Development of HPV Vaccines for HPV-associated Head and Neck Squamous Cell Carcinoma

Genetic diversity, variation and recombination among the human papillomaviruses (HPVs) genomes isolated in China: a comparative genomic and phylogenetic analysis

Human papillomaviruses (HPVs) are widespread, sexually transmitted group of viruses that infect most individuals at some stage, causing genital warts and cancers. They are members of the Papillomaviridae family, which contains about 400 HPV types. China is among the high HPV burden countries with reported infections of multiple HPV types, accounting for 17.3% of global deaths and 18.2% of global new cases. Thus, understanding the genetic variation and geographic diversity characteristics of HPVs isolated in China is critical for global HPV prevention strategies. Thus, we analyzed the available HPV genome sequences isolated in China that grouped into two categories (alpha- and gamma-papillomaviruses) based on full-length genomes. The most common were HPV-16, -6, -58, and -52 respectively. In addition, four of the novel strains isolated in China, e.g. TG550, JDFY01, CH2, and L55 clustered with the HPV-mSK 159, 244, 201, and 200 respectively. Our phylogeographic network analysis indicated that the L55, TG550, and CH2 are genetically identical to the mSK 200, 046, and 201 respectively, while JDFY01 appeared separately, connected to the mSK-040 following five mutational steps. Also, we found ten recombination events among HPV-6/11 types within their E1, E2, E7, L1/L2 proteins, and Long Control Region ORFs. We achieved the consensus amino acid sequences of HPV proteins and found a conserved stretch of amino acids within E5A of all HPVs circulating in China. These findings offer valued insights into the genetic relationships, distribution, and evolution of the HPVs in China that may assist in adapting effective HPV preventive measures.

A Rare Case of Neck Sarcomatoid Squamous Cell Carcinoma With Brain Metastases

Squamous cell carcinoma (SCC) is the second most prominent form of skin malignancy. It occurs most frequently in older males with fair skin complexion that have extensive sun exposure most commonly in their childhood. The metastatic presentation of SCC is rare and is most common in the lung. In this paper, we present the unique case of a 73-year-old patient with sarcomatoid squamous cell carcinoma in their posterior neck that metastasized to the brain.

Human Papillomavirus, MicroRNA and their Role in Cervical Cancer Progression, Diagnosis and Treatment Response: A Comprehensive Review

Human Papillomavirus (HPV) is sexually transmitted and linked with vaginal, vulvar and cervix cancers in females, penile cancer in male, while anal and oropharyngeal cancer in both genders. Cervical cancer is ranked as third most identified cancer among females globally and is the fourth leading reason of cancer related mortality. The main aim of current study is to highlight the key role of miRNA in cervical cancer development, progression and their therapeutic responses. Current study entailed more than 50 PubMed cited articles related to miRNA role in cervical cancer. Studies have elucidated the role of miRNAs regulation in gene expression at post-transcriptional and translational level by targeting significant genes and therefore involved in cervical cancer. miRNAs control several cellular pathways involved in development of pre-malignant to metastatic stage and proliferation to malignancy. Current review elucidated and elaborated the key role of miRNA their application, treatment and therapeutic responses in cervical cancer.

The First Clinical Use of a Recombinant Lactococcus lactis Expressing Human Papillomavirus Type 16 E7 Oncogene Oral Vaccine: A Phase I Safety and Immunogenicity Trial in Healthy Women Volunteers

A dose-escalation, randomized, double-blind, placebo-controlled phase I clinical trial was performed in healthy Iranian volunteer women to assess the safety, tolerability, and immunogenicity of NZ8123-HPV16-optiE7 vaccine involving recombinant Lactococcus lactis expressing the codon-optimized human papillomavirus (HPV)-16 E7 oncogene. Fifty-five eligible subjects were divided into 6 cohorts based on the dosages (1 × 10⁹, 5 × 10⁹, and 1 × 10¹⁰ CFU/mL) of either vaccine or placebo, which were administrated orally a total of 4 times at weeks 1, 2, 4, and 8. Then, adverse events, specific serum IgG and vaginal IgA, and E7-specific IFNγ-secreting CD8⁺ CTL responses were evaluated. The vaccination was well tolerated by 40 subjects who completed the immunization schedule, and no serious adverse effects were reported. The IgG and IgA levels peaked at day 60, and the levels for the 5 × 10⁹ CFU/mL and 1 × 10¹⁰ CFU/mL dose groups were higher than those for the 1 × 10⁹ CFU/mL dose group. Time-to-peak stimulation in E7-specific IFNγ-secreting CD8⁺ CTL responses was seen in cervical lymphocytes 1 month after the last vaccination. Again, no significant increase was seen in the peripheral blood mononuclear cells (PBMC) of the same volunteers. CTL responses in cervical lymphocytes and PBMCs at day 90 were markedly higher in the 5 × 10⁹ and 1 × 10¹⁰ CFU/mL groups than in the 1 × 10⁹ CFU/mL group, demonstrating the dose dependency of NZ8123-HPV16-optiE7 vaccine following oral administration. The 6-month follow-up revealed that antibody levels decreased up to day 240; nevertheless, long-term E7-specific IFNγ-secreting CD8⁺ CTL responses were recorded during follow-up. Overall, the safety and immunogenicity profile achieved in this study encourages further phase II trials with the 5 × 10⁹ CFU/mL dose vaccine.

Identification and characterization of enhancer agonist human cytotoxic T-cell epitopes of the human papillomavirus type 16 (HPV16) E6/E7

Human papillomavirus (HPV) is associated with the etiology of cervical carcinoma, head and neck squamous cell carcinoma, and several other cancer types. Vaccines directed against HPV virus-like particles and coat proteins have been extremely successful in the prevention of cervical cancer through the activation of host HPV-specific antibody responses; however, HPV-associated cancers remain a major public health problem. The development of a therapeutic vaccine will require the generation of T-cell responses directed against early HPV proteins (E6/E7) expressed in HPV-infected tumor cells. Clinical studies using various vaccine platforms have demonstrated that both HPV-specific human T cells can be generated and patient benefit can be achieved. However, no HPV therapeutic vaccine has been approved by the Food and Drug Administration to date. One method of enhancing the potential efficacy of a therapeutic vaccine is the generation of agonist epitopes. We report the first description of enhancer cytotoxic T lymphocyte agonist epitopes for HPV E6 and E7. While the in silico algorithm revealed six epitopes with potentially improved binding to human leukocyte antigen-A2 allele (HLA-A2)-Class I, 5/6 demonstrated enhanced binding to HLA-Class I in cell-based assays and only 3/6 had a greater ability to activate HPV-specific T cells which could lyse tumor cells expressing native HPV, compared to their native epitope counterparts. These agonist epitopes have potential for use in a range of HPV therapeutic vaccine platforms and for use in HPV-specific adoptive T- or natural killer-cell platforms.

Pathophysiological basis of human papillomavirus in penile cancer: Key to prevention and delivery of more effective therapies

Answer questions and earn CME/CNE Squamous cell carcinoma (SCC) of the penis is a rare malignancy in the United States, with a significantly higher incidence-up to 20 to 30 times greater-in areas of Africa and South America. This can be explained in part by the significantly greater prevalence of sexually transmitted diseases among high-risk males often having unprotected sex with multiple sexual partners. Human papillomavirus (HPV) has been implicated as the infectious pathway by which several these penile neoplasms originate from precursor lesions. In this regard, a fundamental understanding of HPV in penile carcinogenesis can have meaningful implications in understanding 1) the diagnosis of HPV-related precursor penile lesions, 2) targeting HPV-specific molecular pathways, and 3) cancer prevention. Using vaccination programs not only may improve patient outcomes but also may minimize the need for highly aggressive and often debilitating surgical resection. CA Cancer J Clin 2016;66:481-495. © 2016 American Cancer Society.

Targeted Therapy in Locally Advanced and Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma (LA-R/M HNSCC)

Surgery and radiotherapy are the standard treatment options for patients with squamous cell carcinoma of the head and neck (SCCHN). Chemoradiotherapy is an alternative for patients with locally advanced disease. In recurrent/metastatic disease and after progression to platin-based regimens, no standard treatments other than best supportive care are currently available. Most SCCHN tumours overexpress the epidermal growth factor receptor (EGFR). This receptor is a tyrosine-kinase membrane receptor that has been implicated in angiogenesis, tumour progression and resistance to different cancer treatments. In this review, we analysed the different drugs and pathways under development to treat SCCHN, especially recurrent/metastatic disease. Until now, the EGFR signalling pathway has been considered the most important target with respect to new drugs; however, new drugs, such as immunotherapies, are currently under study. As new treatments for SCCHN are developed, the influence of therapies with respect to overall survival, progression free survival and quality of life in patients with this disease is changing.

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.

Automated in situ hybridization for human papilloma virus

With the increased number of requests for high-risk human papilloma virus in situ hybridization (HPV ISH), not only for uterine cervical squamous cell carcinoma (SCC) but also for biopsies and resections of oropharyngeal SCC, and fine needle aspiration cell blocks of metastatic SCC in cervical lymph nodes, we optimized an automated method to replace the manual one we had used. The new technique used the Leica BOND-maX or III immunostainer, already in use for immunohistochemical analysis, with the Enzo HPV type 16/18 and 6/11 probes. We stained 55 surgical biopsies and 41 cell blocks of oropharyngeal SCC. Sensitivity was 90% and 73% for biopsies and cell blocks, respectively, with a specificity of 100% in both. Stain is strong and crisp with no background. Turnaround time is short as runs are performed daily, with up to 30 slides per run. Technologists become trained in a few days, and the repeat rate is low. The only disadvantage is that ISH and IHC cannot be performed simultaneously. We highly recommend this automated technique for high-risk and low-risk HPV ISH and probably with other probes.

Human Papillomavirus (HPV) - structure, epidemiology and pathogenesis

The number of cancers is constantly increasing. An important role in the etiology of many of them is played by the viral factor, by oncogenic viruses, such as the Human Papillomavirus. The article shows current epidemiological situation and describes the structure of the virus and modes of transmission. It also explains the role of HPV infection in cancer with particular emphasis on oropharynx and head and neck cancer. Summarizing, HPV infection plays an important role in carcinogenesis of the oropharynx tumors. The presence of viral genetic material in the tumor may influence prognosis and treatment method choices.

T cell-tumor interaction directs the development of immunotherapies in head and neck cancer

The competent immune system controls disease effectively due to induction, function, and regulation of effector lymphocytes. Immunosurveillance is exerted mostly by cytotoxic T-lymphocytes (CTLs) while specific immune suppression is associated with tumor malignancy and progression. In squamous cell carcinoma of the head and neck, the presence, activity, but also suppression of tumor-specific CTL have been demonstrated. Functional CTL may exert a selection pressure on the tumor cells that consecutively escape by a combination of molecular and cellular evasion mechanisms. Certain of these mechanisms target antitumor effector cells directly or indirectly by affecting cells that regulate CTL function. This results in the dysfunction or apoptosis of lymphocytes and dysregulated lymphocyte homeostasis. Another important tumor-escape mechanism is to avoid recognition by dysregulation of antigen processing and presentation. Thus, both induction of functional CTL and susceptibility of the tumor and its microenvironment to become T cell targets should be considered in CTL-based immunotherapy.

A conserved E7-derived cytotoxic T lymphocyte epitope expressed on human papillomavirus 16-transformed HLA-A2+ epithelial cancers

Human Papillomavirus 16 (HPV-16) has been identified as the causative agent of 50% of cervical cancers and many other HPV-associated tumors. The transforming potential/tumor maintenance capacity of this high risk HPV is mediated by two viral oncoproteins, E6 and E7, making them attractive targets for therapeutic vaccines. Of 21 E6 and E7 peptides computed to bind HLA-A*0201, 10 were confirmed through TAP-deficient T2 cell HLA stabilization assay. Those scoring positive were investigated to ascertain which were naturally processed and presented by surface HLA molecules for CTL recognition. Because IFNγ ELISpot frequencies from healthy HPV-exposed blood donors against HLA-A*0201-binding peptides were unable to identify specificities for tumor targeting, their physical presence among peptides eluted from HPV-16-transformed epithelial tumor HLA-A*0201 immunoprecipitates was analyzed by MS(3) Poisson detection mass spectrometry. Only one epitope (E7(11-19)) highly conserved among HPV-16 strains was detected. This 9-mer serves to direct cytolysis by T cell lines, whereas a related 10-mer (E7(11-20)), previously used as a vaccine candidate, was neither detected by MS(3) on HPV-transformed tumor cells nor effectively recognized by 9-mer specific CTL. These data underscore the importance of precisely defining CTL epitopes on tumor cells and offer a paradigm for T cell-based vaccine design.

Differences in history of sexual behavior between patients with oropharyngeal squamous cell carcinoma and patients with squamous cell carcinoma at other head and neck sites

BACKGROUND

An emerging epidemic of human papillomavirus (HPV)-associated oropharyngeal cancer has been proposed. The purpose of this study was for us to compare the sexual behaviors of patients with squamous cell carcinoma of the oropharynx (SCCOP) and patients with squamous cell carcinoma of non-oropharyngeal (SCCNOP) head and neck sites to expand our understanding of sexual behavior as a risk factor for HPV-associated head and neck cancer.

METHODS

The sexual history of 165 patients with SCCOP and 87 patients with SCCNOP was determined in a hospital-based case-to-case comparison study.

RESULTS

Patients with SCCOP were significantly more likely than patients with SCCNOP to have had >9 lifetime sex partners (odds ratio [OR], 39.2; 95% confidence interval [CI], 8.2-187.3), to have engaged in oral-genital sex (OR, 3.5; 95% CI, 1.1-11.1), and to have had >4 oral-genital sex partners (OR, 8.6; 95% CI, 2.2-33.4).

CONCLUSION

The findings of this study suggest that some risk factors are site-specific and provide further evidence that certain sexual behaviors increase the risk of HPV-associated SCCOP.

Oncogenic impact of human papilloma virus in head and neck cancer

There is considerable debate within the literature about the significance of human papilloma virus in head and neck squamous cell carcinoma, and its potential influence on the prevention, diagnosis, grading, treatment and prognosis of these cancers. Cigarette smoking and alcohol consumption have traditionally been cited as the main risk factors for head and neck cancers. However, human papilloma virus, normally associated with cervical and other genital carcinomas, has emerged as a possible key aetiological factor in head and neck squamous cell carcinoma, especially oropharyngeal cancers. These cancers pose a significant financial burden on health resources and are increasing in incidence. The recent introduction of vaccines targeted against human papilloma virus types 16 and 18, to prevent cervical cancer, has highlighted the need for ongoing research into the importance of human papilloma virus in head and neck squamous cell carcinoma.

Immunotherapy of head and neck cancer: current and future considerations

Patients with head and neck squamous cell carcinoma (HNSCC) are at considerable risk for death, with 5-year relative survival rates of approximately 60%. The profound multifaceted deficiencies in cell-mediated immunity that persist in most patients after treatment may be related to the high rates of treatment failure and second primary malignancies. Radiotherapy and chemoradiotherapy commonly have severe acute and long-term side effects on immune responses. The development of immunotherapies reflects growing awareness that certain immune system deficiencies specific to HNSCC and some other cancers may contribute to the poor long-term outcomes. Systemic cell-mediated immunotherapy is intended to activate the entire immune system and mount a systemic and/or locoregional antitumor response. The delivery of cytokines, either by single cytokines, for example, interleukin-2, interleukin-12, interferon-γ, interferon-α, or by a biologic mix of multiple cytokines, such as IRX-2, may result in tumor rejection and durable immune responses. Targeted immunotherapy makes use of monoclonal antibodies or vaccines. All immunotherapies for HNSCC except cetuximab remain investigational, but a number of agents whose efficacy and tolerability are promising have entered phase 2 or phase 3 development.

HPV-induced oropharyngeal cancer, immune response and response to therapy

Approximately 25% of head and neck squamous cell carcinoma (HNSCC) worldwide are associated with high-risk human papillomaviruses (HPV). HPV-positive HNSCCs have a more favorable outcome and greater response to therapy. While chronic HPV infection allows for the evolution of immune evasion mechanisms, viral antigens can still elicit an immune response. Moreover, a robust lymphocytic response is associated with better prognosis in a variety of tumor types including head and neck cancer. This article outlines several mechanisms whereby the observed improved response of HPV-positive tumors to radiotherapy may be related to enhancement of the immune response following radiotherapy.

Molecular pathology of head and neck cancer: implications for diagnosis, prognosis, and treatment

The prototypic head and neck squamous cell carcinoma (HNSCC) arises from the mucosal lining of the upper aerodigestive tract, demonstrates squamous differentiation microscopically, involves older men with a long history of cigarette smoking and alcohol consumption, and is treated by multimodality therapy. HNSCC has long been regarded as a uniform disease process requiring a methodical and unwavering therapeutic approach. Divergence in epidemiologic trends among HNSCCs arising from different anatomic sites has introduced a view that, morphologic repetition aside, head and neck cancers form a heterogeneous group. This view has been supported at the molecular genetic level. A more complete understanding of the molecular genetics of head and neck cancer is providing new insights into long-held but poorly comprehended concepts such as field cancerization and is introducing various biomarkers with potential application for diagnosing, staging, monitoring, and prognosticating HNSCC.

Immunotherapy for head and neck cancer

Overall survival for patients with squamous cell carcinoma of the head and neck (SCCHN) has not improved appreciably over the past few decades. Novel therapeutic approaches, such as immunotherapy, are under clinical investigation since the standard treatments are toxic and have not successfully controlled this disease with sufficiently high success rates. Cancer immunotherapy describes various techniques to expand and activate the immune system to control tumor growth in vivo, and clinical evaluation has so far demonstrated low toxicity. Immunotherapy appears to have the most applicability in settings of minimal residual disease and to reduce distant metastases after other therapeutic interventions, and its potential clinical value is now receiving intensive evaluation. Emerging forms of SCCHN immunotherapy involve both the use of monoclonal antibodies (mAb) that target growth factor receptors where immune activation appears to contribute to tumor cell lysis, as well as various forms of active vaccination strategies which activate and direct the patient's cellular immunity against the tumor. This article reviews immunotherapeutic strategies currently in clinical trials or under development for patients with SCCHN.

Does pretreatment seropositivity to human papillomavirus have prognostic significance for head and neck cancers?

BACKGROUND

Human papillomavirus (HPV) is a risk factor for head and neck cancers (HNC), yet HPV-associated tumors have better prognosis than HPV-negative tumors.

METHODS

We evaluated whether pretreatment presence of antibodies to HPV capsids [virus-like particles (VLP)] or to HPV-16 oncoproteins E6 and E7 was a predictor of HPV-positive HNC and clinical outcomes. Sera from 156 HNC patients were tested for antibodies to HPV-16-derived antigens using ELISA. HPV-16 in tumors was evaluated by PCR and DNA sequencing.

RESULTS

HPV-16 antibodies were found in 33% with HPV-16 VLP, 21% with HPV-16 E6, and 21% with E7. HPV-16 was detected in 26% of tumors. There was a strong correlation between detection of HPV-16 tumor DNA and antibodies to HPV-16 E6 or E7 (kappa = 0.7) but not to HPV-16 VLP (kappa = 0.4). Multivariate analyses showed significantly better disease-specific survival in seropositive HPV-16 VLP [hazard ratio (HR), 0.4; 95% confidence interval (95% CI), 0.1-0.9], HPV-16 E6 (HR, 0.1; 95% CI, 0.02-0.5), and HPV-16 E7 (HR, 0.3; 95% CI, 0.1-0.9) cases. Less disease recurrence occurred among those with antibodies to both E6 and E7 compared with those negative to both (P = 0.003). There was better disease-specific survival in patients who were E6 positive at baseline and remained positive at follow-up compared with individuals who were E6 negative at both time points (P = 0.03; kappa = 0.9).

CONCLUSIONS

The presence of antibodies to HPV-16 E6 and E7 is associated with HPV in tumor cells and with better clinical outcomes. These findings suggest that the presence of E6/E7 antibodies before treatment is predictive of better clinical outcomes and that they may serve as biomarkers for selecting targeted therapeutic modalities developed for HPV-associated tumors.

Use of in situ hybridization to detect human papillomavirus in head and neck squamous cell carcinoma patients without a history of alcohol or tobacco use

CONTEXT

Head and neck squamous cell carcinoma is commonly associated with tobacco and alcohol use. There are, however, a group of patients without a significant history of tobacco or alcohol use, and the etiology of these tumors is incompletely understood.

OBJECTIVE

To examine tumors in this subpopulation for association with human papillomavirus (HPV) using newly available in situ hybridization probes.

DESIGN

Between October 2004 and October 2005, 22 patients who did not use alcohol or tobacco were included. Formalin-fixed, paraffin-embedded tissue sections were used to perform in situ hybridization using newly available probe sets (Ventana Medical Systems, Tucson, Ariz). The slides were examined for the presence of integrated HPV using light microscopy. Positive and negative xenograft controls were run with the assay. Results.-The mean age of the patients was 64 years. There were 14 men and 8 women. The most common anatomic sites included tongue (n = 8), tonsil (n = 7), and larynx (n = 7). All cases and controls were successfully stained. Only 2 cases were positive for high-risk HPV, and both demonstrated an integrated pattern. Both cases were tumors of the tonsil. No cases were positive for low-risk HPV.

CONCLUSIONS

These results demonstrate that the new probe sets for HPV can be used very efficiently in clinical pathology material of head and neck squamous cell carcinoma. Our data show that high-risk HPV is an uncommon finding in head and neck squamous cell carcinoma from patients who do not have a history of tobacco or alcohol use; low-risk HPV was not seen in any case.

Head and neck cancer immunotherapy: clinical evaluation

Overall survival for patients with squamous cell carcinoma of the head and neck (SCCHN) has not improved appreciably over the past few decades. Because standard treatments have not controlled this disease with sufficiently high success rates, novel therapeutic approaches, such as immunotherapy, are under investigation. Cancer immunotherapy involves various techniques used to expand and activate the immune system to control tumor growth in vivo; to date, clinical evaluation has demonstrated low toxicity. An emerging form of SCCHN immunotherapy involves the use of antibodies that target growth factor receptors (where immune activation appears to enhance tumor lysis), resulting in improved clinical outcome. So far, immunotherapy appears to have the most applicability after other therapeutic interventions; however, its vast potential clinical value has yet to be fully explored. This article reviews immunotherapeutic strategies currently in clinical trials or under development for patients with SCCHN.

Therapeutic human papillomavirus vaccines: current clinical trials and future directions

BACKGROUND

Cervical cancer is the second largest cause of cancer deaths in women worldwide. It is now evident that persistent infection with high-risk human papillomavirus (HPV) is necessary for the development and maintenance of cervical cancer. Thus, effective vaccination against HPV represents an opportunity to restrain cervical cancer and other important cancers. The FDA recently approved the HPV vaccine Gardasil for the preventive control of HPV, using HPV virus-like particles (VLP) to generate neutralizing antibodies against major capsid protein, L1. However, prophylactic HPV vaccines do not have therapeutic effects against pre-existing HPV infections and HPV-associated lesions. Furthermore, due to the considerable burden of HPV infections worldwide, it would take decades for preventive vaccines to affect the prevalence of cervical cancer. Thus, in order to speed up the control of cervical cancer and treat current infections, the continued development of therapeutic vaccines against HPV is critical. Therapeutic HPV vaccines can potentially eliminate pre-existing lesions and malignant tumors by generating cellular immunity against HPV-infected cells that express early viral proteins such as E6 and E7.

OBJECTIVE

This review discusses the future directions of therapeutic HPV vaccine approaches for the treatment of established HPV-associated malignancies, with emphasis on current progress of HPV vaccine clinical trials.

METHODS

Relevant literature is discussed.

RESULTS/CONCLUSION

Though their development has been challenging, many therapeutic HPV vaccines have been shown to induce HPV-specific antitumor immune responses in preclinical animal models and several promising strategies have been applied in clinical trials. With continued progress in the field of vaccine development, HPV therapeutic vaccines may provide a potentially promising approach for the control of lethal HPV-associated malignancies.

Immunotherapy for head and neck cancer

Head and neck cancer represents a challenging disease. Despite recent treatment advances, which have improved functional outcomes, the long-term survival of head and neck cancer patients has remained unchanged for the past 25 years. One of the goals of adjuvant cancer therapy is to eradicate local regional microscopic and micrometastatic disease with minimal toxicity to surrounding normal cells. In this respect, antigen-specific immunotherapy is an attractive therapeutic approach. With the advances in molecular genetics and fundamental immunology, antigen-specific immunotherapy is being actively explored using DNA, bacterial vector, viral vector, peptide, protein, dendritic cell, and tumor-cell based vaccines. Early phase clinical trials have demonstrated the safety and feasibility of these novel therapies and the emphasis is now shifting towards the development of strategies, which can increase the potency of these vaccines. As the field of immunotherapy matures and as our understanding of the complex interaction between tumor and host develops, we get closer to realizing the potential of immunotherapy as an adjunctive method to control head and neck cancer and improve long-term survival in this patient population.

Prognostic Significance of Tumor-Infiltrating Lymphocytes in Oropharyngeal Cancer

The presence of tumor-infiltrating lymphocytes has been shown to significantly improve clinical outcomes in many types of cancer. However, their effects on outcomes in patients with oropharyngeal cancer specifically have yet to be elucidated. We conducted a retrospective study in an effort to shed light on this issue. We reviewed the records of 48 consecutively presenting patients with oropharyngeal cancer, and we performed immunohistochemistry to analyze their archived paraffin-embedded tissue samples for the presence of CD3-positive tumor-infiltrating lymphocytes. We also used real-time polymerase chain reaction testing to look for human papillomavirus type 16 (HPV-16) in the tumors. We found that patients with large numbers of tumor-infiltrating lymphocytes (CD3high) had a significantly lower incidence of metastasis at presentation than did those with low numbers of tumor-infiltrating lymphocytes (CD3low) (40.0 vs. 88.5%; p = 0.001), regardless of HPV status. When HPV status was taken into account, the correlation between a high CD3 count and a lower rate of metastasis was maintained in the HPV-positive patients but not in the HPV-negative patients. We also found that the CD3high patients had higher rates of overall survival and disease-free survival at 3 and 5 years than did the CD3low patients; however, these differences only approached but did not reach statistical significance.

Detection of papillomaviral sequences in feline Bowenoid in situ carcinoma using consensus primers

Feline Bowenoid in situ carcinoma (BISC) is a rare disease that presents as multiple discrete plaques of epidermal hyperplasia and dysplasia. Two studies using immunohistochemistry revealed papillomaviral antigens in 11% and 47% of BISCs. Additionally, a recent study detected papillomaviral DNA in 24% of BISC lesions. To further investigate the association between papillomaviruses and BISC, polymerase chain reaction using consensus primers was used to detect papillomaviral DNA in 18 formalin-fixed samples of BISC. Papillomaviral DNA was amplified from 11 of the samples but from none of the controls. Six amplicons were sequenced; one was homologous with a papillomavirus from a human patient with multiple cutaneous squamous cell carcinomas and the other five showed weak homology to human papillomavirus type 17. These five sequences were > 96% homologous over a 235 bp sequence, indicating the presence in all five BISCs of one papillomavirus type distinct from any previously sequenced and more closely related to human than animal papillomaviruses. The results confirm an association between BISC and papillomaviruses, and as all six papillomavirus sequences identified are closely related to human papillomaviruses, it is possible that the virus is transmitted from humans to cats or vice versa.

Induction of CD4-independent E7-specific CD8+ memory response by heat shock fusion protein

Infection with human papillomavirus type 16 (HPV16) is strongly associated with a number of disease states, of which cervical and anal cancers represent the most drastic endpoints. Induction of T-cell-mediated immunity, particularly cytotoxic T lymphocytes (CTL), is important in eradication of HPV-induced lesions. Studies have shown that heat shock protein fusion proteins are capable of inducing potent antigen-specific CTL activity in experimental animal models. In addition, E7-expressing tumors in C57BL/6 mice can be eradicated by treatment with HspE7, an Hsp fusion protein composed of Mycobacterium bovis BCG Hsp65 linked to E7 protein of HPV16. More importantly, HspE7 has also displayed significant clinical benefit in phase II clinical trials for the immunotherapy of HPV-related diseases. To delineate the mechanisms underlying the therapeutic effects of HspE7, we investigated the capability of HspE7 to induce antigen-specific protective immunity. Here, we demonstrate that HspE7 primes potent E7-specific CD8(+) T cells with cytolytic and cytokine secretion activities. These CD8(+) T cells can differentiate into memory T cells with effector functions in the absence of CD4(+) T-cell help. The HspE7-induced memory CD8(+) T cells persist for at least 17 weeks and confer protection against E7-positive murine tumor cell challenge. These results indicate that HspE7 is a promising immunotherapeutic agent for treating HPV-related disease. Moreover, the ability of HspE7 to induce memory CD8(+) T cells in the absence of CD4(+) help indicates that HspE7 fusion protein may have activity in individuals with compromised CD4(+) functions, such as those with invasive cancer and/or human immunodeficiency virus infection.

Human papilloma virus in squamous carcinoma of the head and neck: a study of cases in south east Scotland

Several studies have found human papillomavirus virus (HPV) in tissue from head and neck squamous cell carcinomas (HNSCCs), although the number of positive cases varies greatly from study to study. The extent and molecular epidemiology of HPV in HNSCC were assessed within cases drawn from southeast Scotland by performing broad-spectrum, real-time HPV polymerase chain reaction (PCR) on DNA extracted from 100 cases of HNSCC in formalin-fixed, paraffin wax-embedded material. All HPV-positive specimens were genotyped and sampled by laser capture microdissection. Pure samples of tumour, and, where possible, dysplastic and normal epithelium were then submitted for further HPV PCR and genotyping to investigate the sensitivity of the technique in small tissue samples. 10 of 100 cases tested positive for HPV, with 8 of these being derived from Waldeyer's ring. HPV DNA was found in adjacent epithelium in two of four cases where this was available. These findings confirm that HPV is likely to be involved in a subset of HNSCC in this population and that successful amplification of HPV nucleic acid is possible even using small amounts of paraffin wax-embedded tissue.

Role of human papillomavirus in the etiology of head and neck cancer

Head and neck cancer is the world's sixth most common cancer, but despite advances in treatment, there has been no significant decline in the mortality rate. In recent years, there has been mounting epidemiologic and experimental evidence of a role for human papillomavirus (HPV) as the etiologic agent of a subset of head and neck cancers. The association is strongest for oropharyngeal cancers, especially those of the tonsil. HPV 16 is invariably the predominant type. HPV-positive cancers have been shown to be biologically distinct, clustering among nonsmokers and light drinkers, and have been associated with a favorable prognosis. This review examines the current findings of HPV in head and neck cancers and discusses implications for developing new treatments.

Epigallocatechin-3-gallate enhances CD8+ T cell-mediated antitumor immunity induced by DNA vaccination

Immunotherapy and chemotherapy are generally effective against small tumors in animal models of cancer. However, these treatment regimens are generally ineffective against large, bulky tumors. We have found that a multimodality treatment regimen using DNA vaccination in combination with chemotherapeutic agent epigallocatechin-3-gallate (EGCG), a compound found in green tea, is effective in inhibiting large tumor growth. EGCG was found to induce tumor cellular apoptosis in a dose-dependent manner. The combination of EGCG and DNA vaccination led to an enhanced tumor-specific T-cell immune response and enhanced antitumor effects, resulting in a higher cure rate than either immunotherapy or EGCG alone. In addition, combined DNA vaccination and oral EGCG treatment provided long-term antitumor protection in cured mice. Cured animals rejected a challenge of E7-expressing tumors, such as TC-1 and B16E7, but not a challenge of B16 7 weeks after the combined treatment, showing antigen-specific immune responses. These results suggest that multimodality treatment strategies, such as combining immunotherapy with a tumor-killing cancer drug, may be a more effective anticancer strategy than single-modality treatments.

A Virosomal Immunization Strategy against Cervical Cancer and Pre-Malignant Cervical Disease

In this study, we demonstrate that fusion-active virosomes, containing recombinant human papillomavirus type 16 (HPV16) E7 protein antigen, are capable of inducing a robust class I MHC-restricted cytotoxic T-lymphocyte (CTL) response against HPV-transformed tumour cells in a murine model system. Virosomes are reconstituted viral envelopes, which do not contain the genetic material of the native virus. During the reconstitution process, protein antigens can be encapsulated within the virosomes. In the present study, we used virosomes derived from influenza virus. These virosomes retain the cell binding and membrane fusion characteristics of native influenza virus, and have the capacity to deliver encapsulated antigens to the cytosol of antigen-presenting cells through fusion from within acidic endosomes. After immunization of mice with virosomes containing encapsulated HPV16 E7 protein, the animals developed a strong E7–specific CTL response as assessed by 51Cr release measurements and MHC tetramer staining of spleen cells. Immunization with E7–containing virosomes also resulted in E7-specific antibody responses.

In tumour challenge experiments, immunization of mice with E7-containing virosomes prevented tumour outgrowth in >70% of the animals. Thus, influenza-derived virosomes with encapsulated HPV E7 protein antigen act as an excellent vaccine delivery system for induction of cellular immunity against HPV-transformed cells and represent a promising immunotherapeutic vaccine for the treatment of (precursor lesions of) cervical cancer.

Molecular biology of squamous cell carcinoma of the head and neck

Squamous cell carcinoma of the head and neck (HNSCC) is a heterogeneous but largely preventable disease with complex molecular abnormalities. It arises from a premalignant progenitor followed by outgrowth of clonal populations associated with cumulative genetic alterations and phenotypic progression to invasive malignancy. These genetic alterations result in inactivation of multiple tumour suppressor genes and activation of proto-oncogenes, including p16(ink4A), p53, cyclin D1, p14(ARF), FHIT, RASSF1A, epidermal growth factor receptor (EGFR), and Rb. Intramucosal migration and clonal expansion of transformed cells with formation of abnormal genetic fields appear to be responsible for local recurrences and development of second primary tumours.

The role of human papillomavirus in squamous carcinoma of the head and neck

Human papillomavirus type-16 infection is associated with a significant portion of squamous carcinoma of the head and neck, particularly for the oropharynx and for those lacking the other risk factors of tobacco and alcohol. The link between human papillomavirus type-16 and carcinoma of the oropharynx is based on the identification of human papillomavirus type-16 in oropharyngeal tumors and the association of human papillomavirus type-16 with the risk of oropharyngeal cancer estimated in case-control epidemiologic studies. This review highlights the molecular mechanism of human papillomavirus carcinogenesis and the association of human papillomavirus type-16 as a risk factor for squamous cell carcinoma of the oropharynx as well as recent research efforts utilizing human papillomavirus as a biomarker of clinical outcomes.

T cells specific for HPV16 E7 epitopes in patients with squamous cell carcinoma of the oropharynx

Squamous cell carcinomas of the oropharynx (SCCO) are often infected with oncogenic human papilloma virus (HPV) subtype 16. To determine the frequency of T cells specific for human leukocyte antigen (HLA)-A2.1 restricted HPV16 E7 protein-derived epitopes, tetramer analysis was performed using peripheral blood lymphocytes of 20 HLA-A2.1+ patients and 20 HLA-A2.1+ healthy individuals. Tetramers specific for 3 HPV16 peptides (E711-20, E782-90 and E786-93), an influenza matrix peptide (a model recall antigen) or an HIV reverse transcriptase peptide (a model novel antigen) were used in multicolor flow analysis. The HPV-specific T-cell frequencies were correlated with the HPV16 E7 and p16 status in tumor sections. In vitro stimulation (IVS) with autologous dendritic cells (DC) pulsed with HPV16 E7 epitopes was performed to demonstrate proliferation and antitumor activity of the HPV-responsive T cells. Frequencies of CD8+ T cells specific for HPV16 E7 peptides were not significantly different in patients with SCCO relative to normal donors. However, patients with tumors expressing HPV16 E7 (60%) and p16 (50%) had an increased frequency (p<0.05) of T cells specific for the E711-20 epitope compared to those with tumors negative for both markers. HPV16 E711-20 and HPV16 E786-93 specific T cells were expandable upon IVS with cognate peptide-pulsed DC and were reactive against peptide-pulsed targets or, in case of the E711-20 epitope-specific T cells, against HPV16 E7 expressing CaSki cell line. Thus, in patients with HPV16+ SCCO, precursor T cells specific for E711-20 epitope are present (1/3,947) in the circulation, are responsive to stimulation with the cognate viral peptide and recognize in vitro HPV16 E7+ tumor cells. Further studies have to elucidate why those T cells are unable to eliminate the tumor in vivo and this might also allow for finding potential strategies that will increase the chances of developing a future HPV-based vaccine in patients with SCCO.

Aerodigestive cancers in HIV infection

PURPOSE OF REVIEW

Aerodigestive (lung, head and neck) cancers are among the most prevalent and deadly neoplasms worldwide, and the incidence rates are rising. Given the improvements in life expectancy of persons with HIV/AIDS when treated with highly active antiretroviral agents, persons with HIV infection are therefore increasingly likely to develop these malignancies. This chapter focuses on the epidemiology of these malignancies and reviews the most recent literature and current understanding of the causes and treatment of these malignancies in HIV-positive populations.

RECENT FINDINGS

Aerodigestive neoplasms in patients with HIV infection are associated with younger age at diagnosis, cigarette smoking, advanced stage at presentation, and a more aggressive clinical course. The causes of these cancers, aside from the traditional risk factors of tobacco and alcohol exposure, are not clear. Although these neoplasms are non-AIDS defining, factors that might contribute to risk include HIV-related immunosuppression and co-infection with high-risk human papillomavirus subtypes.

SUMMARY

With continued improvements in therapies for HIV, the expected increase in incidence and mortality of persons with HIV infection from aerodigestive malignancies will likely become a major public health concern. Given the younger age of HIV-infected patients with these malignancies and the apparently higher rates of smoking among HIV-positive individuals, aggressive smoking cessation efforts should be directed to this high-risk population.

Immunity to squamous carcinoma in mice immunized with dendritic cells transfected with genomic DNA from squamous carcinoma cells

Immunotherapy of squamous cell carcinoma (SCC) at an early stage of the disease increases the likelihood of success. We report a new vaccination strategy designed to prepare SCC vaccines from microgram amounts of tumor tissue, enabling the treatment of patients with minimal residual disease. The vaccine was prepared by transfer of sheared genomic DNA-fragments (25 kb) from KLN205 cells, an SCC cell line of DBA/2 mouse origin, into syngeneic bone marrow-derived mature dendritic cells (DCs). More than 90% of the transfected DCs took up DNA from the neoplasm and transferred genes were expressed as protein. The DCs expressed CD11c, CD11b, and the costimulatory molecules CD40, CD80 and CD86, characteristic of mature DCs. Syngeneic DBA/2J mice, highly susceptible to the growth of KLN205 cells, were injected intravenously (i.v.) with the transfected DCs, followed by a subcutaneous (s.c.) injection of the tumor cells. The strong immunogenic properties of the transfected cells were indicated by the finding that the survival of the tumor-bearing mice was prolonged (P<.001), relative to that of mice in various control groups. Enzyme-linked immuno spot (ELISPOT IFN-gamma) assays revealed the activation of cell-mediated immunity directed toward the SCC in mice immunized with the transfected DCs. Two independent in vitro cytotoxicity assays indicated the presence of robust cell-mediated immunity directed toward the SCC in mice immunized with the transfected cells.

Committed memory effector type 2 cytotoxic T (Tc2) cells are ineffective in protective anti-tumor immunity

Cytotoxic CD8+ T cells (Tc) are a major effector cell population in protection against tumor growth and classified into Tc1 or Tc2 based on their cytokine-secreting profiles. However, their relative tumor protective roles remain undefined. In the present study, CD8+ memory T cells were obtained from mice given with CT26-IL 12 and tumor-specific Tc1 and Tc2 cells were induced by in vitro primary stimulation (1 degrees). In vivo anti-tumor immunity and in vitro cytotoxicity of 1 degrees Tc2 memory effector cells were highly protective comparably to 1 degrees Tc1, but they secreted high level of IFNgamma as well as IL 4 and IL 5. Moreover, memory cells obtained again from tumor-protected mice by either 1 degrees Tc1 or Tc2 transfer showed indistinguishable, Tc1-like, cytokine profiles. These results strongly suggest that 1 degrees Tc2 cells are insufficiently polarized. Tc2 memory effector cells were therefore examined for their transitional anti-tumor activity during consecutive stimulation until Th2 commitment. Secondary stimulation (2 degrees) markedly reduced secretion of IFNgamma (by 94%) and in vivo tumor protection (by 83%). Tertiary (3 degrees) and further stimulation completely abrogated both of tumor protective activity and IFNgamma secretion of Tc2 cells. This progressive loss of activity following repeated stimulation was accompanied by a reduction of in vitro cytotoxicity to CT26 tumor cells. In addition, when 1 degrees Tc2 cells were trans-differentiated to Tc1 during secondary stimulation, 2 of 6 cultures recovered tumor protective activity concomitantly with IFNgamma secretion, indicating that repeated stimulation does not deteriorate tumor protective activity of 2 degrees Tc2 cells. Collectively, these data demonstrate that highly committed Tc2 cells are ineffective in tumor protection.

Human papillomaviruses in head and neck cancer: 8 year-survival-analysis of 73 patients

Depending on the primary tumour's anatomical location, squamous cell carcinoma of the head and neck (HNSCC) shows HPV prevalences between 20 and 30% for oro-, hypopharyngeal as well as laryngeal SCC and up to over 50% for SCC of the Waldeyer's tonsillar ring. There is persistent controversy on the role of HPV infection in HNSCC-progression, and on the influence of these infections on the final clinical outcome. To evaluate the possible relevance of HPV infection on survival and prognosis, 73 patients with HNSCC were investigated statistically with a median follow-up time of 28 (0.3-94) months. The statistical analysis revealed no differences in the overall survival of HPV-positive and HPV-negative cancer patients. A correlation between decreased survival and increased lymph node status was expected. Patients with carcinomas of the Waldeyer's tonsillar ring with a high HPV prevalence rate as compared to tumours of other anatomical locations revealed a better survival. Moreover, an association between HPV positivity and higher lymph node status at time of first diagnosis, and a better survival of HPV-positive patients compared to HPV-negative patients given the same initial nodal status (N0 vs. N1-N2b vs. N2c-N3) could be demonstrated. The influence of HPV on the patient's survival can only be observed statistically in combination with other prognostic factors, as the lymph nodal status of the patients. The better prognosis of survival of HPV-positive vs. the HPV-negative patients with lymph node neck metastasis is attributable to a better response of the HPV-positive group to therapy, especially radiotherapy.

Human papillomavirus in head and neck cancer: Molecular biology and clinicopathological correlations

Human papillomaviruses are known to cause cancers of the cervix and other anogenital tract sites. Epidemiologic and molecular pathology studies have also suggested that HPV infection may be associated with cancers of the head and neck. Modes of transmission of HPV infection in the head and neck region have not been fully resolved; however, perinatal transmission and an association between sexual behavior and risk for HPV-positive cancers have been presented. Among the HPV types infecting the mucosa, high-risk, intermediate-risk and low-risk genotypes are defined, depending on their presence in carcinoma or precursor lesions. The phylogenic groups of HPVs also showed a definite correlation with the morphology of head and neck tumors. The groups A6, A7, and A9 include viruses that are frequently demonstrated in basaloid and verrucosus squamous cell carcinomas known to associate with HPV infection. Integration of HPV DNA into the host cell genome occurs early in cancer development and is an important event in malignant transformation. There is a trend for patients with HPV-positive tumors to be nondrinkers or light drinkers, the majority of these patients are females, and the median age is lower than in the case of HPV-negative tumors, but this latter difference was not always statistically significant. In the Kaplan-Meier survival model, the HPV-positive verrucous and basaloid squamous cell carcinomas showed better survival rates than the HPV-negative typical squamous cell carcinomas. An increased radiocurability of HPV-positive head and neck squamous cell carcinoma (HNSCC) has also been demonstrated.

Presence and Influence of Human Papillomaviruses (HPV) in Tonsillar Cancer

Tonsillar cancer is the most common of the oropharyngeal carcinomas and human papillomavirus (HPV) has been found to be present in approximately half of all cases. Patients with HPV-positive tonsillar cancer have been observed to have a better clinical outcome than patients with HPV-negative tonsillar cancer. Moreover, patients with tonsillar cancer and a high viral load have been shown to have a better clinical outcome, including increased survival, compared to patients with a lower HPV load in their tumors. Recent findings show that HPV-positive tumors are not more radiosensitive and do not have fewer chromosomal aberrations than HPV-negative tumors, although some chromosomal differences may exist between HPV-positive and -negative tonsillar tumors. Current experimental and clinical data indicate that an active antiviral cellular immune response may contribute to this better clinical outcome. These data are also in line with the findings that the frequency of tonsillar cancer is increased in patients with an impaired cellular immune system. Thus, therapeutic and preventive HPV-16 antiviral immune vaccination trials may be worthwhile, not only in cervical cancer, but also in tonsillar cancer.

Human papillomavirus-associated head and neck cancer is a distinct epidemiologic, clinical, and molecular entity

There is currently sufficient evidence to conclude that human papillomavirus (HPV) plays a role in the pathogenesis of a distinct subset of head and neck squamous cell cancers (HNSCC), particularly tonsillar cancers. There is a strong and consistent association between high-risk HPV types, specifically HPV16, a known human carcinogen, and these distinctive oropharyngeal cancers with molecular characteristics indicative of viral oncogene function. Risk for HPV-HNSCC is increased by certain sexual behaviors after consideration of alcohol and tobacco exposure, consistent with an extensive literature that has established HPV infection as a sexually transmitted disease. Furthermore, exposure to HPV16 has been associated with increased risk for subsequent development of oropharyngeal cancer. Prophylactic and therapeutic vaccines targeted against the viral capsid components and oncoproteins will provide the ultimate evidence for a role for HPV in HNSCC, if demonstrated to be effective in the prevention or therapy of this disease. It is time for clinician scientists to translate knowledge of this newly recognized disease entity into potential applications for the prevention, detection, and treatment of HPV-HNSCC.

Progress in Head and Neck Cancer Immunotherapy: Can Tolerance and Immune Suppression Be Reversed?

The incidence of squamous cell carcinoma of the head and neck (SCCHN) is greater than 40,000 cases per year in the United States, and approximately 500,000 cases annually worldwide. Despite significant advances in detection, ablation, and reconstruction, survival has not improved appreciably over the past few decades. Therefore, novel approaches are necessary to provide head and neck oncologists with a more effective armamentarium against this challenging disease. Cancer immunotherapy describes various approaches to expand and activate the immune system to control tumor growth in vivo. So far, immunotherapy appears to have had applicability in conjunction with other therapeutic interventions that treat residual tumor cells after therapy or to reduce the occurrence of second primary tumors. In particular, diseases such as SCCHN are attractive candidates for novel therapeutic approaches, since the standard treatments have not yet successfully controlled this disease with sufficiently high success rates. This article reviews adjuvant immunotherapeutic strategies currently in trials or under development for SCCHN patients, including vaccination or cytokine immunostimulation.