Human papillomavirus in head and neck cancer

Evaluation of Oral Squamous Cell Carcinoma Patients Using Polymerase Chain Reaction Regarding the Prevalence of Human Papillomavirus Types 16 and 18

BACKGROUND

Epstein-Barr virus, human papillomavirus (HPV), and herpes simplex virus type 1 (HSV-1) are examples of viruses that have been associated with the development of oral squamous cell carcinoma (OSCC). These viruses can infect various epithelial tissues in the human body. The use of incredibly accurate cellular biology techniques, such as the polymerase chain reaction (PCR), which permits the rapid identification of viruses following infection, has increased. The parameters of human head and neck oncology have been widened.

AIM

In this study, using the PCR, the presence of HPV variants such as HPV 18 and HPV 16 in patients with OSCC was assessed.

MATERIALS AND METHODS

Tissue specimens were obtained from clinically presumed OSCC individuals taken as cases, and tissues from the retromolar region were obtained from people who experienced an operation for partially and completely impacted tooth and taken as controls. The study included 80 samples divided into two separate categories: case category (n = 40) = OSCC-diagnosed individuals; control category (n = 40) = controls with a comparable age. For verification of the diagnosis, a specimen of the tissue has been processed and sections have been stained and inspected for standard hematoxylin and eosin stain. Deoxyribonucleic acid (DNA) was extracted from the leftover histopathologically verified tissue specimens and then exposed to PCR for the assessment of HPV infiltration.

RESULTS

It was observed in this research that 22 cases out of 40 cases of OSCC were found positive for HPV-DNA. While 12 out of 40 age-matched healthy controls were found positive for HPV-DNA. Out of 40 cases of OSCC, 12 cases were found positive for HPV 16. While six out of 40 age-matched healthy controls were found positive for HPV 16. Six cases out of 40 cases of OSCC were found positive for HPV 16. While two out of 40 age-matched healthy controls were found positive for HPV 18. Four cases out of 40 cases of OSCC were found positive for HPV 16. While four out of 40 age-matched healthy controls were found positive for HPV 16 and HPV 18. On carrying out statistical analysis, the variation between the two categories was non-meaningful statistically (p = 0.662). However, the prevalence was greater in the case (OSCC) subgroup.

CONCLUSION

When evaluated against controls in the current investigation, OSCC cases had a greater level of HPV expression and a greater proportion of HPV 16 positives. However, there was no statistically noteworthy change.

Phosphorylation of E2 Serine Residue 402 Is Required for the Transcription and Replication of the HPV5 Genome

Cutaneous human papillomavirus type 5 (HPV5) belongs to the supposedly oncogenic β-HPVs associated with specific types of skin and oral cavity cancers. Three viral proteins, namely, helicase E1 and transcription factors E2 and E8^E2, are master regulators of the viral life cycle. HPV5 E2 is a transcriptional activator that also participates in the E1-dependent replication and nuclear retention of the viral genome, whereas E8^E2 counterbalances the activity of E2 and inhibits HPV transcription and replication. In the present study, we demonstrate that the HPV5 E2 protein is extensively phosphorylated by cellular protein kinases, and serine residue 402 (S402) is the highest scoring phosphoacceptor site. This residue is located within a motif conserved among many β-HPVs and in the oncogenic HPV31 α-type. Using the nonphosphorylatable and phosphomimetic mutants, we demonstrate that phosphorylation of the E2 S402 residue is required for the transcription and replication of the HPV5 genome in U2OS cells and human primary keratinocytes. Mechanistically, the E2-S402-phopshodeficient protein is unable to trigger viral gene transcription and has an impaired ability to support E1-dependent replication, but the respective E8^E2-S213 mutant displays no phenotype. However, phosphorylation of the E2 S402 residue has no impact on the E2 stability, subcellular localization, self-assembly, DNA-binding capacity, and affinity to the E1 and BRD4 proteins. Further studies are needed to identify the protein kinase(s) responsible for this phosphorylation. IMPORTANCE Human papillomavirus type 5 (HPV5) may play a role in the development of specific types of cutaneous and head and neck cancers. The persistence of the HPV genome in host cells depends on the activity of its proteins, namely, a helicase E1 and transcription/replication factor E2. The latter also facilitates the attachment of episomal viral genomes to host cell chromosomes. In the present study, we show that the HPV5 E2 protein is extensively phosphorylated by host cell protein kinases, and we identify serine residue 402 as the highest scoring phosphoacceptor site of E2. We demonstrate that the replication of the HPV5 genome may be blocked by a single point mutation that prevents phosphorylation of this serine residue and switches off the transcriptional activity of the E2 protein. The present study contributes to a better understanding of β-HPV5 replication and its regulation by host cell protein kinases.

Senolytic Therapy: A Potential Approach for the Elimination of Oncogene-Induced Senescent HPV-Positive Cells

Senescence represents a unique cellular stress response characterized by a stable growth arrest, macromolecular alterations, and wide spectrum changes in gene expression. Classically, senescence is the end-product of progressive telomeric attrition resulting from the repetitive division of somatic cells. In addition, senescent cells accumulate in premalignant lesions, in part, as a product of oncogene hyperactivation, reflecting one element of the tumor suppressive function of senescence. Oncogenic processes that induce senescence include overexpression/hyperactivation of H-Ras, B-Raf, and cyclin E as well as inactivation of PTEN. Oncogenic viruses, such as Human Papilloma Virus (HPV), have also been shown to induce senescence. High-risk strains of HPV drive the immortalization, and hence transformation, of cervical epithelial cells via several mechanisms, but primarily via deregulation of the cell cycle, and possibly, by facilitating escape from senescence. Despite the wide and successful utilization of HPV vaccines in reducing the incidence of cervical cancer, this measure is not effective in preventing cancer development in individuals already positive for HPV. Accordingly, in this commentary, we focus on the potential contribution of oncogene and HPV-induced senescence (OIS) in cervical cancer. We further consider the potential utility of senolytic agents for the elimination of HPV-harboring senescent cells as a strategy for reducing HPV-driven transformation and the risk of cervical cancer development.

Human Papillomavirus and Risk of Head and Neck Squamous Cell Carcinoma in Iran

Human papillomavirus (HPV) causes a subset of head and neck squamous cell carcinoma (HNSCC). Knowledge of determinants of α-, β-, and γ-HPVs types in the oral cavity is required for a better understanding of HNSCC development. Oral rinse samples of 498 HNSCC cases and 242 controls from the IROPICAN study-a large multicenter case-control study in Iran-were screened for 21 α-HPV, 46 β-HPVs, and 52 γ-HPVs using bead-based HPV genotyping assays. α-HPVs were detected only in 1.2% of the patients and 2.9% of the controls from which HPV16 was the most prevalent type among participants. β-HPVs were detected in 43.8% of the patients and 38.6% of the controls where the lip and oral cavity (45.5%) had the highest positivity. Values for γ-HPV prevalence in patients and controls were 26.1% and 24.7%, respectively. The highest percentage of γ-HPV positivity was found in the larynx (30.4%). Concerning the β genus, HPV23 and HPV38 were the most prevalent types among the patients and controls, respectively. For the γ genus, SD2 in cases and HPV134 in controls were the most prevalent types. Overall, detection of α-HPVs (aOR, 0.40; 95% CI = 0.1 to 1.2; P = 0.11), β-HPVs (aOR, 1.9; 95% CI = 0.9 to 1.6; P = 0.29), and γ-HPVs infections (aOR, 1.04; 95% CI = 0.7 to 1.5; P = 0.83) was not associated with the HNSCC development. Our data did not suggest an HPV-related etiology for HNSCC pathogenesis. Nonetheless, this study provides novel insights into the diversity of β-, and γ-HPVs in different HNSCC anatomical subsites. IMPORTANCE Infection with human papillomavirus (HPV) is responsible for a subset of neck squamous cell carcinoma (HNSCC), but knowledge of the prevalence of and risk factors for oral HPV infection, especially cutaneous types in Iran, remains unknown. In a large retrospective study, the authors used a sensitive assay for the detection of α-, β-, and γ-HPVs in oral rinse samples of HNSCC and matched controls. They find that the α-HPV contribution to HNSCC in Iran is lower than global prevalence. High-risk α-HPVs or cutaneous β- and γ-HPVs were not associated with the HNSCC development. Besides, this study provides novel insights into the diversity of β- and γ-HPVs in different HNSCC anatomical subsites.

Retrospective study of factors associated with late detection of oral cancer in alberta: A qualitative study

Oral cancer continues to be diagnosed in advanced stages, giving patients lower chances of survival. The objective of this study was to explore reasons for delayed diagnosis of oral cancer in Alberta. A retrospective qualitative design was implemented through seven steps suggested for conducting a narrative clinical document. Data was retrieved from the Alberta Cancer Registry database between 2005 and 2017. A sample of initial consultation notes (ICN) of oral and oropharyngeal cancer patients were identified through a purposeful sampling method and added to the study until saturation was achieved. A deductive analysis approach inspired by the model pathways to treatment health care provider (HCP) was employed. From the 34 ICN included in our analysis, five main categories were identified: appraisal interval, help-seeking interval, diagnosis interval, pre-treatment interval, and other contributing factors such as health-related behaviours, system delay, and tumor characteristics. These factors negatively contributed to early detection of oral and oropharyngeal cancers and affect treatment wait time with patients, providers, and the healthcare system. Patient's lack of awareness, provider's oversight and prolonged access to care were the main reasons of delay in cancer diagnosis and management in our study. A sustainable plan for public awareness interventions and implementation of a solid curriculum for medical and dental students is needed to enhance their related knowledge, competence in clinical judgement, and treatment managements.

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.

Contributions of the international plant science community to the fight against human infectious diseases - part 1: epidemic and pandemic diseases

Infectious diseases, also known as transmissible or communicable diseases, are caused by pathogens or parasites that spread in communities by direct contact with infected individuals or contaminated materials, through droplets and aerosols, or via vectors such as insects. Such diseases cause ˜17% of all human deaths and their management and control places an immense burden on healthcare systems worldwide. Traditional approaches for the prevention and control of infectious diseases include vaccination programmes, hygiene measures and drugs that suppress the pathogen, treat the disease symptoms or attenuate aggressive reactions of the host immune system. The provision of vaccines and biologic drugs such as antibodies is hampered by the high cost and limited scalability of traditional manufacturing platforms based on microbial and animal cells, particularly in developing countries where infectious diseases are prevalent and poorly controlled. Molecular farming, which uses plants for protein expression, is a promising strategy to address the drawbacks of current manufacturing platforms. In this review article, we consider the potential of molecular farming to address healthcare demands for the most prevalent and important epidemic and pandemic diseases, focussing on recent outbreaks of high-mortality coronavirus infections and diseases that disproportionately affect the developing world.

The Role of Human Papilloma Virus in Dictating Outcomes in Head and Neck Squamous Cell Carcinoma

The Human Papilloma Virus (HPV) is an oncogenic virus which is associated with the development of head and neck squamous cell carcinoma (HNSCC), predominantly within the oropharynx. Approximately 25% of oropharyngeal squamous cell carcinoma (OPSCC) cases worldwide are attributable to HPV infection, with an estimated 65% in the United States. Transmission is via exposure during sexual contact, with distinctive anatomical features of the tonsils providing this organ with a predilection for infection by HPV. No premalignant lesion is identifiable on clinical examination, thus no comparative histological features to denote the stages of carcinogenesis for HPV driven HNSCC are identifiable. This is in contrast to HPV-driven cervical carcinoma, making screening a challenge for the head and neck region. However, HPV proffers a favorable prognosis in the head and neck region, with better overall survival rates in contrast to its HPV negative counterparts. This has resulted in extensive research into de-intensifying therapies aiming to minimize the morbidity induced by standard concurrent chemo-radiotherapy without compromising efficacy. Despite the favorable prognosis, cases of recurrence and/or metastasis of HPV positive HNSCC do occur, and are linked with poor outcomes. HPV 16 is the most frequent genotype identified in HNSCC, yet there is limited research to date studying the impact of other HPV genotype with respect to overall survival. A similar situation pertains to genetic aberrations associated in those with HPV positive HNSCC who recur, with only four published studies to date. Somatic mutations in TSC2, BRIP1, NBN, TACC3, NFE2l2, STK11, HRAS, PIK3R1, TP63, and FAT1 have been identified in recurrent HPV positive OPSCC. Finding alternative therapeutic strategies for this young cohort may depend on upfront identification of HPV genotypes and mutations which are linked with worse outcomes, thus ensuring appropriate stratification of treatment regimens.

Virus-Host Protein-Protein Interactions between Human Papillomavirus 16 E6 A1 and D2/D3 Sub-Lineages: Variances and Similarities

High-risk strains of human papillomavirus are causative agents for cervical and other mucosal cancers, with type 16 being the most frequent. Compared to the European Prototype (EP; A1), the Asian-American (AA; D2/D3) sub-lineage seems to have increased abilities to promote carcinogenesis. Here, we studied protein-protein interactions (PPIs) between host proteins and sub-lineages of the key transforming E6 protein. We transduced human keratinocyte with EP or AA E6 genes and co-immunoprecipitated E6 proteins along with interacting cellular proteins to detect virus-host binding partners. AAE6 and EPE6 may have unique PPIs with host cellular proteins, conferring gain or loss of function and resulting in varied abilities to promote carcinogenesis. Using liquid chromatography-mass spectrometry and stringent interactor selection criteria based on the number of peptides, we identified 25 candidates: 6 unique to AAE6 and EPE6, along with 13 E6 targets common to both. A novel approach based on pathway selection discovered 171 target proteins: 90 unique AAE6 and 61 unique EPE6 along with 20 common E6 targets. Interpretations were made using databases, such as UniProt, BioGRID, and Reactome. Detected E6 targets were differentially implicated in important hallmarks of cancer: deregulating Notch signaling, energetics and hypoxia, DNA replication and repair, and immune response.

Prevalence of Epstein-Barr virus, human papillomavirus, cytomegalovirus and herpes simplex virus type 1 in patients with diabetes mellitus type 2 in south-eastern Poland

A microbiota is a complex ecosystem of microorganisms consisting of bacteria, viruses, protozoa, and fungi living in different niches of the human body, which plays an essential role in many metabolic functions. Modifications in the microbiota composition can lead to several diseases, including metabolic disorders. The aim of this study was to analyze the prevalence of four viruses which can cause persistent infections-Epstein-Barr virus (EBV), human papillomavirus (HPV), cytomegalovirus (CMV), and herpes simplex virus type 1 (HSV-1) in patients with diabetes mellitus type 2 (DM2). Blood, saliva and oral swabs were collected from all the study participants. The nested-PCR technique was used to detect the viral DNA. DNA of at least one virus was detected in 71.1% of diabetic patients and in 30% of individuals without diabetes. In patients with diabetes EBV DNA was detected the most frequently (25.4%), followed by HPV- 19.1%, HSV- 10.4% and CMV- 5.2%. A higher percentage of EBV+HPV co-infection was found among men (30.8%). EBV DNA was statistically more often detected in patients living in rural areas (53.7%), while HPV (91.5%) and EBV+HPV co-infection (22.2%) prevailed among patients from urban areas. In patients with a DM2 history longer than 10 years viral infection was detected more frequently. The prevalence of EBV, HPV and the EBV+HPV co-infection was significantly higher in diabetic patients than in individuals without diabetes. The frequency of these infections depended on the duration of the disease (DM2).

The Prevalence, Anatomic Distribution and Significance of HPV Genotypes in Head and Neck Squamous Papillomas as Detected by Real-Time PCR and Sanger Sequencing

Squamous papillomas (SPs) of the head and neck are generally regarded as a human papillomavirus (HPV)-driven process, but reported rates of HPV detection vary dramatically. Moreover, they are generally considered a benign condition, but the detection of high risk HPV types is commonly reported. This latter finding is particularly disturbing to clinicians and their patients given the alarming rise of HPV-associated head and neck cancer. The capriciousness of HPV detection reflects in large part differences in methodologies. The purpose of this study was to review an institutional experience using a state of the art detection method to determine the presence, type and anatomic distribution of HPV in head and neck SPs. The surgical pathology files of the Mount Sinai Hospital were reviewed for all SPs that had undergone HPV testing between 2012 and 2018. HPV screening was performed on tissue blocks with real-time PCR using primers designed to target the L1 region of low and high-risk HPV types. Genotyping was performed on HPV positive cases. HPV detection was repeated for cases that were originally reported to be positive for high risk HPV. 134 cases had undergone HPV analysis. Of the 131 with sufficient cellular material, 2 were excluded because the HPV testing yielded inconclusive results. The remaining 129 cases were the basis of this study. Thirty-eight cases (29%) were HPV positive and 91 (71%) were negative. The most common genotype was HPV 6 (n = 27, 71%), followed by HPV 11 (n = 10, 26%). One case (1%) was HPV positive but the genotype could not be determined. Of the HPV negative cases, 3 were originally reported as HPV 16 positive but found to be HPV negative on re-review and repeat testing. SPs arising in the larynx were more likely to harbor HPV than those arising in the oral cavity and oropharynx (64% vs. 10%, p < 0.00001). Similarly, recurrent respiratory papillomatosis (RRP) were much more likely to be HPV positive than solitary SPs (71% vs. 10%, p < 0.00001). Almost a third of head and neck SPs harbor HPV, but incidence is highly dependent on anatomic site. Those arising in the larynx are more prone to be HPV-driven than those arising in the oral cavity and oropharynx, particularly when occurring in the setting of RRP. High risk HPV could not be confirmed in any of the cases. Routine HPV testing as a strategy to unmask potentially malignant lesions harboring high risk HPV is not likely to be useful.

Differential impact of age on survival in head and neck cancer according to classic Cox regression and decision tree analysis

OBJECTIVES

To assess the impact of age on the survival of patients with head and neck squamous cell carcinoma (HNSCC) using different statistical methods.

DESIGN

A retrospective population-based study.

SETTING

Surveillance, Epidemiology, and End Results database.

SUBJECTS AND METHODS

A total of 28 639 patients with newly diagnosed HNSCC were enrolled between 1 January 2007 and 31 December 2013. The effect of age on 5-year disease-specific survival was calculated using a Kaplan-Meier method and compared using log-rank tests. A Cox proportional hazards model was used for a multivariate analysis. A classification and regression tree (CART) analysis that partitioned patients with significantly different Kaplan-Meier curves was introduced to identify the important cancer-related parameters influencing survival.

RESULTS

Uni- and multivariate analyses indicated that patients who were older than 60 years had poorer 5-year disease-specific survival regardless of tumour subsite and tumor-node-metastasis (TNM) stage. However, the CART analysis determined that age played only a minor role in survival after comparing with other prognosticators. The relative importance of age using the Gini index was as follows: 3.21% for oral cancer, 8.32% for oropharyngeal cancer, 2.56% for hypopharyngeal cancer and 16.51% for laryngeal cancer.

CONCLUSIONS

Different to traditional statistical methods, the CART analysis which was used to identify homogeneous populations revealed that the impact of age varied for different patient groups according to the presence or absence of other prognosticators. This important information could help to guide our clinical decisions and future researches.

A study to assess expression of human papillomavirus types 16 and 18 in oral squamous cell carcinoma using polymerase chain reaction

Objective:

The diverse subset of oral squamous cell carcinoma (OSCC) with different clinical appearance and outcome, independent of traditional risk factors has led to increasing attention in human papillomavirus (HPV) infection.

Materials and Methods:

The investigation followed a case–control design. Information pertaining to the subjects was retrieved from hospital records. Twenty cases of OSCC and twenty age-matched controls were analyzed to ascertain the prevalence of HPV types 16 and 18. DNA was extracted from the blocks of formalin-fixed paraffin embedded tissues, and HPV-DNA was amplified using HPV type-specific primers by polymerase chain reaction (PCR) method. Data analysis was carried out using Chi-square test.

Results:

HPV-DNA was detected in 55% of cases (11/20; HPV 16 = 6, HPV 18 = 3 and HPV 16 and 18 = 2) and 30% of controls (6/20; HPV 16 = 3, HPV 18 = 1 and HPV 16 and 18 = 2) indicating higher percentage of HPV presence among OSCC cases. No significant association was found between the presence of HPV and gender, age, site and grade of differentiation of OSCC.

Conclusion:

Although the presence of HPV was higher in cases compared to controls, none of these differences were statistically significant. HPV 16 and 18 are commonly found in normal oral mucosa mandating the need for distinguishing clinical, subclinical and latent HPV infections.

Integration of Oncogenes via Sleeping Beauty as a Mouse Model of HPV16+ Oral Tumors and Immunologic Control

Human papillomavirus type 16 (HPV16) is the etiologic factor for cervical cancer and a subset of oropharyngeal cancers. Although several prophylactic HPV vaccines are available, no effective therapeutic strategies to control active HPV diseases exist. Tumor implantation models are traditionally used to study HPV-associated buccal tumors. However, they fail to address precancerous phases of disease progression and display tumor microenvironments distinct from those observed in patients. Previously, K14-E6/E7 transgenic mouse models have been used to generate spontaneous tumors. However, the rate of tumor formation is inconsistent, and the host often develops immune tolerance to the viral oncoproteins. We developed a preclinical, spontaneous, HPV16⁺ buccal tumor model using submucosal injection of oncogenic plasmids expressing HPV16-E6/E7, NRas ^G12V , luciferase, and sleeping beauty (SB) transposase, followed by electroporation in the buccal mucosa. We evaluated responses to immunization with a pNGVL4a-CRT/E7(detox) therapeutic HPV DNA vaccine and tumor cell migration to distant locations. Mice transfected with plasmids encoding HPV16-E6/E7, NRas ^G12V , luciferase, and SB transposase developed tumors within 3 weeks. We also found transient anti-CD3 administration is required to generate tumors in immunocompetent mice. Bioluminescence signals from luciferase correlated strongly with tumor growth, and tumors expressed HPV16-associated markers. We showed that pNGVL4a-CRT/E7(detox) administration resulted in antitumor immunity in tumor-bearing mice. Lastly, we demonstrated that the generated tumor could migrate to tumor-draining lymph nodes. Our model provides an efficient method to induce spontaneous HPV⁺ tumor formation, which can be used to identify effective therapeutic interventions, analyze tumor migration, and conduct tumor biology research. Cancer Immunol Res; 6(3); 305-19. ©2018 AACR.

[Analysis of the current status of research on human papillomavirus-associated head and neck cancers based on recent Chinese literature]

OBJECTIVE

To analyze the current status of research on human papillomavirus (HPV)-associated head and neck cancers in China using national and international references.

METHODS

We searched for bibliographies in the electronic databases of Sichuan University, including Chinese Biological and Medical Database (CBM), China Science and Technology Journal Database (VIP), and Wanfang Journal Database. Then, data was selected and extracted to analyze the basic characteristics of HPV-related head and neck cancers, the general prevalence of HPV, and the effects of various clinic pathological indicators on HPV patients.

RESULTS

The general prevalence of HPV was 34.05% among civil patients with head and neck cancers. Our analysis of different clinical and pathological indices that affect HPV-associated oral squamous cell carcinomas revealed that non-smoking and non-drinking groups had higher HPV infection rates compared with smoking (P=0.002) and drinking (P<
0.005) groups. In addition, N2-N3 stage patients had higher detectable rates than N0-N1 stage patients (P=0.027).

CONCLUSIONS

The majority of civil research studies on HPV-associated head and neck cancers are concentrated on clinical studies. Thus, the molecular neuropathology and signaling pathway of HPV should be further explored in the future to advance prognostic methods. Moreover, the perspective view of therapeutic vaccines and molecular-targeting treatments should receive close attention. 
.

Human Papillomavirus Associated Cancers of the Head and Neck: An Australian Perspective

Human papillomavirus (HPV) associated head and neck squamous cell carcinomas (HNSCCs), have become a serious global health problem. Despite decreases in HPV-negative HNSCCs, the prevalence of HPV-positive HNSCCs has significantly increased. HPV-positive cancers are associated with superior survival outcomes when compared to HPV-negative cancers, which appears likely to be associated with differences in the molecular pathogenesis of the two diseases. While therapies are still problematic, the current HPV vaccine programs hold a promise for the primary prevention of HPV-related HNSCCs and since Australia was the first to introduce a nationwide HPV vaccine program, it is in a unique position to observe the effects of the vaccine on HNSCCs. This review discusses the epidemiological trends associated with HPV in HNSCC, with reference to the differences between HPV-positive and HPV-negative HNSCCs and the prevention potential of HPV vaccines.

Augmentation of cellular and humoral immune responses to HPV16 and HPV18 E6 and E7 antigens by VGX-3100

We have previously demonstrated the immunogenicity of VGX-3100, a multicomponent DNA immunotherapy for the treatment of Human Papillomavirus (HPV)16/18-positive CIN2/3 in a phase 1 clinical trial. Here, we report on the ability to boost immune responses with an additional dose of VGX-3100. Patients completing our initial phase 1 trial were offered enrollment into a follow on trial consisting of a single boost dose of VGX-3100. Data show both cellular and humoral immune responses could be augmented above pre-boost levels, including the induction of interferon (IFN)γ production, tumor necrosis factor (TNF)α production, CD8+ T cell activation and the synthesis of lytic proteins. Moreover, observation of antigen-specific regulation of immune-related gene transcripts suggests the induction of a proinflammatory response following the boost. Analysis of T cell receptor (TCR) sequencing suggests the localization of putative HPV-specific T cell clones to the cervical mucosa, which underscores the putative mechanism of action of lesion regression and HPV16/18 elimination noted in our double-blind placebo-controlled phase 2B trial. Taken together, these data indicate that VGX-3100 drives the induction of robust cellular and humoral immune responses that can be augmented by a fourth "booster" dose. These data could be important in the scope of increasing the clinical efficacy rate of VGX-3100.

Buccal injection of synthetic HPV long peptide vaccine induces local and systemic antigen-specific CD8+ T-cell immune responses and antitumor effects without adjuvant

BACKGROUND

Human Papillomavirus is responsible for over 99 % of cervical cancers and is associated with cancers of the head and neck. The currently available prophylactic vaccines against HPV do not generate therapeutic effects against established HPV infections and associated lesions and disease. Thus, the need for a therapeutic vaccine capable of treating HPV-induced malignancies persists. Synthetic long peptides vaccination is a popular antigen delivery method because of its safety, stability, production feasibility, and its need to be processed by professional antigen presenting cells before it can be presented to cytotoxic CD8+ T lymphocytes. Cancers in the buccal mucosa have been shown to elicit cancer-related inflammations that are capable of recruiting inflammatory and immune cells to generate antitumor effects. In the current study, we evaluated the therapeutic potential of synthetic HPV long peptide vaccination in the absence of adjuvant in the TC-1 buccal tumor model.

RESULT

We show that intratumoral vaccination with E7 long peptide alone effectively controls buccal TC-1 tumors in mice. Furthermore, we observed an increase in systemic as well as local E7-specific CD8+ T cells in buccal tumor-bearing mice following the vaccination. Finally, we show that induction of immune responses against buccal tumors by intratumoral E7 long peptide vaccination is independent of CD4+ T cells, and that the phenomenon may be related to the unique environment associated with mucosal tissues.

CONCLUSION

Our results suggest the possibility for clinical translation of the administration of adjuvant free therapeutic long peptide vaccine as a potentially effective and safe strategy for mucosal HPV-associated tumor treatment.

Investigating Patient and Physician Delays in the Diagnosis of Head and Neck Cancers: a Canadian Perspective

Diagnostic delays for head and neck cancer (HNC) patients are common. Patients often disregard symptoms for long periods before seeking help, and some family physicians may not be alert to the warning symptoms and signs of HNCs. This study evaluated the factors associated with length of delays in the diagnosis of HNCs in a Canadian population. This was a mixed-method study consisting of patient interviews and surveys in an academic health center. A questionnaire requesting demographic and disease information was completed by HNC patients followed by a 30 min semi-structured interview in a private setting. Interviews were audio recorded, transcribed, anonymized, and descriptively coded for emergent themes. Twenty-eight head and neck cancer patients participated in the study. More patients experienced physician delay (71 %) than patient delay (36 %). The median physician delay and patient delay were 108 and 31 days, respectively. Two main themes regarding these delays were (1) physician lack of knowledge and (2) lack of patient awareness. Results indicate that physician delay needs to be focused on compared to patient delay, as it is more common and has longer delays. More comprehensive training in head and neck clinical examination skills during undergraduate and residency training is recommended to reduce physician delay. Patient delay could be targeted by public education programs via both physicians and dentists.

Oral Human Papillomavirus Infection in Children

Oral human papillomavirus infection is rare in children, but the presence of a villous lesion with slow but continuous growth concerns parents, who need information and therapeutic solutions from the physician. All these aspects are discussed based on a case report of a 9-year-old child with an oral human papillomavirus infection.

Prevalence of Human papillomavirus (HPV) and Epstein-Barr virus (EBV) in oral and oropharyngeal squamous cell carcinoma in south-eastern Poland

OBJECTIVE

The aim of this study was to analyze the prevalence of HPV and EBV in oral and oropharyngeal squamous cell carcinoma in south-eastern Poland. The correlation between viral infection, OSCC, alcohol use, tobacco smoking, demographic data (gender, age, place of residence), anatomic location, pre-treatment staging, evidence of metastases to lymph nodes, and grading was also investigated.

METHODS

The examination samples were collected from paraffin tissue blocks, from 154 patients. Viral DNA was amplified by the nested-PCR method.

RESULTS

HPV DNA was detected in 29.2 % of the tested samples (in 27.4 % of oropharyngeal and in 30.4 % of oral cavity). The HPV type 16 was detected in 15.6 % of all samples, and in 53.3 % of HPV-positive group. In HPV-positive samples from oropharyngeal HPV 16 constitute 76.5 %, and in HPV-positive samples from oral cavity HPV 16 constitute 39.3 %. Mixed infection (more than one type of HPV) was observed in 23.5 and 60.7 %, respectively, and in 46.7 % of all HPV-positive samples, and in 12.3 % of the whole study group. EBV DNA was detected in 27.3 % of the cases and HPV-EBV co-infection in 7.8 % of samples.

CONCLUSIONS

In major patients from Southeastern region of Poland with oropharyngeal cancer HPV type 16 was detected but in oral cavity cancer other mixed infections were observed (i.e. 51, 52, 59, 66, 68, 71, 74). HPV 16 was detected more often among patients younger than 50 years of age, whereas the mixed HPV in the group aged 50-59. The pathogenesis of oral squamous cell carcinoma may be connected with EBV infection. Future studies on the mechanisms of HPV/EBV co-infection and/or superinfection and their role in oral squamous cell carcinoma are necessary.

Recent Progress in Therapeutic Treatments and Screening Strategies for the Prevention and Treatment of HPV-Associated Head and Neck Cancer

The rise in human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) has elicited significant interest in the role of high-risk HPV in tumorigenesis. Because patients with HPV-positive HNSCC have better prognoses than do their HPV-negative counterparts, current therapeutic strategies for HPV⁺ HNSCC are increasingly considered to be overly aggressive, highlighting a need for customized treatment guidelines for this cohort. Additional issues include the unmet need for a reliable screening strategy for HNSCC, as well as the ongoing assessment of the efficacy of prophylactic vaccines for the prevention of HPV infections in the head and neck regions. This review also outlines a number of emerging prospects for therapeutic vaccines, as well as for targeted, molecular-based therapies for HPV-associated head and neck cancers. Overall, the future for developing novel and effective therapeutic agents for HPV-associated head and neck tumors is promising; continued progress is critical in order to meet the challenges posed by the growing epidemic.

The human papillomavirus 16 European-T350G E6 variant can immortalize but not transform keratinocytes in the absence of E7

Human papillomavirus type 16 is commonly implicated in HPV-related cancers. However, only a small number of infected individuals progress to this stage. Epidemiological evidence demonstrated that oncogenic risk is population-specific and variations within the viral oncogene, E6, have been suggested to play a role in these findings. Of focus in this study is the European-T350G variant, which is characterized by an L>V amino acid substitution at residue 83 of the prototype E6 protein. To elucidate the functional effects of this polymorphism, we followed keratinocytes transduced with E-T350G E6 for over 60 passages and compared them to keratinocytes transduced, in parallel, with prototype or Asian-American (Q14H/L83V/H78Y) E6. We found that although E-T350G E6 immortalized transduced keratinocytes in the absence of E7, these cells were not fully transformed. We also found that E-T350G down-regulated E-cadherin compared to the other variants, providing a possible link between its population-based oncogenicity and host genetic variations.

High expression of survivin and its splice variants survivin ΔEx3 and survivin 2 B in oral cancers

OBJECTIVES

We have previously reported inactivation of p53 in 46% of Indian patients with oral cancer. Survivin, a p53 target gene and an inhibitor of apoptosis protein (IAP), is overexpressed in several cancers, including oral cancers. Studies assessing the role of survivin and its splice variants in oral cancers are, however, rare.

MATERIALS AND METHODS

The expression of 6 survivin isoforms in 4 oral cancer cell lines (AW8507, AW13516, UPCI-SCC040, UPCI-SCC029 B), a dysplastic oral cell line (DOK), 75 paired oral tumor and adjacent normal tissues, and 12 normal oral tissue samples from healthy individuals was analyzed by real-time PCR. The expression was correlated with clinicopathologic parameters, which included age, sex, tumor-node-metastasis (TNM) staging, tobacco and/or alcohol consumption, site, and differentiation status of tumor.

RESULTS

This is the first study to find overexpression of the 6 characterized survivin isoforms in oral cancers compared with normal tissues (P < .05). Additionally, a significant (P < .05) correlation among the fold changes of all 6 survivin isoforms was observed. Survivin wild type (wt) was the predominantly expressed isoform in oral cell lines and tumor tissues versus normal tissues (P < .05). Among the minor isoforms, survivin ΔEx3 and survivin 2 B were dominantly expressed, whereas survivin 2 α and survivin 3 α overexpression was found for the first time. Further high survivin 3 B expression exhibited a significant association (P < .05) with poorly differentiated tumors. Interestingly the combined expression of the antiapoptotic survivin isoforms, survivin wt, survivin ΔEx3, and survivin 3 B, exhibited a significant association with TNM staging of the tumor.

CONCLUSIONS

Our studies thus indicate that oral cancers overexpress the antiapoptotic survivin variants, which exhibit an association with advanced tumor stage, implying a role for these variants in oral tumorigenesis.

The Human Papillomavirus E6 PDZ Binding Motif: From Life Cycle to Malignancy

Cancer-causing HPV E6 oncoproteins are characterized by the presence of a PDZ binding motif (PBM) at their extreme carboxy terminus. It was long thought that this region of E6 had a sole function to confer interaction with a defined set of cellular substrates. However, more recent studies have shown that the E6 PBM has a complex pattern of regulation, whereby phosphorylation within the PBM can regulate interaction with two classes of cellular proteins: those containing PDZ domains and the members of the 14-3-3 family of proteins. In this review, we explore the roles that the PBM and its ligands play in the virus life cycle, and subsequently how these can inadvertently contribute towards the development of malignancy. We also explore how subtle alterations in cellular signal transduction pathways might result in aberrant E6 phosphorylation, which in turn might contribute towards disease progression.

Involvement of potassium channels in the progression of cancer to a more malignant phenotype

Potassium channels are a diverse group of pore-forming transmembrane proteins that selectively facilitate potassium flow through an electrochemical gradient. They participate in the control of the membrane potential and cell excitability in addition to different cell functions such as cell volume regulation, proliferation, cell migration, angiogenesis as well as apoptosis. Because these physiological processes are essential for the correct cell function, K+ channels have been associated with a growing number of diseases including cancer. In fact, different K+ channel families such as the voltage-gated K+ channels, the ether à-go-go K+ channels, the two pore domain K+ channels and the Ca2+-activated K+ channels have been associated to tumor biology. Potassium channels have a role in neoplastic cell-cycle progression and their expression has been found abnormal in many types of tumors and cancer cells. In addition, the expression and activity of specific K+ channels have shown a significant correlation with the tumor malignancy grade. The aim of this overview is to summarize published data on K+ channels that exhibit oncogenic properties and have been linked to a more malignant cancer phenotype. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.