Viral load, integration and methylation of E2BS3 and 4 in human papilloma virus (HPV) 16-positive vaginal and vulvar carcinomas

Increased prevalence of human papillomavirus in fresh tissue from penile cancers compared to non-malignant penile samples: a case-control study

BACKGROUND

HPV has been detected in approximately 50% of invasive penile cancers but with a large span between 24 and 89%, most likely due to different types of tumors and various methods for HPV analysis. Most studies of HPV in penile cancer have been performed using paraffin-embedded tissue, argued to be at risk for contaminated HPV analysis. Viral activity of HPV, by the use of HPV mRNA expression is well studied in cervical cancer, but seldom studied in penile cancer. The aim was to determine prevalence of HPV types in fresh tissue of penile cancers compared to non-malignant age-matched penile controls. Additional aims were to analyze the viral expression and copy numbers of HPV16-positive tumors and 10 mm adjacent to the tumor.

METHODS

Fresh tissue from penile cancer cases was biopsied inside the tumor and 10 mm outside the tumor. Controls were males circumcised for non-malignant reasons, biopsied at surgery. PCR and Luminex assays were used for identification of HPV types. HPV16-positive samples were investigated for copy numbers and expression of HPV16-mRNA.

RESULTS

Among tumors (n = 135) and age-matched controls (n = 105), HPV was detected in 38.5% (52/135) and 11.4% (12/105), respectively (p < 0.001), adjusted odds ratio 12.8 (95% confidence interval 4.9-33.6). High-risk HPV types were found in 35.6% (48/135) of tumors and 4.8% (5/105) of controls (p < 0.001). Among tumors and controls, HPV16 was present in 27.4% (37/135) and 1% (1/105), respectively (p < 0.001). Among HPV16-positive penile cancers, mean HPV16 viral copy/cell was 74.4 (range 0.00003-725.4) in the tumor and 1.6 (range 0.001-14.4) 10 mm adjacent from the tumor. HPV16-mRNA analysis of the tumors and 10 mm adjacent from the tumors demonstrated viral activity in 86.5% (32/37) and 21.7% (5/23), respectively.

CONCLUSIONS

The prevalence of HPV was significantly higher in penile cancer (38.5%) than among age-matched non-malignant penile samples (11.4%). HPV16 predominates (27.4%) in penile tumors. HPV16 expression was more common in penile cancer than in adjacent healthy tissue, strongly suggesting an etiological role for HPV16 in the development of penile cancer.

Association of viral load and physical status of HPV-16 with survival of patients with head and neck cancer

Introduction

Head and neck cancers (NHCs) are of multifaceted origins, and tobacco and alcohol are the primary risk factors. Currently, other factors associated with the genesis of these tumours are being considered, among these viral infections, especially human papillomavirus (HPV) infection.

Objective

The objective was to evaluate HPV infection, HPV-16 E6 load and its physical status in patients with squamous cell carcinoma in the head and neck and evaluate its effects in the survival of these patients.

Methodology

A total of 80 fresh biopsies of HNC were evaluated. The genetic material was extracted using the commercial kit QIAGEN. The detection and classification of HPV were carried out using INNO-LiPA, whereas the quantification and analysis of integration of the viral genome into the host cell were carried out using real-time PCR.

Results

The average age of the patients included was 60.34 ± 14.48 years, with a predominance of the male gender. The most frequent HPV infection was genotype 16 (52.8%), with an average of 10 copies of the HPV-16 E6/β-globin gene. Furthermore, an integration of the viral genome in the host cell was observed in 86% of cases with a statistically significant relationship between the location of the tumour and the viral load (p < 0.05).

Conclusions

HPV-16 is the most common infection, and its physical status in the host cell is the determining factor in establishing response to treatment. However, more studies are needed to demonstrate the role of HPV infection in carcinogenesis.

Methylation of CpG 5962 in L1 of the human papillomavirus 16 genome as a potential predictive marker for viral persistence: A prospective large cohort study using cervical swab samples

Several studies have demonstrated that the viral genome can be methylated by the host cell during progression from persistent infection to cervical cancer. The aim of this study was to investigate whether methylation at a specific site could predict the development of viral persistence and whether viral load shows a correlation with specific methylation patterns. HPV16‐positive samples from women aged 20–29 years (n = 99) with a follow‐up time of 13 years, were included from a Danish cohort comprising 11 088 women. Viral load was measured by real‐time PCR and methylation status was determined for 39 CpG sites in the upstream regulatory region (URR), E6/E7, and L1 region of HPV16 by next‐generation sequencing. Participants were divided into two groups according to whether they were persistently (≥ 24 months) or transiently HPV16 infected. The general methylation status was significantly different between women with a persistent and women with a transient infection outcome (P = .025). One site located in L1 (nt. 5962) was statistically significantly (P = .00048) different in the methylation status after correction using the Holm‐Sidak method (alpha = 0.05). Correlation analyses of samples from HPV16 persistently infected women suggest that methylation is higher although viral load is lower. This study indicates that methylation at position 5962 of the HPV16 genome within the L1 gene might be a predictive marker for the development of a persistent HPV16 infection.

BS-virus-finder: virus integration calling using bisulfite sequencing data

Background

DNA methylation plays a key role in the regulation of gene expression and carcinogenesis. Bisulfite sequencing studies mainly focus on calling single nucleotide polymorphism, different methylation region, and find allele-specific DNA methylation. Until now, only a few software tools have focused on virus integration using bisulfite sequencing data.

Findings

We have developed a new and easy-to-use software tool, named BS-virus-finder (BSVF, RRID:SCR_015727), to detect viral integration breakpoints in whole human genomes. The tool is hosted at https://github.com/BGI-SZ/BSVF.

Conclusions

BS-virus-finder demonstrates high sensitivity and specificity. It is useful in epigenetic studies and to reveal the relationship between viral integration and DNA methylation. BS-virus-finder is the first software tool to detect virus integration loci by using bisulfite sequencing data.

HPV16 viral characteristics in primary, recurrent and metastatic vulvar carcinoma

Vulvar carcinoma is the fourth most common gynecological malignancy. Two separate carcinogenic pathways are suggested, where one is associated with the human papillomavirus (HPV) and HPV16 the most common genotype. The aim of this study was to evaluate HPV-markers in a set of primary tumors, metastases and recurrent lesions of vulvar squamous cell carcinomas (VSCC). Ten HPV16-positive VSCC with metastatic regional lymph nodes, distant lymphoid/hematogenous metastases or local recurrent lesions were investigated for HPV genotype, HPV16 variant, HPV16 viral load, HPV16 integration and HPV16 E2BS3 and 4 methylation. In all 10 analyzed case series, the same HPV genotype (HPV16), HPV16 variant and level of viral load were detected in all lesions within a patient case. Primary tumors with a high E2/E6 ratio were found to have fewer vulvar recurrences and/or metastases after diagnosis and treatment. Also, a significantly lower viral load was evident in regional lymph nodes compared to primary tumors. The data presented strengthens the evidence for a clonal HPV-induced pathway for vulvar carcinoma.

HPV-16 viral load in oropharyngeal squamous cell carcinoma using digital PCR

CONCLUSIONS

We did not identify any strong associations between HPV-16 viral load and any of the clinical or lifestyle factors.

OBJECTIVE

The epidemiology of oropharyngeal SCC is changing, with an increasing proportion of HPV-positive cases seen in the last decade. It is known that a high viral load is linked to the development of cervical cancer, the relation between viral load and oropharyngeal SCC is less clear. We sought to determine HPV-16 viral load in HPV-positive oropharyngeal SCCs using highly sensitive digital PCR and to identify clinical and lifestyle factors associated with viral load.

SUBJECTS AND METHODS

We analysed 45 HPV-16 positive oropharyngeal SCCs diagnosed between 2013 and 2015. All patients completed a lifestyle questionnaire and clinical data were extracted from medical charts. Viral load was determined using digital PCR assays for HPV-L1 and RNAseP.

RESULTS

We found large variations in HPV-16 viral load from 1 to 930 copies per cell (median 34 copies per cell).

Digital droplet PCR (ddPCR) for the detection and quantification of HPV 16, 18, 33 and 45 - a short report

Purpose

Human papilloma virus (HPV) infection is associated with several anogenital malignancies. Here, we set out to evaluate digital droplet PCR (ddPCR) as a tool for HPV 16, 18, 33 and 45 viral load quantification and, in addition, to compare the efficacy of the ddPCR assay for HPV 16 detection with that of quantitative real-time PCR (qPCR).

Methods

Clinical samples, positive for HPV genotypes 16, 18, 33 and 45 were analyzed for viral load using ddPCR. Sample DNA was cleaved before droplet generation and PCR. Droplets positive for VIC and FAM fluorescence were read in a QX200 Droplet reader™ (BIO-RAD) after which the viral load was calculated using Quantasoft software.

Results

We found that DNAs extracted from formalin fixed paraffin embedded (FFPE) tissue samples yielded lower amplification signals compared to those obtained from liquid based cytology (LBC) samples, but they were clearly distinguishable from negative background signals. The viral limit of detection was 1.6 copies of HPV 16, 2.8 copies of HPV 18, 4.6 copies of HPV 33 and 1.6 copies of HPV 45. The mean inter-assay coefficients of variability (CV) for the assays ranged from 3.4 to 7.0%, and the mean intra-assay CV from 2.6 to 8.2%. The viral load in the different cohorts of tumor samples ranged from 154 to 340,200 copies for HPV 16, 244 to 31,300 copies for HPV 18 and 738 to 69,100 copies for HPV 33. One sample positive for HPV 45 contained 1331 viral copies. When comparing qPCR data with ddPCR copy number data, the qPCR values were found to be 1 to 31 times higher.

Conclusions

Separation of fragments in nanodroplets may facilitate the amplification of fragmented human and viral DNA. The method of digital droplet PCR may, thus, provide a new and promising tool for evaluating the HPV viral load in clinical samples.

Physical state and copy numbers of HPV16 in oral asymptomatic infections that persisted or cleared during the 6-year follow-up

Persistent human papillomavirus (HPV) infection is a key event in HPV-induced carcinogenesis. As part of the prospective Finnish Family HPV Study, we analysed the physical state and viral copy numbers of HPV16 in asymptomatic oral infections that either persisted or cleared during the 6-year follow-up. The persister group comprised 14 women and 7 men with 51 and 21 HPV16-positive brush samples. The clearance group included 41 women and 13 men, with 64 and 24 samples, respectively. Physical state and viral DNA load were assessed by using quantitative PCR for HPV16 E2 and E6 genes. E2/E6 ratio was calculated and HPV16 was classified as episomal, mixed or integrated with values of 0.93-1.08, <0.93 and 0, respectively. In both genders, the physical state of HPV16 was significantly different between the cases and controls (P<0.001). HPV16 was episomal in all men and 66 % (27/41) of women who cleared their infection. HPV16 was mixed and/or integrated in71 % and 57 %of the women and men persisters, respectively. The mean HPV16 copy number per 50 ng genomic DNA was nearly 5.5-fold higher in the women than in the men clearance group (P=0.011). Only in men, HPV16 copy numbers were higher in persisters than in the clearance group (P=0.039). To conclude, in both genders, persistent oral HPV16 infections were associated with the mixed or integrated form of HPV16, while in the clearance groups, episomal HPV16 predominated. This indicates that HPV16 integration is a common event even in asymptomatic oral infections, which might predispose the infected subjects to progressive disease.

CpG Methylation Analysis of HPV16 in Laser Capture Microdissected Archival Tissue and Whole Tissue Sections from High Grade Anal Squamous Intraepithelial Lesions: A Potential Disease Biomarker

Incidence and mortality rates of anal cancer are increasing globally. More than 90% of anal squamous cell carcinomas (ASCC) are associated with human papillomavirus (HPV). Studies on HPV-related anogenital lesions have shown that patterns of methylation of viral and cellular DNA targets could potentially be developed as disease biomarkers. Lesion-specific DNA isolated from formalin-fixed paraffin-embedded (FFPE) tissues from existing or prospective patient cohorts may constitute a valuable resource for methylation analysis. However, low concentrations of DNA make these samples technically challenging to analyse using existing methods. We therefore set out to develop a sensitive and reproducible nested PCR-pyrosequencing based method to accurately quantify methylation at 10 CpG sites within the E2BS1, E2BS2,3,4 and Sp1 binding sites in the viral upstream regulatory region of HPV16 genome. Methylation analyses using primary and nested PCR-pyrosequencing on 52 FFPE tissue [26 paired whole tissue sections (WTS) and laser capture microdissected (LCM) tissues] from patients with anal squamous intraepithelial lesions was performed. Using nested PCR, methylation results were obtained for the E2BS1, E2BS2,3,4 and Sp1 binding sites in 86.4% of the WTS and 81.8% of the LCM samples. Methylation patterns were strongly correlated within median values of matched pairs of WTS and LCM sections, but overall methylation was higher in LCM samples at different CpG sites. High grade lesions showed low methylation levels in the E2BS1 and E2BS2 regions, with increased methylation detected in the E2BS,3,4/Sp1 regions, showing the highest methylation at CpG site 37. The method developed is highly sensitive in samples with low amounts of DNA and demonstrated to be suitable for archival samples. Our data shows a possible role of specific methylation in the HPV16 URR for detection of HSIL.

Human Papillomavirus and students in Brazil: an assessment of knowledge of a common infection - preliminary report

Introduction

Human Papillomavirus (HPV) infection is the most prevalent sexually transmitted disease worldwide. One of the barriers to the implementation of prevention programs against the disease is the limited knowledge possessed by most populations regarding the virus and its possible consequences.

Objective

The purpose of this study was to evaluate the knowledge of Brazilian college students on transmission, clinical manifestations, and diseases correlated with HPV, highlighting the poor knowledge of a very common infection.

Methods

A total of 194 students answered a questionnaire about transmission, clinical features and the possible consequences of persistent HPV infection. The questionnaire was self-applied under the supervision of the authors.

Results

The clinical manifestations of HPV infection were not clear to most students. Incorrect assumptions of the clinical manifestations of HPV infection included: bleeding (25%), pain (37%) and rashes (22%). Twelve per cent of respondents did not recognize warts as an HPV-related disease. Regarding potential consequences of persistent infection, students did not recognize a relationship between HPV and laryngeal carcinoma (80.9%), pharyngeal carcinoma (78.9%), anal carcinoma (73.2%), vulvar carcinoma (65.4%) and vaginal carcinoma (54.6%). Large portions of the population evaluated were unaware of modes of HPV transmission beyond genital contact.

Conclusion

Knowledge of HPV by the population evaluated in this study is partial and fragmented. Lack of knowledge may contribute to the further spread of the disease. Public health policies for education and guidance of the population should be implemented in Brazil.