Beta Human Papillomavirus Research Articles

Genome composition-based deep learning predicts oncogenic potential of HPVs.

Human papillomaviruses (HPVs) account for more than 30% of cancer cases, with definite identification of the oncogenic role of viral E6 and E7 genes. However, the identification of high-risk HPV genotypes has largely relied on lagged biological exploration and clinical observation, with types unclassified and oncogenicity unknown for many HPVs. In the present study, we retrieved and cleaned HPV sequence records with high quality and analyzed their genomic compositional traits of dinucleotide (DNT) and DNT representation (DCR) to overview the distribution difference among various types of HPVs. Then, a deep learning model was built to predict the oncogenic potential of all HPVs based on E6 and E7 genes. Our results showed that the main three groups of Alpha, Beta, and Gamma HPVs were clearly separated between/among types in the DCR trait for either E6 or E7 coding sequence (CDS) and were clustered within the same group. Moreover, the DCR data of either E6 or E7 were learnable with a convolutional neural network (CNN) model. Either CNN classifier predicted accurately the oncogenicity label of high and low oncogenic HPVs. In summary, the compositional traits of HPV oncogenicity-related genes E6 and E7 were much different between the high and low oncogenic HPVs, and the compositional trait of the DCR-based deep learning classifier predicted the oncogenic phenotype accurately of HPVs. The trained predictor in this study will facilitate the identification of HPV oncogenicity, particularly for those HPVs without clear genotype or phenotype.

Synchronous Epidermodysplasia Verruciformis and Intraepithelial Lesion of the Vulva Is Caused by Coinfection With Alpha-Human Papillomavirus and Beta-Human Papillomavirus Genotypes and Facilitated by Mutations in Cell-Mediated Immunity Genes.

There have been exceedingly few reports of epidermodysplasia verruciformis (EV) or EV-like lesions in the vulva. We describe the first observation of vulvar lesions displaying synchronous EV-like histology and conventional high-grade squamous intraepithelial lesion (HSIL), a finding hitherto unreported in medical literature. To describe this novel vulvar lesion with hybrid features of HSIL and EV, attempt to confirm the hypothesis of coinfection with α and β human papillomavirus (α-HPV and β-HPV) genotypes, and describe relevant underlying genetic mutations. Cases were retrospectively selected from our institutional archive. Detailed review of clinical information, histologic examination, and whole genome sequencing (WGS) were performed. Five samples from 4 different patients were included. Three of 4 patients had a history of either iatrogenic immune suppression or prior immune deficiency, and all 3 featured classic HSIL and EV changes within the same lesion. One patient had no history of immune disorders, presented with EV-like changes and multinucleated atypia of the vulva, and was the sole patient without conventional HSIL. By WGS, several uniquely mappable reads pointed toward infection with multiple HPV genotypes, including both α-HPVs and β-HPVs. Mutations in genes implicated in cell-mediated immunity, such as DOCK8, CARMIL2, MST1, and others, were also found. We provide the first description of vulvar lesions harboring simultaneous HSIL and EV features in the English-language literature, a phenomenon explained by coinfection with α-HPV and β-HPV genotypes. The finding of EV-like changes in a vulvar specimen should prompt assessment of the patient's immune status.

The cutaneous beta human papillomavirus type 8 E6 protein induces CCL2 through the CEBPα/miR-203/p63 pathway to support an inflammatory microenvironment in epidermodysplasia verruciformis skin lesions.

Human papillomavirus type 8 (HPV8), a cutaneous genus beta HPV type, has co-carcinogenic potential at sun-exposed sites in patients suffering from the inherited skin disease epidermodysplasia verruciformis (EV). We had previously shown that Langerhans cells responsible for epithelial immunosurveillance were strongly reduced at infected sites and that the HPV8 E7 protein interferes with the CCAAT/enhancer-binding protein (C/EBP)β to suppress the Langerhans cell chemokine CCL20. At the same time, however, we observed that EV lesions are heavily infiltrated with inflammatory immune cells, which is similar to the situation in HPV8 E6 transgenic mice. To identify critical inflammatory factors, we used a broad multiplex approach and found that the monocyte attracting chemokine CCL2 was significantly and strongly induced by HPV8 E6 but not E7-expressing HaCaT cells, which were used as a model for UV-damaged skin keratinocytes. Conditioned media from HPV8 E6-expressing keratinocytes enhanced CCL2-receptor (CCR2)-dependent monocyte recruitment in vitro, and macrophages predominated in the stroma but were also detected in the epidermal compartment of EV lesions in vivo. CCL2 induction by HPV8 E6 was even stronger than stimulation with the proinflammatory cytokine TNF-α, and both HPV8 E6 and TNF-α resulted in substantial suppression of the transcription factor C/EBPα. Using RNAi-mediated knockdown and overexpression approaches, we demonstrated a mechanistic role of the recently identified C/EBPα/miR-203/p63 pathway for HPV8 E6-mediated CCL2 induction at protein and transcriptional levels. Epithelial co-expression of p63 and CCL2 was confirmed in HPV8 E6-expressing organotypic air-liquid interface cultures and in lesional EV epidermis in vivo. In summary, our data demonstrate that HPV8 oncoproteins actively deregulate epidermal immune homeostasis through modulation of C/EBP factor-dependent pathways. While HPV8 E7 suppresses immunosurveillance required for viral persistence, the present study provides evidence that E6 involves the stemness-promoting factor p63 to support an inflammatory microenvironment that may fuel carcinogenesis in EV lesions.

Comparative Analysis of Alpha and Beta HPV E6 Oncoproteins: Insights into Functional Distinctions and Divergent Mechanisms of Pathogenesis.

Human papillomaviruses (HPVs) represent a diverse group of DNA viruses that infect epithelial cells of mucosal and cutaneous tissues, leading to a wide spectrum of clinical outcomes. Among various HPVs, alpha (α) and beta (β) types have garnered significant attention due to their associations with human health. α-HPVs are primarily linked to infections of the mucosa, with high-risk subtypes, such as HPV16 and HPV18, being the major etiological agents of cervical and oropharyngeal cancers. In contrast, β-HPVs are predominantly associated with cutaneous infections and are commonly found on healthy skin. However, certain β-types, notably HPV5 and HPV8, have been implicated in the development of non-melanoma skin cancers in immunocompromised individuals, highlighting their potential role in pathogenicity. In this review, we comprehensively analyze the similarities and differences between α- and β-HPV E6 oncoproteins, one of the major drivers of viral replication and cellular transformation, and how these impact viral fitness and the capacity to induce malignancy. In particular, we compare the mechanisms these oncoproteins use to modulate common cellular processes-apoptosis, DNA damage repair, cell differentiation, and the immune response-further shedding light on their shared and distinct features, which enable them to replicate at divergent locations of the human body and cause different types of cancer.

Prevalence of Alpha, Beta, and Gamma Human Papillomaviruses in Patients With Head and Neck Cancer and Noncancer Controls and Relation to Behavioral Factors.

Human papillomaviruses (HPVs) cause head and neck cancer (HNC), which is increasing in incidence in developed countries. We investigated the prevalence of alpha (α), beta (β), and gamma (γ) HPVs among HNC cases and controls, and their relationship with sociodemographic, behavioral, and oral health factors. We obtained oral rinse and brush samples from incident HNC cases (n = 369) and hospital-based controls (n = 439) and tumor samples for a subsample of cases (n = 121). We genotyped samples using polymerase chain reaction with PGMY09-PGMY11 primers and linear array for α-HPV and type-specific multiplex genotyping assay for β-HPV and γ-HPV. Sociodemographic and behavioral data were obtained from interviews. The prevalence of α-, β-, and γ-HPV among controls was 14%, 56%, and 24%, respectively, whereas prevalence among cases was 42%, 50%, and 33%, respectively. Prevalence of α- and γ-HPV, but not β-HPV, increased with increase in sexual activity, smoking, and drinking habits. No HPV genus was associated with oral health. Tumor samples included HPV genotypes exclusively from the α-genus, mostly HPV-16, in 80% of cases. The distribution of α- and γ-HPV, but not β-HPV, seems to vary based on sociodemographic and behavioral characteristics. We did not observe the presence of cutaneous HPV in tumor tissues.

Beta human papillomavirus as a facilitator in the initial phase but not a perpetuator of skin carcinogenesis

Beta human papillomavirus as a facilitator in the initial phase but not a perpetuator of skin carcinogenesis

Alpha, Beta, and Gamma Human Papillomaviruses in Genital Lichen Sclerosus: A Retrospective Cross-Sectional Study.

Lichen sclerosus (LS) is an inflammatory disease mostly arising at the genital level. It is unclear whether human papillomaviruses (HPVs) have an etiological significance in LS, and data on their prevalence in patients with LS are controversial. The authors assessed alpha, beta, and gamma HPV prevalence in patients with genital LS. The association of HPV positivity with demographic and clinical factors was also investigated. One hundred thirty-two formalin-fixed, paraffin-embedded LS samples (2016-2020) were retrieved from the archives of a pathology department. Alpha HPVs were genotyped with the INNO-LiPA HPV Genotyping Extra II kit. Beta and gamma HPVs were searched by multiplex Polymerase Chain Reaction. Immunostaining for p16 INK4a was performed on high-risk HPV-positive samples. Patients had a median age of 61 years, were mostly women ( n = 73, 55.3%), and with an early disease stage ( n = 79, 59.8%). Alpha HPVs were detected in 12/132 cases (9.1%). Among the 5 high-risk HPV-positive cases, only 2 displayed a strong and diffuse p16 INK4a staining. Beta genus was the most prevalent (35/132, 26.5%) and HPV5 was the most frequent beta genotype (25/132, 18.9%). There were 3 gamma HPV-positive cases among those with a valid result (3/131, 2.3%). Multiple infections with genotypes belonging to different genera were infrequent (3/131, 2.3%). No significant differences in the prevalence of the individual genera were observed according to sex and disease stage. Of the 3 HPV genera, beta genus showed the highest prevalence. Further research is needed to clarify whether the presence of beta HPVs in genital LS has a clinical significance.

MAML1-induced HPV E6 oncoprotein stability is required for cellular proliferation and migration of cervical tumor-derived cells.

While a small proportion of high-risk (HR) alpha (α) human papillomaviruses (HPVs) is associated with numerous human malignancies, of which cervical cancer is the most prevalent, beta (β) HPVs predominantly act as co-factors in skin carcinogenesis. A characteristic feature of both α- and β-E6 oncoproteins is the presence of the LXXLL binding motif, which α-E6s utilize to form a complex with E6AP and which enables β-E6s to interact with MAML1. Here we show that multiple α-E6 oncoproteins bind to MAML1 via the LXXLL binding motif and that this results in increased protein stability. Moreover, β-E6 oncoprotein stability is also dependent on the interaction with MAML1. Additionally, in the absence of MAML1, endogenous HPV-8 E6 and HPV-18 E6 are rapidly degraded at the proteasome. Ablation of both E6AP and MAML1 leads to an even more profound downregulation of α-E6 protein expression, whereas this is not observed with β-E6. This highly suggests that there is one cellular pool for most of β-E6 that interacts solely with MAML1, whereas there are two cellular pools of HR α-E6, one forming a complex with MAML1 and the other interacting with E6AP. Furthermore, MAML1 induces HPV-8 E6 shuttling from the nucleus to the cytosolic fraction, while MAML1 interaction with HR E6 induces a drastic nuclear and membrane upregulation of E6. Interestingly, the HR α-E6/MAML1 complex does not affect targeting of some of the known HR E6 cellular substrates such as p53 and DLG1. However, MAML1 and E6AP joint co-expression with HR α-E6 leads to a significant increase in cellular proliferation, whereas silencing MAML1 decreases wound closure in HeLa cells. These results demonstrate that HR α-E6 interaction with MAML1 results in a stable form of E6, which likely modulates MAML1's normal cellular activities, one consequence of which being an increased proliferative capacity of HPV-transformed cancer cells. Thus, this study shows a novel function of the α-E6 oncoprotein and how it's activity might affect HPV-induced pathogenesis.

Beta human papillomavirus 8E6 promotes alternative end joining.

Double strand breaks (DSBs) are one of the most lethal DNA lesions in cells. The E6 protein of beta-human papillomavirus (HPV8 E6) impairs two critical DSB repair pathways: homologous recombination (HR) and non-homologous end joining (NHEJ). However, HPV8 E6 only delays DSB repair. How DSBs are repaired in cells with HPV8 E6 remains to be studied. We hypothesize that HPV8 E6 promotes a less commonly used DSB repair pathway, alternative end joining (Alt-EJ). Using CAS9-based Alt-EJ reporters, we show that HPV8 E6 promotes Alt-EJ. Further, using small molecule inhibitors, CRISPR/CAS9 gene knockout, and HPV8 E6 mutant, we find that HPV8 E6 promotes Alt-EJ by binding p300, an acetyltransferase that facilitates DSB repair by HR and NHEJ. At least some of this repair occurs through a subset of Alt-EJ known as polymerase theta dependent end joining. Finally, whole genome sequencing analysis showed HPV8 E6 caused an increased frequency of deletions bearing the microhomology signatures of Alt-EJ. This study fills the knowledge gap of how DSB is repaired in cells with HPV8 E6 and the mutagenic consequences of HPV8 E6 mediated p300 destabilization. Broadly, this study supports the hypothesis that beta-HPV promotes cancer formation by increasing genomic instability.

High Prevalence of Beta-Human Papilloma Virus in Patients with Concurrent Chronic Lymphocytic Leukemia and Non-Melanoma Skin Cancer

Introduction Patients with chronic lymphocytic leukemia (CLL) are at least twice as likely to develop a second malignancy as their age-matched peers, which is likely secondary chronic CLL-related immunosuppression (Royle 2011). Non-melanoma skin cancers (NMSC) are the most common type of second cancer and those with CLL are seven times more likely to have recurrent NMSC than those without CLL (Mehrany 2005). The etiology of NMSC is likely multifactorial, but we hypothesized that viral load of beta-subtype of human papillomavirus (B-HPV) is correlated with likelihood of NMSC in patients with CLL. Virtually all of the currently available commercial HPV testing targets alpha-subtypes of HPV, but B-HPV has recently been associated with NMSC's (Rollison 2021). The prevalence and viral load of B-HPV in patients with CLL has not been studied. Methods We collected blood samples from patients with CLL and non-CLL controls (patients with solid malignancies) through the ORIEN AVATAR program and performed whole exome sequencing. We used Kraken2 metagenomic software to identify co-purifying HPV DNA using a custom-built viral database composed of unique sequences from alpha and beta HPV reference genomes. Comparison of viral load between patients with and without CLL, and CLL patients with and without NMSC was performed by a 2 sample t-test. Statistic significance was set as p<0.05. Results We measured B-HPV viral loads in the peripheral blood of 333 CLL patients and 69 non-CLL control patients. We determined that the average B-HPV viral load in the peripheral blood of CLL patients was double the load in our non-CLL controls (2724.9 versus 1315.0 viral counts; p<0.001). When we classified the B-HPV subtypes, we found higher viral loads of the subtypes 8, 15, 110, 143, 150 in CLL patients than non-CLL controls (p<0.001 for all CLL vs control comparisons). B-HPV subtype 8 (B-HPV8) was the subtype with the highest viral load as determined by exact matches to our Kraken2 HPV database. We identified 29 CLL patients with known diagnosis of NMSC. In this population, the viral load of B-HPV8 was >6-fold higher than that found in the non-CLL control patients (1009.8 vs 149.6 viral sequences; p<0.001; 2-sample t-test). Conclusions These preliminary data support our hypothesis that B-HPV infection is associated with NMSC in CLL patients. At minimum, it may serve as a biomarker for level of immunosuppression, which predisposes to NMSC. We are currently enrolling a prospective clinical trial for CLL patients with recurrent NMSC (NCT04844528). We plan to sequence both the peripheral blood and the skin cancer samples from these patients to determine whether there is a correlation between B-HPV subtype and NMSC occurrence. We will also evaluate components of the immune system such as T-cell function in an attempt to quantify and correlate immune dysfunction in these patients.

Beta Human Papillomavirus 8 E6 Induces Micronucleus Formation and Promotes Chromothripsis.

Cutaneous beta genus human papillomaviruses (β-HPVs) are suspected to promote the development of nonmelanoma skin cancer (NMSC) by destabilizing the host genome. Multiple studies have established the genome destabilizing capacities of β-HPV proteins E6 and E7 as a cofactor with UV. However, the E6 protein from β-HPV8 (HPV8 E6) induces tumors in mice without UV exposure. Here, we examined a UV-independent mechanism of HPV8 E6-induced genome destabilization. We showed that HPV8 E6 reduced the abundance of anaphase bridge resolving helicase, Bloom syndrome protein (BLM). The diminished BLM was associated with increased segregation errors and micronuclei. These HPV8 E6-induced micronuclei had disordered micronuclear envelopes but retained replication and transcription competence. HPV8 E6 decreased antiproliferative responses to micronuclei and time-lapse imaging revealed HPV8 E6 promoted cells with micronuclei to complete mitosis. Finally, whole-genome sequencing revealed that HPV8 E6 induced chromothripsis in nine chromosomes. These data provide insight into mechanisms by which HPV8 E6 induces genome instability independent of UV exposure. IMPORTANCE Some beta genus human papillomaviruses (β-HPVs) may promote skin carcinogenesis by inducing mutations in the host genome. Supporting this, the E6 protein from β-HPV8 (8 E6) promotes skin cancer in mice with or without UV exposure. Many mechanisms by which 8 E6 increases mutations caused by UV have been elucidated, but less is known about how 8 E6 induces mutations without UV. We address that knowledge gap by showing that 8 E6 causes mutations stemming from mitotic errors. Specifically, 8 E6 reduces the abundance of BLM, a helicase that resolves and prevents anaphase bridges. This hinders anaphase bridge resolution and increases their frequency. 8 E6 makes the micronuclei that can result from anaphase bridges more common. These micronuclei often have disrupted envelopes yet retain localization of nuclear-trafficked proteins. 8 E6 promotes the growth of cells with micronuclei and causes chromothripsis, a mutagenic process where hundreds to thousands of mutations occur in a chromosome.

Cottontail rabbit papillomavirus E6 proteins: Interaction with MAML1 and modulation of the Notch signaling pathway

Animal models are necessary to study how cutaneous human papillomaviruses (HPVs) are associated with carcinogenesis. The cottontail rabbit papillomavirus (CRPV) induces papilloma in the -cutaneous skin of rabbits and serves as an established animal model for HPVlinked carcinogenesis where viral E6 proteins play crucial roles. Several studies have reported the dysregulation of the Notch signaling pathway by cutaneous beta HPV, bovine PV and mouse PV E6 via their association with Mastermind-like 1 protein (MAML1), thus interfering with cell proliferation and differentiation. However, the CRPV E6 gene encodes an elongated E6 protein (long E6, LE6) and an N-terminally truncated product (short E6, SE6) making it unique from other E6 proteins. Here, we describe the interaction between both CRPV E6 proteins and MAML1 and their ability to downregulate the Notch signaling pathway which could be a way CRPV infection induces carcinogenesis similar to beta HPV.

Beta HPV Deregulates Double-Strand Break Repair.

Beta human papillomavirus (beta HPV) infections are common in adults. Certain types of beta HPVs are associated with nonmelanoma skin cancer (NMSC) in immunocompromised individuals. However, whether beta HPV infections promote NMSC in the immunocompetent population is unclear. They have been hypothesized to increase genomic instability stemming from ultraviolet light exposure by disrupting DNA damage responses. Implicit in this hypothesis is that the virus encodes one or more proteins that impair DNA repair signaling. Fluorescence-based reporters, next-generation sequencing, and animal models have been used to test this primarily in cells expressing beta HPV E6/E7. Of the two, beta HPV E6 appears to have the greatest ability to increase UV mutagenesis, by attenuating two major double-strand break (DSB) repair pathways, homologous recombination, and non-homologous end-joining. Here, we review this dysregulation of DSB repair and emerging approaches that can be used to further these efforts.

Merkel Cell Polyoma Virus and Cutaneous Human Papillomavirus Types in Skin Cancers: Optimal Detection Assays, Pathogenic Mechanisms, and Therapeutic Vaccination.

Oncogenic viruses are recognized to be involved in some cancers, based on very well-established criteria of carcinogenicity. For cervical cancer and liver cancer, the responsible viruses are well-known (e.g., HPV, HBV); in the case of skin cancer, there are still many studies which are trying to identify the possible viral etiologic agents as principal co-factors in the oncogenic process. We analysed scientific literature published in the last 5 years regarding mechanisms of carcinogenicity, methods of detection, available targeted therapy, and vaccination for Merkel cell polyomavirus, and beta human papillomavirus types, in relation to skin cancer. This review is targeted at presenting the recent findings which support the involvement of these viruses in the development of some types of skin cancers. In order to optimize the management of skin cancer, a health condition of very high importance, it would be ideal that the screening of skin cancer for these two analysed viruses (MCPyV and beta HPV types) to be implemented in each region’s/country’s cancer centres’ molecular detection diagnostic platforms, with multiplex viral capability, optimal sensitivity, and specificity; clinically validated, and if possible, at acceptable costs. For confirmatory diagnosis of skin cancer, another method should be used, with a different principle, such as immunohistochemistry, with specific antibodies for each virus.

Restriction of viral gene expression and replication prevents immortalization of human keratinocytes by a beta-human papillomavirus

SignificanceHigh-risk (HR) human papillomaviruses (HPV) from the genus alpha cause anogenital and oropharyngeal cancers, whereas the contribution of HPV from the genus beta to the development of cutaneous squamous cell cancer is still under debate. HR-HPV genomes display potent immortalizing activity in human keratinocytes, the natural target cell for HPV. This paper shows that immortalization of keratinocytes by the beta-HPV49 genome requires the inactivation of the viral E8^E2 repressor protein and the presence of the E6 and E7 oncoproteins but also of the E1 and E2 replication proteins. This reveals important differences in the carcinogenic properties of HR-HPV and beta-HPV but also warrants further investigations on the distribution and mutation frequencies of beta-HPV in human cancers.

Beta human papillomavirus 8 E6 allows colocalization of non-homologous end joining and homologous recombination repair factors.

Beta human papillomavirus (β-HPV) are hypothesized to make DNA damage more mutagenic and potentially more carcinogenic. Double strand breaks (DSBs) are the most deleterious DNA lesion. They are typically repaired by homologous recombination (HR) or non-homologous end joining (NHEJ). HR occurs after DNA replication while NHEJ can occur at any point in the cell cycle. HR and NHEJ are not thought to occur in the same cell at the same time. HR is restricted to cells in phases of the cell cycle where homologous templates are available, while NHEJ occurs primarily during G1. β-HPV type 8 protein E6 (8E6) attenuates both repair pathways. We use a series of immunofluorescence microscopy and flow cytometry experiments to better define the impact of this attenuation. We found that 8E6 causes colocalization of HR factors (RPA70 and RAD51) with an NHEJ factor (activated DNA-PKcs or pDNA-PKcs) at persistent DSBs. 8E6 also causes RAD51 foci to form during G1. The initiation of NHEJ and HR at the same lesion could lead to antagonistic DNA end processing. Further, HR cannot be readily completed in an error-free manner during G1. Both aberrant repair events would cause deletions. To determine if these mutations were occurring, we used next generation sequencing of the 200kb surrounding a CAS9-induced DSB. 8E6 caused a 21-fold increase in deletions. Chemical and genetic inhibition of p300 as well as an 8E6 mutant that is incapable of destabilizing p300 demonstrates that 8E6 is acting via p300 destabilization. More specific chemical inhibitors of DNA repair provided mechanistic insight by mimicking 8E6-induced dysregulation of DNA repair in a virus-free system. Specifically, inhibition of NHEJ causes RAD51 foci to form in G1 and colocalization of RAD51 with pDNA-PKcs.

Human Papillomavirus Oral Infection: Review of Methodological Aspects and Epidemiology

Oral infection by Human Papillomavirus (HPV) has recently gained great attention because of its involvement in the development of a subset of head and neck squamous cell carcinoma. The role of specific Alpha-HPVs in this regard has been well established, whereas the contribution of other genera is under investigation. Despite their traditional classification as “cutaneous” types, Beta and Gamma HPVs are frequently detected in oral samples. Due to the lack of a standardized protocol, a large variety of methodologies have been used for oral sample collection, DNA extraction, HPV detection and genotyping. Laboratory procedures influence the evaluation of oral HPV prevalence, which largely varies also according to the population characteristics, e.g., age, gender, sexual behavior, Human Immunodeficiency Virus (HIV) status. Nevertheless, oral infection by Beta and Gamma HPVs seems to be even more common than Alpha-HPVs. The latter is 5–7% in the general population, and increases up to 30% approximately in HIV-infected men who have sex with men. Despite major advances in the evaluation of oral HPV prevalence, its natural history is still little understood, especially for Beta and Gamma HPVs. The latest technologies, such as Next Generation Sequencing (NGS), can be exploited to gain new insights into oral HPV, and to improve the identification of novel HPV types.

Host genetic polymorphisms associated with beta human papillomavirus seropositivity.

Human papillomaviruses (HPVs) cause superficial epidermal infections and are only cleared if they trigger an immunological response. We analysed SNPs that had previously been investigated for association with HPV infection to determine whether they play a role in the serological response to cutaneous beta-HPVs in an Australian population. Serum samples from 1,142 participants were analysed for seropositivity against the L1 protein of 21 beta-HPV types. Associations between seropositivity to beta-HPV types and the SNPs rs9264942 (HLA-C; HPV-9, p = 0.022, HPV-15, p = 0.043 and HPV-17, p = 0.004), rs12449858 (EVER1; HPV-23, p = 0.029), and rs2981451 (FGFR2; HPV-22, p = 0.049) were identified. We found that certain SNPs could be involved in the serological response to beta-HPVs.

HPV Infection in Middle Ear Squamous Cell Carcinoma: Prevalence, Genotyping and Prognostic Impact.

Middle ear squamous cell carcinoma (MESCC) is rare. Human Papilloma Virus (HPV) infection has been found in a significant number of cases of MESCC. Despite the emerging role of HPV in oncogenesis, its role in the pathogenesis and prognosis of MESCC is not known. This study aims to identify the prognostic impact of alpha and beta HPV in MESCC and its correlation with p16 protein. We retrospectively investigated 33 patients with MESCC surgically treated between 2004 and 2016. HPV DNA was ascertained by polymerase chain reaction (PCR) and P16INK4a detection was performed. Disease-specific survival (DSS) and cumulative incidence of recurrence were calculated in relation to HPV presence and genotype. p16 sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in predicting HPV infection were calculated. HPV was detected in 66.7% of patients (36.4% alpha HPV, 63.6% beta HPV). Five-year DSS was 55.0% and was not statistically related to HPV presence (p = 0.55) or genotype (p = 0.87). Five-year cumulative incidence of recurrence was 46 %, and was not statistically related to HPV presence (p = 0.22) or genotype (p = 0.44). p16 sensitivity, specificity, PPV, and NPV in predicting HPV infection were 27.3%, 36.4%, 46.2%, and 20.0%, respectively. In our experience, beta HPV was more frequent than alpha HPV in MESCC. Neither HPV presence nor HPV genotypes relate to DSS or cumulative incidence of recurrence. p16 expression was not predictive for HPV infection in MESCC. The role of HPV infection in oncogenesis, maintenance, and prognosis of MESCC seems to be different from that in oropharynx and skin cancer.

Effects of β-HPV on DNA damage response pathways to drive carcinogenesis: a review.

The DDR is a complex signaling network responsible for the preservation of genomic integrity. Beta human papillomaviruses (β-HPVs) are able to destabilize the host genome by attenuating the DDR machinery at the molecular scale following expression of the oncogenes E6 and E7. In the event of β-HPV infection, the E6- and E7-mediated inhibition of the DDR enhances the oncogenicity of UV-induced mutations to enable carcinogenesis in an otherwise immunocompetent host, marking an important mechanistic divergence from the alpha genus of HPVs. In this review, we summarize recent updates to build upon the 'hit-and-run' hypothesis of β-HPV pathomechanism and highlight strain-dependent variations. Simultaneously, we illuminate points within the β-HPV-DDR interface that may unravel new insights for HPV viral genetics, genus-specific mechanistic models, and developments in targeted molecular therapy of β-HPV-related cancers.