Sensitivity of digoxigenin and biotin labelled probes for detection of human papillomavirus by in situ hybridisation

The sensitivity of digoxigenin and biotin labelled DNA probes for the detection of human papillomavirus (HPV) by dot blotting and in situ hybridisation was compared in tissues from cervical, laryngeal, and anogenital neoplasia. Probes were either labelled with digoxigenin by the random primer technique and detected with anti-digoxigenin antibody, or labelled with biotin by nick translation and detected with streptavidin, both methods having a common final visualisation procedure using alkaline phosphatase. Digoxigenin labelled probes proved two to 10-fold more sensitive by quantitative dot blotting and four-fold more sensitive in detecting HPV 16 DNA in a series of 31 anal carcinomas, compared with biotinylated probes. The digoxigenin method also produced less non-specific background staining of tissue sections than biotin labelled probes. It is concluded that digoxigenin DNA labelling and detection provides a simple, reliable, and efficient alternative to the use of biotin or radioactive isotopes for the detection of HPV DNA by in situ hybridisation. Digoxigenin labelled probes also offer the possibility of double labelling in situ hybridisation procedures when used with biotin labelled probes to provide simultaneous identification of different DNA sequences.

Human papillomaviruses in anogenital warts in children: typing by in situ hybridisation

OBJECTIVE

To identify the types of human papillomaviruses found in anogenital warts in children and to relate these to clinical and social information.

DESIGN

In situ hybridisation using biotin labelled DNA probes to 11 types of human papillomavirus was performed on biopsy specimens from 17 children with anogenital warts.

SETTING

Nuffield department of pathology and the department of dermatology, Oxford.

PATIENTS

Children in one group were referred by general practitioners or paediatricians to the dermatology department, where biopsies were performed. The other children were seen in four different hospitals, and biopsy specimens were submitted to the laboratory at the physician's or pathologist's request.

RESULTS

Of the 17 biopsy specimens, 10 contained cells positive with a probe to a genital human papillomavirus type (types 6 or 11), while six were positive with a skin virus type (types 2 or 3). One was negative. The virus type present bore no relation to the site or appearance of the warts. The virus type did, however, appear to correlate with groups of children. Skin types were commoner in older children (over 4 years), in those with a relative who had skin warts, and in children with warts elsewhere; there was no relation with the child's sex and no suspicion of sexual abuse in these children. These circumstances suggested non-sexual transmission, such as autoinoculation. In contrast, genital types were commoner in girls, in children under 3 years, in children with relatives with genital warts, and in those with no warts elsewhere. Nevertheless, there was suspicion or evidence of sexual abuse in only half these children, suggesting that other routes of transmission--for example, perinatal--might have been implicated.

CONCLUSION

Anogenital warts in children may contain either skin or genital wart virus type. Although the type of human papillomavirus present may give some indication of the likely mode of transmission, this can be interpreted only in conjunction with all available clinical and social information. The type of virus does not provide proof of the presence or absence of sexual transmission.

Detection of human papillomavirus (HPV) in genital warts and carcinomas by DNA in situ hybridization in Chinese patients

A series of 51 genital biopsies from normal epithelium, condylomata acuminata, leucoplakia and squamous cell carcinoma from Chinese male and female patients were analysed for the presence of human papillomavirus (HPV) types 6, 11, 16 and 18 by DNA in situ hybridization. All of the nine genital condyloma acuminata were positive for HPV DNA, in which HPV 6 was found in six cases, HPV 11 in two cases and HPV 18 in one case. Twelve out of the 21 cases (57.1% of the total) of cervical squamous cell carcinoma were shown to contain HPV DNA; HPV 16 was found in nine cases, HPV 18 in two cases and HPV 16/18 in one case. Present results support the earlier concept that HPV 6/11 are closely associated with benign genital lesions, and HPV 16/18 are mostly confined to higher grade of intra-epithelial neoplasias and carcinoma.

The subtypes, distribution and location of human papillomavirus DNA in genital warts and genital Bowen's disease--a study using in situ DNA.DNA hybridization

The aim of this study is to investigate the difference in subtypes and distribution of human papillomavirus (HPV) between the benign pathological condition- Genital wart (condyloma acuminatum, verruca- like lesion and papular lesion) and genital Bowen's disease (Bowenoid papulosis, Mollucum contagiosum with Bowenoid papulosis and Condyloma acuminatum with verruca- like lesion and pathological bowenoid change) of genitalia by in situ DNA.DNA hybridization. In situ DNA.DNA hybridization was performed by hybridizing the RNAse treated and denatured frozen skin section with 3H-labeled HPV 6, 11, 16 and 18-DNAs probes and then developed autoradiogram on a glass slide. The results reveal that: (1) The benign cases are strongly associated with HPV 6/11, while the bowenoid cases are associated with HPV 16/18, indicating 16 positive in 24 cases and 3 positive in 5 cases respectively; (2) Four of sixteen benign cases were doubly infected with HPV 6/11 and 16/18; and 2 of 2 bowenoid cases were infected with HPV 16/18 only (3) In benign cases, HPV distributes through the upper third of epidermis and in bowenoid cases, HPV scatters throughout the whole epidermis including parabasal layers. These findings may indicate that the subtypes of HPV, the interaction of weak oncogenic virus (HPV 6/11) and strong oncogenic virus (HPV 16/18) and the presence of HPV on proliferating cells (parabasal layers) all play a part in oncogenicity. The detectability of HPV 6/11 DNA in both the nucleus and cytoplasm indicate that: 1). In situ DNA.DNA hybridization is a more sensitive method than the immunological detection of capsid antigen. 2). In addition to the nucleus, the cytoplasm is a site through which HPV 6/11 virus should pass during their life cycle. Using PEG hybridization mixture, it was revealed that 6 of the 6 HPV 6/11 positive condyloma acuminata harbored HPV 6. This result indicates that the subtype of HPV determine the gross morphology of skin lesion.

Papillomaviruses in anogenital cancer as a model to understand the role of viruses in human cancers

Infections with specific types of human papillomaviruses (HPV) have emerged as necessary but not sufficient factors for the development, at least, of the majority of cervical, vulvar, penile, and perianal cancers. Evidence has accumulated for their causal role in the induction of anogenital premalignant lesions. Genetic events underlying the mechanism of anogenital carcinogenesis have become increasingly understood. A host cell-mediated intracellular control down-regulating specific HPV genes (E6, E7) in replicating normal cells appears to be interrupted in cancer cells, probably due to structural modifications of the respective host cell genes acquired in the course of HPV DNA persistence. Since genital HPV infections are ubiquitous, cofactors which modify controlling host cell genes are likely to determine the different geographic rates of cervical cancer incidence.

Progesterone and glucocorticoid response elements occur in the long control regions of several human papillomaviruses involved in anogenital neoplasia

We have previously identified in the long control region of the genome of human papillomavirus type 16 (HPV-16) a DNA segment which functions as a cell-type-specific enhancer as well as mediating glucocorticoid response. It contains multiple transcription-factor-binding sites, including several for nuclear factor I and one for the glucocorticoid receptor, which binds to the partially palindromic sequence TGTACANNNTGTCAT. We report here that this sequence element, when separated from the surrounding transcription-factor-binding sites and placed as an oligonucleotide into a test vector, retains its function as a glucocorticoid response element (GRE) in HeLa cells. In T47D cells, which express the progesterone receptor, the HPV-16 enhancer fragment mediates progesterone responsiveness. A point mutant in this fragment and the response of the oligonucleotide clone to both steroids prove the identity of the progesterone response element (PRE) with the GRE. The antiprogesterone and antiglucocorticoid RU486 interferes with both hormonal responses. In SiHa cells, the HPV-16 GRE mediates an increase in transcripts encoding E6 and E7 proteins, which are involved in transformation by HPV-16. Hormonal regulation is not restricted to HPV-16: DNA segments containing the cell-type-specific enhancers of HPV-11 and HPV-18 also mediate glucocorticoid and progesterone response. We identified sequence elements in the long control regions of HPV-11 and HPV-18 which function as GRE/PREs when tested as oligonucleotides. These findings suggest that GRE/PREs are an integral part of gene expression regulation in genital HPVs.

Immunosuppression in men with bowenoid papulosis

The immune status of four men with bowenoid papulosis was evaluated. Each case had been refractory to multiple methods of treatment. Three of the men had other infections and demonstrated a depletion of T4-helper cells. Two of these patients were anergic on skin testing, and the third showed weak reactivity. The fourth patient, who had no evidence of additional infections, had a normal T4 value and T4/T8 ratio, but was anergic on skin testing. All the men were serologically negative for human immunodeficiency virus antibodies. One of the immunosuppressed patients developed squamous cell carcinoma of the tongue, which, along with his bowenoid papulosis, contained human papillomavirus 16 DNA. We suggest that patients with persistent bowenoid papulosis be investigated for altered immune status and followed up as potential candidates for the development of epithelial malignant neoplasms.

[Papillomavirus and cancer]

Papillomaviruses are causative agents of benign tumor (papilloma) and are widely distributed in most of animals. The papillomaviruses are small DNA viruses grouped in the papovavirus family. The genomes of all papillomaviruses pce double stranded circular DNA of approximately 8 K. base pairs. Classification of the viruses is presently based on the host range and relatedness of the nucleic acids. In the case of human papillomavirus (HPV), more than 50 types have been isolated. The amount of information about the HPV has grown considerably in the last few years, and at present it has been considered that the specific types of HPV are involved in the development of human genital cancer and the skin cancer developed in the patients with EV (epidermodysplasia verruciformis). The reasons are; i) Epidemiological evidence distinctly indicates that cervical carcinoma and other high-grade lesions of female and male genital tracts derive from a sexually transmitted disease. ii) Many cervical carcinomas, most cell lines derived from the carcinoma and almost all skin tumors of EV patient contain specific types of HPV DNA (genital tumors; HPV-16, 18, 31, 33 and 25, skin tumor of EV patient; HPV-5, 8, 17 and 20). Moreover, genetic information of the viruses can be detected in the cancer cells. iii) Follow-up studies of HPV carriers suggested that HPV-16, 18 have high oncogenic potential. iv) Oncogenic functions (transformation and immortalization) can be detected in the early genetic region of HPV-16 DNA. v) Cottontail rabbit papillomavirus (CRPV) induces tumor in rabbit (and that almost all of these tumors contain CRPV DNA. When rabbits are infected with CRPV, benign papillomas are induced in 100% of the rabbits and the lesion are progressed to skin cancer at the frequency of 40-60%). In human cases, however, the presence of specific types of HPV does not seem to be sufficient to assure the development of benign tumors into carcinomas, since only a part of all such cases progress after latent period of several to several ten years. This emphasizes that other etiological agents or cofactors must be involved.

Papillomaviruses in lesions of the lower genital tract in Israeli patients

Human papillomaviruses (HPVs) have been strongly associated with benign lesions of the genital tract (condylomata) and with genital cancer of the vulva and cervix. Since the incidence of these lesions in Israel is considered to be low, we have studied the presence of HPV 6, 11, 16 and 18 DNAs in benign, premalignant and malignant tissue samples or gynecological swabs of the lower genital tract. HPV sequences were detected in 48 out of 66 condylomatous lesions (72%), 5/11 grades I-II intraepithelial neoplasia (45%), 4/6 grade III intraepithelial neoplasia (carcinoma in situ) (66.6%) and 8/22 invasive carcinoma (36%). The latter included six cases of vulvar carcinoma which were all negative for HPV sequences. No additional HPV types could be detected in any of the tissue biopsies examined. HPV 18 DNA has been found in one vulvar condyloma where it persisted as an episomal molecule, this being the first report of that specific viral DNA in a condylomatous lesion. In all the benign and premalignant lesions containing HPV, the viral sequences were maintained in an episomal state. In two cases of invasive carcinoma, the HPV 16/18 related sequences were integrated in the cellular genome, but in five cases (three containing HPV 16/18 related DNAs and two containing HPV 6/11 related DNAs) the viral sequences were episomal. HPV 16/18 related sequences detected in one out of three cases of vaginal carcinoma were also found to be episomal. This data indicates that human papillomavirus sequences are indeed found in genital lesions of Israeli patients, although to a lesser extent than in other countries, especially for benign lesions and invasive carcinomas. Although HPVs may have a causative role in the development of genital lesions, also in this low tumor incidence area, other factors should be also considered in the etiology of these lesions.

Evaluation of methods for detecting human papillomavirus deoxyribonucleotide sequences in clinical specimens

Specimens from 26 condylomatous lesions, 24 invasive cancer cells, and 33 cervices, without evidence of the diseases, were tested for the presence of human papillomavirus (HPV) types 6, 11, 16, and 18 by Southern blot hybridization, in situ filter hybridization, or in situ tissue hybridization methods. A total of 89% (23 of 26) of the condylomatous lesions contained HPV DNAs, as determined by one or more of the methods. The positive rates for the detection of HPV DNA in condylomas by the different methods were 82% for Southern blot hybridization, 62% for in situ filter hybridization, and 72% for in situ tissue hybridization. Among the specimens from patients with cancer, HPV DNA was found in 83% (19 of 23) by one or more of the methods. Positive rates of 89 and 70%, respectively, were obtained for cancer lesions tested by the filter in situ and Southern blot hybridization methods; however, only 30% of those lesions were positive by the in situ tissue hybridization method. Thirteen percent of the control cervices were positive for HPV DNA by one or more of the assays. With respect to all disease categories, the methods had comparable sensitivities and specificities, except for the in situ tissue hybridization method, which revealed a specificity of 72% for condylomatous lesions and 30% for invasive cancer cells.

Anogenital warts of the condyloma acuminatum type in HIV-positive patients

Anogenital warts of the condyloma acuminatum type seem to occur quite often during HIV infection. These warts--according to our study--are not commonly caused by malignancy-associated human papilloma virus types, but by types 6 and 11 as seen in the nonimmune-compromised population. Widespread condylomata acuminata may appear in rather early stages of HIV infection and they may therefore represent early warning signs of HIV infection.

Herpes simplex virus and human cytomegalovirus: their role in morphological transformation and genital cancers

Herpes simplex virus (HSV) and human cytomegalovirus (HCMV) are candidates for the induction of premalignant or malignant disease. Morphological transformation studies have failed to demonstrate a viral oncogene, a virus-coded transforming protein or any sequence of DNA that uniquely transforms cells according to one-hit kinetics. Thus the mechanism of transformation is complex. The transformed cells are, however, all oncogenic in the host animal and in immunocompetent mice. Direct evidence for the presence of these viruses in human genital tumours is the finding that a small proportion (about 10%) retain fragments of virus DNA from different regions of the virus genomes. In contrast human papillomavirus (HPV) is strongly associated with genital neoplasia, being present in over 80% of tumours. However, HPV can also be detected in histologically normal tissue. The most persuasive roles for HSV and HCMV in human tumourigenesis are as mutagens, as activators of cellular transcription or in switching on the synthesis of host cell proteins not normally expressed in untransformed cells. In these roles the prospects of further defining roles for HSV and HCMV in the multistage process of oncogenic transformation are good.

Relationship of papillomaviruses to anogenital cancer

A variety of HPV types infect the anogenital mucosa, giving rise to lesions that differ in clinical appearance, histology, and their risk of malignant progression. HPV-16 is distinguished by a strong association with high-grade intraepithelial neoplasia and the greatest prevalence in anogenital malignancy. Most cancers appear to have a multifactorial etiology, and HPV infection alone is probably insufficient for malignant transformation. However, the consistent association between HPV infection and anogenital cancers emphasizes that the sexually transmitted papillomaviruses may have a necessary role in carcinogenesis. Hence, there is a prospect that vaccination programs may one day allow public health control of HPV infection, thereby eliminating an important risk factor.

In situ hybridization detection of human papillomavirus DNAs and messenger RNAs in genital condylomas and a cervical carcinoma

Routinely processed formalin-fixed paraffin-embedded sections from anogenital condyloma acuminatum and an invasive squamous cell carcinoma of the cervix were examined by in situ hybridization for the detection of human papillomavirus (HPV) DNAs and messenger RNAs. Asymmetric, single-stranded, tritium-labeled RNA probes for both the coding and the nonsense strands of HPVs 6, 11, 16, 18, and 31 were hybridized and washed under stringent conditions and detected by autoradiography. Type-specific HPV DNAs were detected with specific nuclear localization, while HPV messenger RNAs gave much higher signals and had clear-cut cytoplasmic localization. Cross-hybridization was observed only with closely related viruses. The level of signal obtained seemed to be linked to the degree of cellular differentiation, with koilocytotic cells labeling the most heavily. However, messenger RNA could be detected in even relatively undifferentiated cells within areas of dysplasia and invasive carcinoma. In situ hybridization is a sensitive and specific method for investigation of the dynamic interplay of papillomavirus replication and gene expression, cellular differentiation, and neoplastic transformation.

Genital tract papillomavirus infection in children

Genital tract papillomas in five children were examined for the presence of human papillomavirus (HPV) DNA by molecular hybridization. Papillomavirus DNA was detected in each sample and was identified as HPV-6 (three cases), HPV-6 or HPV-11 (one case), or HPV-16 (one case). These viruses are the same as are responsible for genital papillomas (condylomata) of adults. The transmission of adult genital tract viruses to children occurs primarily by a venereal route but may occur by a nonvenereal route.