Human papillomaviruses: basic mechanisms of pathogenesis and oncogenicity

Clearance of anal and penile HPV 6, 11, 16, and 18 DNA and antibodies among adolescent men who have sex with men (HYPER): An observational cohort study

Background

Clearance of human papillomavirus (HPV) among adolescent men who have sex with men (MSM) is not well studied. This study aimed to evaluate the clearance of HPV DNA and antibodies among adolescent MSM.

Methods

In our cohort study, we enrolled adolescent MSM in Melbourne between October 2010 and September 2013. At baseline, 3, 6, and 12 months, anal and penile swabs for HPV DNA and serum for HPV antibodies against genotypes 6, 11, 16, and 18, were collected. Definite clearance was defined as HPV DNA (same site) /antibodies for the same genotype undetected following a positive HPV DNA /antibodies test at baseline or month 3. Possible clearance was defined as HPV DNA (same site) /antibodies for the same genotype undetected at month 12 following a positive HPV DNA/antibodies test at month 6. Overall clearance was defined as either definite or possible clearance. The agreement between HPV DNA clearance and antibodies clearance was calculated.

Results

A total of 183 MSM were included (median age: 19 years, interquartile [IQR]: 18 to 20). At the anus, overall clearance rate was 21.6 (95 % confidence interval[CI]: 7.9 to 47.0), 44.8 (19.3 to 88.3), 51.9 (20.9 to 106.9) and 33.7 (7.0 to 98.5) per 1000 person months (PM) for HPV 6, 11, 16 and 18. At the penis, overall clearance rate was 64.5 (13.3 to 188.5), 71.3 (14.7 to 208.2), 96.5 (31.3 to 225.3) and 333.3 (8.4 to 1857.2) per 1000 PM for HPV 6, 11, 16 and 18. For antibodies, overall clearance rate was 22.2 (9.6 to 43.7), 18.8 (3.9 to 55.0), 10.8 (0.3 to 60.1) and 19.0 (2.3 to 68.8) per 1000 PM. Agreement between anal/penile HPV DNA clearance and antibodies clearance was low: kappa = -0.18 (95 % CI: -0.28 to 0.08)/-0.13 (-0.24 to -0.02), 0.04 (-0.29 to 0.36)/0.22 (-0.32 to 0.76), -0.10 (-0.27 to 0.08)/-0.14 (-0.37 to 0.10) and -0.14 (-0.28 to 0.01)/-0.14 (-0.33 to 0.06) for HPV 6, 11, 16 and 18, respectively.

Conclusion

Clearance rates of HPV DNA were low and varied by genotypes and anatomical sites among adolescent MSM. Antibodies against HPV were stable during the study period.

Anal carcinoma - exploring the epidemiology, risk factors, pathophysiology, diagnosis, and treatment

Anal carcinoma is a relatively rare tumor that accounts for approximately 2% of gastrointestinal malignancies and less than 7% of anorectal cancers. Most anal tumors originate between the anorectal junction and the anal verge. Risk factors for the disease include human papillomavirus infection, human immunodeficiency virus, tobacco use, immunosuppression, female sex, and older age. The pathogenesis of anal carcinoma is believed to be linked to human papillomavirus-related inflammation, leading to dysplasia and progression to cancer. Squamous cell carcinoma is the most common type of anal tumor, with an annual incidence of approximately 1 to 2 per 100000 persons. Treatment regarding anal cancer has emerged over time. However, chemoradiation therapy remains the mainstay approach for early localized disease. Patients with metastatic disease are treated with systemic therapy, and salvage surgery is reserved for disease recurrence following chemoradiation. This article aims to provide background information on the epidemiology, risk factors, pathology, diagnosis, and current trends in the management of anal cancer. Future directions are briefly discussed.

Quantitative Proteomics Reveal the Mechanism of MiR-138-5p Suppressing Cervical Cancer via Targeting ZNF385A

MicroRNAs are short, noncoding RNA molecules that exert pivotal roles in cancer development and progression by modulating various target genes. There is growing evidence that miR-138-5p is significantly involved in cervical cancer (CC). However, its precise molecular mechanism has yet to be fully understood. In the current investigation, a quantitative proteomics approach was utilized to detect possible miR-138-5p targets in HeLa cells systematically. In total, 364 proteins were downregulated, and 150 were upregulated after miR-138-5p overexpression. Bioinformatic analysis of these differentially expressed proteins (DEPs) revealed significant enrichment in several cancer-related pathways. Zinc finger protein 385A (ZNF385A) was determined as a novel direct target of miR-138-5p and discovered to facilitate the proliferation, migration, and cell cycle progression of HeLa cells. SFN and Fas cell surface death receptor(FAS) were then identified as functional downstream effectors of ZNF385A and miR-138-5p. Moreover, a tumor xenograft experiment was conducted to validate the association of miR-138-5p-ZNF385A-SFN/FAS axis with the development of CC in vivo. Our findings have collectively established a catalog of proteins mediated by miR-138-5p and have provided an in-depth comprehension of the molecular mechanisms responsible for the inhibitory effect of miR-138-5p on CC. The miR-138-5p-ZNF385A-SFN/FAS axis could also be beneficial to the identification of new therapeutic targets.

Pathology of Squamous Cell Carcinoma of the Penis: Back to Square One

The landscape of squamous cell carcinoma of the penis (SCC-P) has undergone a significant transformation since the new World Health Organization classification of genitourinary cancers and recent European Association of Urology/American Association of Clinical Oncology guidelines. These changes emphasize the necessity to categorize SCC-P into 2 groups based on its association with human papillomavirus (HPV) infection. This shift has major implications, considering that prior knowledge was derived from a mix of both groups. Given the distinct prognosis, treatment options, and staging systems observed for HPV-associated tumors in other body areas, the question now arises: will similar patterns emerge for SCC-P?

The role of neoadjuvant chemotherapy before radical surgery in stage IB2/IIA2 squamous cell cervical cancers

BACKGROUND

This study aimed to evaluate the outcomes of patients diagnosed with stage IB2/IIA2 cervical squamous cell carcinoma who underwent neoadjuvant chemotherapy (NACT) prior to radical hysterectomy compared to those who did not receive NACT before surgery.

MATERIALS AND METHODS

This is a multicenter study including data of 6 gynecological oncology departments. The study is approved from one of the institution's local ethics committee. Patients were stratified into two cohorts based on the receipt of NACT preceding their surgical intervention. Clinico-pathological factors and progression-free survival were analyzed.

RESULTS

Totally 87 patients were included. Lymphovascular space invasion (LVSI) was observed as 40% in the group receiving NACT, while it was 66.1% in the group not receiving NACT (p = 0.036). Deep stromal invasion (> 50%) was 56% in the group receiving NACT and 84.8% in the group not receiving NACT (p = 0.001). In the univariate analysis, application of NACT is statistically significant among the factors that would be associated with disease-free survival. Consequently, a multivariate analysis was conducted for progression-free survival, incorporating factors such as the depth of stromal invasion, the presence of LVSI, and the administration of NACT. Of these, only the administration of NACT emerged as an independent predictor associated with decreased progression-free survival. (RR:5.88; 95% CI: 1.63-21.25; p = 0.07).

CONCLUSIONS

NACT shouldn't be used routinely in patients with stage IB2/IIA2 cervical cancer before radical surgery. Presented as oral presentation at National Congress of Gynaecological Oncology & National Congress of Cervical Pathologies and Colposcopy (2022/ TURKEY).

High-Risk HPV CISH Detection in Cervical Biopsies with Weak and/or Focal p16 Immunohistochemical Positivity

In cervical biopsies, for diagnosis of Human Papilloma Virus (HPV) related conditions, the immunohistochemical staining for p16 has a diagnostic value only if diffusely and strongly positive, pattern named "block-like". "Weak and/or focal (w/f) p16 expression" is commonly considered nonspecific. In our previous study, we demonstrated the presence of high-risk HPV (hrHPV) DNA by LiPa method in biopsies showing w/f p16 positivity. The aim of the present study was to investigate the presence of hrHPV-DNA by CISH in the areas showing w/f p16 expression. We assessed the presence of hrHPV16, 18, 31, 33, 51 by CISH in a group of 20 cervical biopsies showing w/f p16 expression, some with increased Ki67, and in 10 cases of block-like expression, employed as control. The immunohistochemical p16 expression was also assessed by digital pathology. hrHPV-CISH nuclear positivity was encountered in 12/20 cases of w/f p16 expression (60%). Different patterns of nuclear positivity were identified, classified as punctate, diffuse and mixed, with different epithelial distributions. Our results, albeit in a limited casuistry, show the presence of HPV in an integrated status highlighted by CISH in w/f p16 positive cases. This could suggest the necessity of a careful follow-up of the patients with "weak" and/or "focal" immunohistochemical patterns of p16, mainly in cases of increased Ki67 cell proliferation index, supplemented with molecular biology examinations.

Inter-epitope spacer variation within polytopic L2-based human papillomavirus antigens affects immunogenicity

The human papillomavirus minor capsid protein L2 is being extensively explored in pre-clinical studies as an attractive vaccine antigen capable of inducing broad-spectrum prophylactic antibody responses. Recently, we have developed two HPV vaccine antigens - PANHPVAX and CUT-PANHPVAX- both based on heptameric nanoparticle antigens displaying polytopes of the L2 major cross-neutralizing epitopes of eight mucosal and twelve cutaneous HPV types, respectively. Prompted by the variable neutralizing antibody responses against some of the HPV types targeted by the antigens observed in previous studies, here we investigated the influence on immunogenicity of six distinct glycine-proline spacers inserted upstream to a specific L2 epitope. We show that spacer variants differentially influence antigen immunogenicity in a mouse model, with the antigen constructs M8merV6 and C12merV6 displaying a superior ability in the induction of neutralizing antibodies as determined by pseudovirus-based neutralization assays (PBNAs). L2-peptide enzyme-linked immunosorbent assay (ELISA) assessments determined the total anti-L2 antibody level for each antigen variant, showing for the majority of sera a correlation with their repective neutralizing antibody level. Surface Plasmon Resonance revealed that L2 epitope-specific, neutralizing monoclonal antibodies (mAbs) display distinct avidities to different antigen spacer variants. Furthermore, mAb affinity toward individual spacer variants was well correlated with their neutralizing antibody induction capacity, indicating that the mAb affinity assay predicts L2-based antigen immunogenicity. These observations provide insights on the development and optimization of L2-based HPV vaccines.

Differential microRNA Expression Analysis in Patients with HPV-Infected Ovarian Neoplasms

This study aimed to identify microRNAs (miRNAs) whose expression levels are altered by high-risk human papillomavirus (HR-HPV) infection in women with epithelial ovarian neoplasms. MiRNA expression was quantified by real-time polymerase chain reaction, while HR-HPV DNA was quantified using digital-droplet PCR. Analysis of 11 miRNAs demonstrated significantly lower hsa-miR-25-5p expression in HPV-infected compared to uninfected ovarian tissues (p = 0.0405), while differences in miRNA expression in corresponding serum were statistically insignificant. The expression of hsa-miR-218-5p in ovarian tumors was significantly higher in high-grade serous ovarian carcinoma (HGSOC) cases than in other neoplasms (p = 0.0166). In addition, hsa-miR-218-5p was significantly upregulated, whereas hsa-miR-191-5p was significantly downregulated in tissues with stage III/IV FIGO (p = 0.0009 and p = 0.0305, respectively). Using unsupervised clustering, we identified three unique patient groups with significantly varied frequencies of HPV16/18-positive samples and varied miRNA expression profiles. In multivariate analysis, high expression of hsa-miR-16-5p was an independent prognostic factor for poor overall survival (p = 0.0068). This preliminary analysis showed the changes in miRNA expression in ovarian neoplasms during HPV infection and those collected from HGSOCs or patients with advanced disease. This prospective study can provide new insights into the pathogenesis of ovarian neoplasms and host-virus interactions.

Association of thyroid cancer with human papillomavirus infections

While Human Papillomavirus (HPV) particles have been detected in a small proportion of benign thyroid nodules or thyroid cancer cases, a role of HPV in these thyroid conditions has not been established. This study aims to investigate the association of HPV infection with thyroid cancer (TC) using a nationwide population-based study. We retrieved data for this case-control study from Taiwan's Longitudinal Health Insurance Database 2010. The study sample included 3062 patients with TC and 9186 propensity-scored matched controls. We employed multivariate logistic regression models to quantitatively evaluate the association of TC with HPV infections after taking age, sex, monthly income, geographic location and urbanization level of the patient's residence, diabetes, hypertension, and hyperlipidemia into considerations. Chi-squared test revealed that there was a significant difference in the prevalence of prior HPV infections between patients with TC and controls (15.3% vs. 7.6%, p < 0.001). The adjusted odds ratio of prior HPV infections for patients with TC was 2.199 (95% CI = 1.939-2.492) relative to controls. The adjusted ORs of prior HPV infections for patients with TC was similar for males and females. Our research suggests a significant link between HPV infection and the development of TC.

Prevalence of Human Papillomavirus Infection and Cervical Abnormalities among Women Attending a Tertiary Care Center in Saudi Arabia over 2 Years

Human papillomavirus (HPV) genotype distribution varies according to the assessment method and the population targeted. This study aimed to assess HPV infection prevalence in women aged 23 to 82 with abnormal cytology attending King Fahad Medical City (KFMC), Riyadh, Saudi Arabia, using retrospective data collected from January 2021 to December 2022. Cytological distribution included 155 samples of atypical squamous cells of undetermined significance (ASCUS) (n = 83), low-grade squamous intraepithelial lesion (LSIL) (n = 46), high-grade squamous intraepithelial lesion (HSIL) (n = 14), atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (ASC-H) (n = 10), and squamous cell carcinoma (SCC) (n = 2). All samples were submitted to HPV detection and genotyping using Xpert HPV assay specimens. The most prevalent epithelial abnormalities were ASCUS (53.50%). Positive HPV infection results were observed in 52.9% of the samples. The highest prevalence of HPV genotypes, accounting for 31%, was attributed to the other high-risk genotypes, including 31, 33, 35, 39, 51, 52, 56, 58, 59, 66, and 68, followed by high-risk genotype 16, which counted in 11.60% of cases. Individuals who tested positive for HPV 16 were at a high risk of ASC-H, HSIL, and LSIL. Those testing positive for HPV 18-45 exhibited an elevated risk of LSIL, and those with positive results for other high-risk HPV genotypes were at an increased risk of ASCUS and LSIL, suggesting a low oncogenic potential. The results suggest that the percentage of association between samples with abnormal cervical presentation and negative high-risk HPV diagnosis is noticeably increasing. This underscores the need for effective screening programs and an understanding of the impact of specific HPV genotypes on cervical abnormalities.

Human Papillomavirus Infection in Penile Cancer: Multidimensional Mechanisms and Vaccine Strategies

Penile cancer (PC) is a rare male malignant tumor, with early lymph node metastasis and poor prognosis. Human papillomavirus (HPV) plays a key role in the carcinogenesis of PC. This review aims to summarize the association between HPV infection and PC in terms of virus-host genome integration patterns (the disrupted regions in the HPV and PC genome), genetic alterations, and epigenetic regulation (methylation and microRNA modification) occurring in HPV and PC DNA, as well as tumor immune microenvironment reprogramming. In addition, the potential of HPV vaccination strategies for PC prevention and treatment is discussed. Understanding of the HPV-related multidimensional mechanisms and the application of HPV vaccines will promote rational and novel management of PC.

Recent advances in treating female genital human papillomavirus related neoplasms with topical imiquimod

Human papillomavirus (HPV) encompasses a group of viruses that infect the skin and mucous membranes. In the presence of certain factors, persistent infection with high-risk HPVs can trigger a process of neoplastic transformation. Imiquimod is a topical agent that acts as a Toll-like receptor 7/8 agonist, stimulating the innate and adaptive immune system to exert antitumor and antiviral effects. It has been approved for the treatment of various skin conditions, however, its efficacy and safety in the management of HPV-related-neoplasms of the lower genital tract, such as vulvar, vaginal, and cervical neoplasia, are still under investigation. This review summarizes the current evidence on the use of imiquimod for the treatment of HPV-induced lesions of the female lower genital tract, focusing on its indications, mechanisms of action, outcomes, and predictors of response.

Microparticle-Based Detection of Viruses

Surveillance of viral pathogens in both point-of-care and clinical settings is imperative to preventing the widespread propagation of disease-undetected viral outbreaks can pose dire health risks on a large scale. Thus, portable, accessible, and reliable biosensors are necessary for proactive measures. Polymeric microparticles have recently gained popularity for their size, surface area, and versatility, which make them ideal biosensing tools. This review cataloged recent investigations on polymeric microparticle-based detection platforms across eight virus families. These microparticles were used as labels for detection (often with fluorescent microparticles) and for capturing viruses for isolation or purification (often with magnetic microparticles). We also categorized all methods by the characteristics, materials, conjugated receptors, and size of microparticles. Current approaches were compared, addressing strengths and weaknesses in the context of virus detection. In-depth analyses were conducted for each virus family, categorizing whether the polymeric microparticles were used as labels, for capturing, or both. We also summarized the types of receptors conjugated to polymeric microparticles for each virus family.

Current Status of Human Papillomavirus-Targeted Therapies Development in Head and Neck Cancer

PURPOSE

While the incidence of smoking-related head and neck squamous cell carcinoma (HNSCC) has been declining, that of human papillomavirus (HPV)-mediated HNSCC has rapidly increased in the past decades worldwide. Despite rapid advances in therapeutics for solid tumors with novel immunotherapy and targeted therapeutic agents, no breakthroughs have yet been made in the treatment of advanced HPV+ HNSCCs. This review aims to summarize the concepts and designs, early trial results, and future directions of various HPV-targeted experimental therapeutics for HPV+ HNSCC.

MATERIALS AND METHODS

Guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, a systemic literature search of PubMed was conducted for HPV-targeted therapeutics using the following search terms: HPV, head and neck squamous cell carcinoma, and therapy. For clinical trial data, publications, major oncology conference abstracts, and the National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov) information were reviewed. This review focused on the ones that are in the clinical stage and currently in active ongoing evaluation. The therapeutics not actively evaluated in HNSCC, in the preclinical stage, or terminated for further development were excluded.

RESULTS

Diverse approaches are being actively explored to target HPV+ HNSCC, including therapeutic vaccines of various modalities, HPV-specific immune cell-activating agents, and adaptive cellular therapeutics. All these novel agents use immune-based mechanisms and target constitutively expressed oncogenic HPV E6 and/or E7 viral proteins. Most therapeutics demonstrated excellent safety but single-agent activities are only modest. Many are being tested in combination with immune checkpoint inhibitors.

CONCLUSION

Our review summarized various novel HPV-targeted therapeutics that are in the clinical phase for HPV+ HNSCC. Early-phase trial data suggest the feasibility and promising efficacy. Further strategies, including selecting the optimal combination and understanding and overcoming resistant mechanisms, are warranted for successful development.

Comprehensive analysis of lncRNA-mRNA co-expression networks in HPV-driven cervical cancer reveals the pivotal function of LINC00511-PGK1 in tumorigenesis

BACKGROUND

Mounting evidence suggests that noncoding RNAs (lncRNAs) were involved in various human cancers. However, the role of these lncRNAs in HPV-driven cervical cancer (CC) has not been extensively studied. Considering that HR-HPV infections contribute to cervical carcinogenesis by regulating the expression of lncRNAs, miRNAs and mRNAs, we aim to systematically analyze lncRNAs and mRNAs expression profile to identify novel lncRNAs-mRNAs co-expression networks and explore their potential impact on tumorigenesis in HPV-driven CC.

METHODS

LncRNA/mRNA microarray technology was utilized to identify the differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) in HPV-16 and HPV-18 cervical carcinogenesis compared to normal cervical tissues. Venn diagram and weighted gene co-expression network analysis (WGCNA) were used to identify the hub DElncRNAs/DEmRNAs that were both significantly correlated with HPV-16 and HPV-18 CC patients. LncRNA-mRNA correlation analysis and functional enrichment pathway analysis were performed on these key DElncRNAs/DEmRNAs in HPV-16 and HPV-18 CC patients to explore their mutual mechanism in HPV-driven CC. A lncRNA-mRNA co-expression score (CES) model was established and validated by using the Cox regression method. Afterward, the clinicopathological characteristics were analyzed between CES-high and CES-low groups. In vitro, functional experiments were performed to evaluate the role of LINC00511 and PGK1 in cell proliferation, migration and invasion in CC cells. To understand whether LINC00511 play as an oncogenic role partially via modulating the expression of PGK1, rescue assays were used.

RESULTS

We identified 81 lncRNAs and 211 mRNAs that were commonly differentially expressed in HPV-16 and HPV-18 CC tissues compared to normal tissues. The results of lncRNA-mRNA correlation analysis and functional enrichment pathway analysis showed that the LINC00511-PGK1 co-expression network may make an important contribution to HPV-mediated tumorigenesis and be closely associated with metabolism-related mechanisms. Combined with clinical survival data, the prognostic lncRNA-mRNA co-expression score (CES) model based on LINC00511 and PGK1 could precisely predict patients' overall survival (OS). CES-high patients had a worse prognosis than CES-low patients and the enriched pathways and potential targets of applicable drugs were explored in CES-high patients. In vitro experiments confirmed the oncogenic functions of LINC00511 and PGK1 in the progression of CC, and revealed that LINC00511 functions in an oncogenic role in CC cells partially via modulating the expression of PGK1.

CONCLUSIONS

Together, these data identify co-expression modules that provide valuable information to understand the pathogenesis of HPV-mediated tumorigenesis, which highlights the pivotal function of the LINC00511-PGK1 co-expression network in cervical carcinogenesis. Furthermore, our CES model has a reliable predicting ability that could stratify CC patients into low- and high-risk groups of poor survival. This study provides a bioinformatics method to screen prognostic biomarkers which leads to lncRNA-mRNA co-expression network identification and construction for patients' survival prediction and potential drug applications in other cancers.

Deregulation of host gene expression by HPV16 E8^E2 knock-out genomes is due to increased productive replication

Productive replication of human papillomaviruses (HPV) only takes place in differentiating keratinocytes. The HPV16 E8^E2 protein acts as a repressor of viral gene expression and genome replication and HPV16 E8^E2 knock-out (E8-) genomes display enhanced viral late protein expression in differentiated cells. Global transcriptome analysis of differentiated HPV16 wild-type and E8-cell lines revealed a small number of differentially expressed genes which are not related to cell cycle, DNA metabolism or keratinocyte differentiation. The analysis of selected genes suggested that deregulation requires cell differentiation and positively correlated with the expression of viral late, not early transcripts. Consistent with this, the additional knock-out of the viral E4 and E5 genes, which are known to enhance productive replication, attenuated the deregulation of these host cell genes. In summary, these data reveal that productive HPV16 replication modulates host cell transcription.

An in vitro carcinogenesis model for cervical cancer harboring episomal form of HPV16

Deregulated expression of viral E6 and E7 genes often caused by viral genome integration of high-risk human papillomaviruses (HR-HPVs) into host DNA and additional host genetic alterations are thought to be required for the development of cervical cancer. However, approximately 15% of invasive cervical cancer specimens contain only episomal HPV genomes. In this study, we investigated the tumorigenic potential of human cervical keratinocytes harboring only the episomal form of HPV16 (HCK1T/16epi). We found that the HPV16 episomal form is sufficient for promoting cell proliferation and colony formation of parental HCK1T cells. Ectopic expression of host oncogenes, MYC and PIK3CAE545K, enhanced clonogenic growth of both early- and late-passage HCK1T/16epi cells, but conferred tumor-initiating ability only to late-passage HCK1T/16epi cells. Interestingly, the expression levels of E6 and E7 were rather lower in late-passage than in early-passage cells. Moreover, additional introduction of a constitutively active MEK1 (MEK1DD) and/or KRASG12V into HCK1T/16epi cells resulted in generation of highly potent tumor-initiating cells. Thus an in vitro model for progression of cervical neoplasia with episomal HPV16 was established. In the model, constitutively active mutation of PIK3CA, PIK3CAE545K, and overexpression of MYC, in the cells with episomal HPV16 genome were not sufficient, but an additional event such as activation of the RAS-MEK pathway was required for progression to tumorigenicity.

KNTC1, regulated by HPV E7, inhibits cervical carcinogenesis partially through Smad2

Cervical cancer is the second most common malignancy of the female reproductive tract worldwide. Although cervical cancer is caused by human papillomavirus (HPV) infection, its underlying pathogenesis requires further investigation. The present study investigated the role of kinetochore associated protein 1 (KNTC1) in cervical cancer and its association with the key virus oncoprotein, HPV E7. A series of bioinformatic analyses revealed that KNTC1 might be involved in the tumorigenesis of multiple human malignancies, including cervical cancer. Tissue microarray analysis showed that in vivo KNTC1 expression was higher in high-grade squamous intraepithelial lesions (HSILs) than in normal cervix and even higher in cervical cancer. In vitro silencing of KNTC1 increased the proliferation, invasion and migration of cervical cancer cell lines. Although not affecting apoptosis, KNTC1 silencing significantly promoted G1/S phase transition of the cell cycle. High-throughput analysis of mRNA expression showed that KNTC1 could regulate its downstream target protein Smad2 at the transcriptional level. Moreover, as the key oncoprotein of the virus, HPV E7 could inhibit the expression of KNTC1 protein, and decrease Smad2 protein expression with or without the aid of KNTC1. These results indicated that KNTC1 is a novel tumor suppressor that can impede the initiation and progression of cervical carcinoma, providing insight into the molecular mechanism by which HPV induces cervical cancer.

Towards Novel Gene and Cell Therapy Approaches for Cervical Cancer

Cervical cancer is one of the most common malignancies in women, and the majority of cases are caused by infection with high-risk human papilloma virus (HPV) subtypes. Despite effective preventative measures, such as vaccinations against HPV, over 300,000 women die world-wide from cervical cancer each year. Once cervical cancer is diagnosed, treatment may consist of radial hysterectomy, or chemotherapy and radiotherapy, or a combination of therapies dependent upon the disease stage. Unfortunately, overall prognosis for patients with metastatic or recurrent disease remains poor. In these cases, immunotherapies may be useful based on promising preclinical work, some of which has been successfully translated to the clinic. For example, approaches using monoclonal antibodies directed against surface proteins important for control of immune checkpoints (i.e., immune checkpoint inhibitors) were shown to improve outcome in many cancer settings, including cervical cancer. Additionally, initial clinical studies showed that application of cytotoxic immune cells modified to express chimeric antigen receptors (CAR) or T cell receptors (TCR) for better recognition and elimination of tumor cells may be useful to control cervical cancer. This review explores these important topics, including strengths and limitations of standard and developing approaches, and how some novel treatment strategies may be optimally used to offer the best possible treatment for cervical cancer patients.

Recurrent or primary metastatic cervical cancer: current and future treatments

Despite screening programs for early detection and the approval of human papillomavirus vaccines, around 6% of women with cervical cancer (CC) are discovered with primary metastatic disease. Moreover, one-third of the patients receiving chemoradiation followed by brachytherapy for locally advanced disease will have a recurrence. At the end, the vast majority of recurrent or metastatic CC not amenable to locoregional treatments are considered incurable disease with very poor prognosis. Historically, cisplatin monotherapy, then a combination of cisplatin and paclitaxel were considered the standard of care. Ten years ago, the addition of bevacizumab to chemotherapy demonstrated favorable data in terms of response rate and overall survival. Even with this improvement, novel therapies are needed for the treatment of recurrent CC in first as well as later lines. In the last decades, a better understanding of the interactions between human papillomavirus infection and the host immune system response has focused interest on the use of immunotherapeutic drugs in CC patients. Indeed, immune checkpoint inhibitors (pembrolizumab, cemiplimab, and others) have recently emerged as novel therapeutic pillars that could provide durable responses with impact on overall survival in patients in the primary (in addition to chemotherapy) or recurrent (monotherapy) settings. Tisotumab vedotin, an antibody-drug conjugate targeting the tissue factor, is another emerging drug. Several trials in monotherapy or in combination with immunotherapy, chemotherapy, or bevacizumab showed very promising results. There is a high need for more potent biomarkers to better accurately determine which patients would receive the greatest benefit from all these aforementioned drugs, but also to identify patients with specific molecular characteristics that could benefit from other targeted therapies. The Cancer Genome Atlas Research Network identified several genes significantly mutated, potentially targetable. These molecular data have highlighted the molecular heterogeneity of CC.

The E6 and E7 proteins of beta3 human papillomavirus 49 can deregulate both cellular and extracellular vesicles-carried microRNAs

BACKGROUND

The β3 human papillomavirus (HPV)49 induces immortalization of primary keratinocytes through the action of E6 and E7 oncoproteins with an efficiency similar to alpha high risk (HR)-HPV16. Since HR-HPV oncoproteins are known to alter microRNA (miRNA) expression and extracellular vesicle (EV) production, we investigated the impact of HPV49 E6 and E7 proteins on miRNA profile and EV expression, and their involvement in the control of cell proliferation.

METHODS

The miRNA expression was evaluated by a miRNA array and validated by RT-qPCR in primary human keratinocytes immortalized by β3 HPV49 (K49) or α9 HR-HPV16 (K16), and in EVs from K49 and K16. The modulation of miRNA target proteins was investigated by immunoblotting analyses.

RESULTS

By comparing miRNA expression in K49 and K16 and the derived EVs, six miRNAs involved in HPV tumorigenesis were selected and validated. MiR-19a and -99a were found to be upregulated and miR-34a downregulated in both cell lines; miR-17 and -590-5p were upregulated in K49 and downmodulated in K16; miR-21 was downregulated only in K16. As for EV-carried miRNAs, the expression of miR-17, -19a, -21 and -99a was decreased and miR-34a was increased in K49 EVs. In K16 EVs, we revealed the same modulation of miR-19a, -34a, and -99a observed in producing cells, while miR-21 was upregulated. Cyclin D1, a common target of the selected miRNAs, was downmodulated in both cell lines, whereas cyclin-dependent kinase 4 was down-modulated in K49 but upregulated in K16.

CONCLUSION

These data suggest that E6 and E7 proteins of β3 HPV49 and α9 HR-HPV16 affect key factors of cell cycle control by indirect mechanisms based on miRNA modulation.

NF-κB over-activation portends improved outcomes in HPV-associated head and neck cancer

Evolving understanding of head and neck squamous cell carcinoma (HNSCC) is leading to more specific diagnostic disease classifications. Among HNSCC caused by the human papilloma virus (HPV), tumors harboring defects in TRAF3 or CYLD are associated with improved clinical outcomes and maintenance of episomal HPV. TRAF3 and CYLD are negative regulators of NF-κB and inactivating mutations of either leads to NF-κB overactivity. Here, we developed and validated a gene expression classifier separating HPV+ HNSCCs based on NF-κB activity. As expected, the novel classifier is strongly enriched in NF-κB targets leading us to name it the NF-κB Activity Classifier (NAC). High NF-κB activity correlated with improved survival in two independent cohorts. Using NAC, tumors with high NF-κB activity but lacking defects in TRAF3 or CYLD were identified; thus, while TRAF3 or CYLD gene defects identify the majority of tumors with NF-κB activation, unknown mechanisms leading to NF-kB activity also exist. The NAC correctly classified the functional consequences of two novel CYLD missense mutations. Using a reporter assay, we tested these CYLD mutations revealing that their activity to inhibit NF-kB was equivalent to the wild-type protein. Future applications of the NF-κB Activity Classifier may be to identify HPV+ HNSCC patients with better or worse survival with implications for treatment strategies.

The ‘Why and How’ of Cervical Cancers and Genital HPV Infection

Knowing about the virology of human papillomavirus (HPV) including its structure, functions and mechanism of infection, helps in understanding the disease process and morphology of precancerous lesions for cervical cancer. Two types of HPV, low- and high-risk type, adopt different mechanisms of infection which cannot be differentiated on morphological basis. In addition to HPV infection, many other factors such as genetic predisposition, hormonal factors, host immune response, and multiple sexual partners can modify the course and progression of the disease. The viral genome comprises early and late proteins. These early and late genes are expressed in particular course of time after initial infection. Various products of early genes (E1–E7) coordinate for completion of viral life cycle in maturing squamous epithelium by utilizing replication factors and DNA polymerase enzyme of the host cell nucleus. The late genes are mainly concerned with packaging of the viral particles and their release through mature squamous cells. The episomal form of infection seen in the low-risk group of viruses results in productive infection whereas the integrated form seen in high-risk group of viruses is the basis of disruption of host cell growth cycle by inactivating two important tumor suppressor genes p53 and Rb gene by products of E6 and E7 genes. Cervical precancerous lesions and cancer are the resultant effect of the accumulation of mutations. This article discusses the virology of HPV, pathogenesis of HPV infection, and various other factors modifying the disease course.

Human Papillomaviruses as Infectious Agents in Gynecological Cancers. Oncogenic Properties of Viral Proteins

Human papillomaviruses (HPVs), which belong to the Papillomaviridae family, constitute a group of small nonenveloped double-stranded DNA viruses. HPV has a small genome that only encodes a few proteins, and it is also responsible for 5% of all human cancers, including cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers. HPV types may be classified as high- and low-risk genotypes (HR-HPVs and LR-HPVs, respectively) according to their oncogenic potential. HR-HPV 16 and 18 are the most common types worldwide and are the primary types that are responsible for most HPV-related cancers. The activity of the viral E6 and E7 oncoproteins, which interfere with critical cell cycle points such as suppressive tumor protein p53 (p53) and retinoblastoma protein (pRB), is the major contributor to HPV-induced neoplastic initiation and progression of carcinogenesis. In addition, the E5 protein might also play a significant role in tumorigenesis. The role of HPV in the pathogenesis of gynecological cancers is still not fully understood, which indicates a wide spectrum of potential research areas. This review focuses on HPV biology, the distribution of HPVs in gynecological cancers, the properties of viral oncoproteins, and the molecular mechanisms of carcinogenesis.

CK2 Phosphorylation of Human Papillomavirus 16 E2 on Serine 23 Promotes Interaction with TopBP1 and Is Critical for E2 Interaction with Mitotic Chromatin and the Viral Life Cycle

During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication, and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 in vitro and in vivo and that E2 is phosphorylated on this residue during the HPV16 life cycle. We investigated the consequences of mutating serine 23 on E2 functions. E2-S23A (E2 with serine 23 mutated to alanine) activates and represses transcription identically to E2-WT (wild-type E2), and E2-S23A is as efficient as E2-WT in transient replication assays. However, E2-S23A has compromised interaction with mitotic chromatin compared with E2-WT. In E2-WT cells, both E2 and TopBP1 levels increase during mitosis compared with vector control cells. In E2-S23A cells, neither E2 nor TopBP1 levels increase during mitosis. Introduction of the S23A mutation into the HPV16 genome resulted in delayed immortalization of human foreskin keratinocytes (HFK) and higher episomal viral genome copy number in resulting established HFK. Remarkably, S23A cells had a disrupted viral life cycle in organotypic raft cultures, with a loss of E2 expression and a failure of viral replication. Overall, our results demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 and that this interaction is critical for the viral life cycle. IMPORTANCE Human papillomaviruses are causative agents in around 5% of all cancers, with no specific antiviral therapeutics available for treating infections or resultant cancers. In this report, we demonstrate that phosphorylation of HPV16 E2 by CK2 promotes formation of a complex with the cellular protein TopBP1 in vitro and in vivo. This complex results in stabilization of E2 during mitosis. We demonstrate that CK2 phosphorylates E2 on serine 23 in vivo and that CK2 inhibitors disrupt the E2-TopBP1 complex. Mutation of E2 serine 23 to alanine disrupts the HPV16 life cycle, hindering immortalization and disrupting the viral life cycle, demonstrating a critical function for this residue.

Prognostic impact of hepatitis B virus infection in patients with primary cervical cancer

Background

Hepatitis B virus (HBV) infection has been associated with an increased risk of a few malignancies. However, the prognostic impact of HBV infection remains unclear in cervical cancer.

Objective

To explore the association between HBV infection and survival outcomes of patients with primary cervical cancer, using overall survival (OS) and disease‐free survival (DFS) as primary endpoints.

Methods

This analysis was performed retrospectively with newly diagnosed cervical cancer patients admitted to the Department of Gynecologic Oncology at the Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University from June 2013 to October 2019, who were enrolled and followed up. The Kaplan–Meier method and Cox proportional hazard analysis were used to examine the performance of HBV infection in predicting OS and DFS.

Results

Patients were followed up for a median of 37.17 months (95% CI, 34.69–39.65). Among the 695 patients, 87 (12.5%) were serologically positive for hepatitis B surface antigen (HBsAg), and 276 (39.7%) had a prior history of HBV infection. There was no significant difference between HBsAg‐positive group and HBsAg‐negative patients concerning OS or DFS. Multivariate analysis showed prior HBV infection was an independent favorable prognosticator for OS (HR, 0.335; 95% CI, 0.153–0.0.734; p = 0.006) and DFS (HR, 0.398; 95% CI, 0.208–0.691; p = 0.002).

Conclusion

We provide the first clinical evidence that suggests prior HBV infection as an independent favorable prognostic factor for patients with primary cervical cancer.

Role of Epstein-Barr Virus and Human Papillomavirus Coinfection in Cervical Intraepithelial Neoplasia in Chinese Women Living With HIV

Given that only a small percentage of human papillomavirus (HPV)-positive women develop cancer, HPV is necessary but insufficient for carcinogenesis. Mucosally transmitted viral cofactors appear to contribute to HPV-related cervical cancer, such as Epstein-Barr virus (EBV), but previous studies have shown inconsistent outcomes. The exact role of EBV in cervical cancer remains unclear, and more studies are needed to determine its involvement. In this study, we describe the prevalence of EBV and HPV coinfection in HIV-positive women and explore how abnormal host immune status induced by viral coinfections modulates epithelial gene expression. We found a significant correlation between EBV-HPV coinfection and the incidence of high-grade cervical intraepithelial neoplasia (CIN2+). RNA sequencing indicated that CIN tissues coinfected with EBV and HPV led to significant changes in the gene expression of epithelial differentiation and development compared to normal tissues with HPV infection alone. In particular, several differentially expressed genes (DEGs) are closely associated with cancer, such as CACNG4, which was confirmed to be upregulated at both the mRNA and protein levels. Therefore, these findings provide some evidence that EBV may act as a cofactor or mediator in HPV-related cervical cancer. Specific genes or proteins, such as CACNG4, may serve as biomarkers that can risk stratify patients based on pathological changes in the cervix.

Human Papillomavirus (HPV) Detection by Chromogenic In Situ Hybridization (CISH) and p16 Immunohistochemistry (IHC) in Breast Intraductal Papilloma and Breast Carcinoma

PURPOSE

This study explored human papillomavirus (HPV) amplification in breast benign and malignant lesions by chromogenic in situ hybridization (CISH) and the concordance of p16 expression by immunohistochemistry.

PATIENTS AND METHODS

The presence of HPV6/11 and HPV16/18 in 33 cases of intraductal papilloma, 34 cases of ductal carcinoma in situ (DCIS), and 56 cases of invasive breast carcinoma (IBC) was evaluated using matched-background breast parenchyma and breast reduction as control groups. Association with clinicopathologic factors including prognosis was assessed.

RESULTS

HPV 6/11 was observed in 0 cases (0%) of breast reduction, one case (3%) of intraductal papilloma, 11 cases (32.4%) of DCIS, and eight cases (14.3%) of IBC. HPV 16/18 was detected in three cases of (9.1%) breast reduction, six cases (18.8%) of intraductal papillomas, 14 cases (41.2%) of DCIS, and 25 cases (44.6%) of IBC. There was no difference in the HPV status between intraductal papilloma and breast reduction. HPV amplification in intraductal papilloma did not associate with developing atypia or carcinoma after long-term follow-up. However, HPV 6/11 and HPV 16/18 amplification was significantly higher in both DCIS and IBC when compared with breast reduction (P < .05). Compared with background breast parenchyma, HPV 16/18 amplification was significantly higher in both DCIS and IBC (P = .003 and P = .013, respectively). No correlation between p16 immunohistochemical staining and either of the HPV CISH testing was found (P > .05).

CONCLUSION

HPV infection was detected in both breast lesions and background parenchyma. HPV infection may play a role in the pathogenesis of breast cancer but is not associated with intraductal papilloma. Immunohistochemical stain for p16 is not a good surrogate marker for HPV infection in breast lesions.

Human papillomavirus infection associated with increased risk of new-onset psoriasis: a nationwide population-based cohort study

BACKGROUND

This study investigated whether patients with a history of human papillomavirus (HPV) infection are at increased risk of developing psoriasis.

METHODS

We enrolled 66 274 patients with HPV infection between 1997 and 2013 from the Taiwan National Health Insurance Research Database, and compared them with control individuals who had never been diagnosed with HPV infection (at a 1:4 ratio matched by age, sex and index year) in relation to the risk of developing psoriasis. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), with the control group as reference.

RESULTS

The adjusted hazard ratio (aHR) was 1.177 (95% CI, 1.010-1.373) after adjusting for demographic characteristics, comorbidities, dermatology-related outpatient visits and medications. The HPV group had an increased risk of psoriasis compared with the control group in all of the different age groups. The P-value for interaction between age and exposure of HPV is 0.009 in our sub-group analysis.

CONCLUSIONS

A higher risk of psoriasis was found after HPV infection, and age acted as an effect modifier between the HPV infection and risk of psoriasis.

Long non-coding RNAs regulate the hallmarks of cancer in HPV-induced malignancies

High-risk human papillomavirus (HPV) is the most frequent sexually transmitted agent worldwide and is responsible for approximately 5% of human cancers. Identifying novel biomarkers and therapeutic targets for these malignancies requires a deeper understanding of the mechanisms involved in the progression of HPV-induced cancers. Long non-coding RNAs (lncRNAs) are crucial in the regulation of biological processes. Importantly, these molecules are key players in the progression of multiple malignancies and are able to regulate the development of the different hallmarks of cancer. This review highlights the action of lncRNAs in the regulation of cellular processes leading to the typical hallmarks of cancer. The regulation of lncRNAs by HPV oncogenes, their targets and also their mechanisms of action are also discussed, in the context of HPV-induced malignancies. Overall, accumulating data indicates that lncRNAs may have a significant potential to become useful tools for clinical practice as disease biomarkers or therapy targets.

Focus on HPV Infection and the Molecular Mechanisms of Oral Carcinogenesis

This study is focused on the epidemiological characteristics and biomolecular mechanisms that lead to the development of precancerous and cancerous conditions of oral lesions related to Human Papilloma Virus (HPV) infections. Current evidence from the literature demonstrates the role of HPV in potentially malignant oral disorders. Therefore, the underlying biomolecular processes can give arise, or contribute to, benign lesions as well as to oral carcinogenesis.

Evaluation of HPV and EBV in OSCC and the expression of p53, p16, E-cadherin, COX-2, MYC, and MLH1

OBJECTIVE

This study aimed to evaluate the presence of human papillomavirus (HPV) and Epstein-Barr virus (EBV) and the expression of p53, p16, E-cadherin, COX-2, MLH1, and MYC in oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

One hundred OSCC specimens were submitted to in situ hybridization for HPV and EBV, and immunohistochemistry for detection of the human proteins.

RESULTS

Thirty-one cases showed HPV in tumor tissue. EBV was not detected in any case investigated. The HPV(+) group demonstrated an increase of staining scores for nuclear p16 (p = .047), cytoplasmic MYC (p = .002), while a decrease for nuclear MLH1 (p = .048), suggesting that HPV may upregulate the expression of the first two proteins and down-regulate the latter.

CONCLUSION

Our findings reinforce the hypothesis of the HPV-related oral carcinogenesis involving the expression of p16 and MYC, and MLH1 suppression. Exclusively cytoplasmic stainings for p16, MLH1, and MYC were also associated with more advanced tumors. Finally, in view of the lack of studies correlating the HPV or EBV infection to the expression of oncoproteins, more researches assessing a broader panel of markers and employing different approaches are still necessary in order to understand the role of these viruses as well as the molecular mechanisms involved in the development and progression of oral carcinomas.

RPRD1B is a potentially molecular target for diagnosis and prevention of human papillomavirus E6/E7 infection-induced cervical cancer: A case-control study

BACKGROUND

The objective of the study is to investigate the biomarkers for diagnosis and prevention of human papillomavirus (HPV) infection-induced cervical cancer.

METHODS

Cervical cancer tissues were collected from patients with cervical cancer, while noncancer tissues were collected from patients diagnosed with cervical lesions or uterine fibroids at the Chinese PLA General Hospital 301 and 309, China from December 2017 to June 2018. The cancer tissues were collected from the site of lesion, while the noncancer tissues were collected from similar anatomical locations. Quantitative real-time PCR, Western blot (WB), and immunohistochemistry (IHC) were used to detect the mRNA and protein levels of HPV E6/E7, RPRD1B (regulation of nuclear pre-mRNA domain containing 1B), cyclin D1, and transcription factor 4 (TCF4) between cervical cancer tissues and noncancer tissues. The correlation of HPV E6/E7, RPRD1B, cyclin D1, and TCF4 expressions was analyzed.

RESULTS

Twenty patients with cervical cancer and 27 controls without cervical cancer were included in this study. The mRNA expression of HPV E6/E7and RPRD1B was significantly higher in patients with cervical cancer than controls, while cyclin D1 mRNA expression was significantly lower in patients with cervical carcinoma in situ stage, compared with controls. RPRD1B protein expression was significantly higher in patients compared to controls when analyzed by IHC. TCF4 was significantly lower in clinical stage I and Ib of cervical cancer when analyzed by WB. The mRNA and protein expressions of RPRD1B and cyclin D1 were significantly different between patients younger than 50 years old, compared to patients 50 years and older.

CONCLUSIONS

HPV E6/E7 expression was associated with RPRD1B level in cervical cancer. The expression of RPRD1B and cyclin D1 in patients with cervical cancer might be affected by age.

Pathogenesis of Human Papillomaviruses Requires the ATR/p62 Autophagy-Related Pathway

High-risk human papillomaviruses (HPVs) constitutively activate the ataxia telangiectasia and Rad3-related (ATR) DNA damage response pathway, and this is required for viral replication. In fibroblasts, activated ATR regulates transcription of inflammatory genes through its negative effects on the autophagosome cargo protein p62. In addition, suppression of p62 results in increased levels of the transcription factor GATA4, leading to cellular senescence. In contrast, in HPV-positive keratinocytes, we observed that activation of ATR resulted in increased levels of phosphorylated p62, which in turn lead to reduced levels of GATA4. Knockdown of ATR in HPV-positive cells resulted in decreased p62 phosphorylation and increased GATA4 levels. Transcriptome sequencing (RNA-seq) analysis of HPV-positive cells identified inflammatory genes and interferon factors as negative transcriptional targets of ATR. Furthermore, knockdown of p62 or overexpression of GATA4 in HPV-positive cells leads to inhibition of viral replication. These findings identify a novel role of the ATR/p62 signaling pathway in HPV-positive cells.IMPORTANCE High-risk human papillomaviruses (HPVs) infect epithelial cells and induce viral genome amplification upon differentiation. HPV proteins activate the ATR DNA damage repair pathway, and this is required for HPV genome amplification. In the present study, we show that HPV-induced ATR activation also leads to suppression of expression of inflammatory response genes. This suppression results from HPV-induced phosphorylation of the autophagosome cargo protein p62 which regulates the levels of the transcription factor GATA4. Activation of p62 in normal fibroblasts results in senescence, but this is not seen in HPV-positive keratinocytes. Importantly, knockdown of p62 or overexpression of GATA4 in HPV-positive cells abrogates viral replication. This study demonstrates that activation of ATR in HPV-positive cells triggers a p62-directed pathway inducing suppression of inflammatory gene expression independent of DNA repair and facilitating HPV replication.

High-Risk Human Papillomavirus and Tobacco Smoke Interactions in Epithelial Carcinogenesis

Cervical, anogenital, and some head and neck cancers (HNC) are etiologically associated with high-risk human papillomavirus (HR-HPV) infection, even though additional cofactors are necessary. Epidemiological studies have established that tobacco smoke (TS) is a cofactor for cervical carcinogenesis because women who smoke are more susceptible to cervical cancer when compared to non-smokers. Even though such a relationship has not been established in HPV-related HNC, a group of HPV positive patients with this malignancy are smokers. TS is a complex mixture of more than 4500 chemical compounds and approximately 60 of them show oncogenic properties such as benzo[α]pyrene (BaP) and nitrosamines, among others. Some of these compounds have been evaluated for carcinogenesis through experimental settings in collaboration with HR-HPV. Here, we conducted a comprehensive review of the suggested molecular mechanisms involved in cooperation with both HR-HPV and TS for epithelial carcinogenesis. Furthermore, we propose interaction models in which TS collaborates with HR-HPV to promote epithelial cancer initiation, promotion, and progression. More studies are warranted to clarify interactions between oncogenic viruses and chemical or physical environmental factors for epithelial carcinogenesis.

The Double-Edged Sword Role of Viruses in Gastric Cancer

Due to its high morbidity and mortality, gastric cancer is a topic of a great concern throughout the world. Major ways of treatment are gastrectomy and chemotherapy, unfortunately they are not always successful. In a search for more efficient therapy strategies, viruses and their potential seem to be an important issue. On one hand, several oncogenic viruses have been noticed in the case of gastric cancer, making the positive treatment even more advantageous, but on the other, viruses exist with a potential therapeutic role in this malignancy.

The Role of Ataxia Telangiectasia Mutant and Rad3-Related DNA Damage Response in Pathogenesis of Human Papillomavirus

Human papillomavirus (HPV) infection leads to a variety of benign lesions and malignant tumors such as cervical cancer and head and neck squamous cell carcinoma. Several HPV vaccines have been developed that can help to prevent cervical carcinoma, but these vaccines are only effective in individuals with no prior HPV infection. Thus, it is still important to understand the HPV life cycle and in particular the association of HPV with human pathogenesis. HPV production requires activation of the DNA damage response (DDR), which is a complex signaling network composed of multiple sensors, mediators, transducers, and effectors that safeguard cellular DNAs to maintain the host genome integrity. In this review, we focus on the roles of the ataxia telangiectasia mutant and Rad3-related (ATR) DNA damage response in HPV DNA replication. HPV can induce ATR expression and activate the ATR pathway. Inhibition of the ATR pathway results in suppression of HPV genome maintenance and amplification. The mechanisms underlying this could be through various molecular pathways such as checkpoint signaling and transcriptional regulation. In light of these findings, other downstream mechanisms of the ATR pathway need to be further investigated for better understanding HPV pathogenesis and developing novel ATR DDR-related inhibitors against HPV infection.

Genome-Wide Transcriptome Analysis of Human Papillomavirus 16-Infected Primary Keratinocytes Reveals Subtle Perturbations Mostly due to E7 Protein Expression

It is established that the host cell transcriptomes of natural lesions, organotypic rafts, and human papillomavirus (HPV)-immortalized keratinocytes are altered in the presence of HPV genomes. However, the establishment of HPV-harboring cell lines requires selection and immortalization, which makes it impossible to distinguish between alterations directly induced by HPV or indirectly by the need for immortalization or selection. To address direct effects of HPV infection on the host cell transcriptome, we have used our recently established infection model that allows efficient infection of primary keratinocytes with HPV16 virions. We observed only a small set of genes to be deregulated at the transcriptional level at 7 days postinfection (dpi), most of which fall into the category regulated by pocket proteins pRb, p107, and p130. Furthermore, cell cycle genes were not deregulated in cells infected with a virus lacking E7 despite the presence of episomal genome and viral transcripts. These findings imply that the majority of transcriptional changes are due to the E7 protein impairing pocket protein function. Additional pathways, such as the Fanconi anemia-BRCA pathway, became perturbed only after long-term culturing of infected cells. When grown as organotypic raft cultures, keratinocytes infected with wild-type but not E7 mutant virus had perturbed transcriptional regulation of pathways previously identified in natural lesions and in rafts derived from immortalized keratinocytes. We conclude that the HPV infection model provides a valuable tool to distinguish immediate transcriptional alterations from those induced by persistent infection and the need for selection and immortalization.IMPORTANCE To establish infection and complete the viral life cycle, human papillomavirus (HPV) needs to alter the transcriptional program of host cells. Until recently, studies were restricted to keratinocyte-derived cell lines immortalized by HPV due to the lack of experimental systems to efficiently infect primary keratinocytes. Need for selection and immortalization made it impossible to distinguish between alterations induced by HPV and secondary adaptation due to selection and immortalization. With our recent establishment of an extracellular matrix (ECM)-to-cell transfer system allowing efficient infection of primary keratinocytes, we were able to identify transcriptional changes attributable to HPV16 infection. Most perturbed genes fall into the class of S-phase genes, which are regulated by pocket proteins. Indeed, infection with viruses lacking E7 abrogated most transcriptional changes. It is important to note that many transcriptional alterations thought to be important for the HPV life cycle are actually late events that may reflect immortalization and, possibly, disease progression.

Cellular RNA Hubs: Friends and Foes of Plant Viruses

RNA granules are dynamic cellular foci that are widely spread in eukaryotic cells and play essential roles in cell growth and development, and immune and stress responses. Different types of granules can be distinguished, each with a specific function and playing a role in, for example, RNA transcription, modification, processing, decay, translation, and arrest. By means of communication and exchange of (shared) components, they form a large regulatory network in cells. Viruses have been reported to interact with one or more of these either cytoplasmic or nuclear granules, and act either proviral, to enable and support viral infection and facilitate viral movement, or antiviral, protecting or clearing hosts from viral infection. This review describes an overview and recent progress on cytoplasmic and nuclear RNA granules and their interplay with virus infection, first in animal systems and as a prelude to the status and current developments on plant viruses, which have been less well studied on this thus far.

Prevalence of human papillomavirus in Jeddah, Saudi Arabia

BACKGROUND

Human papillomaviruses (HPVs) are small, non-enveloped, double-stranded DNA viruses that consist of more than 200 genotypes. Low-risk genotypes are associated with warts or benign lesions, whereas high-risk genotypes are usually associated with malignancies and cancers including cervical cancer. However, the real prevalence and incidence of HPV in Saudi Arabia may be understated due to a lack of comprehensive data reporting.

OBJECTIVES

Determine the positivity rate of HPV in men and women in Jeddah, Saudi Arabia.

DESIGN

Cross-sectional.

SETTING

Tertiary care center in Jeddah.

SUBJECTS AND METHODS

Self-collected vaginal swab samples were obtained from females attending the gynecological clinic in the period between October 2017 and April 2018 at a tertiary care center, Jeddah, Saudi Arabia. PCR-positive HPV samples were sequenced to determine genotype. Additionally, serum samples were collected from healthy male and female blood donors and screened for HPV IgG antibodies by ELISA.

MAIN OUTCOME MEASURES

Molecular and serological positivity for HPV.

SAMPLE SIZE

119 self-collected vaginal swabs from females at a gynecology clinic and 966 serum samples from healthy blood donors.

RESULTS

Of the 119 tested vaginal swabs, 7 samples (5.9%) were positive for HPV DNA. Several genotypes were identified. Most of the positive samples were from Saudi females in the age range of 31-50 years seeking care for infertility. Of the 966 serum samples, only 16 samples (1.7%) were positive for HPV IgG antibodies.

CONCLUSION

While the prevalence of HPV in men and women in our sample from the western region of Saudi Arabia was low, our data clearly show that it is not uncommon among high-risk groups and people are still exposed to the risk of HPV infection. Most importantly, these data provide valuable information that could aid in enhancing national awareness about HPV and in introducing an HPV vaccination program.

LIMITATIONS

Single hospital and a convenience sample CONFLICT OF INTEREST: None.

Current strategies against persistent human papillomavirus infection (Review)

Human papillomavirus (HPV) is the most common sexually transmitted infection, exhibiting a tropism for the epidermis and mucosae. The link between persistent HPV infection and malignancies involving the anogenital tract as well as the head and neck has been well‑established, and it is estimated that HPV‑related cancers involving various anatomical sites account for 4.5% of all human cancers. Current prophylactic vaccines against HPV have enabled the prevention of associated malignancies. However, the sizeable population base of current infection in whom prophylactic vaccines are not applicable, certain high‑risk HPV types not included in vaccines, and the vast susceptible population in developing countries who do not have access to the costly prophylactic vaccines, put forward an imperative need for effective therapies targeting persistent infection. In this article, the life cycle of HPV, the mechanisms facilitating HPV evasion of recognition and clearance by the host immune system, and the promising therapeutic strategies currently under investigation, particularly antiviral drugs and therapeutic vaccines, are reviewed.

Molecular mechanisms in progression of HPV-associated cervical carcinogenesis

Cervical cancer is the fourth most frequent cancer in women worldwide and a major cause of mortality in developing countries. Persistent infection with high-risk human papillomavirus (HPV) is a necessary cause for the development of cervical cancer. In addition, genetic and epigenetic alterations in host cell genes are crucial for progression of cervical precancerous lesions to invasive cancer. Although much progress has been made in understanding the life cycle of HPV and it’s role in the development of cervical cancer, there is still a critical need for accurate surveillance strategies and targeted therapeutic options to eradicate these cancers in patients. Given the widespread nature of HPV infection and the type specificity of currently available HPV vaccines, it is crucial that molecular details of the natural history of HPV infection as well as the biological activities of viral oncoproteins be elucidated. A better understanding of the mechanisms involved in oncogenesis can provide novel insights and opportunities for designing effective therapeutic approaches against HPV-associated malignancies. In this review, we briefly summarize epigenetic alterations and events that cause alterations in host genomes inducing cell cycle deregulation, aberrant proliferation and genomic instability contributing to tumorigenesis.

Acetylation of E2 by P300 Mediates Topoisomerase Entry at the Papillomavirus Replicon

Human papillomavirus (HPV) E2 proteins are integral for the transcription of viral genes and the replication and maintenance of viral genomes in host cells. E2 recruits the viral DNA helicase E1 to the origin. A lysine (K111), highly conserved among almost all papillomavirus (PV) E2 proteins, is a target for P300 (EP300) acetylation and is critical for viral DNA replication (E. J. Quinlan, S. P. Culleton, S. Y. Wu, C. M. Chiang, et al., J Virol 87:1497-1507, 2013, https://doi.org/10.1128/JVI.02771-12; Y. Thomas and E. J. Androphy, J Virol 92:e01912-17, 2018, https://doi.org/10.1128/JVI.01912-17). Since the viral genome exists as a covalently closed circle of double-stranded DNA, topoisomerase 1 (Topo1) is thought to be required for progression of the replication forks. Due to the specific effect of K111 mutations on DNA unwinding (Y. Thomas and E. J. Androphy, J Virol 92:e01912-17, 2018, https://doi.org/10.1128/JVI.01912-17), we demonstrate that the E2 protein targets Topo1 to the viral origin, and this depends on acetylation of K111. The effect was corroborated by functional replication assays, in which higher levels of P300, but not its homolog CBP, caused enhanced replication with wild-type E2 but not the acetylation-defective K111 arginine mutant. These data reveal a novel role for lysine acetylation during viral DNA replication by regulating topoisomerase recruitment to the replication origin.IMPORTANCE Human papillomaviruses affect an estimated 75% of the sexually active adult population in the United States, with 5.5 million new cases emerging every year. More than 200 HPV genotypes have been identified; a subset of them are linked to the development of cancers from these epithelial infections. Specific antiviral medical treatments for infected individuals are not available. This project examines the mechanisms that control viral genome replication and may allow the development of novel therapeutics.

Prevalence of human papillomavirus type-18 in head and neck cancer among the Chinese population: A PRISMA-compliant meta-analysis

BACKGROUND

China has a high burden of head and neck cancer globally and oncogenic human papillomavirus (HPV) has been hypothesized as a risk factor for head and neck cancer, but research was absent for establishing HPV prevalence in China. We aimed to conduct a meta-analysis to estimate the high-risk HPV-18 prevalence of head and neck cancer in the Chinese population.

METHODS

This meta-analysis was reported following the guideline of PRISMA. The reports on HPV and head and neck cancer in a Chinese population published between Jan 1, 2006 and May 31, 2018 were retrieved via CNKI/WANFANG/MEDLINE/EMBASE/COCHRANE databases. A random-effect model was used to calculate pooled prevalence and corresponding 95% confidence intervals.

RESULTS

A total of 1881 head and neck cancer cases from 19 studies were included in this meta-analysis. Overall, the pooled HPV-18 prevalence among head and neck cancer cases was 6.0% (4.1%-7.9%) in China, 31.2% (13.0%-49.4%) in laryngeal cancer, 7.2% (3.9%-10.5%) in oral cancer and 0.6% (0.0%-1.3%) in oropharyngeal cancer, 18.7% (6.2%-31.2%) in fresh or frozen biopsies and 4.3% (2.5%-6.1%) in paraffin-embedded fixed biopsies, 29.5% (15.6%-43.3%) by E6/E7 region and 3.9% (0.5%-7.4%) by L1 region of HPV gene. The highest HPV-18 prevalence was found in Central China.

CONCLUSIONS

High prevalence of HPV-18 was found in the samples of Chinese head and neck cancers. Prophylactic HPV-vaccination may reduce the burden of HPV-related head and neck cancer in China.

Topoisomerase IIβ-binding protein 1 activates expression of E2F1 and p73 in HPV-positive cells for genome amplification upon epithelial differentiation

High-risk human papillomaviruses (HPVs) constitutively activate the ataxia telangiectasia mutated (ATM) and the ataxia telangiectasia and Rad3-related (ATR) DNA damage repair pathways for viral genome amplification. HPVs activate these pathways through the immune regulator STAT-5. For the ATR pathway, STAT-5 increases expression of the topoisomerase IIβ-binding protein 1 (TopBP1), a scaffold protein that binds ATR and recruits it to sites of DNA damage. TopBP1 also acts as a transcriptional regulator and we investigated how this activity influenced the HPV life cycle. We determined that TopBP1 levels are increased in cervical intraepithelial neoplasias as well as cervical carcinomas, consistent with studies in HPV-positive cell lines. Suppression of TopBP1 by shRNAs impairs HPV genome amplification and activation of the ATR pathway but does not affect the total levels of ATR and CHK1. In contrast, knockdown reduces the expression of other DNA damage factors such as RAD51 and Mre11 but not BRCA2 or NBS1. Interestingly, TopBP1 positively regulates the expression of E2F1, a TopBP1 binding partner, and p73, in HPV positive cells in contrast to effects in other cell types. TopBP1 transcriptional activity is regulated by AKT and treatment with AKT inhibitors suppresses expression of E2F1 and p73 without interfering with ATR signaling. Importantly, the levels of p73 are elevated in HPV-positive cells and knockdown impairs HPV genome amplification. This demonstrates that p73, like p63 and p53, is an important regulator of the HPV life cycle that is controlled by the transcriptional activating properties of the multifunctional TopBP1 protein.