Genomic diversity and evolution of papillomaviruses in rhesus monkeys

We are studying the diversity of and relationships among papillomaviruses (PVs) to understand the modes and timescales of PV evolution and in the hope of finding animal PVs that may serve as model systems for disease caused by human PVs (HPVs). Toward this goal, we have examined 326 genital samples from rhesus monkeys and long-tailed macaques with a PCR protocol optimized for detecting genital HPV types. In 28 of the rhesus monkey samples, we found amplicons derived from 12 different and novel PV genomes, RhPV-a to RhPV-m, with the likely taxonomic status of "type." The frequency with which novel RhPVs were detected suggests that rhesus monkeys may play host to PVs with a diversity similar to that of humans. In phylogenetic trees, all 12 of the different RhPVs and the previously described type RhPV-1 were members of the genital HPV supergroup and formed three minor branches distinct from the 11 branches formed by genital HPVs. We also identified a novel PV amplicon, MfPV-a, from a long-tailed macaque, a species belonging to the same genus as rhesus monkeys. MfPV-a turned out to be a close relative of five RhPVs. It appears that the evolution of primate lineages leading to the genus Macaca and to humans created transmission barriers for PVs, resulting in viral evolution closely linked to the host. Additional support for the linked-evolution hypothesis comes from considering the phylogenetic association of two other ape and monkey PVs with the genital HPVs, the supergroup formed by at least seven ungulate PVs, and the isolated phylogenetic position of the only known bird PV.

Genital papillomaviruses (PVs) and epidermodysplasia verruciformis PVs occur in the same monkey species: implications for PV evolution

Portions of the genome from two different papillomaviruses (PVs) of the Abyssinian Colobus monkey were sequenced and phylogenetically analyzed. This revealed that the major evolutionary separation between genital PVs and epidermodysplasia verruciformis-associated PVs (EV-PVs) hitherto found only in human papillomaviruses (HPVs) also exists in animal PVs. The sequence of the long control region (LCR) of Colobus monkey PV type 2 (CgPV-2) reveals a small size and an arrangement of potential cis-responsive elements typical of the EV-HPVs; namely four binding sites for the viral E2 protein, with one of them being located within the L1 gene, a cluster of nuclear factor I (NFI)- and AP-1-binding sites and a 50-bp sequence upstream of the E6 gene consisting only of the nucleotides A and T. This level of conservation of functional elements within the highly variable LCR suggests that CgPV-2 could be adopted as a model for studying human skin cancer associated with EV-HPVs. Although isolated from the same monkey species, the other Colobus monkey PV, CgPV-1, is a typical genital PV as shown by E1 and L1 sequence comparisons. The presence of these two major phylogenetic divisions of PVs in both human and monkey hosts strongly suggests that this diversification predated the evolutionary split between monkeys and apes. In other words, at least two different groups of PVs have been evolving separately in their respective primate hosts for more than 22 million years with only moderate sequence changes since their genesis.

The E5 gene product of rhesus papillomavirus is an activator of endogenous Ras and phosphatidylinositol-3'-kinase in NIH 3T3 cells

We examined the effect of two rhesus papillomavirus 1 (RhPV) oncogenes on cytokine-induced signal transduction pathways leading to the possible activation of Ras protein (p21ras) and phosphatidylinositol kinase. p21ras in both the activated (GTP-bound) and inactivated (GDP-bound) states were quantitated. NIH 3T3 cell lines expressing the RhPV 1 E5 gene or epidermal growth factor receptor cDNA had about a sixfold higher ratio of p21ras-bound GTP to p21ras-bound GDP as compared with parental NIH 3T3 cells or a cell line expressing the RhPV 1 E7 gene under normal culture conditions, yet expressed similar levels of p21ras. Quiescent cells had dramatically reduced levels of activated p21ras, except those containing RhPV 1 E7. Levels were restored by stimulation with epidermal growth factor or platelet-derived growth factor. Both epidermal growth factor and platelet-derived growth factor receptor of RhPV 1 E5- and E7-containing cells responded to cytokine stimulation. Endogenous phosphatidylinositol-3'-kinase was up-regulated in NIH 3T3 cells transformed with the E5 genes of RhPV 1 and bovine papillomavirus 1. These results suggest that E5 genes of papillomaviruses play a major role in the regulation of transduction pathways.

The expression levels of the human papillomavirus type 16 E7 correlate with its transforming potential

The transforming potential of the human papillomavirus (HPV) type 16 has been defined largely in the E7, E6, and E5 oncoproteins, with the major transforming capability residing in the E7 gene. In this paper, we found that in cooperation with the activated ras, the HPV16 E7 gene when expressed in a retroviral vector could fully transform baby rat kidney (BRK) cells in transfections, whereas the same construct could only immortalize the BRK cells following retroviral infection. This inability to transform correlated with the low levels of E7 gene RNA expression in the viral infected cells, which harbor a lower number of copies of the E7 gene constructs. Cotransfection of the expression vector FV2E7, which gives high levels of E7 gene expression, and activated ras lead to rapid and efficient morphological transformation of BRK cells which grew easily in soft agar and induced large tumors in athymic nude mice. In contrast, cotransfections of the expression vector FV1E7, which gives lower levels of E7 gene expression, produced much lower numbers of transformed colonies which took longer to form, showed a retarded growth on soft agar, and induced smaller tumors in nude mice. Under these conditions, colonies of immortalized, but morphologically untransformed cells formed in large numbers. These results indicate that the transforming potential is directly correlated to the expression levels of the oncoprotein and that a threshold level of the E7 oncoprotein may be required before the cells can be fully transformed. This supports the hypothesis that the transformation processes include at least two separate and continuous steps which first lead to immortalization and then to metastasis, in agreement with the clinical progression of genital tumors from benign to malignancy. Such a progression may involve enhanced expression of the oncoproteins.

Serological and molecular evidence of rhesus papillomavirus type 1 infections in tissues from geographically distinct institutions

We have previously demonstrated the presence of rhesus monkey papillomavirus type 1 (RhPV-1), from molecular and pathological evidence, in a mating group within a single institution. We have now also obtained a number of fresh or archival tissues of rhesus monkeys from other geographically distinct institutions. Using PCR amplification, we observed two animals from one of these institutions and five animals from another which demonstrated RhPV-1 DNA sequences. In addition we molecularly cloned the E7, E2, E4, L2 and L1 genes of RhPV-1 into bacterial expression vectors. The fusion gene products were used to test for serological response to RhPV-1 antigens by Western blot analysis. Responses were observed in up to 52% of the animals tested. While some serologically positive animals were also RhPV-1 DNA-positive, most were not.

The E6 gene of human papillomavirus type 16 is sufficient for transformation of baby rat kidney cells in cotransfection with activated Ha-ras

The transforming potential of the E6 open reading frame (ORF) of the human papillomavirus type 16 was investigated with transformation assays in cotransfections with an activated ras gene. The E6 ORF driven by the heterologous CMV promoter could fully transform baby rat kidney cells (BRK) in cooperation with ras. The transformed cells grew in soft agar and induced tumors in athymic nude mice. The E6 ORF with mutations at the splicing donor site, which only encodes the full length E6 but not E6*s, could also fully transform the BRK cells at a similar efficiency as the wild-type E6 ORF, indicating that the full-length E6 was sufficient for the transformed phenotype.

Topical CTC-96 accelerates wart growth in rabbits infected with cottontail rabbit papillomavirus

CTC-96, a cobalt containing complex, was tested as a putative topical therapeutic agent for the treatment of papillomavirus-induced tumors in our cottontail rabbit papillomavirus (CRPV)-rabbit model system. Following experimental infection of domestic rabbits with CRPV, CTC-96 was applied to infection sites twice daily, 5 days a week for a total of 8 weeks. Two levels of concentrations of aqueous CTC-96 were compared to placebo control-treated animals. With increasing dose of CTC-96 we observed tumors earlier, larger, and more often across eight infected sites on each animal.

Pilot trial of ribavirin for the treatment of laryngeal papillomatosis

The antiviral drug ribavirin was used as an adjunct to laser surgery for the treatment of patients with laryngeal papillomatosis (LP). An uncontrolled clinical trial for four patients with ribavirin treatment at a daily dose of 23 mg/kg was performed. Three adults received drug prior to laser surgery and continuing orally for 6 months. One infant was treated for 3 months. Two adults achieved complete remissions for at least 2 consecutive months, and both patients developed only minimal recurrent disease in 4 months of follow-up. The other adult and the child sustained a partial response and an increased interval between the required surgeries. Ribavirin caused only a mild, reversible reduction in hemoglobin and reticulocytosis. This preliminary trial shows that ribavirin may be an effective therapy in combination with surgery for LP in a larger controlled clinical trial.

The products of the E5, E6, or E7 open reading frames of RhPV 1 can individually transform NIH 3T3 cells or in cotransfections with activated ras can transform primary rodent epithelial cells

Rhesus papillomavirus (RhPV) type 1 was recently shown to cooperate with the activated ras oncogene to transform primary rodent epithelial cells at a level comparable to HPV 16. In similar cotransfection studies, subgenomic portions of RhPV 1 driven by either their natural or a strong heterologous promoter were used in primary baby rat kidney cells to demonstrate that transforming properties of RhPV 1 could be localized individually to the E5, E6, and E7 open reading frames. Fully transformed cells were observed when either E5 or E7 were downstream of a strong heterologous promoter. Similarly, either E6 or E6 and E7 downstream of the native promoter fully transformed these cells as determined by immortalization, anchorage independent growth and tumorigenicity studies.

Cellular transformation by a unique isolate of human papillomavirus type 11

Infection with human papillomavirus type 11 (HPV 11) is associated with benign epithelial proliferations and rarely with malignant and metastasizing tumors. Because of the biological diversity displayed in tissues infected with HPV 11, we have examined the capacity of various isolates of HPV 11 to transform cultured cells and compared their molecular differences by DNA sequence analysis. Five isolates of HPV 11 were examined for their ability to transform primary neonatal rat kidney epithelial cells and NIH 3T3 mouse fibroblasts in DNA transfection experiments using calcium phosphate precipitation. Included in these studies are the prototype isolate from a laryngeal papilloma (HPV 11P); HPV 11VC from a verrucous carcinoma of the penis; HPV 11Epi from the viral episomes of a primary squamous cell carcinoma; and two integrated genomes (HPV 11Int 1 and HPV 11Int 2) of the metastases. Only HPV 11VC cotransfected with the oncogene Ha-ras transformed neonatal rat kidney epithelial cells with an efficiency comparable to that of HPV 16 DNA. HPV 11VC DNA alone transformed NIH 3T3 cells. Analysis of the DNA sequence of HPV 11P and 11VC revealed 16 single nucleotide changes in the upstream regulatory region and open reading frames E1, E2, E4, and E5, five resulting in amino acid substitutions. This is the first demonstration of cellular transformation by a natural isolate HPV 11 DNA in vitro and illustrates that minimal changes in the DNA sequence of certain viruses confer oncogenicity to what are normally nontransforming viruses.

Ribavirin mitigates wart growth in rabbits at early stages of infection with cottontail rabbit papillomavirus

The challenge to develop antiviral agents effective against DNA viruses such as human papillomavirus (HPV) has been dependent on finding an animal model which mimics the human forms of the disease. We have used an existing model system for the purpose of measuring the effect of antiviral drugs on the inhibition of growth of these lesions. This was based upon domestic rabbits which efficiently grow cutaneous papillomas (warts) when infected with cottontail rabbit papillomavirus (CRPV). One agent which had shown significant success in achieving these goals was ribavirin. Ribavirin was administered intradermally shortly prior to infection at multiple sites with CRPV. Following daily injections of this drug for eight weeks, we have shown a dose-dependent response which had markedly reduced the number of warts, the time of first appearance of warts and reduced the tumor mass as compared to placebo-treated control animals. At the highest dose of ribavirin tested, 30 mg/kg/day, compared to controls, the average reduction in the number of warts was 52%, the average time of first appearance of warts was 49% longer, and the average mass of the warts was reduced by 98%. No detectable antibodies to CRPV were observed in any of the animals. The only side effects which were observed was focal alopecia, and a decrease in body growth upon prolonged treatment, both of which were completely reversible. Pharmacokinetic studies established the metabolism of ribavirin over a 24-h period of time. Ribavirin administered beginning 12 or 30 days post-infection, while not reducing the number of warts, slightly retarded the growth of warts as determined by date of first appearance of warts and mass of warts.

Implication of human papillomavirus in postirradiation dysplasia

The presence of human papillomavirus (HPV) DNA and association of condylomata acuminata (CA) in the biopsy tissues of postirradiation dysplasia (PRD) of the cervix and/or vagina from 17 patients who previously had radiation therapy for malignancies of the uterine cervix, vagina, and endometrium were evaluated with DNA in situ hybridization. Eight of 17 patients (47.1%) had HPV DNA identified in the lesions of postirradiation dysplasia (PRD). Five of eight cases (62.5%) contained HPV DNA of more than one type. Type 16 HPV DNA (HPV-16) was the most frequently identified type. Several PRD lesions also contained HPV-6, HPV-18, HPV-31, and/or HPV-33 DNA. Eleven patients (64.7%) showed CA in the vicinity of PRD. In two cases, different types of HPV were found in the lesions of PRD and contiguous CA. The frequency of the cases containing HPV DNA, the types of HPV, and the distribution pattern of silver grains in the preparations of in situ hybridization over the nuclei of cells of PRD were very similar to those found in naturally occurring dysplasia. Based on these findings, persistent or repeat HPV infection was the most likely etiologic factor of PRD, which might be facilitated by immunosuppression due to pelvic irradiation.

Expression of cytokine receptors and markers of differentiation in human papillomavirus-infected cervical tissues

Human papillomavirus infection of the uterine cervix is associated with a spectrum of benign, premalignant, and malignant epithelial lesions, a process that appears to require the coordinated effects of secondary cellular and environmental events. We have used flow cytometry and immunohistochemistry to examine the expression of the cellular markers for proliferation (interleukin-1, epidermal growth factor receptor, and transferrin receptor) and the markers of cellular differentiation (filaggrin and low-molecular-weight cytokeratin) in normal and human papillomavirus--infected human cervical tissues representing the natural range of human papillomavirus--induced disease. The results were correlated with the histologic grade of disease, human papillomavirus type, cellular deoxyribonucleic acid content, and cell cycle status. Interleukin-1 and transferrin receptor were slightly increased in high-grade dysplasias and in squamous cell carcinomas. Filaggrin expression was found to be inversely related and cytokeratin and epidermal growth factor receptor expression directly related to the degree of neoplasia. These findings indicate that cytokeratin and epidermal growth factor receptor are useful markers of cell proliferation in human papillomavirus--infected tissues and that their expression may directly increase as a result of infection.

Rhesus papillomavirus type 1 cooperates with activated ras in transforming primary epithelial rat cells independent of dexamethasone

Rhesus Papillomavirus type 1 (RhPV-1) was recently cloned from a rhesus monkey lymph node metastasis of a penile squamous cell carcinoma. In this paper, we demonstrate that RhPV-1 cooperates with the activated ras oncogene to transform primary cells at a level comparable to human papillomavirus type 16. The viral DNAs were cloned such that their expression was under the control of their natural promoter elements. Unlike human papillomavirus type 16, RhPV-1 DNA cooperated with ras independently of the hormone dexamethasone. However, dexamethasone did have a positive influence on the ability of some RhPV-1 cotransformed cells to grow in soft-agar assays. The transformed cells are highly tumorigenic in vivo in nude mice.

Characterization of the complete RhPV 1 genomic sequence and an integration locus from a metastatic tumor

The complete nucleotide sequence of the rhesus papillomavirus type 1 (RhPV 1) genome was determined. The genome is 8026 nucleotides in length and has a genomic organization similar to that of other characterized papillomaviruses. Sequence comparison of RhPV 1 to other papillomaviruses found similarities closest to HPV 16, a sexually transmitted human virus with a high oncogenic potential. Slight differences in the glucocorticoid responsive elements may explain disparate reliance upon added dexamethasone for transformation in vitro of these two papillomaviruses. In addition, a previously described DNA clone consisting of contiguous RhPV 1 and cellular sequences was partially sequenced. The disruption of the RhPV 1 genome due to integration occurred within the L1 open reading frame of RhPV 1, and no significant similarities were observed between the adjacent cellular sequences and information in various data banks.

A rhesus monkey model for sexual transmission of a papillomavirus isolated from a squamous cell carcinoma

Recently we molecularly cloned and characterized a papillomavirus from a lymph node metastasis of a primary penile carcinoma found in a rhesus monkey; this virus species, rhesus papillomavirus type 1 (RhPV-1), is similar to oncogenic human papillomaviruses (HPVs), such as HPV-16 or HPV-18, in that the RhPV-1 DNA was found to be integrated in the tumor cell DNA. To compare the sexual transmission and oncogenic nature of RhPV-1 with these HPVs, we undertook an extensive retrospective study of a group of rhesus monkeys whose sexual mating and offspring histories were known. These animals had mated directly with the index male mentioned above or were secondarily exposed to this virus through intermediate sexual partners. This study combines cytological, histopathological, and several complementary hybridization and DNA amplification techniques on multiple tissue samples to demonstrate the sexually transmitted nature of RhPV-1. The oncogenic potential of RhPV-1 is suggested in several of the infected animals by the presence of various degrees of neoplasia including squamous cell cancer of the cervix.

Human papillomavirus type 27: detection of a novel human papillomavirus in common warts of a renal transplant recipient

The cloning and partial characterization of the genome of human papillomavirus type 27 (HPV-27) is described. Hybridization analyses reveal that this is a new HPV type, with the strongest homology to HPV-2.

Human papillomavirus DNA in glandular dysplasia and microglandular hyperplasia: presumed precursors of adenocarcinoma of the uterine cervix

Presumed precursors of adenocarcinoma of the uterine cervix were investigated with specific techniques to identify human papillomavirus (HPV) DNA. The presence of HPV DNA in 36 lesions of glandular dysplasia and 16 lesions of microglandular hyperplasia of the uterine cervix was studied by in situ hybridization using 3H-labeled HPV 16 and HPV 18 DNA probes. Only two of 36 lesions (6%) of glandular dysplasia contained HPV 18 DNA, although 64% of coexisting adenocarcinoma in situ, microinvasive adenocarcinoma, and cervical squamous intraepithelial neoplasia III lesions contained HPV 18 and/or HPV 16 DNA. Two lesions of HPV 18 DNA-positive glandular dysplasia coexisted with adenocarcinoma in situ that contained the same type of HPV DNA. None of the microglandular hyperplasia lesions contained HPV 16 DNA or HPV 18 DNA. These results suggest that, if HPV infection is an initial step toward carcinogenesis, it is unlikely that glandular dysplasia and microglandular hyperplasia are precursor lesions of adenocarcinoma of the uterine cervix. A large proportion of glandular dysplasia may represent reactive lesions of endocervical columnar epithelium. Two lesions of HPV 18 DNA-positive glandular dysplasia may represent well-differentiated components of adenocarcinoma in situ of the uterine cervix.

Characterization of integrated human papillomavirus type 11 DNA in primary and metastatic tumors from a renal transplant recipient

A primary perianal squamous cell carcinoma and two metastatic tumors from a renal transplant recipient with a previous history of condyloma acuminatum were analyzed by filter hybridization for the presence of human papillomavirus (HPV) DNA. Each of the DNA extracts from these three tissues was found to contain HPV DNA. Stringent hybridization and restriction endonuclease analysis identified this viral DNA as HPV 11 related, which largely comigrated with cellular DNA, suggesting the presence of integrated viral DNA. Each DNA extract was analyzed by two-dimensional gel electrophoresis, which separates circular and linear forms of DNA and can demonstrate linear viral DNA, which comigrated with high molecular weight linear cellular DNA, thus implying viral integration. In all three cases the vast majority of viral DNA was found to comigrate with linear DNA; in addition, a significant portion comigrated with high molecular weight cellular DNA, suggesting the presence of integrated viral DNA in these tumors. Restriction endonuclease analysis of high molecular weight cellular DNA from each of these tumors revealed identical banding patterns, indicating that the integration site in each tissue is identical and, therefore, that all three tumors most likely originated from a single clonal event. These molecular results are presented in light of the clinical history of this patient with a histologically "low grade," but biologically aggressive, squamous cell carcinoma and suggest that HPV 11 may be associated with the initiation of malignant epithelial neoplasms.

Human papillomavirus-16 DNA in a cutaneous invasive cancer

A middle-aged man with a 20-year history of a warty lesion on his finger was diagnosed histologically as having an invasive carcinoma at that location. Molecular analysis of the lesion showed that human papillomavirus (HPV) DNA was present in this tumor. Under stringent hybridization conditions, only HPV-16 DNA, which is commonly associated with genital neoplasia or cutaneous bowenoid lesions, was detected. Two-dimensional gel electrophoresis revealed that various sections of the tumor contained mostly episomal viral DNA; but in one case, low levels of integrated HPV-16 DNA were detected as well.

Human papillomavirus DNA in adenocarcinoma in situ, microinvasive adenocarcinoma of the uterine cervix, and coexisting cervical squamous intraepithelial neoplasia

Previously, human papillomavirus (HPV) DNA, mainly HPV-18 DNA, was detected in more than 40% (17/40 cases) of invasive adenocarcinoma of the uterine cervix in our laboratory. In order to identify HPV DNA in the precursor lesions of adenocarcinoma of the cervix, 11 cases of adenocarcinoma in situ containing microinvasive adenocarcinoma and 10 cases of adenocarcinoma in situ were studied for the presence of HPV DNA by in situ hybridization using highly sensitive 3H-labeled HPV-16 and HPV-18 DNA probes. HPV types present in cervical squamous intraepithelial neoplasia (CIN) coexisting with adenocarcinoma in situ and microinvasive adenocarcinoma were also studied. Apart from the coexisting CIN II-III with glandular neoplasms, 48 cases of CIN III (severe dysplasia and squamous carcinoma in situ) removed by conization or hysterectomy and known to be free of adenocarcinoma were used for comparison. HPV DNA was detected in 64% of microinvasive adenocarcinoma, 70% of adenocarcinoma in situ, and 63% of the control CIN III. HPV-18 DNA was the preponderant type of HPV DNA found in adenocarcinoma in situ and microinvasive adenocarcinoma. All cases of HPV DNA-positive microinvasive adenocarcinoma contained the same type of HPV DNA as the lesions of coexisting adenocarcinoma in situ. CIN coexisting with microinvasive adenocarcinoma or adenocarcinoma in situ contained the same type of HPV as identified in the glandular lesions, whereas all of the HPV DNA-positive control CIN III cases contained HPV-16 DNA. These results suggest that adenocarcinoma in situ is a precursor lesion of adenocarcinoma of the cervix that contains HPV DNA, and that CIN coexisting with adenocarcinoma may be a result of a metaplastic process of adenocarcinoma or of bidirectional differentiation of the affected reserve cells.

The analysis of carcinomas of the vagina for human papillomavirus DNA

Invasive cancers of the vagina are relatively rare and often resistant to effective treatment. While studies on the more abundant premalignant lesions of the vagina and premalignant and malignant tumors of the vulva and cervix have shown a frequent association with human papillomavirus (HPV) DNA infection, lack of fresh tissue samples has precluded similar studies on malignant tumors of the vagina. Using mostly in situ hybridization, we have retroactively examined 14 formalin-fixed, paraffin-embedded biopsies of invasive squamous cell carcinomas of the vagina. We have found 21% of the samples to have HPV DNA. These findings confirm a role for HPV in malignancies of the entire female lower genital tract.

Molecular cloning and characterization of the DNA of two papillomaviruses from monkeys

Benign and malignant lesions from monkeys were analyzed for the presence of papillomavirus (PV) DNA. By hybridization with different PV DNA probes under conditions of lowered stringency, two tumors were found to contain PV-specific DNA sequences: (1) a cutaneous papilloma from a Colobus monkey; and, (2) a lymph node metastasis of a squamous cell carcinoma of the penis from a Rhesus monkey. Analysis of the DNA of the papilloma from the Colobus monkey indicated the presence of extrachromosomal DNA whereas analysis of DNA from the Rhesus tumor suggested the presence of integrated viral DNA. The physical size (7.8 and 8.1 kb), colinear alignment to HPV-5, and cross-hybridization with other PV types under low stringency indicate that the two genomic DNA clones represent new PV types that have been tentatively designated as Rhesus papillomavirus type 1 (RhPV 1) and Colobus guereza papillomavirus type 2 (CgPV 2). A putative viral-host DNA junction fragment was also isolated from the Rhesus genomic library. Nucleotide sequences very closely related to RhPV 1 were observed by in situ hybridization in a laryngeal carcinoma from the Colobus guereza monkey. This report communicates the finding of novel papillomaviruses associated with a benign cutaneous tumor and genital and laryngeal malignancies in non-human primates which may have significance as a putative system for the study of papillomavirus-induced genital and laryngeal malignancies in humans.

Condylomatous carcinoma of the vulva with special reference to human papillomavirus DNA

Nine cases of condylomatous carcinoma (squamous cell carcinoma arising in condyloma acuminatum) of the vulva were studied for their clinical history, histopathology, and presence of human papillomavirus (HPV) DNA. Condylomatous carcinoma occurred primarily in an elderly population with a mean age of 70 years. There was an antecedent history of vulvar condyloma in 77%, with a median of nine months before the documentation of an invasive lesion. The disease had a good prognosis, with few recurrences and no metastasis or deaths from the disease. Human papillomavirus DNA was demonstrated to be present in 55% of these tumors by either filter or in situ hybridization techniques. Both HPV 6 and HPV 16 DNA were identified in an equal number of cases.

Human papillomavirus DNA in adenosquamous carcinoma and squamous cell carcinoma of the vulva

The tissues from 16 cases of adenosquamous carcinoma (pseudoglandular squamous cell carcinoma or adenoacanthoma of the sweat glands of Lever) and 26 cases of invasive squamous cell carcinoma of the vulva were studied for the presence of human papillomavirus (HPV) genomes using Southern blot hybridization on fresh tissues. Types 1, 2, 3, 4, 5, 6, 16, and 18 HPV DNA probes and in situ hybridization were used on formalin-fixed paraffin sections using type 2, 6, 16, and 18 HPV DNA probes. Only one case of adenosquamous carcinoma contained an undetermined type of HPV DNA, whereas five cases of squamous cell carcinoma contained HPV DNA. Three of these five cases contained type 16, one type 6 HPV, and two an undetermined type. These results demonstrate HPV DNA associations with malignancy of the vulva that are similar to those observed elsewhere in the genital tract.

Human papillomavirus types and localization in adenocarcinoma and adenosquamous carcinoma of the uterine cervix: a study by in situ DNA hybridization

Formalin-fixed, paraffin-embedded tissues from 108 cases of invasive carcinoma of the uterine cervix, consisting of 40 cases of adenocarcinoma, 44 cases of adenosquamous carcinoma, and, as a control, 24 cases of squamous cell carcinoma were examined for the presence of human papillomavirus (HPV) DNA by in situ hybridization of high sensitivity using tritium-labeled HPV-2, HPV-6, HPV-16, and HPV-18 DNA probes. This method detects five genome copies of homologous HPV DNA per cell. HPV DNA was detected with mixed HPV DNA probes in 17 cases (42.5%) of adenocarcinoma, 16 cases (36.4%) of adenosquamous carcinoma, and in 13 cases (54.2%) of squamous cell carcinoma. The types of HPV DNA in the HPV-positive tissues were also analyzed with each individual probe under high stringency conditions. HPV-18 DNA was detected in all but one case of the HPV DNA-positive adenocarcinoma and one-half of the HPV DNA-positive adenosquamous carcinoma. HPV-16 DNA was detected in one case of the HPV DNA-positive adenocarcinoma, one-half of the HPV DNA-positive adenosquamous carcinoma, and all cases of the HPV DNA-positive squamous cell carcinoma. HPV DNA was confined to the areas of carcinoma and squamous cervical intraepithelial neoplasia (CIN) associated with carcinoma. Among 36 cases in which CIN was associated with adenocarcinoma (9 cases), adenosquamous carcinoma (19 cases), and squamous cell carcinoma (8 cases), the same type of HPV DNA was present in the carcinoma and the associated CIN that constituted 12 cases (3 adenocarcinoma, 5 adenosquamous carcinoma, and 4 squamous cell carcinoma). Two cases (one adenocarcinoma and one adenosquamous carcinoma) contained HPV DNA in the carcinoma but not in the associated CIN. The incidence of HPV DNA did not show a significant correlation with the existence of CIN or histological differentiation of carcinoma.

The molecular biology of human papillomaviruses and the pathogenesis of genital papillomas and neoplasms

Numerous studies over the past several years have demonstrated that human papillomaviruses (HPV) may play a significant role in the development of several types of human neoplasia. Although it has been accepted for some time that HPVs are responsible for benign epithelial tumors, data accumulated in more recent years have implicated this group of animal viruses in a number of premalignant lesions, as well as a variety of epithelially derived malignancies. Genital, oral, and some rare types of cutaneous cancers have all been found to contain varying degrees of HPV DNA. In several instances secondary tumors resulting from metastases to lymph nodes and lungs have also been demonstrated to contain HPV DNA. Although there is a strong correlation between the presence of the virus and the malignant phenotype in several of these cancers, the precise role of the virus in the development of malignant tumors has not yet been elucidated. A major difficulty in elucidating the role of papillomaviruses in oncogenesis has been the lack of an appropriate in vitro culture system that would permit the growth of the virus and allow an analysis of its transforming properties. Nevertheless, recent advances in molecular biology have permitted the molecular cloning and amplification of HPV viral DNA, thereby facilitating its use as a probe for the detection of miniscule amounts of HPV DNA and HPV RNA in tumor biopsies. Moreover, DNA transfections of cells in culture have been extremely useful in the study of viral DNA replication and transformation properties, providing information on the maintenance and oncogenicity of HPV DNA. These advances have implications for the improved detection of HPV infections, which will aid in patient diagnosis and prognosis. In addition, future treatment and prevention programs may come as a direct result of these basic studies on the mechanism of HPV-induced oncogenesis.

Epidermodysplasia verruciformis. A case associated with primary lymphatic dysplasia, depressed cell-mediated immunity, and Bowen's disease containing human papillomavirus 16 DNA

Epidermodysplasia verruciformis is a rare, often hereditary disease characterized by a generalized cutaneous infection with human papillomavirus (HPV), depressed cell-mediated immunity, and a propensity for transformation of the warty lesions to squamous cell carcinoma on primarily sun-exposed areas of the skin. A 37-year-old man with congenital lymphatic dysplasia and a history of squamous cell carcinoma of the groin and foot was observed by us to have edema of all four extremities, numerous flat warts, and pityriasis versicolor-like papules over the trunk and arms. Condylomatous lesions were noted in the groin and a periungual verrucous nodule on the thumb. Biopsies showed the trunk and arm lesions to be verrucae and the thumb lesion to be Bowen's disease. Results of molecular hybridization studies from four lesions of the arms showed the presence of only HPV 3 DNA; HPV 16-related DNA was detected in the intraepidermal carcinoma on the thumb. Immunologic evaluation revealed anergy to routine skin testing, depressed mitogen-stimulated lymphocyte transformation, decreased B-lymphocyte count, and a severe reversal of the T-lymphocyte helper:suppressor ratio.

Nucleotide sequence and genome organization of human papillomavirus type 5

Human papillomavirus (HPV) type 5 is associated with benign and malignant lesions of the disease epidermodysplasia verruciformis (EV). Because of the strong correlation between the presence of HPV-5 and malignant progression in these patients, we have elucidated the nucleotide sequence of the HPV-5 genome. The size of the HPV-5 genome is 7746 nucleotides and its organization is similar to that of other papillomaviruses. The HPV-5 genome exhibits extensive sequence homology with another EV-associated papillomavirus, HPV-8, although HPV-5 appears to contain at least one additional open reading frame.

Molecular cloning and nucleotide sequence analysis of several naturally occurring HPV-5 deletion mutant genomes

Three deletion mutants of naturally occurring human papillomavirus type 5 (HPV-5) were molecularly cloned into phage vectors. The nature of these deletions was characterized initially by restriction endonuclease mapping and electron microscopic heteroduplex analysis and ultimately by nucleotide sequence analysis. The sizes of the deletions are 353, 1329, 1571, and 2267 bp and map to the late gene region of the HPV-5 genome. The 80 nucleotides immediately adjacent to the deletions exhibit no significant detectable sequence homologies or symmetries and therefore were probably not formed by the sequence-dependent events of homologous recombination or site-specific recombination.

Human papillomavirus heterogeneity in 36 renal transplant recipients

Immunosuppressed patients such as renal transplant recipients are prone to increased incidence of wart disease. We examined 48 tissue specimens from 36 renal transplant recipients using human papillomaviruses (HPVs) 1, 2, 3, 4, 5, and 6 in filter hybridization under stringent conditions. The results showed that 90% of the samples contained HPV DNA. Of these 43 positive samples, we found HPV-1 in 2%, HPV-2 in 56%, HPV-3 in 19%, HPV-4 in 47%, HPV-5 in 9%, and HPV-6 in 5%. In several cases, more than one type of HPV DNA was observed. In a few of these cases, the clinical appearance of the lesions differed from what might have been expected, such as those lesions containing HPV-3- or HPV-5-related DNAs.

A survey of human cancers for human papillomavirus DNA by filter hybridization

We examined 217 tissue samples of various human malignancies for the presence of human papillomavirus (HPV) DNA using low-stringency filter hybridization techniques. These techniques were sufficiently sensitive for crosshybridization of the HPV DNA probes to all the known types of papillomavirus DNAs, both human and animal. Approximately 2% of the cancers analyzed contained HPV DNA. These included carcinomas of the lung, cecum, tongue, and neck. Three of four cancers contained HPV-16-related nucleotide sequences. Thus, in addition to previous data demonstrating the association of HPV DNA with certain cancers of the skin and genital tract, data is presented that indicates that several additional human cancers also contain HPV-related nucleotide sequences.

Detection of human papillomavirus DNA in invasive carcinomas of the cervix by in situ hybridization

An examination of 27 invasive cancers of the cervix was performed using the technique of in situ hybridization using human papillomavirus DNA probes. Four tissues, previously found to harbor papillomavirus DNA by filter hybridization, were confirmed by in situ analysis. One further tissue never previously studied was also found to be positive by in situ hybridization. Overall, we found 33% of invasive cancers of the cervix to contain human papillomavirus DNA. In contrast, 55% of carcinoma in situ and severe dysplasia of the cervix were found to be positive for human papillomavirus DNA. These results confirmed that the sample population of patients in our studies have a relatively low association of human papillomavirus DNA with invasive cancers of the cervix and that in situ hybridization provides an effective complementation to filter hybridization for human papillomavirus-infected tumors.

Sensitivity of koilocytosis, immunocytochemistry, and electron microscopy as compared to DNA hybridization in detecting human papillomavirus in cervical and vaginal condyloma and intraepithelial neoplasia

The sensitivity in detecting human papillomavirus (HPV) by histological observation of koilocytosis, immunocytochemistry, and electron microscopy with reference to the results of Southern blot deoxyribonucleic acid (DNA) hybridization were reviewed in 41 lesions (37 patients) of cervical and vaginal condylomata acuminata and intraepithelial neoplasia. Human papillomavirus DNA was demonstrated in fresh tissues by Southern blot DNA hybridization in all but one lesion of moderate dysplasia (98%). The rate of koilocytosis observed in tissue sections was 80% in condyloma, and ranged from 89-20% in cervical intraepithelial neoplasia (CIN), with steady reduction as the grade of CIN or vaginal intraepithelial neoplasia (VaIN) was higher. The immunocytochemistry for HPV capsid antigens was positive in 80% of condylomata and ranged from 61-0% in CIN or VaIN. The rate declined in inverse proportion to the grade of CIN or VaIN. Electron microscopy of preselected areas containing intranuclear inclusions in paraffin sections of 10 lesions demonstrated HPV-like particles in 90% of the lesions. Although immunocytochemistry and observation of koilocytosis may be useful in detecting HPV in condylomata acuminata and mild dysplasia, their sensitivity was poor in CIN or VaIN of higher grades. Electron microscopy on preselected areas in paraffin blocks showed better sensitivity, presumably due to its ability to detect immature virions.

Human genital papilloma infections: an evaluation of immunologic competence in the genital neoplasia-papilloma syndrome

Immunologic evaluations of women with genital neoplasia-papilloma syndrome demonstrated the presence of subclinical immunodeficiency when compared with results in 20 control women. All patients with genital neoplasia-papilloma syndrome were previously found to have human papillomavirus deoxyribonucleic acid in genital neoplasias or papillomas occurring either synchronously (in at least two genital organs at the same time) or metachronously (at different times during a period of months to years). Immunologic tests included blastogenic responses of lymphocytes to mitogens (phytohemagglutinin, concanavalin A, pokeweed mitogen, and tetanus antigen) and lymphocyte phenotyping with the use of monoclonal antibodies (OKT3, OKT4, OKT8, and OKT11). As compared with those of control subjects, the responses of the lymphocytes of patients with genital neoplasia-papilloma syndrome to mitogens were significantly decreased. The group with genital neoplasia-papilloma syndrome had a significantly higher percentage of suppressor-cytotoxic T cells (OKT8-positive cells) when compared with that of control subjects (mean 33% versus 18%) and a lower proportion of helper T cells (OKT4-positive cells) when compared with that of control subjects (35% versus 50%). The mean helper-to-suppressor/cytotoxic T-cell ratio (mean OKT4/OKT8 ratio) in the human papillomavirus-infected women was 1.72 +/- 0.29 (SE) as compared with 3.21 +/- 0.33 (SE) in the control group, demonstrating a significant reduction of the ratio in the patients with genital neoplasia-papilloma syndrome. These findings suggest that patients with genital neoplasia-papilloma syndrome have a reduced suppressor/cytotoxic T-cell ratio (mean OKT4/OKT8 ratio; that in the human papillomavirus-infected women was 1.72 +/- 0.29 (SE) as compared with 3.21 +/- 0.33 (SE) in the control group, demonstrating a significant reduction of the ratio in patients with genital neoplasia-papilloma syndrome. These findings suggest that patients with genital neoplasia-papilloma syndrome have reduced immunocompetence of unknown etiology.

Detection of papillomavirus DNA in human semen

Human papillomavirus DNA has been detected in the semen of three patients, two of whom have severe chronic wart disease. These data support the contention that sexual transmission of human papillomavirus DNA could occur via semen, a possibility suggested by epidemiological data on the sexual transmission of human papillomavirus.

Bowenoid papulosis of the genitalia associated with human papillomavirus DNA type 16 in an infant with atopic dermatitis

A case of bowenoid papulosis occurred in a 2-year-old male with atopic dermatitis. Clinical and histologic features of the lesions were typical, and human papillomavirus type 16 DNA was identified using high-stringency hybridization techniques. Although the lesions had been present for approximately one year prior to examination, they subsequently resolved spontaneously over six months. We postulate that our patient's susceptibility to human papillomavirus may have been related to his severe atopic tendency.

Histological types of carcinoma of the uterine cervix and the detectability of human papillomavirus DNA

Using the Southern DNA hybridization technique, tissues from 17 cases of invasive carcinoma of the uterine cervix, including nine cases of squamous cell carcinoma, four cases of adenocarcinoma, one case of adenosquamous carcinoma, and three cases of undifferentiated carcinoma, were examined for the presence of human papillomavirus (HPV) DNA. None of the studied cases had histologically confirmed association of condyloma acuminatum or cervical intraepithelial neoplasia in the vicinity. HPV DNA was detected in two of 17 cases under low stringency conditions. One lesion was undifferentiated carcinoma, and another was squamous cell carcinoma. Hybridization under high stringency conditions with a variety of HPV DNA probes indicated the presence of HPV-16 in these two lesions. The other HPV-positive lesion was adenocarcinoma, demonstrating weak hybridizations with HPV-2 and HPV-16 DNA probes only under high stringency conditions. Altogether, three of 17 cases (17.6%) contained HPV DNA. This observation contrasts to the rate of HPV DNA present in 15 of 18 cases (83.3%) of the tissues of cervical intraepithelial neoplasia. Our data suggest that HPV was not consistently detected in invasive squamous cell carcinoma, despite the frequent association of HPV with its supposed precursor lesions of cervical intraepithelial neoplasia.

Epidermodysplasia verruciformis in a setting of common variable immunodeficiency

A 14-year-old native American female with common variable immunodeficiency was admitted for bone marrow transplantation. Preoperative evaluation showed a generalized lichenoid papular eruption present for several years. Light microscopy revealed expansion of the epidermis by atypical keratinocytes; electron microscopy showed intranuclear papillomavirus inclusions within the granular keratinocytes; DNA hybridization revealed a type 5-related human papilloma virus homology. Four days after bone marrow transplantation the lichenoid papules blackened and began to disappear. Within 30 days after bone marrow transplantation the distribution and appearance of the papules was similar to that of the pretransplantation evaluation. One year after transplantation the patient showed evidence of a successful T lymphocyte graft. No transformation to squamous cell carcinoma had occurred. Epidermodysplasia verruciformis has been associated with deficient cell-mediated immunity, the varying severity of which does not predict the tendency to neoplasm formation (2, 5). Several distinct human papillomavirus genomes have been recovered with DNA hybridization techniques in these patients. It is hoped that the bone marrow transplantation might be associated with diminished transformation to squamous cell carcinoma.

Cellular transformation by human papillomavirus DNA in vitro

Molecularly cloned DNA's of human papillomaviruses HPV-5 and HPV-l induced morphological transformation of mouse C127 cells in culture. Single-cell clones of cells transformed by papillomavirus contained multiple persistent episomal copies of the transfected DNA species and were analyzed for growth characteristics indicating malignant potential.

Presence of human papillomavirus in verrucous carcinoma (Ackerman) of the vagina. Immunocytochemical, ultrastructural, and DNA hybridization studies

Human papillomavirus (HPV) genomes were identified in two cases of verrucous carcinoma of the vagina, using Southern blot DNA hybridization under low-stringency conditions. Type (group) 6 HPV DNA (HPV-6) was identified, using molecularly cloned HPV-1 through HPV-6 DNA probes under high-stringency conditions in both cases. In addition, DNA extract in one case hybridized with HPV-1, HPV-3, and HPV-4 DNA probes. No HPV structural proteins were demonstrated in either case by immunocytochemical tests, using HPV antibodies. In one case viruslike intranuclear particles were observed by transmission electron microscopy. These two cases suggest a strong associative relationship between HPV and verrucous carcinoma (Ackerman) of the lower part of the genital tract.

Molecular cloning and characterization of a unique type of human papillomavirus from an immune deficient patient

Several papillomas from a single patient who exhibited an unusual immune deficiency syndrome were analyzed for the presence of specific human papillomavirus (HPV) types. Preliminary analysis indicated that the HPV DNA species present in each of these tissues was quite unlike any of the previously characterized HPV types. In order to more rigorously analyze the HPV from this patient we have isolated the HPV DNA by molecularly cloning it into a bacteriophage lambda vector and have constructed a detailed restriction endonuclease map. Comparative hybridization studies using S1 nuclease analyses showed 6% or less nucleotide sequence homology of this viral DNA with HPV types 1, 2, 3, 4, 5, 6, or an HPV-11, molecularly cloned in this laboratory. Moreover, Southern blot analyses under stringent hybridization conditions revealed little, if any, hybridization to HPV types 1, 2, 4, 5, 7, 8, 10, 11, HPV-EV isolated from a patient with epidermodysplasia verruciformis (EV), or 2 previously described HPVs (HPV-P and HPV-PW) related to HPV-3. There was, however, a very weak sequence homology detected with HPV-6 and an extremely weak homology to HPV-3. No filter hybridization was observed with the recently characterized HPVs 9 or -12 to -24. These data accumulatively indicate that the HPV species from this immunosuppressed patient represents a new, hitherto unidentified HPV type.

Immunology of human papillomavirus: warts

Great progress has been made over the last five years in our understanding of papillomavirus (PV) biology. New technology has enabled investigators to understand the relationship between the PV and its host. The PV cannot be cultured in vitro, and this has led to limitations for those wishing to study the biology of this virus. However, utilizing recombinant DNA technology, investigators now have abundant quantities of human papillomavirus (HPV) DNA for study. Such HPV genomes may be labeled with a radioisotope such as P32 and used as a "probe" in hybridization studies to see if a given tissue contains HPV DNA. No longer are we limited to electron microscopy and immune studies in our efforts to identify HPV within benign or malignant tissues. Ultimately, we hope to understand the relationship between the virus and its host. This paper will concentrate on one aspect of this relationship--the immunology of HPV.

Identification of human papillomavirus DNA in cervical and vaginal intraepithelial neoplasia with molecularly cloned virus-specific DNA probes

The presence of human papillomavirus (HPV) DNA was identified in the tissues of cervical and vaginal intraepithelial neoplasia by Southern blot DNA hybridization under conditions of low stringency. The specific types of HPV present in the tissues were identified by using molecularly cloned types 1 through 6 (HPV-1 through HPV-6) HPV DNA probes under high-stringency conditions. All tissues of cervical and vaginal intraepithelial neoplasia analyzed contained HPV genomes. Fifteen of 19 samples (79%) contained HPV-6 DNA, and 10 of 19 samples (53%) HPV-3 DNA. Hybridization with HPV-1, HPV-2, HPV-4, and HPV-5 DNAs was also observed in several of the samples. Four of the samples did not hybridize with any of the probes tested (HPV-1 through HPV-6); yet, all showed hybridization with an HPV-EV DNA (a type 3-related DNA) probe under low-stringency conditions, indicating the presence of HPV types other than those belonging to HPV-1 through HPV-6.

Identification of three distinct papillomavirus genomes in a single patient with epidermodysplasia verruciformis

Benign papillomas from a patient with a family history of epidermodysplasia verruciformis were examined for the presence of human papillomavirus (HPV) DNA. Employing stringent hybridization conditions that allow identification of a single type of HPV and radioactively labeled HPV-5 DNA as a probe, we have detected HPV DNA exhibiting sequence homology to HPV-5 in these tumors. Restriction endonuclease analysis of this HPV DNA confirmed its identity as HPV type 5. However, when hybridization was performed under less stringent conditions that allow all of the known types of HPV to react with the radioactively labeled HPV-5 DNA probe, two additional species of HPV DNA unrelated to HPV-5 were identified. As these two HPV types do not hybridize with HPV 1, 2, 3, or 4 under stringent conditions, they appear unique and have, as yet, not been reported to be associated with patients exhibiting epidermodysplasia verruciformis. Thus we have observed three distinct HPV species in benign papillomas from a single patient. These observations have important implications when attempting to correlate the type of HPV present in the various wart disease syndromes that have been described to date and further suggest that extreme care must be taken when analyzing carcinomas, occupying similar anatomic sites and suspected to have arisen from papillomas, for HPV species.

Free cottontail rabbit papillomavirus DNA persists in warts and carcinomas of infected rabbits and in cells in culture transformed with virus or viral DNA

We have compared warts and carcinomas from cottontail and domestic rabbits for the presence of cottontail rabbit papillomavirus (CRPV) and the status of the viral DNA genome. Our studies indicate that benign warts from cottontail rabbits, whether found naturally or induced in the laboratory, contain large amounts of virus and on the average 1000 copies of the virus genome per cell. Both benign warts and carcinomas from domestic rabbits contain significantly reduced levels of virus relative to cottontail rabbit warts and an average of 100 copies of the virus genome per cell. A single sample of a naturally occurring cottontail rabbit carcinoma contained approximately 80 copies of the viral genome per cell. None of the tumors that we have analyzed thus far appear to have integrated viral genomes by Southern blot analysis of undigested and restriction endonuclease-digested DNA samples. Furthermore, the CRPV genome present in domestic rabbit carcinomas and a cottontail rabbit carcinoma appears identical by restriction endonuclease mapping to that present in papillomas of cottontail and domestic rabbits indicating that no major deletions or rearrangements of the CRPV genome had occurred during the progression of benign to malignant tumors nor was a variant of wild-type CRPV responsible for this phenomenon. Finally, we have demonstrated morphological transformation in vitro of NIH 3T3 and C127 cells upon infection with purified CRPV and upon transfection with purified CRPV DNA. Furthermore, single cell clones derived from transformed foci contain free forms of CRPV DNA that persist through continued passage in culture. Cells transformed by CRPV grow in soft agar in vitro and produce tumors in athymic nude mice.

Detection of human papillomavirus DNA in anogenital neoplasias

The presence of papillomaviruses in epithelial-derived cancers from several animal species has led to the speculation that these viruses may also have a pathogenic role in the development of certain human carcinomas, particularly those associated with the anogenital tract. Recently, human papillomavirus (HPV) DNA has been detected in epithelial-derived cancers, both cutaneous and metastatic, from patients exhibiting the rare, chronic flat wart disease, epidermodysplasia verruciformis (EV). Except for patients exhibiting this chronic wart syndrome, the association of HPV genomes with human epithelial cancers has not been demonstrated. In an attempt to delineate the association and possible involvement of papillomaviruses with human anogenital carcinomas, we have begun an analysis of these cancers for the presence of HPV-specific nucleotide sequences by using highly sensitive hybridization procedures capable of detecting distantly related papillomaviruses at low copy number. Here we demonstrate the presence of HPV DNA in several types of anogenital tumours: Bowenoid papulosis, carcinoma in situ, and verrucous carcinoma. These data indicate that HPV can be detected in several types of premalignant and malignant tumours, supporting the contention that this group of viruses may be involved in the development of certain types of human epithelial-derived cancers.

Human papillomavirus DNA in cutaneous primary and metastasized squamous cell carcinomas from patients with epidermodysplasia verruciformis

DNA extracted from squamous cell carcinomas from patients with the chronic wart disease syndrome, epidermodysplasia verruciformis, was analyzed for the presence of human papillomavirus (HPV)-specific DNA sequences by Southern blot hybridization analysis. Employing an HPV probe obtained by molecular cloning of viral DNA purified from benign warts from these patients, we have unequivocally identified HPV-specific nucleotide sequences in squamous cell carcinomas from these patients. Restriction endonuclease mapping indicated that the DNA present in the carcinomas was of the same type (type 5) as that found in the benign tumors from these patients and was present as unintegrated, free viral DNA. Moreover, we have demonstrated the presence of HPV-5 DNA in a subcutaneous metastatic tumor from one of these patients. This latter observation essentially eliminates the possibility that the HPV-5 DNA present in the malignant tumors in these patients resulted from cross-contamination from an adjacent benign warty lesion. In addition to wild-type HPV-5 DNA, both the primary and metastatic carcinomas analyzed also contained an HPV-5 DNA species lacking approximately 20% of the HPV-5 DNA genome. These subgenomic forms of HPV-5 DNA could not be detected in benign papillomas from these patients.