus type 16-immortalized keratinocytes is related to the endothelin-1 autocrine loop

Some human papillomaviruses (HPVs) such as HPV type 16 (HPV16) and HPV18 are involved in cervical carcinoma, and they can immortalize and transform keratinocytes. Endothelin-1 (ET-1) is produced in keratinocytes and has been shown to act through ETA receptors as an autocrine growth factor for keratinocytes. This study examines whether HPV16 alters the ET-1-mediated autocrine loop in human keratinocytes, providing a selective growth advantage for transformed cells. ET-1 is released in similar amounts from normal and HPV-transfected keratinocytes. All HPV-transfected cell lines express high-affinity ETA receptors. A two-fold increase in ET-1 binding sites is present in HPV16-immortalized keratinocytes, and this effect seems to be linked to the overexpression of mRNA for this receptor rather than to differences in the surface/internalized ratio of the receptors. ET-1 induces significant increases in [3H]thymidine incorporation and cell proliferation. Furthermore, HPV-transfected keratinocytes can proliferate in the absence of any growth factor added to the growth medium, and the ETA receptor antagonist BQ123 prevents this proliferation. These data suggest a new mechanism in the growth control of HPV-transformed cells mediated by the upregulation of ET-1 autocrine loop.

A general purification protocol for E7 proteins from "high- and low-risk" human papillomavirus types expressed in the yeast Schizosaccharomyces pombe

A purification protocol was developed to obtain human papillomavirus (HPV) type 16 E7 protein expressed in the yeast Schizosaccharomyces pombe. Only three chromatographic steps were necessary to purify the unfused HPV 16 E7 protein to homogeneity (95-99%) as shown by silver staining after polyacrylamide gel electrophoresis. Approximately 0.8 mg of highly purified E7 was obtained from 5 x 10(10) yeast cells. The purified HPV 16 E7 phosphoprotein (Ser 31/32) was refolded and assayed for functionality. Binding to the proteins Rb1 and p107 in vitro and induction of DNA synthesis after microinjection into serum-deprived NIH 3T3 cells suggest that the E7 protein retains some of its biological activities. Most importantly, the purification strategy is also applicable for different HPV 16 E7 mutants and for E7 proteins from other HPV types such as HPV 18 and 11.

Human papillomavirus-associated tumors of the skin and mucosa

This review discusses diseases of the lower genital tract in which the presence of human papillomavirus (HPV) DNA is well documented. We discuss epidemiologic, clinical, and experimental data supporting a causative role for HPV in mucosal malignancies, with emphasis on the role of viral and host factors in their pathogenesis. Of special interest is the recently discovered association of cutaneous tumors with HPVs, previously known only for tumors in epidermodysplasia verruciformis (EV). The frequent detection of EV-specific or EV-related HPVs in immunosuppressed persons and in cutaneous tumors in the general population supports the importance of EV as a model of cutaneous oncogenesis. We also discuss recent serologic findings based on enzyme-linked immunosorbent assay results with the use of viruslike particles. This is important both for detection of present or past HPV infection and for epidemiologic and immunologic studies. Novel therapeutic modalities for HPV tumors and prospects for prophylactic and therapeutic vaccination are presented.

Human papillomaviruses and cervical cancer

Molecular and epidemiological studies conducted over the last 20 years led to the recognition of certain types of human papillomavirus (HPV) as the etiological agents of cervical cancer, a very common neoplasia, particularly in developing countries. More than 70 HPVs have been described, including both cutaneous and mucosal types. About half of the known HPVs, and an even higher number of variants, have been isolated from genital mucosas. The association of certain types primarily with normal tissues and benign lesions, as opposed to cancer-associated types, has led to the concept of low and high oncogenic risk HPVs, respectively. The latter express oncogenic proteins that interfere with cell growth control functions. As a consequence of the continuous expression of these viral genomes, chromosome instability may occur, leading to fully transformed cells. Studies indicate that persistence of high-risk HPVs may determine progression to more severe stages of cervical disease, while the majority of HPV infections are transient and do not seem to be important in cervical carcinogenesis. The risk for disease progression seems also to be associated with viral burden. Prospective epidemiological studies will contribute to the knowledge of the natural history of HPV infections and provide information on the determinants of viral persistence. Data derived from these studies may define the clinical utility of HPV testing and its use in cervical cancer prevention programs.

Papillomavirus infections--a major cause of human cancers

The papillomavirus family represents a remarkably heterogeneous group of viruses. At present, 77 distinct genotypes have been identified in humans and partial sequences have been obtained from more than 30 putative novel genotypes. Geographic differences in base composition of individual genotypes are generally small and suggest a low mutation rate and thus an ancient origin of today's prototypes. The relatively small size of the genome permitted an analysis of individual gene functions and of interactions of viral proteins with host cell components. Proliferating cells contain the viral genome in a latent form, large scale viral DNA replication, as well as translation and functional activity of late viral proteins, and viral particle assembly are restricted to differentiating layers of skin and mucosa. In humans papillomavirus infections cause a variety of benign proliferations: warts, epithelial cysts, intraepithelial neoplasias, anogenital, oro-laryngeal and -pharyngeal papillomas, keratoacanthomas and other types of hyperkeratoses. Their involvement in the etiology of some major human cancers is of particular interest: specific types (HPV 16, 18 and several others) have been identified as causative agents of at least 90% of cancers of the cervix and are also linked to more than 50% of other anogenital cancers. These HPV types are considered as 'high risk' infections. Their E6/E7 oncoproteins stimulate cell proliferation by activating cyclins E and A, and interfere with the functions of the cellular proteins RB and p53. The latter interaction appears to be responsible for their mutagenic and aneuploidizing activity as an underlying principle for the progression of these HPV-containing lesions and the role of high risk HPV types as solitary carcinogens. In non-transformed human keratinocytes transcription and function of viral oncoproteins is controlled by intercellular and intracellular signalling cascades, their interruption emerges as a precondition for immortalization and malignant growth. Recently, novel and known HPV types have also been identified in a high percentage of non-melanoma skin cancers (basal and squamous cell carcinomas). Similar to observations in patients with a rare hereditary condition, epidermodysplasia verruciformis, characterized by an extensive verrucosis and development of skin cancer, basal and squamous cell carcinomas develop preferentially in light-exposed sites. This could suggest an interaction between a physical carcinogen (UV-part of the sunlight) and a 'low risk' (non-mutagenic) papillomavirus infection. Reports on the presence of HPV infections in cancers of the oral cavity, the larynx, and the esophagus further emphasize the importance of this virus group as proven and suspected human carcinogens.