Touchdown General Primer (GP5+/GP6+) PCR and optimized sample DNA concentration support the sensitive detection of human papillomavirus

miRNAs Dysregulated in Human Papillomavirus-Associated Benign Prostatic Lesions and Prostate Cancer

Prostate pathologies, including chronic prostatitis, benign prostatic hyperplasia (BPH), and prostate cancer (PCa), are strongly associated with chronic inflammation, which is a key risk factor and hallmark of these diseases [...].

Prevalence, genotyping and phylogenetic analysis of HPV infecting Palestinian women

BACKGROUND

Human Papillomavirus (HPV) is a significant global public health concern due to its association with cervical, other anogenital, and oropharyngeal cancers. This study aimed to evaluate the prevalence and the phylogenetic relationships of HPV among Palestinian in order to inform public health strategies.

METHODS

A cross-sectional study was conducted between September 2023 and April 2024 involving 379 Palestinian women over the age of 18 from 11 governorates in the West Bank. Cervical swabs were collected and analyzed using nested PCR and Sanger sequencing methods to detect and genotype HPV. The study also included phylogenetic analysis to understand the genetic relationships between HPV strains.

RESULTS

The overall HPV prevalence was 14.5%. The highest prevalence was observed in the 20-29 age group (19.6%), the Middle region of the West Bank (19.0%), and lower educational attainment. Genotyping revealed a diverse distribution of HPV types, with HPV 11 and HPV 6 being the most common low-risk types, while HPV 16 was the most common high-risk type. About 21.8% of the detected strains were high-risk strains. Phylogenetic analysis indicated significant regional clustering of HPV strains.

CONCLUSION

The study highlights the need for targeted public health interventions, including vaccination and regular screening, particularly for younger women and those with lower educational attainment. Continued surveillance and research are essential to reduce the burden of HPV-related diseases in the West Bank, Palestine.

Development of a touchdown droplet digital PCR assay for the detection and quantitation of human papillomavirus 16 and 18 from self-collected anal samples

IMPORTANCE

The quantity of the human papillomavirus (HPV) is associated with disease outcome. We designed an accurate and precise digital PCR assay for quantitating HPV in anal samples, a sample type that is typically problematic due to the presence of PCR inhibitors.

Aspergillus Species and Human Papillomavirus Infections in Epithelial Tumors of Nasal and Paranasal Cavities

Background: There are diverse lesions originating from the paranasal sinuses and nasal cavity. Tobacco use, alcohol consumption, and malnutrition have been identified to play a role in the development of head and neck carcinomas. Recently, fungi and viruses have been recognized as potential causes of nasal cavity and paranasal tumors. Objectives: This study aimed at specifying the prevalence of Aspergillus and human papillomavirus (HPV) infections in the epithelial tumors of nasal cavity and paranasal sinuses. Methods: In this cross-sectional study, 57 paraffin-embedded tissue samples of malignant and benign lesions of the paranasal sinuses and nasal cavity were evaluated for the presence of Aspergillus and HPV DNA by nested polymerase chain reaction (nPCR) technique with specific primers. Results: Despite the absence of angular hyphae (acute angle) of the fungus on histopathological slides, overall, 10 (17.54%) out of 57 paraffin-embedded samples were found to be positive for Aspergillus species. However, HPV-DNA was not found in any of the samples. Conclusions: Our data suggest that fungal infections (especially aspergillosis) as an etiological factor can be contributed to the development of sinonasal cancer and, therefore, they should be considered in the management of patients with sinonasal cancer. In addition, PCR can provide an alternative to culture-dependent identification methods.

Usefulness of high-risk human papillomavirus mRNA silver in situ hybridization diagnostic assay in oropharyngeal squamous cell carcinomas

AIMS

The transcriptional activity of high-risk human papillomaviruses (HR-HPV) within oropharyngeal squamous cell carcinomas (OPSCC) has been linked to improved survival of patients. HR-HPV mRNA silver in situ hybridization (SISH) was evaluated on a cohort of OPSCC and compared with viral HPV DNA tests and p16 expression. Clinical outcomes of HPV-driven OPSCC and non-HPV related OPSCC were also studied.

METHODS

We evaluated 67 OPSCC and 3 papillomas, obtained from 62 patients, for detection of HR-HPV DNA by PCR tests. The positive samples were additionally studied by the SISH method using three probes of HPV16, HPV18, and HP33, and for p16 expression detected by immunohistochemistry. SISH assays were evaluated for the presence/number and intensity of signals in cancer cells. Prognostic significance of HPV status in our cohort was evaluated with univariate and multivariate statistics.

RESULTS

According to the HR-HPV PCR tests, 46 (69%) OPSCC cases were HPV positive, while three papillomas were negative. Of total 46 HPV-positive OPSCCs, 43 cases were also SISH-positive, while p16 overexpression was found in 45 of 46 HPV positive OPSCC cases. In OPSCC specimens, the sensitivity and specificity of the combined SISH probes (HPV16 and 33) were both 100.00%, when compared to HPV PCR. HPV positivity of the tumors appeared significant for predicting progression-free survival, cause specific survival and overall survival in a multivariate setting.

CONCLUSIONS

The recently developed mRNA SISH methodology can detect HPV-driven OPSCCs without any additional test in 79% of cases. Positive SISH signals enable the visualization of viral transcripts required to recognize clinically relevant HPV infection. However, rare and tiny signals require an experienced pathologist to establish a consensus interpretation of results. The currently applied HR-HPV mRNA SISH analysis may serve as a groundwork for additional studies.

Downregulated Expression of WWOX in Cervical Carcinoma: A Case-Control Study

Integration of human papilloma virus (HPV) in human genome is a random event, and fragile sites are one of the most susceptible sites for viral integrations. WWOX (WW-domain containing oxidoreductase) gene harbours the second most common fragile site, FRA16D, and can be an important candidate for HPV integration and cervical carcinogenesis. Our aim was to evaluate the potential role of WWOX in cervical carcinogenesis. Presence of HPV and its genotype was detected by PCR in normal cervix tissues and human cervical carcinoma. The expression of WWOX transcript and its protein was examined by RT-PCR, RNA in situ hybridization, and immunoblotting. Southern blotting and sequencing were used to determine the alternative transcripts of WWOX. Statistical analysis were performed by Mann Whitney U-test, Pearson correlation coefficient test at significance level of P value < 0.05. Prevalence of HPV was observed in cervicitis (40%), cervical intraepithelial neoplasia patients (50%), and invasive cervical carcinoma patients (89.6%). Clinicopathological findings suggested a correlation of reduced level of WWOX protein and progression of cervical carcinoma deciphering its role in tumorigenesis. Furthermore, we observed aberrant WWOX transcript having deleted exon 6-8 region in invasive cervical cancer tissues as well as normal cervix samples. More than 60% of cervical carcinoma samples showed reduced protein level with an increase in wild type transcript level suggesting the involvement of a negative regulator, pAck1 (activated Cdc42- associated kinase) which might ubiquitinate WWOX protein leading to its degradation. Also, nuclear retention of WWOX transcript in invasive cervical carcinoma tissues suggests its regulation at post-transcriptional level. Our findings suggest that WWOX acts as a tumor suppressor in cervical carcinoma and could act as a potential therapeutic target for the disease.

Association between oncogenic human papillomavirus type 16 and Killian polyp

BACKGROUND

Killian polyp (KP) is a benign lesion that arises from the maxillary sinus. The etiology of KP is unknown. The aim of this study was to investigate the potential involvement of human papilloma- (HPV) and polyoma-viruses (HPyV) infections in the onset of KP.

METHODS

DNA from antral (n = 14) and nasal (n = 14) KP fractions were analyzed for HPV and HPyV sequences, genotypes, viral DNA load and physical status along with expression of viral proteins and p16 cellular protein.

RESULTS

The oncogenic HPV16 was detected in 3/14 (21.4%) antral KPs, whilst nasal KPs tested HPV-negative (0/14). The mean HPV16 DNA load was 4.65 ± 2.64 copy/104 cell. The whole HPV16 episomal genome was detected in one KP sample, whereas HPV16 DNA integration in two KPs. P16 mRNA level was lower in the KP sample carrying HPV16 episome than in KPs carrying integrated HPV16 and HPV- negative KPs (p< 0.001). None of the antral and nasal KP samples tested positive for HPyV DNA (0/28).

CONCLUSIONS

A fraction of KP tested positive for the oncogenic HPV16. HPV16 detection in the KP antral portion may be consistent with HPV16 infection derived from the maxillary sinus. HPV16 DNA integration represents a novel finding. Altogether, these data improve our knowledge on the association between KP and HPV infection, whereas it indicates that the KP onset is heterogeneous.

Whole exome sequencing and establishment of an organoid culture of the carcinoma showing thymus-like differentiation (CASTLE) of the parotid gland

Carcinoma showing thymus-like differentiation (CASTLE) is a rare tumor, especially in the parotid gland. We encountered a CASTLE of the parotid gland and analyzed its clinicopathological features, as well as the genotype using whole exome sequencing (WES). Moreover, we successfully established an organoid culture cell line from the primary tumor tissue. The patient was a 23-year-old woman who underwent superficial parotidectomy with peripheral neck dissection, followed by radiotherapy. Pathologically, the resected specimen showed atypical epithelioid nests and trabeculae with squamous differentiation, separated by thick fibrous septa, accompanied by dense lymphocytes and plasma cell infiltration. Immunohistochemistry revealed that the tumor cells were positive for AE1/AE3, p40, p63, p16, CK5/6, and CD5, and the background lymphocytes were positive for CD5 and CD99. Based on these findings, the tumor was diagnosed as CASTLE. WES uncovered five nonsynonymous and splicing somatic mutations, namely, FREM2 p.Val861Phe, CLK3 p.Phe376Leu, DLGAP1 p.Lys294Asn, NOX1 p.Val165Met, and PSG9 c.430 + 4A > T. Organoid culture cells preserved the histopathological characteristics of the epithelioid component of CASTLE and harbored all five somatic mutations detected in the primary tumor. In conclusion, for the first time to the best of our knowledge, we successfully analyzed a comprehensive genotype and established an organoid culture cell line of a parotid gland CASTLE, which should serve for analyzing the nature of this rare tumor.

Risk factors for the development of high-grade dysplasia and carcinoma in patients with laryngeal squamous cell papillomas: Large retrospective cohort study

BACKGROUND

The incidence and risk factors for the development of high-grade dysplasia (HG-D) and laryngeal squamous cell carcinoma (LSCC) were assessed in patients with laryngeal squamous cell papillomas (LSP).

METHODS

Clinical data, human papillomaviruses (HPV) typing, HPV E6/E7 mRNA in situ hybridization, and sequencing of host genes in LSP biopsies of 163 patients were analyzed.

RESULTS

Progression to HG-D and LSCC was identified in 21.5% and 4.3% of LSP patients, respectively. A more advanced age at LSP onset and lack of HPV infection were detected as risk factors for the development of HG-D and LSCC (P < .05). The identification of HG-D was associated with its progression to LSCC (P < .05). Host gene mutations were identified in 3 of 7 patients with LSCC.

CONCLUSIONS

The histological monitoring of LSP and HPV typing are necessary for early detection of epithelial changes. Further research is needed to elucidate the role of host gene mutations in LSCC transformation.

Simultaneous Detection and Viral DNA Load Quantification of Different Human Papillomavirus Types in Clinical Specimens by the High Analytical Droplet Digital PCR Method

Human papillomaviruses (HPVs) are small DNA tumor viruses that mainly infect mucosal epithelia of anogenital and upper respiratory tracts. There has been progressive demand for more analytical assays for HPV DNA quantification. A novel droplet digital PCR (ddPCR) method was developed to simultaneously detect and quantify HPV DNA from different HPV types. DdPCR was initially tested for assay sensitivity, accuracy, specificity as well as intra- and inter-run assay variation employing four recombinant plasmids containing HPV16, HPV18, HPV11, and HPV45 DNAs. The assay was extended to investigate/quantify HPV DNA in Cervical Intraepithelial Neoplasia (CIN, n = 45) specimens and human cell lines (n = 4). DdPCR and qPCR data from clinical samples were compared. The assay showed high accuracy, sensitivity and specificity, with low intra-/inter- run variations, in detecting/quantifying HPV16/18/11/45 DNAs. HPV DNA was detected in 51.1% (23/45) CIN DNA samples by ddPCR, whereas 40% (18/45) CIN tested HPV-positive by qPCR. Five CIN, tested positive by ddPCR, were found to be negative by qPCR. In CIN specimens, the mean HPV DNA loads determined by ddPCR were 3.81 copy/cell (range 0.002-51.02 copy/cell), whereas 8.04 copy/cell (range 0.003-78.73 copy/cell) by qPCR. DdPCR and qPCR concordantly detected HPV DNA in SiHa, CaSki and Hela cells, whereas HaCaT tested HPV-negative. The correlation between HPV DNA loads simultaneously detected by ddPCR/qPCR in CINs/cell lines was good (R 2 = 0.9706, p < 0.0001). Our data indicate that ddPCR is a valuable technique in quantifying HPV DNA load in CIN specimens and human cell lines, thereby improving clinical applications, such as patient management after primary diagnosis of HPV-related lesions with HPV-type specific assays.

Identification by high-throughput sequencing of HPV variants and quasispecies that are untypeable by linear reverse blotting assay in cervical specimens

The linear reverse blotting assays are valid methods for accurate human papillomavirus (HPV) typing required to manage women at risk of developing cervical cancer. However, some samples showed a positive signal in HPV lines but failed to display a positive signal in subsequent typing lines (designated as HPV-X), which indicate that certain types were not available on the respective typing blots. The aim of this study is to elucidate the types or variants of HPV through the high-throughput sequencing (HTS) of 54 ASCUS cervical samples in which the viruses remained untypeable with INNO LiPA HPV® assays. Low-risk (LR)-HPV types (HPV6, 30, 42, 62, 67, 72, 74, 81, 83, 84, 87, 89, 90 and 114), high-risk (HR)-HPV35 and possibly (p)HR-HPV73 were detected among HPV-X. Individual multiple infections (two to seven types) were detected in 40.7% of samples. Twenty-two specimens contained variants characterised by 2-10 changes. HPV30 reached the maximal number of 17 variants with relative abundance inferior or equal to 2.7%. The presence of L1 quasispecies explains why linear reverse blotting assays fail when variants compete or do not match the specific probes. Further studies are needed to measure the LR-HPV quasispecies dynamics and its role during persistent infection.

Assessment of a new low-cost, PCR-based strategy for high-risk human papillomavirus DNA detection for cervical cancer prevention

Background

HPV test implementation as a primary screening tool has the potential to decrease cervical cancer incidence as shown by several studies around the world. However, in many low-resource settings, the HPV test introduction has been backed down mainly due to its price. In this study, we present a novel low-cost strategy involving simple devices and techniques for high-risk human papillomavirus (HR-HPV) detection. The analytical performance to detect HR-HPV infections of this novel strategy was assessed by comparing it with the Hybrid Capture 2 system (HC2), which is used as gold standard.

Methods

Paired-cervical samples were collected from 541 women assisting to gynecological services in an outpatient clinic. One sample was transported in the Hybrid Capture Standard Transport Medium for HR-HPV detection by the HC2. The second sample was transported on glass slide for detection by PCR-based techniques (GP-EIA, BSGP-EIA and pU 1 M-L/2R).

Results

The level of agreement between the PCR-based techniques and HC2 system was determined with the Cohen’s kappa value. The kappa values between HC2 and GP-EIA, BSGP-EIA and pU 1 M-L/2R were 0.71 (CI 95% 0.63–0.78), 0.78 (CI 95% 0.71–0.84) and 0.63 (CI 95% 0.55–0.72), respectively. However, when the results from both BSGP-EIA and pU 1 M-L/2R were combined, the level of agreement with HC2 was increased to 0.82 (CI 95% 0.76–0.88), reflecting a very good agreement between the two HR-HPV detection strategies. Furthermore, the sensitivity of both techniques combined was also increased compared to the BSGP-EIA (88.7% vs 77.4%) and the pU (88.7 vs 60.9%) without penalizing the specificity obtained with the BSGP-EIA (95.1% vs 96.9%) and the pU (95.1% vs 96.5%).

Conclusions

This novel strategy, combining two PCR-based techniques for HR-HPV detection, could be useful for cervical cancer screening in self-collected samples in low-income countries.

Association of TLR4 and TLR9 gene polymorphisms and haplotypes with cervicitis susceptibility

BACKGROUND

Cervicitis is one of the major health problems amongst women caused by infection of various pathogens including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) as well as human papillomavirus (HPV), and persistent cervical inflammation is one of the etiologic agents of cervical cancer. Toll-like receptors (TLRs) play an important role in the recognition and subsequent elimination of these pathogens. Variations in the Toll-like receptor genes influence susceptibility to pathogens as well as disease progression independently.

METHODS

Ten single nucleotide polymorphisms, five each of TLR4 and TLR9 genes were analyzed among 130 cervicitis patients and 150 controls either using polymerase chain reaction-restriction fragment length polymorphism or allele specific-PCR.

RESULTS

T. vaginalis infection was found at the highest frequency (30.7%) as compared to C. trachomatis (1.5%), N. gonorrhoeae (2.3%) and HPV (4.6%) infections in cervicitis patients. TLR4 rs11536889 CC (age-adjusted OR, 2.469 [95% CI, 1.499 to 4.065]; p < 0.001) and TLR9 rs187084 TC (age-adjusted OR, 2.165 [95% CI, 1.267-3.699]; p = 0.005) genotypes showed the higher distribution in cervicitis patients compared to controls. In addition, TLR4 rs11536889 C allele was shown to increase the risk of cervicitis (age-adjusted OR, 1.632 [95% CI, 1.132 to 2.352]; p = 0.009) compared to controls. The TLR4 haplotype GCA (OR, 0.6 [95% CI, 0.38-0.95]; p = 0.0272) and TLR9 haplotype GTA (OR, 1.99 [95% CI, 1.14-3.48]; p = 0.014) were found to be associated with decreased and increased risk of cervicitis respectively.

CONCLUSIONS

TLR4 and TLR9 polymorphisms, as well as haplotypes were shown to modulate the cervicitis risk.

Effect of vaccination against oral HPV-16 infection in high school students in the city of Cali, Colombia

INTRODUCTION

In recent years, an association between HPV-16 and oropharyngeal cancers has been reported. Therefore, it is necessary to evaluate whether vaccination decreases the exposure of HPV-16 in the oral cavity.

OBJECTIVE

To evaluate the effect of vaccination on oral HPV-16 infection in high school students in the city of Cali, Colombia.

METHODS

In this cross-sectional study, HPV-16 DNA was detected in samples from the oral cavity and throat of 1,784 high school students of both genders, aged 14-17 years old, in 21 schools in the city of Cali, Colombia. The number in vaccinated girls were 944 vs., 95 unvaccinated girls and 745 unvaccinated boys.

RESULTS

The HPV exposure percentages were: 0.7% in vaccinated girls, 3.2% in unvaccinated girls and 2.3% in unvaccinated boys. The odds ratio (OR) of detection of HPV-16 in vaccinated versus unvaccinated students was 0.28 (95% CI: 0.07-0.88), representing a 72% reduction in HPV-16 detection in students immunized with two doses. The odds of detection of HPV-16 in unvaccinated male students were 3.6 times those of vaccinated girls (OR = 3.6, 95% CI: 1.21-12.81) and increased to almost eight-fold in boys who had initiated sexual activity (OR = 7.74, 95% CI: 1.53-75.09).

CONCLUSIONS

HPV vaccination was associated with the reduction of HPV-16 exposure percentages in the oral and oropharyngeal cavity.

High frequency of multiple HPV types detection in Fanconi anemia patients oral swabs

BACKGROUND

Fanconi anemia (FA) is a rare genetic disease usually characterized by bone marrow failure and congenital malformations. The risk of development of malignancies in the oral cavity of FA patients, such as squamous cell carcinoma (SCC), increases significantly after a hematopoietic stem cells transplant (HSCT), and may also be linked with the presence of human papillomavirus (HPV) infections in the oral cavity. We investigated the prevalence and the HPV genotypes in oral mucosa of Brazilian FA patients.

METHODS AND RESULTS

Oral swabs of 49 FA patients were collected. The median age of patients was 20 years (range 5-44) and 57% were over 18 years. Oral lesions were present in 20% of all patients, being 90% leukoplakia. HPV DNA was detected in 28% (14/49) of patients, and one of them also reported genital HPV lesions. Sixty-seven percent of all patients had undergone HSCT, including 12 patients (86%) of those with HPV results. Multiple HPV types were detected in 78% and 71% of HPV samples by Sanger sequencing and reverse hybridization methods, respectively. The most prevalent HPV types detected were 6, 11, 18, and 68.

CONCLUSIONS

HPV prevalence in the oral mucosa of the assessed FA patients was higher than reported in the general population. Additional studies with collection of sequential samples are needed to know the natural history of the presence of multiple HPV types in these individuals and its association with the development of tumors, to evaluate the implementation of preventive measures, such as vaccination, and to guide early treatment.

Association of DFNA5, SYK, and NELL1 variants along with HPV infection in oral cancer among the prolonged tobacco-chewers

Southeast Asia, especially India, is well known for the highest use of smokeless tobacco. These products are known to induce oral squamous cell carcinoma. However, not all long-term tobacco-chewers develop oral squamous cell carcinoma. In addition, germline variants play a crucial role in susceptibility, prognosis, development, and progression of the disease. These prompted us to study the genetic susceptibility to oral squamous cell carcinoma among the long-term tobacco-chewers. Here, we presented a retrospective study on prolonged tobacco-chewers of Northeast India to identify the potential protective or risk-associated germline variants in tobacco-related oral squamous cell carcinoma along with HPV infection. Targeted re-sequencing (n = 60) of 170 genetic regions from 75 genes was carried out in Ion-PGM™ and validation (n = 116) of the observed variants was done using Sequenom iPLEX MassARRAY™ platform followed by polymerase chain reaction-based HPV genotyping and p16-immunohistochemistry study. Subsequently, estimation of population structure, different statistical and in silico approaches were undertaken. We identified one nonsense-mediated mRNA decay transcript variant in the DFNA5 region (rs2237306), associated with Benzo(a)pyrene, as a protective factor (odds ratio = 0.33; p = 0.009) and four harmful (odds ratio > 2.5; p < 0.05) intronic variants, rs182361, rs290974, and rs169724 in SYK and rs1670661 in NELL1 region, involved in genetic susceptibility to tobacco- and HPV-mediated oral oncogenesis. Among the oral squamous cell carcinoma patients, 12.6% (11/87) were HPV positive, out of which 45.5% (5/11) were HPV16-infected, 27.3% (3/11) were HPV18-infected, and 27.3% (3/11) had an infection of both subtypes. Multifactor dimensionality reduction analysis showed that the interactions among HPV and NELL1 variant rs1670661 with age and gender augmented the risk of both non-tobacco- and tobacco-related oral squamous cell carcinoma, respectively. These suggest that HPV infection may be one of the important risk factors for oral squamous cell carcinoma in this population. Finally, we newly report a DFNA5 variant probably conferring protection via nonsense-mediated mRNA decay pathway against tobacco-related oral squamous cell carcinoma. Thus, the analytical approach used here can be useful in predicting the population-specific significant variants associated with oral squamous cell carcinoma in any heterogeneous population.

Anal verrucous carcinoma is not related to infection with human papillomaviruses and should be distinguished from giant condyloma (Buschke-Löwenstein tumour)

AIMS

Verrucous carcinoma (VC) is a variant of well-differentiated squamous cell carcinoma and in the anal region is regarded as synonymous with giant condyloma (Buschke-Löwenstein tumour) (BLT). Aetiology, diagnostic criteria and clinical behaviour of both lesions are controversial. Recent studies suggest that VC at other sites is not associated with human papillomaviruses (HPV). We hypothesized that anal VC is also not related to HPV, while BLT is a HPV-induced lesion.

METHODS AND RESULTS

Ten cases of VC and four cases of BLT were included. Several techniques were used for HPV detection: in-situ hybridization for HPV6, 11, 16 and 18, six different polymerase chain reaction (PCR) protocols for detection of at least 89 HPV types from alpha-, beta-, gamma- and mu-PV genera and in-situ hybridization for high-risk HPV E6/E7 mRNA; p16 immunohistochemistry and morphometric analysis were also performed. Alpha-, gamma- and mu-PVs were not found in any case of VC, while HPV6 was detected in all cases of BLT. p16 overexpression was not present in any of the lesions. Among microscopic features, only the absence of koilocytosis and enlarged spinous cells seem to be useful to distinguish VC from BLT.

CONCLUSIONS

Our results suggest that anal VC, similarly to VC at other sites, is not associated with HPV infection, and must be distinguished from BLT, which is associated with low-risk HPV. Only with well-set diagnostic criteria will it be possible to ascertain clinical behaviour and optimal treatment for both lesions.

Detection and Genotyping of Human Papillomaviruses from Archival Formalin-Fixed Tissue Samples

Pathology departments routinely process and store formalin-fixed, paraffin-embedded (FFPE) tissue samples for clinical diagnosis. These collections often contain decades' worth of samples and represent a treasure trove of specimens that can be analyzed for retrospective epidemiological studies, diagnostics, and pathogen discovery. Accurate amplification and sequencing of DNA from these samples is critical for the usability of these FFPE samples. Here we present a collection of protocols that describe extraction of DNA from FFPE tissues, PCR amplification of human papillomavirus DNA, and subsequent genotyping of the infecting virus. © 2016 by John Wiley & Sons, Inc.

Low prevalence of transcriptionally active human papilloma virus in Indian patients with HNSCC and leukoplakia

OBJECTIVES

In the present study, we comprehensively analyzed the prevalence of transcriptionally active human papilloma virus (HPV) in tissue samples of Indian patients with leukoplakia, predominantly hyperplastic lesions and head and neck squamous cell carcinoma (HNSCC). In addition, saliva samples from patients with HNSCC were screened for HPV detection.

STUDY DESIGN

P16 overexpression was analyzed by immunohistochemistry. Tissue samples of leukoplakia (n = 121) and HNSCC (n = 427) and saliva from patients with HNSCC (n = 215) were tested for HPV using nested polymerase chain reaction. Positive samples were sequenced for subtyping. The presence of HPV E6/E7 mRNA was confirmed by RNA in situ hybridization.

RESULTS

P16 expression and HPV DNA were not detected in any of the leukoplakia specimens. Of the 427 HNSCC tumors, 9 showed p16 overexpression and 7/427 cases were positive for HPV16 DNA, in saliva or tissue. E6/E7 mRNA positivity was observed in 8 HNSCC samples, primarily from patients with no habit of tobacco consumption. The prevalence of high-risk HPV was restricted to oropharynx and larynx, with very little concordance between p16 overexpression and HPV positivity. All patients with HPV-positive saliva samples had transcriptionally active HPV present in their tumors.

CONCLUSION

The presence of HPV DNA does not necessarily reflect transcriptionally active virus in tumors; hence, it is important to consider this fact while categorizing HPV-associated tumors.

Distribution of human papilloma virus infections of uterine cervix among women of reproductive age--a cross sectional hospital-based study from North East India

Infection of the uterine cervix by human papilloma viruses (HPV) may be associated with cervical pre-cancer and invasive cervical carcinoma if left untreated. With advance in molecular techniques, it has become easier to detect the resence of HPV DNA long before the appearance of any lesion. This study concerned cervical scrape samples of 310 married non-pregnant women attending a gynecology outpatient department for both Pap and PCR testing to detect HPV DNA. Nested PCR using primers for L1 consensus gene with My9/My11 and GP6+/ GP5+followed by multiplex PCR were carried out to detect HPV 16 and HPV18.

RESULT

HPV prevalence was 11.9% out of which 3.67% cases of negative for intra-epithelial lesion or malignancy (NILM) and in 71.1% (27/38) of atypical cervical smears were HPV positive. There was increasing trend of high-risk-HPV positivity (HR HPV 16 and 18), from 20% in benign cytology (NILM) to 42.9 % in LSIL, 71.41% in HSIL and 100% in SCC. There was highly significant association of HPV infection with cervical lesion (x2=144.0, p<0.01) and also with type specific HPV prevalence (x2=7.761*(p<0.05).

Detection of alpha human papillomaviruses in archival formalin-fixed, paraffin-embedded (FFPE) tissue specimens

Formalin-fixed, paraffin-embedded (FFPE) tissue specimens stored in pathology departments worldwide are an invaluable source for diagnostic purposes when fresh clinical material is unavailable as well as for retrospective molecular and epidemiological studies, especially when dealing with rare clinical conditions for which prospective collection is not feasible. Accurate detection of HPV infection in these specimens is particularly challenging because nucleic acids are often degraded and therefore, not suitable for amplification of larger fragments of the viral genome or viral gene transcripts. This review provides a brief summary of molecular methods for detecting alpha-HPV DNA/RNA in FFPE tissue specimens. We specifically address the key procedural and environmental factors that have the greatest impact on the quality of nucleic acids extracted from FFPE tissue specimens, and describe some solutions that can be used to increase their integrity and/or amplifiability. Moreover, commonly used methods for HPV DNA/RNA detection in FFPE tissue specimens are presented and discussed, focusing on studies using polymerase chain reaction as an HPV detection method and published after 1999. Finally, we briefly summarize our 22 years of experience with HPV detection in FFPE tissue specimens.

Epidemiological patterns of cervical human papillomavirus infection among women presenting for cervical cancer screening in North-Eastern Nigeria

Background

Sub-Saharan countries including Nigeria have the highest burden of Human Papillomavirus (HPV) infection in the world. Most studies on HPV surveillance in Nigeria were done in the southern part of the country. Geographical and socio-cultural diversity of Nigeria makes these data unlikely to be universally representative for the entire country. Northern Nigeria especially the North-East carries a higher prevalence of cervical cancer and many of its risk factors. The region may be harbouring a higher prevalence of HPV infection with a possibility of different genotypic distribution. This study was carried out to determine the burden and confirm the predominant HPV genotypes among women presenting for cervical cancer screening at the Federal Teaching Hospital Gombe (FTHG), North-eastern, Nigeria.

Methods

The study was an observational hospital based cross sectional study among women who presented for cervical cancer screening in FTHG. A total of 209 consenting women were tested for cervical HPV infection using PCR. DNA sequencing was carried out on positive samples to determine the prevalent HPV genotypes.

Results

The prevalence of cervical HPV infection among the participants with mean age of 39.6 ± 10.4 years was 48.1 %. The five most predominant genotypes were 18, 16, 33, 31 and 35, with prevalence of 44.7 %, 13.2 %, 7.9 %, 5.3 % and 5.3 % respectively. Other genotypes observed were 38, 45, 56, 58, 82 and KC5. Multiple HPV infections were detected among 7.9 % of participants. Risk factors such as level of education (X² = 15.897; p = 0.007), age at sexual debut (X² = 6.916; p = 0.009), parity (X² = 23.767; p = 0.000), number of life time sexual partners (X² = 7.805; p = 0.005), age at first pregnancy (X² = 10.554; p = 0.005) and history of other malignancies (X² = 7.325; p = 0.007) were found to have a statistically significant association with HPV infection.

Conclusion

This study identified a high burden of HPV infection in Northern Nigeria while also confirming HPV 18 and 16 as the most predominant genotypes. It further justifies the potential benefit of the currently available HPV vaccines in the area. A larger and community based study is however recommended for better representation of the area.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-015-0035-8) contains supplementary material, which is available to authorized users.

Prevalence of HPV infection in head and neck carcinomas shows geographical variability: a comparative study from Brazil and Germany

Rising prevalence rates of high-risk human papillomaviruses (hrHPV) infection in oropharyngeal carcinoma (up to 80 %) have been reported in North America and Scandinavia. We have analysed 424 German and 163 Brazilian head and neck squamous cell carcinomas (HNSCC) from the oral cavity (OSCC), oropharynx (OPSCC) and hypopharynx (HPSCC) using p16 immunohistochemistry, HPV DNA PCR and sequencing, hrHPV DNA in situ hybridisation (ISH) and hrHPV E6/E7 RNA ISH. In the German series, 52/424 cases (12.3 %) were p16-positive/hrHPV-positive (OSCC 3.8 % [10/265], OPSCC 34.4 % [42/122], HPSCC 0 % [0/37]). In addition, there were 9 cases that were p16-positive/hrHPV-negative (5 OPSCC and 4 OSCC). In the Brazilian series, the overall hrHPV DNA prevalence by PCR was 11.0 % ([18/163]; OSCC 6 % [5/83], OPSCC 15.5 % [11/71], HPSCC 22.2 % [2/9]). Ten of these cases were hrHPV-positive/p16-positive. The remaining 8 hrHPV-positive/p16-negative cases were also negative in both ISH assays. Furthermore, 5 p16-positive/hrHPV-negative cases (2 OPSCC and 3 OSCC) were identified. In both series, HPV16 was by far the most common HPV type detected. We confirm that regardless of geographical origin, the highest hrHPV prevalence in HNSCC is observed in oropharyngeal carcinomas. The proportion of HPV-associated OPSCC was substantially higher in the German cohort than in the Brazilian series (34.4 vs. 15.5 %), and in both groups, the prevalence of hrHPV in OPSCC was much lower than in recent reports from North America and Scandinavia. We suggest, therefore, that it may be possible to define areas with high (e.g. USA, Canada, Scandinavia), intermediate (e.g. Germany) and low (e.g. Brazil) prevalences of HPV infection in OPSCC.

Prevalence of human papillomavirus types and phylogenetic analysis of HPV-16 L1 variants from Southern India

BACKGROUND

The human papillomavirus (HPV) and its variants show wide geographical distribution and have been reported to cause cervical lesions. With cervical neoplasia as the leading cancer in Indian women, the aim of the present study was to evaluate the multiple infection HPV type distribution and variant genotypes in cervical samples from the coastal Karnataka region, India.

MATERIALS AND METHODS

A total of 212 samples were screened by nested polymerase chain reaction using PGMY9/11 and GP5+/6+ primers. HPV positive samples were sequenced to identify the types and a phylogenetic tree was constructed using the neighbor-joining method.

RESULTS

Sequence analysis identified a total of 14 HPV types distributed in 20%, 73.3% and 82.5% of non-malignant, pre-malignant [low grade squamous intraepithelial lesion (LSIL) and high grade squamous intraepithelial lesion (HSIL)] and cervical cancer samples. The distribution of high risk HPV in cancer samples was HPV 16, 76.4%, HPV18, 11.7%, HPV81, 2.9%, HPV31, 1.4%, HPV35, 1.4% and HPV 45, 1.4%. Multiple infections were observed in 11.8% of tumor samples with HPV 16 contributing to 62.5% of cases. In non-malignant samples, 20% of HPV positive samples were detected with HPV16, 82.3%, HPV33, 5.8% and HPV58, 5.8% and very low incidence of multiple infections. Comparative phylogenetic analysis of HPV variants identified 9 HPV sequences as new papillomavirus species, predominantly classified as European lineage type.

CONCLUSIONS

The findings for HPV infections associated with progression of cervical cancer in coastal Karnataka region and HPV variant analysis provide baseline data for prevention and HPV vaccination programs.

From Human Papillomavirus (HPV) Detection to Cervical Cancer Prevention in Clinical Practice

The newly gained knowledge of the viral etiology in cervical carcinogenesis has prompted industrial interests in developing virology-based tools for cervical cancer prevention. Due to the long incubation period from viral infection to developing an invasive cancer, a process whose outcome is influenced by numerous life-style and genetic factors, the true efficacy of the genotype-specific human papillomavirus (HPV) vaccines in cervical cancer prevention cannot be determined for another 30 years. Most HPV DNA test kits designed to replace the traditional Papanicolaou (Pap) smears for precancer detection lack the analytical sensitivity and specificity to comprehensively detect all potentially carcinogenic HPVs and to perform reliable genotyping. The authors implemented the classic nested PCR and Sanger DNA-sequencing technology for routine HPV testing. The results showed a true negative HPV PCR invariably indicates the absence of precancerous cells in the cytology samples. However, 80.5% of single positive HPV-16 tests and 97.3% of single positive HPV-18 tests were associated with a negative or a largely self-reversible Pap cytology. Routine sensitive and reliable HPV type-specific or perhaps even variant-specific methods are needed to address the issues of persistence of HPV infection if a virology-based primary cervical screen is used to replace the Pap cytology screening paradigm.

Polymerase chain reaction and deoxyribonucleic acid-sequencing based study on distribution of human papillomavirus 16/18 among histopathological types of cervical intra-epithelial neoplasia and primary invasive cervical carcinoma: A scenario in North Bengal, India

Introduction:

Human papillomavirus (HPV) types 16/18 are reportedly most common in cervical cancer (CaCx) with geographical variation of genotypes. HPV16 predominates both in squamous cell carcinoma (SCC) and adenocarcinoma in India, contrary to reported global predominance of HPV18 in the latter. Our study was aimed to determine the occurrence of HPV16/18 among histopathological types of cervical intra-epithelial neoplasia (CIN) and invasive CaCx from North Bengal, India and to identify any major deviation from the known Indian scenario of distribution of HPV16/18 genotypes in cases of SCC and adenocarcinoma.

Materials and Methods:

This was a retrospective, cross-sectional, case-only type of study, in which 40 cases were histopathologically diagnosed as CIN/CaCx, on which polymerase chain reaction (PCR), deoxyribonucleic acid (DNA)-sequencing and bioinformatics by basic search local alignment tool were performed for HPV-genotyping.

Statistical Analysis:

The distribution of HPV genotypes among cases of SCC and adenocarcinoma was compared by Fisher's exact-test.

Results:

HPV was detected in 97.5% (39/40) cases. HPV16-infected cases (32/39; 82.05%) predominated over HPV18-infected ones (7/39; 17.95%). However, HPV18-only infection was significantly (P = 0.0045, one-sided Fisher's exact test) more among adenocarcinoma (3/4; 75%) than SCC (2/26; 7.69%) contrary to HPV16-only infection (SCC = 24/26, 92.31%; adenocarcinoma = 1/4; 25%) whereas both CIN3 cases were HPV16-positive.

Conclusion:

Predominance of HPV18 over HPV16 in cases of adenocarcinoma in this region was contrasting to that of earlier Indian studies suggesting research on HPV18 related cervical carcinogenesis. PCR and DNA-sequencing could prove to be highly effective tools in HPV detection and genotyping. The study reported HPV16/18 infection in almost 98% of the cases, the knowledge about which might prove useful in future population based studies on HPV genotyping and designing of appropriate HPV-vaccines for this region.

HPV E6/E7 RNA in situ hybridization signal patterns as biomarkers of three-tier cervical intraepithelial neoplasia grade

Cervical lesion grading is critical for effective patient management. A three-tier classification (cervical intraepithelial neoplasia [CIN] grade 1, 2 or 3) based on H&E slide review is widely used. However, for reasons of considerable inter-observer variation in CIN grade assignment and for want of a biomarker validating a three-fold stratification, CAP-ASCCP LAST consensus guidelines recommend a two-tier system: low- or high-grade squamous intraepithelial lesions (LSIL or HSIL). In this study, high-risk HPV E6/E7 and p16 mRNA expression patterns in eighty-six CIN lesions were investigated by RNAscope chromogenic in situ hybridization (CISH). Specimens were also screened by immunohistochemistry for p16INK4a (clone E6H4), and by tyramide-based CISH for HPV DNA. HPV genotyping was performed by GP5+/6+ PCR combined with cycle-sequencing. Abundant high-risk HPV RNA CISH signals were detected in 26/32 (81.3%) CIN 1, 22/22 (100%) CIN 2 and in 32/32 (100%) CIN 3 lesions. CIN 1 staining patterns were typified (67.7% specimens) by abundant diffusely staining nuclei in the upper epithelial layers; CIN 2 lesions mostly (66.7%) showed a combination of superficial diffuse-stained nuclei and multiple dot-like nuclear and cytoplasmic signals throughout the epithelium; CIN 3 lesions were characterized (87.5%) by multiple dot-like nuclear and cytoplasmic signals throughout the epithelial thickness and absence/scarcity of diffusely staining nuclei (trend across CIN grades: P<0.0001). These data are consistent with productive phase HPV infections exemplifying CIN 1, transformative phase infections CIN 3, whereas CIN 2 shows both productive and transformative phase elements. Three-tier data correlation was not found for the other assays examined. The dual discernment of diffuse and/or dot-like signals together with the assay's high sensitivity for HPV support the use of HPV E6/E7 RNA CISH as an adjunct test for deciding lesion grade when CIN 2 grading may be beneficial (e.g. among young women) or when 'LSIL vs. HSIL' assignment is equivocal.

DNA promoter methylation-dependent transcription of the double C2-like domain β (DOC2B) gene regulates tumor growth in human cervical cancer

Double C2-like domain β (DOC2B) gene encodes for a calcium-binding protein, which is involved in neurotransmitter release, sorting, and exocytosis. We have identified the promoter region of the DOC2B gene as hypermethylated in pre-malignant, malignant cervical tissues, and cervical cancer cell lines by methylation-sensitive dimethyl sulfoxide-polymerase chain reaction and bisulfite genome sequencing; whereas, it was unmethylated in normal cervical tissues (p < 0.05). The promoter hypermethylation was inversely associated with mRNA expression in SiHa, CaSki, and HeLa cells and treatment with demethylating agent 5-aza-2-deoxycytidine restored DOC2B expression. The region -630 to +25 bp of the DOC2B gene showed robust promoter activity by a luciferase reporter assay and was inhibited by in vitro artificial methylation with Sss1 methylase prior to transient transfections. Overexpression of the DOC2B gene in SiHa cells when compared with controls showed significantly reduced colony formation, cell proliferation, induced cell cycle arrest, and repressed cell migration and invasion (p < 0.05). Ectopic expression of DOC2B resulted in anoikis-mediated cell death and repressed tumor growth in a nude mice xenograft model (p < 0.05). DOC2B expressing cells showed a significant increase in intracellular calcium level (p < 0.05), impaired AKT1 and ERK1/2 signaling, and induced actin cytoskeleton remodeling. Our results show that promoter hypermethylation and silencing of the DOC2B gene is an early and frequent event during cervical carcinogenesis and whose reduced expression due to DNA promoter methylation may lead to selective cervical tumor growth.

Distribution of HPV Genotypes and Involvement of Risk Factors in Cervical Lesions and Invasive Cervical Cancer: A Study in an Indian Population

Human papilloma virus (HPV) is considered as the main sexually transmitted etiological agent for the cause and progression of preneoplastic cervical lesions to cervical cancer. This study is discussing the prevalence of HPV and its genotypes in cervical lesions and invasive cervical cancer tissues and their association with various risk factors in women from Varanasi and its adjoining areas in India. A total of 122 cervical biopsy samples were collected from SS Hospital and Indian Railways Cancer Institute and Research Centre, Varanasi and were screened for HPV infection by PCR using primers from L1 consensus region of the viral genome. HPV positive samples were genotyped by type-specific PCR and sequencing. The association of different risk factors with HPV infection in various grades of cervical lesion was evaluated by chi-square test. A total of 10 different HPV genotypes were observed in women with cervicitis, CIN, invasive squamous cell cervical carcinoma and adenocarcinoma. Increased frequency of HPV infection with increasing lesion grade (p=0.002) was observed. HPV16 being the predominant type was found significantly associated with severity of the disease (p=0.03). Various socio- demographic factors other than HPV including high parity (p<0.0001), rural residential area (p<0.0001), elder age (p<0.0001), low socio-economic status (p<0.0001) and women in postmenopausal group (p<0.0001) were also observed to be associated with cervical cancer.These findings show HPV as a direct cause of cervical cancer suggesting urgent need of screening programs and HPV vaccination in women with low socio-economic status and those residing in rural areas.

Verrucous carcinoma of the head and neck - not a human papillomavirus-related tumour?

Association between verrucous carcinoma (VC) of the head and neck and human papillomaviruses (HPV) is highly controversial. Previous prevalence studies focused mostly on α-PV, while little is known about other PV genera. Our aim was to investigate the prevalence of a broad spectrum of HPV in VC of the head and neck using sensitive and specific molecular assays. Formalin-fixed, paraffin-embedded samples of 30 VC and 30 location-matched normal tissue samples were analysed, by using six different polymerase chain reaction-based methods targeting DNA of at least 87 HPV types from α-PV, β-PV, γ-PV and μ-PV genera, and immunohistochemistry against p16 protein. α-PV, γ-PV and μ-PV were not detected. β-PV DNA was detected in 5/30 VC (16.7%) and in 18/30 normal tissue samples (60.0%): HPV-19, -24 and -36 were identified in VC, and HPV-5, -9, -12, -23, -24, -38, -47, -49 and -96 in normal tissue, whereas HPV type was not determined in 2/5 cases of VC and in 6/18 normal tissue samples. p16 expression was detected in a subset of samples and was higher in VC than in normal tissue. However, the reaction was predominantly cytoplasmic and only occasionally nuclear, and the extent of staining did not exceed 75%. Our results indicate that α-PV, γ-PV and μ-PV are not associated with aetiopathogenesis of VC of the head and neck. β-PV DNA in a subset of VC and normal tissue might reflect incidental colonization, but its potential biological significance needs further investigation.

Evidence that alpha-9 human papillomavirus infections are a major etiologic factor for oropharyngeal carcinoma in black South Africans

Human papillomavirus (HPV) infection, most commonly genotype 16 of the alpha-9 family, is implicated in the etiology of a subset of oropharyngeal squamous cell carcinomas (OPSC) worldwide. Data are scarce regarding OPSC in South Africans, and three prior studies suggest no significant etiologic role for HPV. We aimed to investigate for evidence of HPV etiology in OPSCs from black South Africans by polymerase chain reaction (PCR) methodologies with determination of HPV subtype by sequencing, in situ hybridization (ISH), and p16INK4a immunohistochemistry (IHC), as a surrogate marker for an HPV-driven tumor. It was hypothesized that HPV-driven tumors would be positive by PCR plus IHC and/or ISH whereas OPSCs with HPV background infections (HPV-passenger) would be positive by PCR alone. Formalin-fixed, paraffin embedded tissues from 51 OPSCs collected between 2005 and 2010 from 41 patients were analyzed for HPV by GP5?6? PCR (targeting the HPV L1 region), pU-1M/pU- 2R PCR (targeting the HPV E6/E7 region) and HPV-31 specific PCR (targeting the E5 region), chromogenic ISH, and p16INK4a IHC. All cases positive by PCR were subject to sequencing to determine HPV genotype. The patient mean age was 58.0 years and 88 % were male. Of the 51 evaluable tumors, 48 (94.1 %) were positive for HPV DNA by PCR: 25 (49.1 %) met criteria for an HPV-driven tumor, 23 (45.1 %) for HPV-passenger, and 3 (5.9 %) were HPV unrelated. Sequencing of the PCR-positive cases revealed the following genotypes: combined HPV-16 and 31 (41.7 %), HPV-31 (25.0 %), HPV-16 (22.9 %), combined HPV-16 and 18 (6.3 %), and a single case each of HPV 18 and HPV 33. Studies via ISH were negative in all cases. In accordance with worldwide trends but contrary to prior South African data, HPV likely plays an etiologic role in a significant subset (at least 49.1 %) of OPSC in black South Africans. We found that the alpha-9 HPV family, particularly HPV-16 and 31 either in combination or separately, to predominate in our sample tumors. The use of multiple PCR primers increased sensitivity of viral detection, and a HPV-31 specific primer confirmed the presence of this genotype in many samples. Further studies including HPV E6/E7 mRNA assays are needed to better elucidate the pathogenic role of HPV in black South African OPSCs.

Detection of HPV infection in head and neck squamous cell carcinoma: a practical proposal

Detecting human papillomavirus (HPV) infection in head and neck squamous cell carcinoma (HNSCC) is clinically relevant, but there is no agreement about the most appropriate methodology. We have studied 64 oropharyngeal carcinomas using p16 immunohistochemistry, HPV DNA in situ hybridisation (ISH) and HPV DNA polymerase chain reaction (PCR) followed by pyrosequencing. We have also evaluated a new assay, RNAscope, designed to detect HPV E6/E7 RNA transcripts. Using a threshold of 70 % labelled tumour cells, 21 cases (32.8 %) were p16 positive. Of these, 19 cases scored positive with at least one HPV detection assay. Sixteen cases were positive by HPV DNA-ISH, and 18 cases were positive using the E6/E7 RNAscope assay. By PCR and pyrosequencing, HPV16 was detected in 15 cases, while one case each harboured HPV33, 35 and 56. All p16-negative cases were negative using these assays. We conclude that p16 expression is a useful surrogate marker for HPV infection in HNSCC with a high negative predictive value and that p16-positive cases should be further evaluated for HPV infection, preferably by PCR followed by type determination. Using RNase digestion experiments, we show that the RNAscope assay is not suitable for the reliable discrimination between E6/E7 RNA transcripts and viral DNA.

Mitochondrial DNA copy number and risk of oral cancer: a report from Northeast India

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer globally. Tobacco consumption and HPV infection, both are the major risk factor for the development of oral cancer and causes mitochondrial dysfunction. Genetic polymorphisms in xenobiotic-metabolizing enzymes modify the effect of environmental exposures, thereby playing a significant role in gene-environment interactions and hence contributing to the individual susceptibility to cancer. Here, we have investigated the association of tobacco - betel quid chewing, HPV infection, GSTM1-GSTT1 null genotypes, and tumour stages with mitochondrial DNA (mtDNA) content variation in oral cancer patients.

METHODOLOGY/PRINCIPAL FINDINGS

The study comprised of 124 cases of OSCC and 140 control subjects to PCR based detection was done for high-risk HPV using a consensus primer and multiplex PCR was done for detection of GSTM1-GSTT1 polymorphism. A comparative ΔCt method was used for determination of mtDNA content. The risk of OSCC increased with the ceased mtDNA copy number (Ptrend  = 0.003). The association between mtDNA copy number and OSCC risk was evident among tobacco - betel quid chewers rather than tobacco - betel quid non chewers; the interaction between mtDNA copy number and tobacco - betel quid was significant (P = 0.0005). Significant difference was observed between GSTM1 - GSTT1 null genotypes (P = 0.04, P = 0.001 respectively) and HPV infection (P<0.001) with mtDNA content variation in cases and controls. Positive correlation was found with decrease in mtDNA content with the increase in tumour stages (P<0.001). We are reporting for the first time the association of HPV infection and GSTM1-GSTT1 null genotypes with mtDNA content in OSCC.

CONCLUSION

Our results indicate that the mtDNA content in tumour tissues changes with tumour stage and tobacco-betel quid chewing habits while low levels of mtDNA content suggests invasive thereby serving as a biomarker in detection of OSCC.

Salivary mucoepidermoid carcinoma: demonstration of transcriptionally active human papillomavirus 16/18

Herein we test the following hypotheses: (1) High-risk Human Papillomavirus (HR-HPV) may be involved in the etiology of mucoepidermoid carcinoma (MEC), and (2) The detection rate of HR-HPV in MEC has been increasing over time. Ninety-eight archival MEC specimens from three institutions spanning three decades were studied for HPV16/18 E6/E7 transcripts. RNA was extracted from formalin-fixed paraffin embedded specimens and HPV16/18 E6/E7 expression assessed by nested reverse transcription polymerase chain reaction (RT-PCR). A subset of MEC were also studied for MECT1-MAML2 fusion transcripts by nested RT-PCR and amplicon sequencing. The HPV expression data was validated by immunofluorescence (IF) with monoclonal HPV16/18 E6 antibody, PCR with the GP5+/6+ consensus primers, and sequencing of RT-PCR amplicons. HPV genome was localized by in-situ hybridization with the Ventana Inform HPVIII Family 16 probe. P16(INK4a) overexpression and aberrant p53 expression were assessed by immunohistochemistry. HPV16 E6/E7 transcripts were demonstrated in (29/98) 30% of MEC by RT-PCR. HPV18 E6/E7 transcripts were demonstrated in 13/98 (13%) of MEC by RT-PCR. Seven of 98 tumors (7%) demonstrated both HPV16/18. No significant association was found between HPV status and gender, age, and tumor site. All 13 HPV18+ MEC were diagnosed between 2001 and 2010, whereas 45 MEC diagnosed from 1977 to 2000 were negative for HPV18 (p = 0.002). By contrast, there was no significant difference with respect to HPV16 detection and date of diagnosis. All MEC that were positive for E6 protein were also HPV16/18 positive by RT-PCR. Sequencing a subset of RT-PCR amplicons confirmed HPV type- and region-specific sequences. PCR using GP5+/6+ consensus primers demonstrated HPV status concordance in 9 of 10 cases. DNA degradation was present in the last case; the RT-PCR amplicons were sequenced from this case which confirmed the presence of HPV type- and region-specific sequences. Strong (+4/+4) and diffuse (>50%) nuclear and cytoplasmic p16 expression was seen in 64% of MEC in the glandular regions, and 18% of MEC in the solid, squamoid regions. No correlation was seen between p16 expression and HPV status. Twenty-nine MEC (22 HPV+ and 7 HPV-negative) were selected for further evaluation for p53 expression. Strong aberrant nuclear p53 expression was present in only 2/22 HPV + MEC (9%, both Grade 3); no HPV-negative MEC demonstrated aberrant p53 expression. MECT1-MAML2 fusion transcripts were demonstrated in 23/37 (62%) MEC. No significant association was found between the presence of the MECT1-MAML2 fusion transcripts and tumor grade, HPV status, gender, era of diagnosis (2000 and earlier vs. 2001-2010) or tumor site. We demonstrate for the first time that transcriptionally active HPV16/18 is common to MEC. These findings were validated by demonstrating concordant results by separate PCR with consensus primers, and/or confirming the presence of HPV type- and region-specific sequences in the RT-PCR amplicons. We also visualized E6 viral oncoprotein and HPV genome within tumor cells. HR-HPV is thus potentially implicated in the pathogenesis of MEC. The frequency of HPV18 detection is significantly increased in MEC diagnosed after 2001, whereas we found no differences in the HPV16 detection rates per era of diagnosis.

Guidelines for the use of molecular tests for the detection and genotyping of human papilloma virus from clinical specimens

Accurate genotyping of a human papilloma virus (HPV) isolated from clinical specimens depends on molecular identification of the unique and exclusive nucleotide base sequence in the hypervariable region of a highly conserved segment of the HPV L1 gene. Among other options, a heminested (nested) polymerase chain reaction (PCR) technology using two consecutive PCR replications of the target DNA in tandem with three consensus general primers may be used to detect a minute quantity of HPV DNA in crude proteinase K digestate of cervicovaginal cells, and to prepare the template for genotyping by automated direct DNA sequencing. A short target sequence of 40-60 bases excised from the computer-generated electropherogram is sufficient for BLAST determination of all clinically relevant HPV genotypes, based on the database stored in the GenBank. This chapter discusses the principle and the essential technical elements in performing nested PCR DNA amplification for the detection of HPV from clinical specimens and short target sequence genotyping for HPV, using standard molecular biology laboratory equipment and commercially available reagents.

Evaluation of a new multiplex real-time polymerase chain reaction assay for the detection of human papillomavirus infections in a referral population

OBJECTIVES

Human papillomavirus (HPV) testing is an important part of cervical cancer screening and management of women with atypical screening results. This study was conducted to evaluate the analytical and clinical performance of the Abbott RealTime High-Risk HPV assay (RealTime) in a referral population, in comparison to the Qiagen Hybrid Capture 2 High-Risk HPV DNA Test (hc2).

METHODS

RealTime is a new polymerase chain reaction assay that detects 14 high-risk HPV genotypes with simultaneous differentiation between HPV 16 and HPV 18. Five hundred forty-five routine cervical smear samples (ThinPrep) from women who were referred to 2 German colposcopy clinics were included in the study. All samples were tested with both assays for the detection of high-risk HPV DNA. Specimens with repeatedly discordant results were genotyped by Linear Array (Roche) and in-house polymerase chain reaction assays.

RESULTS

Both assays showed excellent overall agreement (92.8%; κ = 0.86) on 545 samples. Analytical sensitivity of RealTime was comparable to that of hc2 (97.6% vs 95.1%, P = 0.189), whereas RealTime demonstrated significantly higher analytical specificity compared with hc2 (100% vs 93.1%, P < 0.0001). RealTime showed no cross-reactivity with untargeted HPV genotypes in this study. The clinical performance of the assays was evaluated based on histology results available from 319 women (90 nonpathological, 73 cervical intraepithelial neoplasia [CIN] 1, 75 CIN 2, 74 CIN 3, and 7 invasive cancers). High-risk HPV detection rates observed in women with CIN 1, CIN 2+, and CIN 3+ diagnosis, respectively, were comparable for both assays: 47.9%, 92.3%, and 97.5% (RealTime) and 47.9%, 92.3%, and 93.8% (hc2). Detection of HPV 16/18 with RealTime was highly correlated with severity of dysplasia: less than CIN 2, 30.5%; CIN 2+, 59.0%; CIN 3+, 71.6%.

CONCLUSIONS

These results support the use of RealTime for routine detection of HPV infections in a referral population.

High prevalence of oncogenic HPV-16 in cervical smears of asymptomatic women of eastern Uttar Pradesh, India: a population-based study

In developing countries like India, occurrence of Human papillomavirus (HPV) in cervical cancer as well as in the asymptomatic population was observed to be very high. Studies on HPV prevalence have been conducted in different parts of the country but no data were available from the eastern region of Uttar Pradesh (UP). The present study aimed to determine the status of HPV prevalence and its association with different socio-demographic factors in this population. Prevalence of HPV was investigated in a total of 2424 cervical scrape samples of asymptomatic women. Primer sets from L1 consensus region of viral genome were used to detect the presence of HPV, and the positive samples were genotyped by sequencing. Univariate binary logistic regression analysis was used to evaluate association of socio-demographic factors with HPV. 9.9% of the clinically asymptomatic women were found to be infected with HPV comprising 26 different genotypes. Among HPV-positive women, 80.8% showed single infection, while 15.4% harboured multiple infections. HPV-16 (63.7%) was the most prevalent, followed by HPV-31 (6.7%), HPV-6 (5.4%), HPV-81 (4.6%) and HPV-33 (4.2%). Significant association of HPV with non-vegetarian diet (P less than 0.05) and rural residential areas (P less than 0.01) were observed. High prevalence of HPV-16 in asymptomatic women of this population, a frequency comparable to invasive cervical cancers, highlights an urgent need for a therapeutic HPV vaccine covering HPV-16 and other high-risk types to provide protection against the disease.

In situ hybridization signal patterns in recurrent laryngeal squamous papillomas indicate that HPV integration occurs at an early stage

Laryngeal papillomas are benign tumors that frequently recur and can compromise airways. We investigated HPV genotype, physical status, and protein expression in juveniles versus adults. Thirty-five laryngeal papilloma specimens were obtained from ten juveniles (1-16 years) and eleven adults (24-67 years). In cases of recurrent papillomatosis (7 juveniles, 7 adults), the first and last papillomas were assayed. HPV type was determined by GP5+/6+ PCR and dot blot hybridization. In situ hybridization (ISH) was performed on 34 specimens; the data were recorded in terms of diffuse (episomal HPV) and punctate (integrated HPV) signal patterns. Immunohistochemistry for the HPV L1 capsid protein, a marker of HPV productive status, was performed on 32 samples. All samples tested HPV positive: HPV 11 in 2/10 (20.0%) juveniles and 5/11 (45.5%) adults; HPV 6 in 7/10 (70%) juveniles and 5/11 (45.5%) adults; and HPV 6/11 double infection was noted in one juvenile and one adult. ISH signals (punctate ± diffuse) were detected among 7/10 (70.0%) juveniles and 7/11 (63.6%) adults. L1 staining was detected in 1/9 (11.1%) juveniles and 6/10 (60.0%) adults (P = 0.06). These data support the idea that integration of low-risk HPV types into the cell genome is an early and common event in the etiology of juvenile and adult recurrent laryngeal papillomas. Productive HPV infections may be more common in adults; accordingly, constant laryngeal re-infection by HPV shed from a productive lesion may contribute to adult recurrent lesions, whereas the mechanism of papilloma recurrence in juveniles may be more attributable to HPV integration.

Discrimination of 'driver' and 'passenger' HPV in tonsillar carcinomas by the polymerase chain reaction, chromogenic in situ hybridization, and p16(INK4a) immunohistochemistry

Human papillomavirus (HPV) positive tonsillar squamous cell carcinoma (TSCC) is associated with a favorable clinical outcome. However, the HPV detected in a given tumor may be causal (driver HPV) or an incidental bystander (passenger HPV). There is a need to discriminate these forms of HPV in TSCCs to understand their impact on HPV as a biomarker for use in TSCC patient management. This study has compared the polymerase chain reaction (PCR), chromogenic in situ hybridization (CISH), and p16(INK4a) immunohistochemistry in the assessment of HPV status in TSCC. Archival specimens of TSCC from thirty patients were investigated. HPV was detected by PCR in 25/30 (83.3%) tumors; HPV16 (70.0%) and HPV52 (6.7%) were the most common types. HPV was corroborated by CISH in 22/25 (88.0%) specimens; integrated HPV was implicated by the presence of punctate signals in each of these cases. p16(INK4a) staining was found in 20/22 (90.9%) HPV PCR positive samples; two PCR/CISH HPV positive cases were p16(INK4a) negative and two HPV negative samples were p16(INK4a) positive. These data suggest that a minority of HPV positive TSCCs are positive for passenger HPV and that two or more assays may be required for diagnosing driver HPV status. Further studies are required to exam whether oropharyngeal tumors positive for passenger HPV have a less favorable prognosis than tumors that are driver HPV positive. The clinical significance of TSCCs that test HPV negative/p16(INK4a) positive, PCR and CISH HPV positive/p16 (INK4a) negative, or PCR HPV positive/p16 (INK4a) and CISH negative, also requires further investigation.

Comparison of clinical and analytical performance of the Abbott Realtime High Risk HPV test to the performance of hybrid capture 2 in population-based cervical cancer screening

The clinical performance of the Abbott RealTime High Risk HPV (human papillomavirus) test (RealTime) and that of the Hybrid Capture 2 HPV DNA test (hc2) were prospectively compared in the population-based cervical cancer screening setting. In women >30 years old (n = 3,129), the clinical sensitivity of RealTime for detection of cervical intraepithelial neoplasia of grade 2 (CIN2) or worse (38 cases) and its clinical specificity for lesions of less than CIN2 (3,091 controls) were 100% and 93.3%, respectively, and those of hc2 were 97.4% and 91.8%, respectively. A noninferiority score test showed that the clinical specificity (P < 0.0001) and clinical sensitivity (P = 0.011) of RealTime were noninferior to those of hc2 at the recommended thresholds of 98% and 90%. In the total study population (women 20 to 64 years old; n = 4,432; 57 cases, 4,375 controls), the clinical sensitivity and specificity of RealTime were 98.2% and 89.5%, and those of hc2 were 94.7% and 87.7%, respectively. The analytical sensitivity and analytical specificity of RealTime in detecting targeted HPV types evaluated with the largest sample collection to date (4,479 samples) were 94.8% and 99.8%, and those of hc2 were 93.4% and 97.8%, respectively. Excellent analytical agreement between the two assays was obtained (kappa value, 0.84), while the analytical accuracy of RealTime was significantly higher than that of hc2. RealTime demonstrated high intralaboratory reproducibility and interlaboratory agreement with 500 samples retested 61 to 226 days after initial testing in two different laboratories. RealTime can be considered to be a reliable and robust HPV assay clinically comparable to hc2 for the detection of CIN2+ lesions in a population-based cervical cancer screening setting.

HPV is detectable in virtually all abnormal cervical cytology samples after reinvestigation of HPV negatives with multiple alternative PCR tests

The demonstration of human papillomavirus (HPV) in 99.7% of cervical carcinoma surgical specimens from around the world required investigations by multiple alternative polymerase chain reaction (PCR) assays. A similar approach may therefore be necessary to best characterize HPV prevalence and genotype distribution among cervical cytology samples. In an earlier study, 752 of 799 (94.1%) abnormal and 82 of 300 (27.3%) normal cytology specimens tested HPV positive after PCR using GP5+/6+primers. This study has reinvestigated the "HPV negative" abnormal samples (20 atypical squamous cells of undetermined significance, 5 low-grade squamous intraepithelial lesion, 14 atypical squamous cells, cannot exclude HSIL, 6 high-grade squamous intraepithelial lesion) and an age-matched cohort of "HPV negative" normal (negative for an intraepithelial lesion or malignancy) samples by PCR using PGMY09/11, FAP59/64, and LCR-E7 primers. PGMY09/11-GP5+/6+ nested PCR was performed on samples that were HPV negative by PGMY09/11 PCR. After the first 3 assays, HPV was detected in 41 of 45 (91.1%) abnormal and in 10 of 47 (21.3%) normal samples (P<0.0001). Eighteen HPV genotypes were detected and in some samples the genotype that was identified differed between the tests. The nondetection of common HPV genotypes (eg, HPVs 6, 11, 16, and 18) was notable. High-grade histopathology was found for 2 patients with HPV52-positive cytopathology. Combined with our earlier study, HPV (40 different genotypes) is shown in 99.5% of abnormal samples (99.8% inclusive of the nested PCR data). These findings show that HPV genotype and prevalence estimates are dependent on the method(s) of detection and indicate that suboptimal analytical sensitivity for one or more of the less common high-risk HPV genotypes could lead to impaired clinical sensitivity. HPV may be causal in almost every instance of abnormal cervical cytology; however, passenger HPV that is incidental to an abnormality may also have been detected.