Signal-amplified colorimetric in situ hybridization for assessment of human papillomavirus infection in cervical lesions

Superinfection Exclusion between Two High-Risk Human Papillomavirus Types during a Coinfection

Superinfection exclusion is a common phenomenon whereby a single cell is unable to be infected by two types of the same pathogen. Superinfection exclusion has been described for various viruses, including vaccinia virus, measles virus, hepatitis C virus, influenza A virus, and human immunodeficiency virus. Additionally, the mechanism of exclusion has been observed at various steps of the viral life cycle, including attachment, entry, viral genomic replication, transcription, and exocytosis. Human papillomavirus (HPV) is the causative agent of cervical cancer. Recent epidemiological studies indicate that up to 50% women who are HPV positive (HPV⁺) are infected with more than one HPV type. However, no mechanism of superinfection exclusion has ever been identified for HPV. Here, we show that superinfection exclusion exists during a HPV coinfection and that it occurs on the cell surface during the attachment/entry phase of the viral life cycle. Additionally, we are able to show that the minor capsid protein L2 plays a role in this exclusion. This study shows, for the first time, that superinfection exclusion occurs during HPV coinfections and describes a potential molecular mechanism through which it occurs.IMPORTANCE Superinfection exclusion is a phenomenon whereby one cell is unable to be infected by multiple related pathogens. This phenomenon has been described for many viruses and has been shown to occur at various points in the viral life cycle. HPV is the causative agent of cervical cancer and is involved in other anogenital and oropharyngeal cancers. Recent epidemiological research has shown that up to 50% of HPV-positive individuals harbor more than one type of HPV. We investigated the interaction between two high-risk HPV types, HPV16 and HPV18, during a coinfection. We present data showing that HPV16 is able to block or exclude HPV18 on the cell surface during a coinfection. This exclusion is due in part to differences in the HPV minor capsid protein L2. This report provides, for the first time, evidence of superinfection exclusion for HPV and leads to a better understanding of the complex interactions between multiple HPV types during coinfections.

Pre-vaccine era cervical human papillomavirus infection among screening population of women in west Austria

Background

In order to evaluate the newly implemented gender-neutral HPV vaccination program, knowledge on the pre-vaccine prevalence of HPV infection is of paramount importance. Data on HPV infection among the women with no known previous cytological abnormalities are inexistent in Austria. This study presents data on the prevalence and distribution of HPV genotypes among women with no known cytological abnormalities in west Austria.

Methods

Women between 18 and 65 years of age attending annual cervical cancer screening examinations were included in the study. Data on socio-demographic and reproductive factors were collected using structured questionnaires. Corresponding cervical swab samples were tested for the presence of HPV DNA and were genotyped. Questionnaire data and HPV status were linked with the corresponding cytological findings.

Results

A total of 542 women were included in the study. The mean age of the study participants was 35.9 (SD = 11.5). The prevalence of HPV infection was 20.5 %. HPV 16 (6.5 %), HPV 33 (3.3 %) and HPV 31 (3.0 %) were the dominant genotypes detected. Multivariate analysis showed that women younger than 30 years of age, smokers, women with a higher number of lifetime sexual partners and those living in the eastern districts of the study region were at significantly higher risk of HPV infection.

Conclusions

With this study we present the first data on the prevalence of cervical HPV genotypes among a screening population in Austria. The results not only fill the missing information on HPV infection in this group of women in the country, they also provide baseline data for a future evaluation of the impact of the Austrian gender-neutral HPV immunization program. Moreover, our finding of higher HPV prevalence in the eastern compared to the western district of the study region may – at least partly – explain the east–west gradient in the standardized incidence rate of cervical cancer in the region.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3581-0) contains supplementary material, which is available to authorized users.

A clinicopathological study of episomal papillomavirus infection of the human placenta and pregnancy complications

Viral infections are known to adversely affect pregnancy, but scant attention has been given to human papilloma virus (HPV) infection. We aimed to determine the molecular and histopathological features of placental HPV infection, in association with pregnancy complications including fetal growth restriction, pre-maturity, pre-eclampsia, and diabetes. Three hundred and thirty-nine placentae were selected based on the presence or absence of pregnancy complications. Five independent methods were used to identify HPV in the placenta, namely, immunohistochemistry for L1 viral capsid, in situ hybridization to high-risk HPV DNA, PCR, western blotting, and transmission electron microscopy. Pregnancy complications and uterine cervical smear screening results were correlated with placental HPV histopathology. In this study, which was deliberately biased towards complications, HPV was found in the decidua of 75% of placentae (253/339) and was statistically associated with histological acute chorioamnionitis (P<0.05). In 14% (35/253) of the HPV positive cases, HPV L1 immunoreactivity also occurred in the villous trophoblast where it was associated with a lymphohistiocytic villitis (HPV-LHV), and was exclusively of high-risk HPV type. HPV-LHV significantly associated with fetal growth restriction, preterm delivery, and pre-eclampsia (all P<0.05). All cases of pre-eclampsia (20/20) in our cohort had high-risk placental HPV. A further 55 cases (22%, 55/253) of HPV positive placentae had minimal villous trophoblast HPV L1 immunoreactivity, but a sclerosing pauci-immune villitis, statistically associated with diabetes (49.1%, 27/55, P<0.05). For women with placental HPV, 33% (69/207) had an HPV-related positive smear result before pregnancy compared with (9.4% 8/85) of women with HPV-negative placentae (P=0.0001). Our findings support further investigations to determine if vaccination of women and men will improve pregnancy outcomes.

A new colorimetric peptide nucleic acid-based assay for the specific detection of bacteria

AIM

Developments on synthetic molecules, such as peptide nucleic acid (PNA), make FISH procedures more robust for microbial identification. Fluorochromes use might hinder a broader implementation of PNA-FISH, but colorimetric applications are inexistent so far.

METHODS

A biotin-labeled eubacteria probe was used to develop a colorimetric PNA-in situ hybridization (ISH) assay. An enzymatic-conjugate, targeting biotin, was introduced. The procedure was optimized and evaluated regarding sensitivity, specificity and detection limit.

RESULTS

RESULTS have shown strong ISH signals. The method was specific, but permeabilization problems were observed for Gram-positive bacteria. Detection limit was 5 × 10(7) CFU/ml, limiting current applications to pre-enriched samples.

CONCLUSION

The PNA-ISH procedure described here is a simple alternative to other detection methods, and is also the base for the development of other PNA colorimetric systems.

Computerized delineation of nuclei in liquid-based pap smears stained with immunohistochemical biomarkers

BACKGROUND

Infection with high-risk human papillomaviruses (hrHPVs) is a frequent cause of cervical intraepithelial neoplasias and carcinomas. The recently developed p16/Ki67 dual stain of cytologic preparations possesses superior specificity over current HPV testing for detecting moderate- and high-grade dysplasias and can potentially be applied in routine cytology screening. Image analysis can possibly improve the efficiency of evaluating Papanicolaou (Pap) smears, if dual-stained nuclei are accurately localized and reliably distinguished from the background of other cells.

METHODS

Here, we describe a technique comprising color deconvolution, radial symmetry detector, and a superpixel-based segmentation for computerized delineation of nuclei in Pap smears stained with p16/Ki67.

RESULTS

The performance of the method was determined by the precision and recall in 99 images (n = 19,323 cells) and reached 0.952 and 0.958, respectively. The accuracy of delineation, assessed by the Jaccard index (n = 1,080 cells), was 0.794. In single cells the precision and recall was higher than in clumps (P = 0.005).

CONCLUSIONS

In summary, the new technique delineates large and small nuclei irrespectively of coloration with a significantly better performance than a method solely involving the radial symmetry detector. Therefore, it is suited to automatically define nuclear areas for quantification of nuclear biomarkers in smears.

P16INK4A immunohistochemistry for detection of human papilloma virus-associated penile squamous cell carcinoma is superior to in-situ hybridization

We evaluated p16INK4A as a reliable option to detect human papilloma virus (HPV) DNA in penile tumor specimens. Formalin-fixed paraffin embedded samples of 26 patients with penile cancer and another 18 cases with non-tumorigenic lesions were stained by three different widely used commercially available chromogenic in-situ hybridization assays high-risk HPV CISH Y1443 (Genpoint, DAKO), pan HPV CISH Y1404 (Genpoint, DAKO), INFORM HPV III (Ventana, Tucson, Arizona) and p16INK4A immunohistochemistry, then compared to the known gold standard polymerase chain reaction detecting HPV 16, 18, 31, and 33. Immunoreactivity for p16INK4A was evaluated by using a 4-tiered (0, 1, 2, and 3) pattern based system. 19 cases were positive for p16INK4A, 13 of which showed a continuous transepithelial staining (pattern 3). Pan HPV ISH showed positivity in 9 cases, high-risk HPV ISH in 7 cases and INFORM HPVIII ISH in 7 cases. p16INK4A IHC pattern 3 versus pattern 0, 1 and 2 exhibited a specificity and positive predictive value of 100 percent, with a sensitivity and negative predictive value of 72 and 62 percent, respectively, which was much better than all HPV in-situ hybridization methods referred to polymerase chain reaction. p16INK4A seems to be a superior marker for the detection of HPV-associated penile squamous cell carcinoma compared to CISH tests, but is not recommend for the detection of non-tumorigenic lesions, where PCR should be used for the initial assessment.

High-Risk Human Papillomavirus DNA Detected in Primary Squamous Cell Carcinoma of Urinary Bladder

Context.—We reported previously that more than one-third (37%) of primary bladder squamous cell carcinomas (SCCs) demonstrate diffuse p16 immunoreactivity independent of gender. This observation made us question whether p16 overexpression in bladder carcinoma is due to human papillomavirus (HPV)–dependent mechanisms.

Objectives.—To determine whether the presence of high-risk HPV (HR-HPV) DNA could be detected in these tumor cells.

Design.—Fourteen cases of primary bladder SCC, which were positive for p16 by immunohistochemistry, were probed for the detection of HR-HPV by in situ hybridization and the signal amplification Invader assay. Samples positive for detection of HR-HPV by Invader assay were amplified by using HR-HPV type-specific primers, and amplification products were DNA sequenced.

Results.—Detection of HR-HPV by the in situ hybridization method was negative in all cases (0 of 14). However, in 3 of 14 cases (21.4%), the presence of HR-HPV DNA was detected with the Cervista HPV HR Invader assay, which was followed by identification of genotype. All positive cases were confirmed by using HR-HPV type-specific amplification followed by DNA sequencing. Identified HR-HPV genotypes included HPV 16 (2 cases) and HPV 35 (1 case).

Conclusions.—High-risk HPV DNA is detectable in a subset of primary bladder SCCs. Based on the well-documented carcinogenic potential of HR-HPV, there is a necessity for additional studies to investigate the role of HR-HPV in bladder carcinogenesis.

Characterization and enzyme-conjugation of a specific anti-L1 nanobody

Persistent infection of the human papillomaviruses (HPV) has been shown to result in cervical cancer and intraepithelial neoplasia. Early detection and screening programs are essential strategies against cervical cancer. A nanobody is the smallest antigen-binding fragment known and is derived from a camelid heavy-chain antibody. This tiny protein shows high solubility and stability. It can be produced cost-effectively with high yield production. In this study, we enriched a nanobody library against the L1 protein of HPV. Several colons were selected from this enriched library using monoclonal phage-enzyme linked immunosorbent assay (phage-ELISA) and analyzed for identification of nanobody genes. The expression of nanobody fragments was performed in Rosetta gami2. The C74 nanobody that showed strong binding to the L1 protein of HPV16 was selected, purified, and characterized by Western blotting and ELISA. The selected nanobody was tested for sensitivity, specificity, and affinity. A nanobody conjugated to horseradish peroxidase (HRP) was selected and used for detection of L1 protein of HPV16. This study demonstrates that the C74-HRP, due to its specificity and good binding affinity for a specific viral antigen, is a potential diagnostic tool that can be used as a promising reagent for the new generation of HPV diagnosis approaches.

Biomarkers of cervical dysplasia and carcinoma

Although cervical cytology screening has decreased the incidence of cervical cancer in industrialized countries, HPV-related cervical disease, including premalignant and malignant lesions, continues to represent a major burden on the health care system. Some of the problems include the potential for either under- or overtreatment of women due to decreased specificity of screening tests as well as significant interobserver variability in the diagnosis of cervical dysplastic lesions. Although not completely elucidated, the HPV-driven molecular mechanisms underlying the development of cervical lesions have provided a number of potential biomarkers for both diagnostic and prognostic use in the clinical management of these women.

Survival of patients with HPV-positive oropharyngeal cancer after radiochemotherapy is significantly enhanced

BACKGROUND

The purpose of this study was to evaluate the incidence and clinical significance of HPV (Human papilloma virus) infection in patients with head and neck cancer who had received radiotherapy in Eastern Austria.

PATIENTS AND METHODS

88 patients with head and neck cancer including 26 patients with oral cavity cancer, 45 patients with oropharyngeal cancer, seven patients with laryngeal carcinoma and ten patients with carcinoma of the hypopharynx were screened for high risk HPV by immunohistochemistry, PCR (Polymerase Chain Reaction) and in-situ hybridization. 29 out of 45 patients with a squamous cell carcinoma of the oropharynx received radiotherapy alone, radiotherapy in combination with cisplatin or cetuximab.

RESULTS

Of the investigated 29 patients with oropharyngeal cancer receiving conservative treatment, 11 had a HPV-positive and 18 a HPV-negative tumor. Patients received radiation ± cisplatin or cetuximab, where the HPV-positive patients had a significant better response to treatment and overall survival (p = 0.015) as well as disease-free survival (p = 0.001) after therapy.

CONCLUSION

Patients with oropharyngeal carcinoma and a positive HPV status respond considerably better to radiochemotherapy than patients with HPV-negative tumors. HPV screening is a simple procedure and can easily be implemented in routine pathology investigations and should be included in standard operational procedures for the diagnosis and therapy of head and neck cancer patients.

Detection of HPV by in situ hybridization in thin-layer (ThinPrep) cervicovaginal samples

We have studied an automated in situ hybridization (ISH) method as a possible alternative approach for detecting high-risk human papillomavirus (HPV) in monolayer (ThinPrep) cervico-vaginal samples, comparing the results with those obtained by polymerase chain reaction (PCR) using consensus primers and studying the relationship between the ISH staining pattern and the viral integration in HPV 16-positive cases. Eighty atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cases were used for our purposes. The patients were monitored through periodic cytologies. ISH with was performed with an automated Ventana System, analysis by PCR was performed with consensus primers and integration of HPV16 was performed by realtime PCR analyzing E2 and E6 genes. Additionally, 27 HSIL cases were also studied to observe the ISH staining patterns. HPV infection was detected by ISH in 21.7% of the ASCUS cases and 55.8% of the LSIL cases. Two distinct staining patterns were observed: multipunctated (MP) and diffuse (DI). In some cases, a mixed pattern (MP + DI) was observed and these cases were considered as MP. The MP pattern increased with the degree of lesion and seemed to have a prognostic value in ASCUS/LSIL cases. The lesion in MP pattern cases persisted throughout the entire study in 77% of cases, whereas in cases with a DI staining pattern, only 41% of them showed persistence of the lesion (p <0.001). No correlation was found between HPV integration and the ISH staining pattern. Given the lower sensitivity and negative predictive value of ISH and its incapacity to demonstrate the integration of high-risk HPV in ASCUS and LSIL cases using liquid-based cytology, we do not recommend this technique for the triage of ASCUS and LSIL cases.

Evaluation of two commercialised in situ hybridisation assays for detecting HPV-DNA in formalin-fixed, paraffin-embedded tissue

INTRODUCTION

The role of human papilloma virus (HPV) in the pathogenesis of anogenital dysplasia is now conclusive. However, HPV detection in formalin-fixed and paraffin-embedded tissues remains controversial. Therefore, the aim of this study was to evaluate morphological changes directly in tissue specimens using a HPV-DNA detection system involving HPV in situ hybridisation.

MATERIALS AND METHODS

Samples from patients with cervical carcinoma were analysed using the GenPoint HPV DNA Probe Cocktail (Dako, Glostrup, Denmark) and the ZytoFast HPV Screening CISH-Kit (Zytomed, Berlin, Germany). Three cervical carcinoma cell lines with a well-defined HPV copy number per cell (SiHa, HeLa, and CaSki) served as positive controls for sensitivity testing, while two HPV-negative cell lines (AC-1M32, MCF-7) and brain tissue samples served as negative controls. Moreover, to assess the validity of the in situ hybridisation, the expression of HPV-16 DNA in cell lines was demonstrated by HPV-16 E6-specific PCR.

RESULTS

Both HPV-screening assays revealed strong signals of episomal and integrated HPV-DNA at a HPV copy number of more than 50 copies/cell. All cervical carcinoma samples were positive in the Dako assay, which identifies 13 high-risk HPV genotypes, whereas HPV-DNA could be detected in 9/10 cervical carcinoma samples using the Zytofast assay, identifying HPV 16, 18, 31, 33, and 35.

CONCLUSION

HPV in situ hybridisation is a convenient and powerful tool for detecting HPV-DNA in formalin-fixed and paraffin-embedded tissue samples. Therefore, this technique is suitable for analysis of a potential HPV infection using archival pathological slides.

Diagnostic value of p16INK4A, Ki-67, and human papillomavirus L1 capsid protein immunochemical staining on cell blocks from residual liquid-based gynecologic cytology specimens

BACKGROUND

This study was conducted to evaluate the reliability and role of cell block preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix and to improve the value of cell block preparations in diagnosing and predicting the prognosis of cervical lesions through immunostaining of p16INK4A (p16), Ki-67, and human papillomavirus (HPV) L1 capsid protein (HPV L1).

METHODS

In total, 138 specimens were diagnosed on liquid-based cytology (LBC) and cell block preparations, and 63 specimens were subjected subsequently to tissue follow-up and immunostaining for p16, Ki-67, and HPV L1 on cell block sections.

RESULTS

In 42 specimens that were diagnosed as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma (SCC) on cell blocks, 38 specimens (90.5%) were confirmed by histopathologic reports, and there was slightly better than 81.6% agreement between LBC and tissue follow-up. Immunointensity and cells that were positive for p16 were enhanced according to increased pathologic grade and differed statistically between cervical intraepithelial neoplasia 1 (CIN-1) and CIN-2/CIN-3 as well as SCC. The positive rates of HPV L1 decreased gradually according to the severity of cervical neoplasia, and HPV L1/p16 expression patterns were related to the severity of cervical lesions.

CONCLUSIONS

The cell block preparation technique was complementary to LBC, and the authors concluded that the application of LBC combined with cell block preparations may improve the diagnostic accuracy of cytology. Immunostaining for p16 and Ki-67 on cell block preparations can help to improve the diagnostic accuracy of HSIL and SCC. A combined expression pattern of p16 and HPV L1 may serve as a valuable index for predicting prognosis and follow-up of cervical dysplastic lesions.

Prevalence of cervical neoplastic lesions and Human Papilloma Virus infection in Egypt: National Cervical Cancer Screening Project

Background

Data from Egyptian studies provide widely varying estimates on the prevalence of pre-malignant and malignant cervical abnormalities and human papilloma virus (HPVs) infection. To define the prevalence and risk factors of pre-invasive and invasive cervical cancer (cacx), a community based full-scale cross sectional, household survey including 5453 women aged between 35 and 60 years was conducted.

Methods

The study period was between February 2000 and December 2002. Initially, conventional Papanicolaou (Pap) smears were evaluated using the Bethesda system (TBS), followed by colposcopic guided biopsy (CGB) for all epithelial abnormalities (EA). In a third step, HPV was tested on all EA by in-situ hybridization (ISH) using first the broad spectrum HPV probe recognizing HPVs 6, 11, 16, 18, 30, 31, 35, 45, 51 and 52 followed by subtyping with probes 6/11, 16/18 and 31/33. Lastly, unequivocal cases were immunostained for herpes simplex type-2 (HSV-2), cytomegalovirus (CMV), and human immunodeficiency virus (HIV).

Results

EA representing 7.8% (424/5453), were categorized into atypical squamous cell of undetermined significance (ASCUS) (34.4%), atypical glandular cell of undetermined significance (AGCUS) (15.3%), combined ASCUS and AGCUS (3.1%), low grade squamous intraepithelial lesions (SIL) (41.0%), high grade SIL (5.2%) and invasive lesions (1%). CGB of EA (n = 281) showed non neoplastic lesions (12.8%), atypical squamous metaplasia (ASM) (19.2%), cervical intraepithelial neoplasia I (CIN) (44.4%), CIN II (4.4%), CINIII (2.8%), endocervical lesions (5.2%), combined squamous and endocervical lesions (10.0%), invasive squamous cell carcinoma (SCC) (0.02%) and extranodal marginal zone B cell lymphoma (MZBCL) (0.02%). The overall predictive value of cytology was 87% while the predictive value for high grade lesions was 80%. On histological basis, HPVs were present in 94.3% of squamous lesions while it was difficult to be identified in endocervical ones. ISH revealed positivity for pan HPV in 65.9% of the studied biopsies (n = 217), with incorporation of the viral genome HPV 6/11, 16/18 and 31/33 in 11.1%, 33.3% and 17.1% respectively. Multiple HPVs infections were identified in 0.02%.

Conclusion

Pre-invasive high grade lesions and invasive cervical carcinoma represent 0.5% and 0.04% respectively in Egyptian women. HPV mostly 16/18 as a risk factor (p < 0.001), was frequently associated with mixed infections (p < 0.001) and bilharzial infestation (p < 0.001).

Lobular endocervical glandular hyperplasia as a presumed precursor of cervical adenocarcinoma independent of human papillomavirus infection

OBJECTIVES

The aim of this study was to investigate differences in the process of carcinogenesis between adenocarcinoma coexistent with LEGH and conventional adenocarcinoma. And we intend to describe appropriate treatment plans for LEGH in this study.

METHODS

Using the surgical pathology files of patients who visited the University of Yamanashi Hospital, Yamanashi Central Hospital and Kofu Municipal Hospital between 1996 and 2005, pathological diagnoses were reevaluated based on criteria for the diagnosis of LEGH by Nucci et al. As for the cases including adenocarcinoma with LEGH: (a) we created a map showing position of the LEGH component and adenocarcinoma component and squamo-columnar junction (SCJ) in HE-stained specimens, (b) immunohistochemical staining was performed using antibodies to CEA, HIK1083 and p53, and (c) detection of HPV DNA was performed using PCR and in situ hybridization (ISH).

RESULTS

Endocervical adenocarcinoma was observed coexistent with LEGH in 5 cases (19.2%). (a) LEGH was located in a remote place from the SCJ. Sizes of lesions in the 5 cases ranged from 18 to 35 mm in width and 7 to 16 mm in depth. (b) HIK1083 was diffusely immunopositive in the cytoplasm of LEGH component and focal immunopositive in 4 cases with adenocarcinoma component. Immunopositivity for CEA was seen in the cytoplasm of adenocarcinoma component in 4 cases. Immunopositivity for p53 was seen in adenocarcinoma component nuclei in 2 cases. (c) HPV DNA was not detected using PCR and ISH in either LEGH or adenocarcinoma components.

CONCLUSIONS

The present study suggests that clear differences exist in the process of carcinogenesis between adenocarcinoma associated with LEGH and conventional adenocarcinoma. LEGH may represent a precursor of cervical adenocarcinoma independent of HPV infection. As LEGH displays characteristics of precancerous mucinous adenocarcinoma, surgical treatment should be considered for LEGH growing beyond a certain size.

Human Papillomavirus DNA and P16INK4A are not detected in renal tumors with immunohistochemistry and signal-amplified in situ hybridization in paraffin-embedded tissue

The association between human papillomavirus (HPV) infection and carcinogenesis has long been established in literature, with the strongest evidence for its role in cervical carcinoma. The role of HPV in urological tumors has been investigated and sporadic reports have linked HPV infection to bladder, prostate, renal, penile, and testicular cancer. Although less rigorously studied, there are a few conflicting results about the role of HPV in the development of malignant renal tumors. Moreover, no data are available for association of HPV DNA and expression of P16 in benign renal tumors. Formalin-fixed, paraffin-embedded tissues from 62 renal tumors (40 clear cell, 9 papillary, and 3 chromophobe renal cell carcinomas, 1 collecting duct carcinoma, 2 urothelial carcinoma of renal pelvis and 7 oncocytomas) were immunostained with low-risk and high-risk HPV DNA (6, 11, 16, 18, 31, 33, 42, 51, 52, 56, 58). Tissue microarray sections of 62 tumors were stained with P16 by immunohistochemistry. Signal amplified colorimetric in situ hybridization was performed on microarray sections using biotinylated probes for HPV subtypes 6, 11, 16, 18. A nuclear dot-like signal was considered positive for low-risk and high-risk HPV by immunohistochemistry and in situ hybridization and nuclear or cytoplasmic staining is considered positive for P16. No staining for HPV DNA and P16 was found in any type of renal tumors. Our results support that HPV does not seem to play a role in the development of benign and malignant renal tumors.

Comparison of polymerase chain reaction and catalyzed signal amplification in situ hybridization methods for human papillomavirus detection in paraffin-embedded cervical preneoplastic and neoplastic lesions

BACKGROUND

Two molecular methods for HPV genotyping in formalin-fixed, paraffin-embedded tissue were evaluated: in house polymerase chain reaction assay (PCR) with consensus and type-specific primers and a novel procedure of in situ hybridization-a catalyzed signal amplification system (CSA-ISH, Genpoint, DAKO, Glostrup, Denmark). The number of HPV positive cases and detected viral types were compared in cervical biopsies and cone specimens according to histopathological diagnosis. Primer efficiency in detecting various types of HPV by PCR method was evaluated.

METHODS

DNA samples (101) were used as a template to amplify with three pairs of consensus (MY09/11, GP5+/6 +, CPI/IIG) and four type-specific HPV primers (HPV-6/11, 18, 16 and 33). The according histological tissue sections were analyzed with CSA-ISH method, using commercial HPV biotinylated probes HPV-6/11, 16/18 and 31/33/51.

RESULTS

The degree of concordance for PCR and CSA-ISH was 64.4%. In 63 of 101 samples (62.4%), HPV was detected by PCR, while only 35 (34.7%) were positive using CSA-ISH. CSA-ISH found lower percentages for all HPV types, except HPV-6/11. A lower percentage of positive results in all high-grade lesions was detected by CSA-ISH. Multiple infections were detected by PCR in only one sample and in three samples by CSA-ISH. Detection with My09/11 primers followed by Gp5+/6+ primers, in nested reaction, gave the highest number of positive results: 58 of 63 (92%). None of the samples diagnosed as condylomata planum or CIN I was positive for HPV-6/11 (low risk type), which was detected exclusively in condylomata acuminatum group.

CONCLUSIONS

A significantly higher number of positive samples was detected with PCR than with CSA-ISH method. CSA-ISH method should be improved, especially in detecting HPV in high-grade lesions. CSA-ISH may be more accurate in detection of multiple infections. GP5+/6+ in nested reaction after MY09/11 detected the highest number of positive results. Samples diagnosed as benign lesions positive on HPV-X must be monitored as possible candidates for progression. CIN I lesions, which were HPV negative, probably will not progress. This finding may be important in planning therapy and avoiding unnecessary treatment.

Comparison between in situ hybridization and real-time PCR technique as a means of detecting the integrated form of human papillomavirus 16 in cervical neoplasia

Integration of the human papillomavirus (HPV) genome is thought to be one of the causes of cancer progression. However, there is controversy concerning the physical status of HPV 16 in premalignant cervical lesions, and there have been no reports on the concordance between detection of the integrated form of HPV16 by real-time PCR and by in situ hybridization. We investigated specimens of cervical intraepithelial neoplasia (CIN) and invasive carcinomas for the physical status of HPV 16 by real-time PCR and in situ hybridization. The presence of the integrated form was detected by both real-time PCR and in situ hybridization in zero of four cases of CIN1, three of six cases of CIN2, nine of 27 cases of CIN3, and two of six cases of invasive carcinomas. Integrated HPV 16 was present in some premalignant lesions but was not always present in carcinomas. The concordance rate between the two methods for the detection of the presence of the integrated form was 37 of 43 (86%) cases. Real-time PCR and in situ hybridization were found to be complementary and convenient techniques for determining the physical status of the HPV genome. We conclude that a combination of both methods is a more reliable means of assessing the physical status of the HPV genome in cervical neoplasia.

Does HPV play a role in the etiopathogenesis of ameloblastoma? An immunohistochemical, in situ hybridization and polymerase chain reaction study of 18 cases using laser capture microdissection

Ameloblastomas are epithelial tumors of odontogenic origin, biologically characterized by local recurrence. Among different etiologic factors, HPV infection has been recently postulated to be somehow involved in ameloblastoma etiopathogenesis. To address this issue, we studied 18 ameloblastomas by means of immunohistochemistry, in situ hybridization (conventional and amplified), polymerase chain reaction and nested-polymerase chain reaction analyses using laser capture microdissection in order to detect the occurrence of HPV in this setting. No evidence of HPV infection was detected by morphological examination, immunohistochemistry, in situ hybridization and conventional polymerase chain reaction, while nested-polymerase chain reaction showed a weak positive band in two cases. However, the subsequent restriction enzyme analysis carried out from the nested-polymerase chain reaction amplification products of these two samples excluded the presence of HPV subtypes 16, 18, 31, 33, 35, 52, and 58. The search for HPV 6 and 11 in the same specimens was also negative. In conclusion, our data do not support an etiopathogenetic evidence for HPV in ameloblastoma.

Detection of specific human papillomavirus types in paraffin-embedded sections of cervical carcinomas

Human papillomaviruses (HPV) are the causative agents of most cervical carcinomas. A complete understanding of the HPV types that cause cervical carcinoma is needed as vaccines are designed. Fresh tissues are not always available for such studies. We therefore sought to determine the feasibility of HPV studies using formalin-fixed, paraffin-embedded sections of 56 cervical carcinomas, correlating typing information with the pathology and physical state of the HPV sequences within cells. Sections from each specimen were used to extract and purify DNA. Specific HPV types were identified using a PCR/reverse blot strip assay. Tyramide signal-amplified, fluorescent DNA in situ hybridization (FISH) was used to localize HPV within cells. Human beta-globin sequences were amplified in DNA from all specimens. HPV sequences from oncogenic types were identified in 52 of 56 (92.9%) by PCR/reverse blot strip assay, and in one additional case using an HPV 16 multiplex PCR assay. HPV 16 was the most commonly detected type, present in most cases as a solitary isolate. Thirty- five of 42 HPV 16 or HPV 18 PCR-positive specimens were also positive in the FISH assay, in most cases in a pattern consistent with viral integration. We conclude that HPV typing from formalin-fixed, paraffin-embedded sections of cervical carcinomas is possible, with a sensitivity that is similar to that found in studies using fresh tissue.

Comparison of real-time PCR signal-amplified in situ hybridization and conventional PCR for detection and quantification of human papillomavirus in archival cervical cancer tissue

Archival paraffin-embedded tumor specimens offer a wealth of information for both cancer research and for routine clinical applications. However, the use of formalin-fixed, paraffin-embedded specimens for quantitative real-time PCR is not yet a standard diagnostic method in many laboratories, in particular for the quantification of human papillomavirus (HPV). Particularly high-risk HPV types are involved in almost 100% of the carcinogenesis of cervical cancer. We compared the diagnostic applicability and sensitivity of real-time PCR to that of chromogenic tyramide-signal-amplified in situ hybridization and conventional PCR for the detection of HPV from archival tissue in 164 cases of carcinoma in situ and cervical cancer. Furthermore, we examined whether the viral load of HPV is of prognostic relevance. Our findings indicate that patients in tumor stage I with a lower viral load of HPV type 16 (HPV16; up to 1,000 copies/ng of DNA) had a significantly better survival than HPV 16-negative patients (P = 0.037). We observed a greater sensitivity of both real-time PCR and conventional PCR for the detection of HPV16 and -18 compared to signal amplified in situ hybridization. We found a considerable concordance between HPV16 (kappa = 0.661) and HPV18 (kappa = 0.781) status as measured by real-time PCR and conventional PCR, indicating similar sensitivities. We recognized an inhibitory effect of formalin fixation and paraffin embedding on the evaluation of real-time PCR quantification.

p16(INK4A) immunohistochemical overexpression in premalignant and malignant oral lesions infected with human papillomavirus

Human papillomavirus (HPV) is believed to promote the oncogenic process, and the correlation between viral oncoproteins and dysfunction of p16(INK4A) tumor suppressor protein in oral lesions is controversial. To test the hypothesis that anogenital HPV types participate in disruption of the regulation of p16(INK4A) suppressor protein in oral lesions, we analyzed 46 oral biopsy specimens for the presence of HPV 6/11 and 16/18 by in situ hybridization (ISH) and for p16(INK4A) expression by immunohistochemistry (IHC). Eighteen (39%) of the 46 oral lesions were HPV-positive and 28 (61%) were HPV-negative. HPV 6/11 DNA was found in 5 (11%) and HPV 16/18 in 13 (28%) of 46 biopsies. Nine of the 18 HPV-positive oral lesions (50%), assessed by catalyzed signal amplification coupled to ISH (CSA-ISH), gave high-intensity p16(INK4A) immunostaining. Focal and diffuse patterns were observed in 11/13 (77%) lesions with HPV 16/18, focal immunopositivity in 3/5 (80%) with HPV 6/11, and negative or sporadic p16-labeling in 18/28 (64%) without the presence of HPV DNA. These results showed a strong association between overexpression of p16 protein and malignant oral lesions, mainly those infected by HPV 16/18. We can conclude that high-risk HPV types are associated with p16 overexpression, and p16 may serve as a biomarker in oral cancer related to high-risk HPV infection.

Impact of multiple HPV infection on response to treatment and survival in patients receiving radical radiotherapy for cervical cancer

To obtain information on the incidence and the clinical significance of infection with various types of the human papillomavirus (HPV) in cancer of the uterine cervix, we retrospectively examined the HPV status of 106 patients who had received radical radiotherapy for cervical cancer stages IB to IIIB. DNA was extracted from formalin-fixed, paraffin-embedded biopsies and PCR was carried out to identify HPV types 16, 18, 31, 35, 33 and 45. To detect additional HPV types, consensus PCR products were cloned and sequenced. A catalyzed signal-amplified colorimetric in situ hybridization was carried out in 84 of 106 specimens as a positive control. Response to therapy, progression-free survival (PFS) and cervical cancer-specific survival (CCSS) were the statistical endpoints. Survival analysis was carried out using univariate and multivariate analysis (Cox regression). Ninety-six patients (90.6%) were HPV-positive and 42/96 (43.7%) were positive for multiple HPV types. Eight patients had persistent disease after radiotherapy. From these 8 patients, 7 were infected with multiple HPV types and only 1 patient had an infection with a single HPV type. After a median follow up period of 50 months, patients with multiple HPV infection had a significantly shorter PFS and CCSS compared to those with single HPV infection (24.8% and 34.9% vs. 64% and 60.8%, Log rank, p < 0.01 and 0.04). In multivariate analysis, the presence of multiple HPV types (RR 1.9), node status (RR 2.3), tumor size (RR 3.2) and histologic type (RR 4.8) were independent prognostic factors of CCSS. Our results demonstrate that the presence of multiple HPV types is associated with poor response and with reduced survival in cervical cancer patients who receive radiotherapy as the primary treatment.

[Presence of human papillomavirus in malignant oral lesions]

The purpose of this study was to investigate the prevalence of human papillomavirus 6/11 and 16/18 in patients, with oral lesions clinically diagnosed as leucoplakia, attending the School of Dentistry, University of São Paulo State/UNESP, Brazil. After paraffin embedded process, in the sections staining with H&E, 30 biopsies were screened and separated on 3 groups: 10 oral lesions without dysplasia, 10 with dysplasia, and 10 with invasive squamous cell carcinoma. The lesions with dysplasia were classified in agreement with Van Der Wall's histopathological standard method. Oral lesions were investigated for the presence of human papillomavirus (HPV) by in situ hybridization with wide-spectrum, 6/11 and 16/18 biotinylated probes. HPV 16/18 was found in 20% (n = 2) of the leucoplakia with severe-degree dysplasia. The presence of HPV 16/18 in malignant lesions suggests its importance as a risk factor for oral carcinogenesis.