Detection and localization of human papillomavirus in penile condylomas and squamous cell carcinomas using in situ hybridization with biotinylated DNA viral probes

Human papillomavirus (HPV) has been previously demonstrated in male genital neoplasms using Southern blot hybridization (SBH) and in situ hybridization with radiolabeled probes (ISH-R). In this study we used in situ hybridization with biotinylated DNA viral probes (ISH-B), a technique that can be applied to routinely collected and processed tissue. Thirty cases of exophytic penile condyloma acuminatum and nine cases of invasive squamous cell carcinoma of the penis were examined for the presence of HPV using ISH-B for HPV types 6, 11, 16, 18, 31, and 33. HPV DNA was found in 25 of 30 (83%) penile condylomas; HPV type 6 in 13 (43%); and HPV type 11 in 12 (40%). Slight cross-reactivity between HPV types 6 and 11 was noted. None of the condyloma cases was positive for HPV types 16, 18, 31, or 33. One of the nine patients with squamous cell carcinoma of the penis was positive for HPV 16. In situ hybridization with biotinylated DNA viral probes is a highly sensitive method for detecting and localizing HPV in penile condylomas. This method, however, may not be as sensitive as SBH for detecting HPV in invasive penile squamous cell carcinomas.     

Detection and typing of human papillomavirus in histologic specimens by in situ hybridization with biotinylated DNA probes

Eighty tissue biopsies from 73 women suspected of having papillomavirus (HPV) infection of the lower genital tract were examined by in situ hybridization with biotinylated DNA probes derived from the complete genomes of four HPV types (6, 11, 16, and 18) and restriction analysis of the extracted DNA on Southern blots. In a subset of 52 samples, the in situ test had a 90.4% sensitivity (47 of 52) in detecting the presence or absence of virus, whereas Southern blot analysis detected HPV with a sensitivity of 98.1% (51 of 52). For 51 samples, in which the viral type was determined by restriction analysis, comparison of the signals separately generated by the four probes after in situ hybridization allowed a correct identification of the infecting HPV type in 86.2% (44 of 51) of cases.     

Detection and localization of human papillomavirus DNA in human genital condylomas by in situ hybridization with biotinylated probes

We have examined the distribution of human papillomavirus (HPV) DNA in paraffin sections of humans warts by in situ hybridization with biotin-labeled DNA probes. Recombinant plasmid DNAs (HPV-1, -6, -11, -16) were labeled by nick translation with biotinylated deoxyuridine triphosphate. Paraffin sections were hybridized with the probes for 18 h in stringent or non-stringent conditions, and DNA-DNA hybrids were detected by immunocytochemistry. Paraffin sections of warts were also examined for the presence of HPV capsid antigen with the avidin-biotin peroxidase complex method for immunocytochemistry. HPV DNA was detected and localized in paraffin sections from a plantar wart, a laryngeal papilloma, and seven anogenital condylomas. The specific HPV type present in each lesion was determined by hybridization under stringent conditions with the homologous DNA probe. The papillomas were found to contain many more cells with replicating virus DNA, as demonstrated by in situ hybridization, than was apparent from the number of cells containing detectable virus antigen. In situ hybridization with biotin-labeled probes is an effective technique for the identification of HPV infection in routinely collected and processed tissue specimens.     

Detection of human papillomavirus DNA on routine Papanicolaou's smears by in situ hybridization with the use of biotinylated probes.

Specific human papillomavirus (HPV) types have been implicated as playing a major role in the development of cervical neoplasias. HPV DNA types usually have been identified by nucleic acid hybridization assays with the use of radiolabeled probes. These techniques are sensitive and specific but are not suitable for large-scale clinical use. To detect specific HPV DNAs simply and rapidly, in situ hybridization (ISH) with the use of biotinylated HPV DNA 6/11 and 16/18 probes was done on destained Papanicolaou's (Pap) smears from 545 patients. All smears showed koilocytotic changes. HPV DNAs were demonstrated not only in cervical intraepithelial neoplasia (CIN) and atypia, but also in squamous cells with minimal nuclear changes (karyomegaly) and perinuclear halos. HPV DNA 16/18 was detected in 52% of the smears with CIN I, 44% of those with CIN II and III, 19% of those with atypia, and 4% of the minimal changes. HPV DNA 6/11 was detected in 27% of the smears with CIN I, 27% of those with atypia, and 6% of the minimal changes. HPV DNAs were also detected in smears without koilocytotic changes. Thus, ISH with the use of biotinylated probes can serve as an adjunct to Pap smears in detecting HPV infection.     

Detection of human papillomavirus (HPV) DNA type 6/11 in a conjunctival papilloma by in situ hybridization with biotinylated probes.

Four cases of conjunctival papilloma in two different patients were examined by in situ hybridization for HPV DNA type 6/11, 16/18 and 31/33/51. Formalin-fixed and paraffin-embedded tissues were hybridized by biotinylated probes. One tumor and one of its recurrences showed nuclear positivity for HPV 6/11 in the superficial cells of the epithelium. The results suggest that HPV type 6/11 may be etiologic agent of conjunctival papillomas. The benign behavior of these neoplasms may be related to the etiologic role of this type of HPV.     

The use of polymerase chain reaction in generation of biotinylated human papillomavirus DNA probes for in situ hybridization.

The polymerase chain reaction (PCR) was used to produce biotin-labelled human papillomavirus (HPV) 16- and 18-specific DNA probes for in situ hybridization (ISH). PCR was performed by using Amplitaq DNA amplification reagent kit according to the manufacturer's instructions, except that dTTP was substituted by different concentrations of biotinylated dUTP (bio-11-UTP). As template DNA, DNA extracted either from CaSki or HeLa cells was used. The reaction mixture was taken through up to 40 cycles of amplification in a Perkin-Elmer Cetus Thermal Cycler. The highest yield was achieved when the concentrations of dTTP and biotinylated dUTP were 150 and 50 microM, respectively. ISH results compatible with those obtained with biotinylated whole genomic HPV DNA probes were demonstrated when primers from E7 and E6 ORF of the HPV-18 genome were used to produce the biotinylated probe by PCR. With HPV-16, several areas of the genome had to be amplified to generate a PCR probe with equal sensitivity as the whole genomic probe. The background staining was always stronger with the PCR probes than with the whole genomic probes. The sensitivity of the PCR probes does not seem to bear a clear-cut correlation with the size or nucleotide content of the probe, but it might rather depend on the three dimensional structure of the probe and the availability of biotin for the detection system by ISH.     

Influence of fixation on human papillomavirus DNA detection in frozen and embedded paraffin lesions by in situ hybridization with biotinylated probes.

Series of frozen or paraffin-embedded tissues from various body sites, taken from non-immunosuppressed or immunosuppressed patients with persistent papilloma lesions were examined for the presence of group specific antigen from human papillomavirus (HPV) by indirect immunofluorescence or HPV DNA by in situ hybridization with biotinylated probes. We have shown that it is possible to detect HPV DNA after fixation of tissues in neutral formalin, Bouin's or Baker's solution. However, the sensitivity was reduced as compared to frozen tissues. The HPV DNA was detected in nuclei of heavily infected epithelial cells such as plantar or hand warts or in dispersed cells containing high copy numbers of HPV DNA from lesions such as squamous cell carcinomas or keratoacanthomas. In premalignant or malignant lesions of both immunosuppressed or non-immunosuppressed patients, HPV DNA was rarely detected after fixation. HPV types commonly described for skin and genital samples were identified in non-immunosuppressed patients, whereas in transplant recipients oncogenic HPV type 16 was identified in benign warts as well as in premalignant or malignant lesions. Positive reactions with several HPV types were more frequent in lesions from grafted patients than from the normal population. Virus antigen was detectable more frequently in frozen sections than in fixed tissues. Our findings indicate that in situ hybridization is an appropriate and rapid technique to study the presence of HPV infection. However, numerous controls are needed to avoid misinterpretations.     

A comparison of methods for the detection of human papillomavirus DNA by in situ hybridization with biotinylated probes on human carcinoma cell lines. Application to wart sections

We compared nine different techniques for the detection of biotinylated DNA-DNA HPV hybrids on HeLa cells with 10-50 copies of HPV 18 DNA per cell. CaSki cells with 600 copies of HPV 16 DNA per cell and tissue sections from frozen or paraffin-embedded biopsy specimens. The cell samples were either cell deposits or cytocentrifuged or cultured slides. In most cases, the samples (cell deposits and tissue sections) were denatured with hybridization mixture prepared under stringent conditions (Tm = -17 degrees C) containing biotinylated DNA probes (cloned HPV types 1, 2, 6, 11, 16 and 18), at 90 degrees C for 10 min. In other cases (cytocentrifuged or cultured cells), the denaturation was performed by HCl hydrolysis and mild heating at 50 degrees C; the probes were denatured separately by heating. All the samples were further incubated overnight at 37 degrees C. For HPV DNA detection, three amplification levels were used on cell deposits. Only the techniques involving a three-step reaction (a rabbit anti-biotin antibody - a biotinylated goat anti-rabbit antibody - a complex of streptavidin-alkaline phosphatase or streptavidin-gold or streptavidin-fluorescein) gave satisfactory results, on both cell lines. With the one step reaction (an avidin-horseradish peroxidase, or streptavidin-alkaline phosphatase or streptavidin-fluorescein complex), no labeling of HeLa cells was observed with any of the HPV probes, including HPV 18. The techniques involving four steps (avidin or streptavidin - anti-avidin goat antibody or anti-streptavidin rabbit antibody - a biotinylated anti-goat (or anti-rabbit) antibody - a complex of avidin-biotin-peroxidase or streptavidin-biotin-alkaline phosphatase or streptavidin-biotin-horseradish peroxidase) resulted in high background on both cell lines. For the reproducible detection of low copy number of HPV DNA (less than 50 copies) such as occur in HeLa cells our data suggested that the three-step technique with the streptavidin-alkaline phosphatase complex was the method of choice. The most intense labeling was always obtained with cell deposits and the technique was successfully applied to frozen and paraffin-embedded tissue sections from typical warts.     

Detection of human papillomavirus type 16 DNA in cervical swabs and formalin-fixed, paraffin-embedded squamous cell carcinomas of non-genital tissues using a synthetic oligodeoxynucleotide probe

The potential of using a chemically synthesized oligodeoxynucleotide as a diagnostic probe to detect human papillomavirus type 16 (HPV-16) in genital infections was evaluated by comparing it with a cloned full-length HPV-16 probe in dot-blot DNA hybridizations. An oligonucleotide sequence, 20 bases in length from the E6 region of HPV-16 (E6 oligo) and different from the DNA sequences of HPV types 6, 11 and 18 by at least 2 base pairs, was chosen for chemical synthesis. The oligoprobe, which was 5'-end labelled with [32P]dATP, was found to be specific, but approximately ten times less sensitive than the full-length radiolabelled probe of HPV-16, in dot-blot hybridizations with the DNA of HPV-6, -11, -16 and -18, HPV positive and negative cell-lines. From 36 cervical or vulval scrapes two samples were found positive with both cloned HPV-16 and oligoprobe hybridization. Of 21 samples of formalin-fixed, paraffin-embedded squamous cell carcinomas originating from anus, oesophagus, penis, colon, breast and skin only 4 anal squamous cell carcinomas were positives when hybridized with cloned HPV-16 DNA or with the oligoprobe. This study confirms that HPV-16, which is frequently associated with squamous cell carcinoma of the cervix is also strongly associated with squamous cell carcinoma of the anus.     

In-situ hybridization using biotinylated DNA probes to human papillomavirus in adenocarcinoma-in-situ and endocervical glandular dysplasia of the uterine cervix.

In-situ hybridization using biotinylated probes to human papillomavirus (HPV) DNA was performed on formalin fixed paraffin embedded tissue in 30 patients with histologically confirmed adenocarcinoma-in-situ (AIS). Thirteen of the 30 cases contained areas of endocervical glandular dysplasia (EGD) admixed with AIS. Twenty one patients showed positive staining of the AIS nuclei for HPV DNA. Ten cases (33%) were positive for HPV 16 DNA and 11 cases (37%) were positive for HPV 18 DNA. No case showed synchronous expression of HPV 16 and 18 DNA. All cases of AIS were negative for HPV 6b and 11 DNA. Four cases of EGD were positive for HPV 18 DNA and 2 cases were positive for HPV 16 DNA. Four of 6 cases of intestinal dysplasia/AIS were positive for HPV 18 DNA. Associated squamous abnormalities (HPV +/- CIN +/- SCC) were noted in 15 cases. Of these, 7 showed positive staining for HPV DNA in the squamous lesion. Moreover, 5 of these were positive in both the AIS and squamous lesion. In-situ hybridization using biotinylated DNA probes is a sensitive and safe technique readily adaptable to routine histopathology.     

Detection of human papillomavirus type 6/11 DNA in conjunctival papillomas by in situ hybridization with radioactive probes

Twenty-three conjunctival papillomas and 28 conjunctival dysplasias were examined for human papillomavirus (HPV)-DNA sequences by in situ hybridization with nick-translated 35S-labeled HPV probes. Adjacent paraffin sections were hybridized with HPV type 2, 6, 16, and 18 probes at Tm - 17 degrees C. Fifteen tissues, all papillomas, displayed positive hybridization with the HPV-6 probe. Infection with HPV-6 (or the closely related HPV-11) appeared to be responsible for most of the conjunctival papillomas of children and young adults. The presence of genital tract HPV-6 in these lesions suggests that some of the infections were acquired during passage through an infected birth canal. The lack of hybridization in adult conjunctival dysplasias indicates either that HPVs are not associated with this condition or that the probes and the technique utilized were not adequate for demonstration of this association.     

Detection of human papilloma virus (HPV) DNA in genital biopsy specimens by in situ hybridization with digoxigenin-labeled probes

The presence of human papillomavirus (HPV) nucleotide sequences in paraffin sections of genital biopsies was examined by in situ hybridization using non-isotopic, digoxigenin-labeled probes representing HPV types 11, 16 and 18. Digoxigenin-labeling of the probes was performed using DNA labeling and a commercially provided detection kit. Hybridization was performed under stringent conditions. The hybrids were detected by using anti-digoxigenin alkaline phosphatase conjugate and visualized with enzyme catalyzed color reaction. In situ hybridization with digoxigenin-labeled probes was a useful technique for identification of HPV infection. The results were compared with the results obtained with radiolabeled DNA probes. The sensitivity of the digoxigenin-labeled probes was equal to the sensitivity of the radiolabeled probes. The background with digoxigenin-labeled probes was very low. Using nonradioactive probes the localization of hybrids at the cellular level was better than 35S-labeled probes.     

In situ hybridization analysis of human papillomavirus in anal squamous cell carcinoma

To investigate the association between human papillomavirus (HPV) infection and anal carcinoma, we applied a sensitive in situ hybridization technique to detect HPV messenger RNA (HPV m-RNA) in formalin-fixed, paraffin-embedded sections from 18 patients. Using tritium-labeled probes, HPV m-RNA was detected in 12/18 (67%) patients. HPV 6 was detected in four patients, coexisting with HPV 18 in two cases, and HPV 16 was found in eight patients. In six patients, hybridization failed to demonstrate the presence of HPV. With respect to histology, HPV 6 was detected in 1/4 cases of well differentiated invasive squamous cell carcinoma. Ten of thirteen moderately or poorly differentiated invasive squamous cell carcinomas demonstrated HPV m-RNA (HPV 16, eight cases; HPV 6, one case; HPV 6 and 18, one case). HPV 31 was not detected in any specimens. These results suggest that HPV infection may play an important role in the pathogenesis of anal carcinoma.     

Detection of human papillomavirus DNA in gynaecological swabs by filter in situ hybridization.

Gynaecological smears from the endo- and ectocervix of women with and without cytological and colposcopic abnormalities of the epithelium were investigated for human papillomavirus (HPV) types 6, 11, 16, and 18 by filter in situ hybridization (FISH). The data were compared with cytological, colposcopic, and histological findings. Of the 266 gynaecological smears, HPV DNA was detected in 84 (32%); of 101 cytologically and colposcopically HPV negative cases, HPV DNA was found in 10%. Of 56 women, cytologically and colposcopically positive for HPV infection, HPV DNA was detected in 68%. The sensitivity of the method was controlled by comparing the results of FISH with those of Southern-blot analysis of five cervical tumour biopsies. The data presented demonstrate the necessity of FISH for identification of the HPV type that might be of prognostic value in cervical pathology. Cytological and colposcopic positivity is a reliable sign in about 70% of the cases where HPV infection was proved by FISH.     

Sensitivity of in situ hybridization techniques using biotin- and 35S-labeled human papillomavirus (HPV) DNA probes

In order to evaluate the sensitivity of our modified in situ DNA hybridization technique using biotinylated probes, formalin fixed, paraffin embedded biopsies from 20 cervical lesions known to contain human papillomavirus (HPV) DNA were re-examined by the technique using both 35S-labeled- and biotinylated HPV DNA probes. The probe concentrations as well as the detection limits of biotin probing were screened by spotting known amounts of HPV 16 DNA on nylon filter, and allowed to hybridize with biotinylated HPV 16 DNA probe. By this method, 4 pg of HPV 16 DNA could be detected using a probe concentration of 0.2 micrograms/ml. HPV DNA could be demonstrated in all 20 biopsies with both hybridization techniques. However, signals in subrabasal cells were detected more frequently with biotin- than with 35S-labeled probes. Additional experiments were performed using three cervical cancer cell lines (with known copy numbers of HPV DNA), to assess the detection limits of HPV infections by the in situ hybridization techniques. The CaSki cells (500-600 HPV 16 copies/cell) were unequivocally positive with both labelling systems. HeLa cells (10-50 HPV 18 copies/cell) were positive with the biotin probing in 10/10 smears, as compared to 7/10 smears when 35S-labeled probes were used. Radioactive probing was inferior to biotinylated probing in detecting the signals in SiHa cells (1-2 HPV 16 copies/cell). This is because even weak background signals could mask true positive signals when 35S-labeled probes are used. In contrast, no background is generated with the biotinylated probes, detected with streptavidin-biotinylated alkaline phosphatase complex. In situ hybridization with biotinylated DNA probes is as sensitive as techniques using 35S-labeled probes for detecting HPV infections in routine cervical biopsies or smears.     

Oncogene expressions detected by in situ hybridization of squamous metaplasia, dysplasia and primary lung cancer in human

In order to elucidate the dynamic changes of oncogene expression in the sequential cascade of squamous metaplasia, dysplasia, and squamous cell carcinoma of the bronchial epithelium, hybridization in situ was employed with a biotinylated oncogene probe. The expression of c-myc was localized exclusively in nuclei. While normal bronchial epithelium revealed no discernible clumps of c-myc grains, except occasional grains less than 3 per cell, squamous metaplasia showed increased number of grains and a few clusters of c-myc grains. In dysplasia, c-myc expression was more intensive than in squamous metaplasia. Approximately, 1/3 to 2/3 of tumor cell populations of squamous cell carcinomas of the lung revealed tremendously increased c-myc expression. In addition clumpy grains of c-myc in squamous cell carcinoma appeared more frequently than in squamous metaplasia or dysplasia. The c-myc expression was found to vary between different samples and within each cancer, and not all cancer cells expressed c-myc. These data indicate that c-myc oncogene plays it's role on reprogramming for growth control of cell populations particularly in multistage carcinogenesis and progression of lung cancer. These dynamic alterations of c-myc expression suggest that neoplastic transformation may occur conceivably at the dysplastic phase eventually resulting in carcinoma in situ. This means, in turn, squamous dysplasia is a putative precancerous lesion of the human lung.     

Sensitivity of in situ detection with biotinylated probes of human papilloma virus type 16 DNA in frozen tissue sections of squamous cell carcinomas of the cervix.

The sensitivity of human papilloma virus type 16 (HPV-16) DNA detection by DNA in situ hybridization using biotinylated probes (bio-DISH) was estimated by performing this technique on snap-frozen tissue sections of 10 cervical squamous cell carcinomas containing increasing amounts of HPV-16 as determined by Southern blot hybridization. A protocol using serial sections for bio-DISH and DNA extraction was used. The number of positively stained cells and the detection limit were strongly dependent on the treatment of the sections with proteinase K prior to hybridization. At low proteinase K concentration (0.1 micrograms/ml), the detection limit appeared to be 30-40 HPV-16 DNA copies per carcinoma cell, whereas morphology was preserved. A high proteinase K concentration (1-5 micrograms/ml) often resulted in an increase in the number of positively stained cells but also in a poor morphology. The detection limit was improved to at least 20 HPV-16 DNA copies per carcinoma cell.     

Molecular cytogenetic analysis of two primary squamous cell carcinomas of the lung using multicolor fluorescence in situ hybridization

To fully characterize the numerous chromosomal aberrations in two human squamous cell carcinomas (SCCs) of the lung, molecular cytogenetic characterization was carried out utilizing conventional banding analysis and multicolor fluorescence in situ hybridization (mFISH), providing simultaneous color discrimination of all 24 human chromosomes. Both tumors displayed complex aneuploid karyotypes with a host of numerical and structural chromosome abnormalities. Structural aberrations common to both SCCs included rearrangements of chromosomes 1, 3p, 7q, and 8q, contributing to net loss of chromosomal sequences on 1p, 3p, and 8p, and a net gain of 8q. The recently introduced mFISH technique enabled the disclosure of cryptic translocations and the chromosomal composition of previously unrecognized marker chromosomes. Furthermore, mFISH greatly enhanced the ability to delineate chromosomal breakpoints when integrating banding information from conventional banding analysis. Eventually, the application of mFISH as a powerful approach to refine complex tumor karyotypes is expected to result in a more detailed and complete picture of cytogenetic events associated with the development and progression of solid tumors.     

Detection of human papillomaviruses in squamous cell carcinomas of the lung

 The aim of this study was to evaluate the possible association of human papillomaviruses (HPV) with the development of squamous cell lung carcinomas (SqCLCs). Tissue material from 52 cases of SqCLCs were studied, and the data were evaluated according to the degree of differentiation, HPV presence and type. Analysis was performed by polymerase chain reaction (PCR) method using consensus primers, and the results were confirmed by subsequent Southern blot hybridization. Overall, the results showed 69% positivity (n=32). Forty-one cases were examined for the presence of specific HPV types (6/11 and 16/18) by hybridization of the PCR products with ³²P-labelled probes. HPV 6/11 types were detected in 6 of the 29 positive cases (20.6%). HPV 16/18 types were the most prevalent types, and were detected in 11/29 cases (37.9%: 4/10 of well-differentiated cases, 6/25 of moderately and 1/6 of poorly differentiated carcinomas). Our results confirm the possibility that HPV might play a role in the development of SqCLCs and suggest a possible relation of high-risk HPV16/18 types to tumour differentiation. Received: 3 June 1997 / Accepted: 9 February 1998     

Human papillomavirus DNA determination of anal condylomata, dysplasias, and squamous carcinomas with in situ hybridization

Infection with types 6, 11, 16, and 18 of the human papillomavirus (HPV) is associated with condylomatous, dysplastic, or carcinomatous changes in the genital tract. Emerging evidence suggests that a similar series of lesions develops in the anal canal after exposure to the same HPV types. In situ hybridization was performed with the use of biotinylated DNA probes to HPV 6, 11, 16, and 18, so as to determine the frequency of HPV DNA in 45 perianal and/or anal condylomata, 6 anal intraepithelial neoplasias, and 13 anal squamous cell carcinomas. Of the 33 perianal and/or anal condylomata in which HPV DNA was detected, 13 contained HPV 6 and 11, 12 HPV 6, 7 HPV 11, and 1 HPV 6, 11, and 18. Two of four severe anal dysplasias contained HPV 16, whereas one case each of mild and moderate anal dysplasia contained HPV 6. No HPV DNA was detected in the anal squamous cell carcinomas. The study demonstrated the presence of HPV DNA in 73% of condylomata and 67% of anal dysplasias. The observations suggest that the cloacogenically derived anal epithelium is susceptible to infection by the same HPV types as infect the similarly derived epithelium of the lower female genital tract and that these HPV types result in some similar lesions, i.e., condylomata and dysplasias in both sites. A role in the genesis of anal cancer was not found in this study.