Role of papillomaviruses

Human Papilloma Virus Infection and Overexpression of P53 Protein in Bilharzial Bladder Cancer

Aims and Background

An association between human papilloma virus (HPV) and bladder cancer has been reported. However, the role of HPV in bilharzial bladder cancer and its prevalence have not yet been clarified.

Study design

We investigated 50 cases for HPV types 16/18 by in situ hybridization. Also, p53 protein expression by immunohistochemistry was evaluated in 41 of the 50 cases, with correlation of these factors to clinicopathologic parameters and tumor relapse after primary treatment.

Results

HPV was detected in 46% of Egyptian bladder carcinomas (23/50 cases). Positivity was 47.8% for squamous cell carcinoma and 36.4% for transitional cell carcinoma. There was a possible viral-bilharzial association as 52.8% of Bilharzial cases, whereas only 12.5% of non-Bilharzial cases were HPV positive (P <0.05). P53 protein was found in 19/41 (46.3%) cases. There was a concordance between HPV and p53 in 58.5% of cases. Neither factor was related to tumor recurrence after primary treatment.

Conclusions

HPV may thus be implicated in the etiology of bilharzial bladder cancer, but a definite causal relationship remains to be demonstrated. HPV together with p53 alterations work in synergy to accelerate the carcinogenic process, as there was concordance in the results of both parameters in 24/41 (58.5%) cases.

Human papilloma virus in oral cancer

Cervical cancer is the second most prevalent cancer among women, and it arises from cells that originate in the cervix uteri. Among several causes of cervical malignancies, infection with some types of human papilloma virus (HPV) is well known to be the greatest cervical cancer risk factor. Over 150 subtypes of HPV have been identified; more than 40 types of HPVs are typically transmitted through sexual contact and infect the anogenital region and oral cavity. The recently introduced vaccine for HPV infection is effective against certain subtypes of HPV that are associated with cervical cancer, genital warts, and some less common cancers, including oropharyngeal cancer. Two HPV vaccines, quadrivalent and bivalent types that use virus-like particles (VLPs), are currently used in the medical commercial market. While the value of HPV vaccination for oral cancer prevention is still controversial, some evidence supports the possibility that HPV vaccination may be effective in reducing the incidence of oral cancer. This paper reviews HPV-related pathogenesis in cancer, covering HPV structure and classification, trends in worldwide applications of HPV vaccines, effectiveness and complications of HPV vaccination, and the relationship of HPV with oral cancer prevalence.

Human papillomavirus-16 prevalence in gingival tissue and its association with periodontal destruction: a case-control study

BACKGROUND

Human papillomavirus (HPV)-16 is detected in normal oral mucosa and several oral lesions, including squamous cell carcinoma, condyloma acuminatum, verruca vulgaris, focal epithelial hyperplasia, and periodontal diseases. It was hypothesized that HPV may be involved in periodontal breakdown and that periodontal tissue acts as a reservoir for the virus. Therefore, in this study, the prevalence of HPV-16 in the gingival tissue of Brazilians with periodontal health or disease is investigated.

METHODS

Fifty-six gingival samples from subjects with chronic periodontitis, 26 samples from subjects with gingivitis, and 22 samples from subjects with healthy peridontium were analyzed. Total DNA was extracted, and the presence of HPV-16 was assessed using a real-time polymerase chain reaction. Positive and negative controls were included in the reactions.

RESULTS

HPV-16 was not detected in any of the 104 gingival samples evaluated; therefore, this virus showed no association with periodontal disease in this study.

CONCLUSION

In the population studied, HPV-16 may not have participated in the pathogenesis of chronic periodontitis, and the gingival tissue did not act as a reservoir for this virus.

Risk factors for squamous cell carcinoma of the oesophagus

Cancer of the oesophagus has great diversity in geographical distribution and incidence. The rate of oesophageal cancer has been increasing in some areas and the reasons for this are not clear. This review outlines fascinating epidemiological aspects and the risk factor for squamous cell carcinoma of the oesophagus. While in the Western world the effects of alcohol and tobacco are substantial preconditions, worldwide other factors, such as diet, nutritional deficiencies, environmental exposure and infectious agents (especially papillomavirus and fungi), play a significant role. Chronic irritation of the oesophagus appears to participate in the process of carcinogenesis, particularly in patients with thermal and/or mechanical injury, achalasia, oesophageal diverticulum, chronic lye stricture, radiation therapy, injection sclerotherapy and gastric resection before the appearance of oesophageal tumour. The association of Plummer-Vinson syndrome, coeliac disease, tylosis and scleroderma with oesophageal cancer has also been reviewed.

Risk factors for squamous cell carcinoma of the oesophagus

Cancer of the oesophagus has great diversity in geographical distribution and incidence. The rate of oesophageal cancer has been increasing in some areas and the reasons for this are not clear. This review outlines fascinating epidemiological aspects and the risk factor for squamous cell carcinoma of the oesophagus. While in the Western world the effects of alcohol and tobacco are substantial preconditions, worldwide other factors, such as diet, nutritional deficiencies, environmental exposure and infectious agents (especially papillomavirus and fungi), play a significant role. Chronic irritation of the oesophagus appears to participate in the process of carcinogenesis, particularly in patients with thermal and/or mechanical injury, achalasia, oesophageal diverticulum, chronic lye stricture, radiation therapy, injection sclerotherapy and gastric resection before the appearance of oesophageal tumour. The association of Plummer-Vinson syndrome, coeliac disease, tylosis and scleroderma with oesophageal cancer has also been reviewed.

Detection of integrated high risk human papillomavirus in adenoid cystic carcinoma of the uterine cervix

AIM

To investigate the role of human papillomavirus (HPV) in adenoid cystic carcinoma of the uterine cervix.

METHODS

Eleven archival, paraffin wax embedded specimens were analysed by non-isotopic in situ hybridisation (NISH) for HPV types 6, 11, 16, 18, 31, and 33 using digoxigenin labelled probes. The polymerase chain reaction (PCR) was carried out on each of the cases using consensus primers to HPV.

RESULTS

A total of eight adenoid cystic carcinomas harboured the HPV genome by NISH, of which five were PCR positive. Integrated HPV 16 DNA was demonstrated in seven of the eight NISH positive cases. One adenoid cystic carcinoma showed integrated HPV 31. HPV DNA was not detected in the three remaining cases.

CONCLUSIONS

Integrated high risk HPV genome, in particular type 16, is associated with this uncommon type of primary cervical cancer.

Human papillomavirus-associated oral epithelial dysplasia (koilocytic dysplasia): an entity of unknown biologic potential

Intraepithelial neoplasia of the female genital tract has long been associated with human papillomavirus infection. To date, there have been no previously published studies of oral dysplasia that have identified light microscopic features predictive of the presence of human papillomavirus. We identified a variant of oral epithelial dysplasia, koilocytic dysplasia, that exhibited light microscopic features suggestive of HPV infection. To determine if these microscopic features were specifically correlated with human papillomavirus infection, DNA in situ hybridization for human papillomavirus 6/11, 16/18, and 31/33/51 was performed on 31 lesions diagnosed histologically as koilocytic dysplasia. Seventeen matched control cases of conventional oral epithelial dysplasia were also analyzed for human papillomavirus. Human papillomavirus DNA was detected significantly more often (p < 0.001) in koilocytic dysplasia (80.6%) than conventional oral epithelial dysplasia (0.0%). Positive cases of koilocytic dysplasia contained either intermediate-risk (31/33/51) or high-risk (16/18) human papillomavirus types whether or not they contained low-risk human papillomavirus types (6/11). The histologic and clinical presentation of koilocytic dysplasia was unique. Lesions demonstrated koilocytes and other microscopic characteristics of human papillomavirus infection, as well as features of conventional epithelial dysplasia. A striking male predominance was noted, as was a relatively young average age of presentation (39.0 years). On the basis of our preliminary analysis, we conclude that oral koilocytic dysplasia represents a unique pathologic entity and that the presence of human papillomavirus can be predicted on light microscopy with at least 80% accuracy. The clinical significance and potential for malignant transformation of koilocytic dysplasia remain to be investigated.

Human papillomavirus infection and transitional cell carcinoma of the bladder. Immunohistochemistry and in situ hybridization

The aim of the present research was to investigate human papillomavirus (HPV) infection by means of immunohistochemistry and in situ hybridization in 76 bladder cancer specimens. A biotinylated DNA probe that recognizes HPV 6/11, HPV 16/18 and HPV 31/33/35 was used for in situ hybridization. A polyclonal antibody recognizing HPV capsid antigen (HPVcAg) was used for immunohistochemistry. In situ hybridization and immunohistochemistry were developed by alkaline phosphatase and immunogold-silver techniques respectively. Our results showed that 25 (32.8%) out of 76 bladder carcinoma specimens reacted with HPVcAg. Twelve (15.7%) out of 76 cases were positive for HPV 16/18-DNA using non-isotopic in situ hybridization. Sixteen cases had koilocytosis. No positive signals were found for HPV 6/11 or 31/33/35-DNA probes.

Transmission of genital human papillomavirus infections is unlikely through the floor and seats of humid dwellings in countries of high-level hygiene

To evaluate the transmission of genital human papillomavirus (HPV) through the floor and seats of humid dwellings, samples were collected with a toothbrush from the floor and seat surfaces of humid dwellings; showers, saunas and dressing rooms. The survey included 3 bathing resorts, 1 indoor swimming pool, 2 schools and 2 private homes. Polymerase chain reaction (PCR) was used to amplify the human beta-globin gene and HPV DNA. The results for HPV DNA amplification were confirmed by Southern blot hybridization under low stringency using a probe mixture of HPV types 6, 16, 18 and 31. beta-globin could be amplified only from 3 sample taken from a dressing room of and indoor public swimming pool. No HPV DNA-positive samples were found. These results indicate that transmission of genital HPV infection via floor or seat surfaces in the above dwellings in general or family use is highly unlikely.

Human papillomavirus status in the prediction of high-grade cervical intraepithelial neoplasia in patients with persistent low-grade cervical cytological abnormalities

The role of human papillomavirus (HPV) detection in the management of patients with persistent low-grade (mild dyskaryosis or less) cervical cytological abnormalities is unclear. We have analysed cytological material from 167 such patients both cytologically and by non-isotopic in situ hybridisation (NISH) for HPV 16, 18, 31 and 33 and consensus primer polymerase chain reaction (PCR) amplification followed by both generic and specific typing for these HPV types. Cervical intraepithelial neoplasia (CIN) 2 or 3 was present in 40 of 167 patients (23.9%), and the positive predictive values (PPVs) for the presence of CIN 2 or 3, of moderate or severe dyskaryosis at repeat cytology and an HPV-positive NISH and generic PCR signal were 100%, 66% and 42% respectively. The corresponding sensitivities were 48%, 68% and 87%. Addition of cytology to molecular analysis improved both PPV and sensitivity, the best combination being NISH and cytopathology (PPV 71%, sensitivity 87%). These data demonstrate that the presence of CIN 2 or 3 in patients with mild cytological abnormalities can be predicted by molecular detection of HPV in some cases, particularly when combined with cytological analysis. However, the magnitude of this prediction is dependent on the population of patients studied, and the clinical role of this approach therefore remains to be defined.

Laryngeal papillomatosis: molecular, histopathological, and clinical evaluation

Molecular, histopathological, and clinical studies were carried out on a series of 79 laryngeal papillomas (LP) from 36 patients in order to investigate the hypothesis that juvenile and adult LP may represent a biological entity causally related to Human papilloma virus (HPV) infection. Using in situ hybridization with biotin-labelled probes and polymerase chain reaction, we detected human papilloma virus (HPV) 6/11 in 28 of 29 juvenile LP, in 26 of 30 adult multiple, and in 17 of 20 adult solitary LP. None of LP was found to harbour HPV types 16, 18, 31, 33, and 51. There were no clear-cut histological differences between juvenile and adult LP, the presence of koilocytosis was equally observed in both, and there was no prevalent type of epithelial hyperplasia in either form, except that all three cases of atypical hyperplasias (precancerous lesions) were found among adult patients. During a 14 year follow-up, no carcinomatous transformation of LP was observed. All juvenile LP in our study had frequent recurrences of the disease, however, numerous surgical procedures were also required in 16 of 27 adult patients. Our study supports Lindeberg's hypothesis of a similar pathogenesis for all forms of LP caused by the HPV types 6/11.

Detection of HPV DNA in oral carcinoma using polymerase chain reaction together with in situ hybridization

This study determined the prevalence of human papillomavirus 16/18 DNA in deparaffinized oral carcinoma specimens on slides with the use of the different sensitivities of in situ hybridization and a technique that combines polymerase chain reaction and in situ hybridization. Human papillomavirus DNA was not detected in the 30 biopsy specimens analyzed by in situ hybridization alone using biotinylated DNA probes specific for human papillomavirus 16/18. Twenty of 30 specimens (66.7%) were found to have human papillomavirus DNA (p < 0.001) with the use of the polymerase chain reaction-in situ hybridization technique. Human papillomavirus 16 was detected in 18 of 26 specimens (69.2%), and 7 of 25 carcinomas (28%) were found to contain human papillomavirus 18. Dual infections were present in 5 of 21 (23.8%) specimens. Human papillomavirus DNA was more prevalent in men (75%) than women (57.1%). However, there was no difference in the mean age of patients with oral carcinoma (men, 67.8 years; women, 67.5 years) who had human papillomavirus and those who did not (67.2 years). Carcinomas associated with dual infections occurred at a lower mean age (59.4 years) than those associated with a single human papillomavirus type (p < 0.005). We conclude that the polymerase chain reaction-in situ hybridization technique enhances our ability to demonstrate human papillomavirus types highly associated with oral squamous cell carcinoma.

Squamous cell carcinoma of the respiratory tract following laryngeal papillomatosis

With the object to disclose an association between laryngeal papillomatosis and laryngeal carcinoma, we reviewed 102 patients with laryngeal papillomatosis treated between 1950 and 1979. Seven cases of laryngeal carcinomas were recorded and 1 patient with spread of papilloma to the bronchial tree developed a bronchial carcinoma. The time between onset of papilloma and diagnosis of carcinoma was 4-55 years (mean 24 years). For laryngeal carcinoma the ratio of observed to expected cases was 88. Of the 8 patients developing respiratory tract carcinoma, 2 had received treatment with radiation and 2 had been treated with Bleomycin. Four of these 8 patients were known smokers. This study shows that papillomatosis is more often associated with laryngeal carcinoma than previously reported. It appears, however, that laryngeal papillomas alone seldom induce carcinomas. Apart from irradiation and smoking, Bleomycin could be an important co-factor.

Cationic liposomes mediated delivery of antisense oligonucleotides targeted to HPV 16 E7 mRNA in CaSki cells

The "high risk" types 16 and 18 of human papillomavirus (HPV) are involved in the etiology of genital squamous cell carcinoma. The early genes 6 and 7 (E6-E7) of these viruses code for the major transforming proteins, capable of inducing cell transformation alone or acting synergistically with other oncogenes. Antisense oligonucleotides, recently applied to inhibit the functions of a number of cellular and viral proteins, might provide the basis for a new therapeutic strategy against HPV-induced malignancies. We studied the proliferation of CaSki cells by the MTT assay after their exposure to HPV 16 E7 mRNA antisense oligonucleotides with and without cationic liposomes (containing dimethyldioctadecylammonium bromide DDAB, and dioleylphosphatidylethanolamine, DOPE). Unmodified oligonucleotides (either 12- or 23-mers) did not have any effect on either CaSki cell proliferation or morphology when compared with the untreated cells. The cellular uptake of oligonucleotides was significantly enhanced by the cationic liposomes as assessed by confocal laser scanning microscopy (CLSM). The cationic liposomes were toxic to the cells as demonstrated by the reduced cell number and altered cell morphology. Only a slight reduction of the cell proliferation was seen when antisense 12-mer was protected from its 3'- and 5'-ends with thiolate and FITC, respectively. Both the 12- and the 23-mers with the cationic liposomes inhibited cell proliferation, the inhibitory effect being longer with the 23-mer. Overall, the MTT assay was less sensitive than light microscopy to reveal the toxic effects on CaSki cells. The results suggest that antisense oligonucleotides targeted to HPV 16 E7 mRNA can be introduced into CaSki cells with cationic liposomes.

Squamous cell carcinoma of the oral cavity derived from a skin graft: a case report

A case of oral cancer that had derived from a 19-year skin graft on the left buccal mucosa is reported. The patient had had three previous operations due to squamous cell carcinoma, erosion, and squamous cell carcinoma of the left buccal mucosa, respectively. In the last two operations, skin was transplanted, and the present cancer is believed to have derived from the latter one. The tumor was resected, and a new skin was grafted. In situ hybridization of human papilloma virus (HPV) was carried out; the HPV 16 DNA could not be detected in the specimen. Eight months later, a cervical lymph node metastasis was detected; thus, a radical neck dissection was performed.

Screening for human papillomavirus infections in esophageal squamous cell carcinomas by in situ hybridization

BACKGROUND

Infections with specific types of human papillomavirus (HPV) have been closely linked with human squamous cell carcinomas, those of the anogenital tract in particular. Increasing number of reports also suggest that HPV infection could be a risk factor for esophageal cancer. However, most of the previous studies on HPV involvement in esophageal carcinomas have included only small numbers of biopsy specimens, thus necessitating additional studies based on extensive series of esophageal samples.

METHODS

A series of 776 biopsy specimens derived from 363 patients who had undergone esophagectomy for squamous cell carcinoma in the high-incidence area of China were analyzed for the presence of HPV DNA by screening and specific typing in situ hybridization with biotinylated HPV DNA probes.

RESULTS

Under low-stringency conditions, 85 (23.4%) tumors were demonstrated to contain HPV DNA: Positive signals were found on the nuclei of cancer cells in 71 (19.6%), in the surrounding epithelial cells with hyperplastic or dysplastic changes in 13 (3.6%), in the cancer cells and the surrounding epithelial cells in 10 (2.8%), and in the resected margins in 1 (0.3%). Thirty-four (40%) of the 85 HPV-positive tumors were shown to contain at least one type of HPV 6, 11, 16, 18, or 30 DNA sequences. HPV 16 was the type found most frequently, occurring in 18.8% of the 85 HPV-positive specimens. In addition to the primary tumors, HPV DNA sequences were found in 12.3% (7 of 57) of the lymph node metastases.

CONCLUSION

The results confirm the previously reported HPV involvement in esophageal squamous cell lesions and implicate HPV as a potential etiologic agent in the multifactorial pathogenesis of esophageal carcinoma.

Tumourigenesis associated with the p53 tumour suppressor gene

The p53 gene is contained within 16-20 kb of cellular DNA located on the short arm of human chromosome 17 at position 17p13.1. This gene encodes a 393-amino-acid nuclear phosphoprotein involved in the regulation of cell proliferation. Current evidence suggests that loss of normal p53 function is associated with cell transformation in vitro and development of neoplasms in vivo. More than 50% of human malignancies of epithelial, mesenchymal, haematopoietic, lymphoid, and central nervous system origin analysed thus far, were shown to contain an altered p53 gene. The oncoproteins derived from several tumour viruses, including the SV40 large T antigen, the adenovirus E1B protein and papillomavirus E6 protein, as well as specific cellular gene products, e.g. murine double minute-2 (MDM2), were found to bind to the wild-type p53 protein and presumably lead to inactivation of this gene product. Therefore, the inactivation of p53 tumour suppressor gene is currently regarded as an almost universal step in the development of human cancers. The current data on p53-associated tumourigenesis are briefly discussed in this minireview.

Prevalence of HPV in a Melbourne female STD population: comparison of RNA and DNA probes in detecting HPV by dot blot hybridization

A total of 377 women, consecutively selected as first attenders to a sexually transmitted diseases clinic in Melbourne, Australia, were examined for overt Condylomata acuminata and were screened for genital HPV DNA types 6, 11, 16, 18, 31, 33 and (35) using 2 dot blot hybridization methods. Overall, there was a 90% positivity correlation between the 2 methods with HPV DNA being detected in 12% of ectocervical samples. Overt warts were found in 15% of the women and HPV DNA was detected at the cervix in 35% with cytology predicting HPV with or without dysplasia in 27%. Thirteen percent had a past history of warts but none on examination and HPV DNA was evident in 16% while 18% had cytological features of HPV. Those with no warts evident and no past history of warts had both HPV DNA and cytological features of HPV in 7%.

Detection of human papillomavirus 16 and 18 DNA in epithelial lesions of the lower genital tract by in situ hybridization and polymerase chain reaction: cervical scrapes are not substitutes for biopsies

Human papillomavirus (HPV) types 16 and 18 in 66 women with histologically documented lesions of the genital tract and 64 control cohorts were investigated. The efficacies of in situ hybridization and polymerase chain reaction (PCR) in detecting HPV 16 and 18 DNA were analyzed. In order to assess the usefulness of replacing biopsies with cervical scrapes, the two samples were compared by PCR. The prevalence rates of HPV infection by PCR were 59.1 and 10.9% in patients and controls, respectively. PCR was three times more sensitive than in situ hybridization (52.6 versus 17.8%). However, the need to improve PCR sensitivity by subsequent dot blot hybridization reduced one of the main advantages of PCR, i.e., expeditious diagnosis. Cervical scrapes were less sensitive than biopsies (13.6 versus 53%), although with four (6.1%) patients with intraepithelial neoplasias, HPV DNA was identified only by means of cervical scraping. We conclude that obtaining biopsy specimens and cervical scraping are complementary sampling procedures.

Detection of human papillomavirus DNA and mRNA using synthetic, type-specific oligonucleotide probes

Type-specific 30'mer-36'mer oligonucleotide probes complementary to mRNA transcribed from the E6 and E7 open reading frames of HPV 6b/11, 16, 18 and 33 were designed using the published nucleotide sequences. As oligonucleotides are easily and relatively cheaply synthesized in large amounts and are free of vector DNA, they were assessed for potential use in routine clinical detection and typing of HPV. Multiple Southern and dot blots of cloned HPV 6b, 11, 16, 18, 31 and 33 DNA, and of DNA extracted from cell lines carrying integrated HPV 16 and 18 genomes were prepared. In addition, Northern and dot blots of RNA extracted from the HPV-containing cell lines HeLa, CaSki and SiHa, were also prepared. All filters were first probed with the oligonucleotide and then with the corresponding full-genomic HPV DNA probe and their relative sensitivities and specificities compared: both probe types were labelled with 32P. The oligonucleotide probes were all as specific as the full-genomic probes for Southern, DNA and RNA dot blot hybridisations. The HPV 16 and 18 oligonucleotide probes detected HPV transcripts of the appropriate sizes in the cell line RNA. For DNA detection, oligonucleotide probes were up to 10 times less sensitive than the full-genomic probes, but for RNA detection, they were more sensitive. The sensitivity for both HPV DNA and RNA detection could be improved by using two type-specific oligonucleotide probes in combination, without reducing the specificity. The ease of preparation and handling of oligonucleotide probes, together with their lack of contaminating vector DNA, suggests that they may have some advantages over full-genomic probes for the clinical detection and typing of HPV.

Cervical carcinoma: low frequency of allele loss at loci implicated in other common malignancies

Twenty cervical carcinomas were examined for loss of heterozygosity (LOH) using 22 RFLP markers, which mapped to regions of putative oncosuppressor gene loci, identified as candidates in other common solid tumours. Allele losses were identified in six of the eight chromosomal arms examined, but at a significantly lower frequency than that reported in other common solid tumours. No association was observed between allele losses at any chromosomal location and the presence or integration of 'high risk' types of HPV determined by a sensitive, specific PCR method. HPV 16, 18 or 33 were found in the majority (75%) of these tumours. We have looked at only a limited subset of chromosomal regions, but the results, so far, imply that carcinoma of the cervix may arise by different molecular events than other common solid tumours, and support the view that one of the distinctive events may be infection with HPV. Alternatively, similar molecular events may be occurring, but in regions of the genome not yet identified as targets in other solid tumours.

Infectious agents in the etiology of esophageal cancer

Extensive epidemiological and experimental studies have suggested that some chemical agents, nutritional deficiencies, and physical factors are associated with the development of esophageal cancer (EC). Recent evidence also suggests an etiologic role of certain microorganisms in esophageal carcinogenesis either by producing carcinogens or promotors or by acting directly on the host cells. The mutagenic and carcinogenic effects of several fungi and bacteria isolated from the grains and foodstuffs in high-risk areas have been shown by in vitro and in vivo studies. Certain viruses, e.g., human papillomavirus, herpes simplex virus, cytomegalovirus, and Epstein-Barr virus, have been implicated in the pathogenesis of a variety of human cancers, and all of them are known to produce tumors in animals and cell transformation in vitro. These viruses also have been shown to infect the esophageal epithelium. Therefore, although many of the key issues of their mechanisms of action are unclear as yet, they should be considered potential etiologic agents of EC. The present review summarizes the data available on the etiology of EC, emphasizing the current evidence implicating an etiologic role of microorganisms in the pathogenesis of this malignancy.

Multiple HPV 16-related squamous cell carcinomas of the vulva, vagina, anus, skin and cervix in a 31-year-old woman

A 31-year-old woman is reported with in the genital region multiple squamous carcinomas of the skin (buttock), vulva, vagina, anus and cervix uteri. All these carcinomas were HPV 16 positive as tested by DNA in situ hybridization. The existence of areas with normal epithelium between all tumor localisations and the absence of distant metastases indicate multicentric development of these multiple carcinomas. The presence of HPV 16 DNA in all carcinoma cells, as detected by DNA in situ hybridisation, argues for an etiological role of HPV 16 in the development of these multiple tumors.

Human papillomavirus involvement in esophageal precancerous lesions and squamous cell carcinomas as evidenced by microscopy and different DNA techniques

A series of 71 surgically resected esophageal squamous cell carcinomas, including 51 cases of formalin-fixed samples and 20 cases of fresh biopsy specimens derived from the high-incidence area of esophageal cancer in China, were systematically analyzed for the presence of human papillomavirus (HPV) infections by light microscopy, electron microscopy (TEM), in situ DNA hybridization, Southern blot hybridization, and polymerase chain reaction (PCR) techniques. On light microscopy, HPV-suggestive lesions were found in a total of 49.0% (25 of 51) of the specimens, including the flat type (22 of 51) and, less frequently, an inverted one (2 of 51). Of the 51 formalin-fixed, paraffin-embedded specimens, 43.1% (22 of 51) contained HPV DNA sequences by in situ hybridization. Of the positive cases, HPV 6 was present in three (5.9%), HPV 11 in three (5.9%), HPV 16 in eight (15.7%), HPV 18 in six (11.8%), double infections with HPV 11/18 in one (2.0%), and HPV 16/18 in one. In most cases the HPV-positive signals were localized in the hyperplastic and/or dysplastic epithelium adjacent to invasive carcinomas. In two specimens, however, HPV DNA sequences were found in the frankly invasive lesions, one being HPV 6 and the other HPV 18. On TEM, HPV-like particles located in the nuclei of koilocytotic cells were demonstrated in two of the five specimens previously shown to be HPV-positive by in situ hybridization. By means of the PCR technique, all specimens positive for HPV by in situ hybridization also contained amplified HPV sequences. Moreover, three additional samples negative by in situ hybridization were found to contain HPV 11 DNA sequences. Of the 20 DNA samples extracted from the fresh carcinoma samples (containing some surrounding tissues as well) 9 were shown to contain HPV DNA sequences by Southern blot hybridization under low-stringency conditions. Of these, eight samples remained positive when hybridized with the probe cocktail of HPV 11, 16, 18, and 30 DNA under high-stringency conditions. HPV DNA sequences in these carcinoma specimens appeared to be present mainly in an integrated form. The present results confirm the HPV involvement in esophageal squamous cell lesions and suggest that HPV infection might be an important etiologic factor in the pathogenesis of esophageal cancer, most probably acting synergistically with other carcinogenic factors.

Screening for high- and low-risk human papillomavirus types in single routine cervical smears by non-isotopic in situ hybridization

Routine cervical smears (n = 262) from a Sexually Transmitted Diseases clinic were screened by non-isotopic in situ hybridization (NISH) stratifying human papillomavirus (HPV) infections into HPV6/11 (low risk) and HPV16/18/33 (high risk) categories. Of 188 patients with cytologically normal smears, HPV sequences were demonstrated in 41%. Of the 128 cases analysed by dual NISH, 16% contained low risk, 20% high risk and 5% both groups. In patients with cytological evidence of wart virus infection (WVI) only, 54% (n = 50) contained high-risk and 22% low-risk HPV types. The comparable incidences in CIN1/2 plus WVI (n = 24) were not significantly different: 54% and 17%, respectively. Cytological criteria underestimate the prevalence of HPV infection in patients with cytologically normal smears. This represents either 'occult' or 'latent' infection. The identical prevalence of HPVB16/18/33 in WVI only, and CIN1/2 plus WVI, suggests that the cytopathic effect induced by these HPVs may represent one end of a spectrum of morphological change which progresses to cervical intraepithelial neoplasia (CIN).

Genitoanal papillomavirus infection: diagnostic and therapeutic objectives in the light of current epidemiological observations

During the past decade a wide span of heterogeneity has been demonstrated for human papillomaviruses (HPVs), and some basic properties of the HPV genome have been revealed. The use of hybridization assays for HPV DNA detection in infected epithelia, and the recent introduction of synthetic HPV peptides for detection of type-specific circulating antibodies, have resulted in a major rethinking of HPV epidemiology. Recent data indicate that various HPVs may be transmitted perinatally during early infancy and that a long latency with periodic reactivation seems to be quite common. The present review attempts to assess recent epidemiological data with the concept of genitoanal papillomavirus infection (GPVI) as a predominantly sexually transmitted disease. Some diagnostic and therapeutic aspects are outlined with a pragmatic approach to the clinical relevance of GPVI.

RU486 inhibits glucocorticoid hormone-dependent oncogenesis by human papillomavirus type 16 DNA

We have previously reported (Pater et al., Nature 335, 832-835, 1988) the glucocorticoid hormone-dependent oncogenic transformation of primary baby rat kidney (BRK) cells by a combination of human papillomavirus (HPV) type 16 DNA and the activated form of the human Ha-ras-1 (ras) oncogene. In this study we provide evidence for the inhibition of such hormone-dependent transformation by the hormone antagonist, RU486. The level of inhibition was dependent on the ratio of hormone to antagonist and severe inhibition was observed at a 1:5 ratio. The effect of RU486 on the growth of HPV16-transformed cells was also studied. Severe growth inhibition and cell death occurred when cells transformed in the absence of RU486 were subsequently grown in the presence of either a 1:2.5 or 1:5 ratio of hormone to hormone antagonist. RU486 did not alter the level or electrophoretic mobility pattern of HPV16 mRNA expressed in transformed cells, when antihormone was applied either continuously or subsequent to transformation by HPV. These results indicate the importance of continuous viral gene expression for initiation and maintenance of the transformed phenotype.

Human papillomavirus (HPV) infections and their associations with oral disease

More than 65 distinct types of human papillomavirus (HPV) have been identified to date. Several of the HPV types have been proposed as etiologic agents of squamous cell carcinoma. In the oral cavity, HPVs have been found associated with several benign squamous cell proliferations. Evidence from histology and DNA hybridization studies suggests that HPV is also involved in oral carcinogenesis. It is apparent, however, that substantial amount of confusion exists in the diagnosis of oral HPV infections. The keratotic, papillary lesions in the oral cavity are usually small and easily overlooked. The gross appearance of these viral lesions is not distinct enough to be readily diagnosed by the clinicians. Degenerative changes found on oral mucosa frequently simulate koilocytosis. Thus, caution should be exercised to avoid overdiagnosis of HPV infection in the oral cavity. The present review summarizes the current evidence available on HPV infections in general and on oral HPV infections in particular. The diagnostic techniques available as well as the problems encountered in the distinction of these lesions are also discussed in short.

Esophageal squamous cell papillomas. Failure to detect human papillomavirus DNA by in situ hybridization and polymerase chain reaction

Squamous cell papilloma of the esophagus has been regarded as a distinct rarity. After having reviewed the files of the Gastrointestinal Endoscopy Unit of our hospital we found 14 patients diagnosed as having an esophageal papilloma on endoscopy of about 18,000 patients during the period 1985-90. On histologic examination of the biopsy specimens 12 cases showed histologic characteristics typical of a squamous cell papilloma (SQP), 1 was a fibroid polyp, and another showed epithelial dysplasia without the features typical of SQP. To assess the role of human papillomavirus (HPV) recently implicated in the etiology of this tumor, we analyzed all specimens for the presence of HPV types 6, 11, 16, and 18 DNA by in situ DNA hybridization (ISH) and polymerase chain reaction (PCR). No viral DNA was found by either ISH or PCR in any of these lesions. The significance of these findings is discussed in relation to the previous evidence presented on HPV involvement in the development of esophageal squamous cell papillomas and in esophageal carcinogenesis.

In situ evidence for HPV 16, 18, 33 integration in cervical squamous cell cancer in Britain and South Africa

In a previous study three types of HPV signal were described in CIN. It was suggested that a type 1 signal represented episomal HPV while a type 2 signal represented integrated HPV; and a type 3 signal was indicative of both episomal and integrated HPV. To test this hypothesis 91 squamous cell cancers (SCC) of the cervix from Britain and South Africa were examined for HPV 6, 11, 16, 18, 31, 33, 35. Of the South African group (n = 69) 64% contained HPV types 16 (n = 29) and 18 (n = 15). The SCC in the British group (n = 22) contained HPV 16 and HPV 33 in 12 and three cases, respectively. Of the HPV positive biopsy specimens, 86% showed a type 2 signal in keratinising and non-keratinising tumours and the remainder a type 3 signal. Type 3 signal was present only in keratinising tumours. The presence of punctate signal in 100% of HPV containing SCC, together with localisation of HPV signal to sister chromatids in tumour cell mitotic figures in vivo, provides further evidence for type 2, and the punctate component of type 3 signal representing viral integration.

In situ human papillomavirus (HPV) genotyping of cervical intraepithelial neoplasia in South African and British patients: evidence for putative HPV integration in vivo

In South Africa asymptomatic wart virus infection diagnosed by morphological criteria occurs in 16-20% of all ethnic groups; the incidence in black women is 66%. To identify human papillomavirus (HPV) types the prevalence of HPV in cervical intraepithelial neoplasia (CIN) in South African women (n = 72) with age matched British women (n = 73) was compared by non-isotopic in situ hybridisation (NISH) using digoxigenin labelled probes for HPV 6, 11, 16, 18, 31, 33 and 35 on archival biopsy specimens. A higher proportion of British biopsy specimens (68%) contained HPV than those from South Africa (50%) in CIN 2 and 3; this difference was due to HPV 16. Thirty six per cent of the positive biopsy specimens from South African women also contained HPV 33/35 compared with 16% in the United Kingdom. There was no difference in HPV detection with age in either group. These data indicate that HPV types vary geographically, with "minor" HPV types being more common in South Africa. Three qualitatively distinct NISH signals were observed; a diffuse (type 1) signal in superficial cells, mainly koilocytes; a punctate signal (type 2) in basal/"undifferentiated" cells in CIN 3; and combined type 1 and 2 signals in CIN with wart virus infection (type 3). The punctate signal may represent HPV integration.

Detection of human papillomavirus (HPV) DNA in oral squamous cell carcinomas by in situ hybridization and polymerase chain reaction

A series of 156 formalin-fixed, paraffin-embedded biopsies from 40 patients with surgically-treated oral squamous cell carcinomas was analysed for the presence of human papillomavirus (HPV) infection by histopathological evaluation, in situ DNA hybridization and polymerase chain reaction (PCR). Epithelial changes suggesting a HPV lesion within, or adjacent to, the carcinoma lesions were found in 16 out of 40 patients (40%). Morphological signs of a flat HPV lesion were found in four cases (10%), those of inverted type in three cases (7.5%), and those of papillary type in nine cases (22.5%). HPV DNA was demonstrated in one of the lesions by in situ hybridization with biotin-labelled DNA cocktail probe containing HPV types 6, 11, 16 and 18. With the PCR technique, samples from 11 (27.5%) of the 40 patients proved to contain HPV DNA. Of these, HPV 6 was demonstrated in one case, HPV 16 in ten cases and HPV 18 in one case. HPV DNA was exclusively detected in the biopsies showing carcinoma tissue or its adjacent precancer lesions. No viral DNA was found in the biopsies derived from the tumour-free resection margins. These results provide further evidence to support the concept of HPV involvement in the aetiology of oral squamous cell carcinomas, most probably acting synergistically with other carcinogens.