HPV and head and neck cancer

The role of HR-HPV integration in the progression of premalignant lesions into different cancer types

High-risk human papillomavirus (HR-HPV) is associated with the development of different types of cancer, such as cervical, head and neck (including oral, laryngeal, and oropharyngeal), vulvar, vaginal, penile, and anal cancers. The progression of premalignant lesions to cancer depends on factors associated with the host cell and the different epithelia infected by HPV, such as basal cells of the flat epithelium and the cells of the squamocolumnar transformation zone (STZ) found in the uterine cervix and the anal canal, which is rich in heparan sulfate proteoglycans and integrin-like receptors. On the other hand, factors associated with the viral genotype, infection with multiple viruses, viral load, viral persistence, and type of integration determine the viral breakage pattern and the sites at which the virus integrates into the host cell genome (introns, exons, intergenic regions), inducing the loss of function of tumor suppressor genes and increasing oncogene expression. This review describes the role of viral integration and the molecular mechanisms induced by HR-HPV in different types of tissues. The purpose of this review is to identify the common factors associated with the role of integration events in the progression of premalignant lesions in different types of cancer.

Understanding the HPV associated cancers: A comprehensive review

Human papillomavirus (HPV), a common cause of sexually transmitted diseases, may cause warts and lead to various types of cancers, which makes it important to understand the risk factors associated with it. HPV is the leading risk factor and plays a crucial role in the progression of cervical cancer. Viral oncoproteins E6 and E7 play a pivotal role in this process. Beyond cervical cancer, HPV-associated cancers of the mouth and throat are also increasing. HPV can also contribute to other malignancies like penile, vulvar, and vaginal cancers. Emerging evidence links HPV to these cancers. Research on the oncogenic effect of HPV is still ongoing and explorations of screening techniques, vaccination, immunotherapy and targeted therapeutics are all in progress. The present review offers valuable insight into the current understanding of the role of HPV in cancer and its potential implications for treatment and prevention in the future.

Dichloroacetate and Quercetin Prevent Cell Proliferation, Induce Cell Death and Slow Tumor Growth in a Mouse Model of HPV-Positive Head and Neck Cancer

Elevated glucose uptake and production of lactate are common features of cancer cells. Among many tumor-promoting effects, lactate inhibits immune responses and is positively correlated with radioresistance. Dichloroacetate (DCA) is an inhibitor of pyruvate dehydrogenase kinase that decreases lactate production. Quercetin is a flavonoid compound found in fruits and vegetables that inhibits glucose uptake and lactate export. We investigated the potential role and mechanisms of DCA, quercetin, and their combination, in the treatment of HPV-positive head and neck squamous cell carcinoma, an antigenic cancer subtype in need of efficacious adjuvant therapies. C57Bl/6-derived mouse oropharyngeal epithelial cells, a previously developed mouse model that was retrovirally transduced with HPV type-16 E6/E7 and activated Ras, were used to assess these compounds. Both DCA and quercetin inhibited colony formation and reduced cell viability, which were associated with mTOR inhibition and increased apoptosis through enhanced ROS production. DCA and quercetin reduced tumor growth and enhanced survival in immune-competent mice, correlating with decreased proliferation as well as decreased acidification of the tumor microenvironment and reduction of Foxp (+) Treg lymphocytes. Collectively, these data support the possible clinical application of DCA and quercetin as adjuvant therapies for head and neck cancer patients.

Human Papilloma Virus: An Unraveled Enigma of Universal Burden of Malignancies

HPV, or Human Papilloma Virus, has been the primary causative agent of genital warts and cervical cancer worldwide. It is a sexually transmitted infection mainly affecting women of reproductive age group, also infecting men and high-risk group individuals globally, resulting in high mortality. In recent years, HPV has also been found to be the major culprit behind anogenital cancers in both gender and oropharyngeal and colorectal cancers. Few studies have reported the incidence of HPV in breast cancers as well. For a few decades, the burden of HPV-associated malignancies has been increasing at an alarming rate due to a lack of adequate awareness, famine vaccine coverage and hesitancy. The effectiveness of currently available vaccines has been limited to prophylactic efficacy and does not prevent malignancies associated with post-exposure persistent infection. This review focuses on the current burden of HPV-associated malignancies, their causes and strategies to combat the growing prevalence of the cancers. With the advent of new technologies associated with treatment pertaining to therapeutic interventions and employing effective vaccine coverage, the burden of this disease may be reduced in the population.

High-Risk Mucosal Human Papillomavirus 16 (HPV16) E6 Protein and Cutaneous HPV5 and HPV8 E6 Proteins Employ Distinct Strategies To Interfere with Interferon Regulatory Factor 3-Mediated Beta Interferon Expression

Persistent infection with some mucosal α-genus human papillomaviruses (HPVs; the most prevalent one being HPV16) can induce cervical carcinoma, anogenital cancers, and a subset of head and neck squamous cell carcinoma (HNSCC). Cutaneous β-genus HPVs (such as HPV5 and HPV8) associate with skin lesions that can progress into squamous cell carcinoma with sun exposure in Epidermodysplasia verruciformis patients and immunosuppressed patients. Here, we analyzed mechanisms used by E6 proteins from the α- and β-genus to inhibit the interferon-β (IFNB1) response. HPV16 E6 mediates this effect by a strong direct interaction with interferon regulatory factor 3 (IRF3). The binding site of E6 was localized within a flexible linker between the DNA-binding domain and the IRF-activation domain of IRF3 containing an LxxLL motif. The crystallographic structure of the complex between HPV16 E6 and the LxxLL motif of IRF3 was solved and compared with the structure of HPV16 E6 interacting with the LxxLL motif of the ubiquitin ligase E6AP. In contrast, cutaneous HPV5 and HPV8 E6 proteins bind to the IRF3-binding domain (IBiD) of the CREB-binding protein (CBP), a key transcriptional coactivator in IRF3-mediated IFN-β expression. IMPORTANCE Persistent HPV infections can be associated with the development of several cancers. The ability to persist depends on the ability of the virus to escape the host immune system. The type I interferon (IFN) system is the first-line antiviral defense strategy. HPVs carry early proteins that can block the activation of IFN-I. Among mucosal α-genus HPV types, the HPV16 E6 protein has a remarkable property to strongly interact with the transcription factor IRF3. Instead, cutaneous HPV5 and HPV8 E6 proteins bind to the IRF3 cofactor CBP. These results highlight the versatility of E6 proteins to interact with different cellular targets. The interaction between the HPV16 E6 protein and IRF3 might contribute to the higher prevalence of HPV16 than that of other high-risk mucosal HPV types in HPV-associated cancers.

Anti-PD-1 and Anti-PD-L1 in Head and Neck Cancer: A Network Meta-Analysis

Objective

The monoclonal antibodies anti-programmed death protein-1 (anti-PD-1) nivolumab and pembrolizumab are the first immune checkpoint inhibitors (ICIs) approved for treatment of recurrent/metastatic head and neck carcinoma R/M HNSCC in first line and in platinum refractory disease. This network meta-analysis aims to investigate the efficacy of anti-PD-1- vs anti-PD-L1-based therapy in R/M HNSCC cancer patients through a systematic review of the literature to provide support for evidence-based treatment decisions. In particular, the effectiveness of ICIs for R/M HNSCC is analyzed according to the different mechanisms of action of the check-points inhibitory drugs in different subgroups of patients.

Methods

We did a systematic literature review and network meta-analysis (NMA) of randomized controlled trials (RCTs) in PubMed, ClinicalTrials.gov, Embase, Medline, the Cochrane Central Register of Controlled Trials, Web of Science. Our search identified a total of five randomized controlled trials: Keynote 040, Keynote 048, Eagle, Condor, Checkmate 141. These trials included 3001 patients. Treatment was sub-categorized into PD-L1-based, PD-1-based, and standard chemotherapy. Treatments were indirectly compared with anti-PD-L1-based therapy.

Results

The network meta-analysis demonstrated no significant differences in OS between different subgroups except for the metastatic patients in which anti-PD-1-based therapy was associated with significantly less risk of death. Furthermore, anti-PD-1-based therapy appeared to be effective in smoker patients and in human papilloma-negative (HPV) patients. Conversely, anti-PD-L1-based therapy seems to be better efficient in female patients, in locally recurrent setting and in HPV positive patients.

Conclusion

This is the first NMA study that aimed to indirectly compare anti-PD-1- and anti-PD-L1-based therapy in HNSCC patients. The results of our NMA could help define a profile of patient responder or resistant to specific classes of immune drugs and can be used to guide/design future studies in the novel scenario of precision immune-oncology.

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.

Feasibility of Use of the 8th Edition of the American Joint Committee on Cancer Staging for Head and Neck Cancers in Indian Scenario: An Evaluative Study

INTRODUCTION

Inclusion of depth of invasion (DOI) and a separate classification for human papillomavirus (HPV)-associated Oropharyngeal Cancers (OPCs) are two of the many major changes in the 8th edition of the American Joint Committee on Cancer staging system. After more than 2 years of implementation, the authors found the need to evaluate if the Indian clinicians found it feasible to apply the system in their practice and if the same has influenced their decision-making.

METHODS

The survey was done in the form of a questionnaire which was distributed personally and via the internet to 100 clinicians. Seventy-two clinicians responded to the questionnaire. The results were analyzed and frequency distribution was computed.

RESULTS

Eighty-three percent of the clinicians experienced that palpation of the tumour was not a reliable method to determine the DOI. The common issues stated by the clinicians were difficulty in assessing DOI in certain subsites of the oral cavity (most commonly retromolar trigone-83%), inability to determine DOI in patients with trismus, and inability to correlate pathological and clinical DOI. Thirteen percent of the clinicians did not rely on radiological tools for measuring the DOI. Seventy percent of the clinicians did not perform a P16 assay for patients with oropharyngeal cancers. Fifty percent of the clinicians preferred chemoradiotherapy for early HPV positive oropharyngeal cancers.

DISCUSSION

Based on the results of the survey, the authors recommend a need for more interpretative guidelines and methods for determining the DOI. The authors also emphasize the need for determining HPV status for all oropharyngeal carcinomas.

HPV16 drives cancer immune escape via NLRX1-mediated degradation of STING

The incidence of human papillomavirus-positive (HPV+) head and neck squamous cell carcinoma (HNSCC) has surpassed that of cervical cancer and is projected to increase rapidly until 2060. The coevolution of HPV with transforming epithelial cells leads to the shutdown of host immune detection. Targeting proximal viral nucleic acid-sensing machinery is an evolutionarily conserved strategy among viruses to enable immune evasion. However, E7 from the dominant HPV subtype 16 in HNSCC shares low homology with HPV18 E7, which was shown to inhibit the STING DNA-sensing pathway. The mechanisms by which HPV16 suppresses STING remain unknown. Recently, we characterized the role of the STING/type I interferon (IFN-I) pathway in maintaining immunogenicity of HNSCC in mouse models. Here we extended those findings into the clinical domain using tissue microarrays and machine learning-enhanced profiling of STING signatures with immune subsets. We additionally showed that HPV16 E7 uses mechanisms distinct from those used by HPV18 E7 to antagonize the STING pathway. We identified NLRX1 as a critical intermediary partner to facilitate HPV16 E7-potentiated STING turnover. The depletion of NLRX1 resulted in significantly improved IFN-I-dependent T cell infiltration profiles and tumor control. Overall, we discovered a unique HPV16 viral strategy to thwart host innate immune detection that can be further exploited to restore cancer immunogenicity.

mTOR inhibition as an adjuvant therapy in a metastatic model of HPV+ HNSCC

Effective treatments for recurrent/metastatic human papillomavirus-positive (HPV+) head and neck squamous cell cancer (HNSCC) are limited. To aid treatment development, we characterized a novel murine model of recurrent/metastatic HPV+ HNSCC. Further analysis of the parental tumor cell line and its four recurrent/metastatic derivatives led to preclinical testing of an effective treatment option for this otherwise fatal disease. Reverse phase protein arrays identified key signaling cascades in the parental and recurrent/metastatic cell lines. While protein expression profiles differed among the recurrent/metastatic cell lines, activated proteins associated with the mTOR signaling cascade were a commonality. Based on these data, mTOR inhibition was evaluated as an adjuvant treatment for recurrent/metastatic disease. mTOR activity and treatment response were assessed in vitro by western blot, Seahorse, proliferation, clonogenic, and migration assays. Standard-of-care cisplatin/radiation therapy (CRT) versus CRT/rapamycin were compared in vivo. Low-dose rapamycin inhibited mTOR signaling, decreasing proliferation (43%) and migration (62%) while it enhanced CRT-induced cytotoxicity (3.3 fold) in clonogenic assays. Furthermore, rapamycin re-sensitized CRT-resistant, metastatic tumors to treatment in vivo, improving long-term cures (0-30% improved to 78-100%, depending on the recurrent/metastatic cell line) and limiting lymph node metastasis (32%) and lung metastatic burden (30 fold). Studies using immune compromised mice suggested rapamycin's effect on metastasis is independent of the adaptive immune response. These data suggest a role of mTOR activation in HPV+ HNSCC recurrent/metastatic disease and that adjuvant mTOR inhibition may enhance treatment of resistant, metastatic cell populations at the primary site and limit distant metastasis.

Human papilloma virus prevalence in HIV patients with head and neck squamous cell carcinoma

OBJECTIVE

The implication of human papilloma virus (HPV) in head and neck squamous cell carcinoma (HNSCC) is well established, especially in oropharyngeal SCC. HIV patients have a higher risk of persistent HPV infection. We investigated the role of HPV in HNSCC carcinogenesis in HIV population.

DESIGN

Retrospective monocentric study.

METHODS

We studied HIV patients who presented with HNSCC between 1994 and 2014. For each patient, tumor characteristics, HIV disease, and survival information were collected. Tumor HPV testing was performed using p16 immunohistochemistry (IHC), in-situ hybridization and PCR. We assessed the percentage of HPV in this population of HIV patients with HNSCC and compared HIV disease characteristics based on HPV status.

RESULTS

Forty-seven patients were included: 11 women/36 men, the median age was 50 years. Tumor HPV testing was performed in 40 patients. Tumors were located in oropharynx (32%), oral cavity (32%), larynx (21%), and hypopharynx (11%). At the time of diagnosis, median CD4 level was 385 cells/μl, 31% of the patients were stage (Centers for Disease Control, stage C). The percentage of HPV linked to HNSCC for all locations in HIV patients was 30% (n = 12). HPV16 accounted for 50% of all HPV genotypes. HPV positive status was associated with a CD4 nadir of less than 200 (P = 0.026), but not with CD4 level at time of diagnosis (P = 0.414). HPV-negative tumors tend to be associated with poorer 5-year overall survival (hazard ratio = 2.9, P = 0.0711).

CONCLUSION

HPV plays a critical role in HNSCC development in HIV population. HIV immunodeficiency may increase HPV persistence and progression of HNSCC.

MicroRNA expression profiles of cancer stem cells in head and neck squamous cell carcinoma

Increasing evidence indicates that cancer stem cells have essential roles in tumor initiation, progression, metastasis and resistance to chemo-radiation. Recent research has pointed out biological importance of microRNAs in cancer stem cell dysregulation. Total number of mature microRNAs in human genome increased to more than 2,500 with the recent up-date of the database. However, currently no information is available regarding microRNA expression profiles of cancer stem cells in head and neck squamous cell carcinoma (HNSCC). Increased ALDH1 activity has been demonstrated as a reliable marker for isolation of cancer stem cells. Therefore, we evaluated the microRNA expression profile of ALDH1-high subpopulations in the HNSCC cell lines UTSCC-9 and UTSCC-90. Initially, we examined cancer stem cell properties of ALDH1-high subpopulations in both cell lines. We analyzed expression of stemness markers, sphere formation capacity and xenograft transplantation into NOD/SCID mice. Our findings validated that ALDH1-high subpopulations showed significantly increased tumor-initiating ability. Furthermore, we investigated the microRNA expression profile of HNSCC stem cells using microRNA array and confirmed the results by quantitative real-time PCR. We found that expressions of miR‑424, let-7a, miR‑6836, miR‑6873 and miR‑7152 were downregulated, whereas miR‑147b was upregulated with statistical significance in the ALDH1-high subpopulation. In conclusion, we identified a subset of microRNAs that were differentially expressed in ALDH1-high subpopulation, providing new microRNA targets to study dysregulation of HNSCC-initiating cells and develop therapeutic strategies aimed at eradicating the tumorigenic stem cells in HNSCC.

DNA damage and oxidant-antioxidant status in blood of patients with head and neck cancer

Oxidative stress induces a cellular redox imbalance that has been found to be present in various cancer cells, and overproduction of free radicals may be related to oncogenic stimulation. We investigated the activity of the following antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) concentrations in blood of patients with head and neck squamous cell carcinoma (HNSCC) compared with the control group. A comet assay was used to assess DNA damage. A nonsignificant increase of MDA and a decrease of SOD, CAT, and GPx (p>0.05) were seen in HNSCC patients compared with controls. It was found that the level of oxidative DNA damage in HNSCC patients was significantly higher compared with the control group (p ≤ 0.001). Our observations suggest that HNSSC patients may represent an impaired antioxidant defense system, resulting in DNA damage and genome instability. It has to be also considered that an oxidant/antioxidant imbalance may be connected to the complex mechanism leading to the DNA damage indicated in the blood of patients with head and neck cancer.

Identification and characterization of small molecule human papillomavirus E6 inhibitors

Cervical cancer is the sixth most common cancer in women worldwide and the leading cause of women's death in developing countries. Nearly all cervical cancers are associated with infection of the human papillomavirus (HPV). This sexually transmitted pathogen disrupts the cell cycle via two oncoproteins: E6 and E7. Cells respond to E7-mediated degradation of pRB by upregulating the p53 tumor suppressor pathway. However, E6 thwarts this response by binding to the cellular E6-Associating Protein (E6AP) and targeting p53 for degradation. These two virus-facilitated processes pave the way for cellular transformation. Prophylactic HPV vaccines are available, but individuals already infected with HPV lack drug-based therapeutic options. To fill this void, we sought to identify small molecule inhibitors of the E6-E6AP interaction. We designed an ELISA-based high throughput assay to rapidly screen compound libraries, and hits were confirmed in several orthogonal biochemical and cell-based assays. Over 88,000 compounds were screened; 30 had in vitro potencies in the mid-nanomolar to mid-micromolar range and were classified as validated hits. Seven of these hits inhibited p53 degradation in cell lines with HPV-integrated genomes. Two compounds of similar scaffold successfully blocked p53 degradation and inhibited cell proliferation in cells stably transfected with E6. Together, these studies suggest that small molecules can successfully block E6-dependent p53 degradation and restore p53 activity. The compounds identified here constitute attractive starting points for further medicinal chemistry efforts and development into beneficial therapeutics.

Regulation of interleukin-6 in head and neck squamous cell carcinoma is related to papillomavirus infection

The prevalence of head and neck squamous cell carcinoma (HNSCC) related to human papillomavirus (HPV) is increasing, unlike tobacco- and alcohol-associated cancers. To gain a clearer understanding of the molecular mechanisms implicated in HNSCC, depending on the presence or not of a viral sequence, we investigated the expression of proteins detected in the tumor regions of HNSCC patients. Twenty-two untreated HNSCC patients were selected according to the presence of HPV-16. For six patients, tumor and controlateral healthy tissues were tested for viral detection before quantitative proteomic analysis. After confirmation by Western blot, proteins were connected into a network, leading to investigate interleukin-6 (IL-6) by immunocytochemistry and ELISA. 41 ± 5% of proteins quantified by proteomics were differentially expressed in tumor compared with healthy regions. Among them, 36 proteins were retained as modulated in HPV-16 positive or negative tumors, including cytokeratins, tubulins, annexin A1, and serpin B1. Network analysis suggested a central role of IL-6, confirmed by overexpression of IL-6 in tumor tissues as in sera of HPV-negative HNSCC compared with HPV-16-positive tumors. This modulation may contribute to the survival and proliferation of cancer cells, although it was not related to tumor stage or to the level of HPV-16 DNA.

Improved clearance during treatment of HPV-positive head and neck cancer through mTOR inhibition

Human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) incidence is increasing at a near epidemic rate. We investigated whether the mammalian (or mechanistic) target of rapamycin (mTOR) inhibitor, rapamycin, can be used as a concurrent agent to standard-of-care cisplatin/radiation therapy (CRT) to attenuate tumor lactate production, thus enhancing CRT-induced immune-mediated clearance of this antigenic tumor type. A C57Bl/6-derived mouse oropharyngeal epithelial cell line retrovirally transduced with HPV type 16 E6/E7 and human squamous cell carcinoma cell lines were evaluated for their response to rapamycin in vitro with proliferation assays, Western blots, and lactate assays. Clonogenic assays and a preclinical mouse model were used to assess rapamycin as a concurrent agent to CRT. The potential of rapamycin to enhance immune response through lactate attenuation was assessed using quantitative tumor lactate bioluminescence and assessment of cell-mediated immunity using E6/E7-vaccinated mouse splenocytes. Rapamycin alone inhibited mTOR signaling of all cancer cell lines tested in vitro and in vivo. Furthermore, rapamycin administered alone significantly prolonged survival in vivo but did not result in any long-term cures. Given concurrently, CRT/rapamycin significantly enhanced direct cell killing in clonogenic assays and prolonged survival in immunocompromised mice. However, in immunocompetent mice, concurrent CRT/rapamycin increased long-term cures by 21%. Preliminary findings suggest that improved survival involves increased cell killing and enhanced immune-mediated clearance in part due to decreased lactate production. The results may provide rationale for the clinical evaluation of mTOR inhibitors concurrent with standard-of-care CRT for treatment of HPV-positive HNSCC.

Prognostic utility of basaloid differentiation in oropharyngeal cancer

Background

Human papillomavirus (HPV) is recognized as the key risk factor for a distinct subset of oropharyngeal squamous cell carcinoma. P16 is a reliable, sensitive surrogate marker for HPV and confers a positive prognostic advantage. Basaloid differentiation on hematoxylin and eosin (H&E) staining is anecdotally noted by some pathologists to be associated with p16 positivity. This association, however, has not been adequately quantified in the literature, nor has the prognostic implications of basaloid differentiation been described.

Objectives

1) To correlate the H&E staining feature of basaloid differentiation with p16 positivity in oropharyngeal cancer. 2) To investigate the prognostic utility of basaloid differentiation in oropharyngeal cancer survival.

Methods

Retrospective cross-sectional study of all patients diagnosed with and treated for oropharyngeal cancer at a single tertiary cancer center from 2002 to 2009. Tissue microarrays (TMAs) were generated from 208 oropharyngeal tumor specimens stained with H&E and immunohistochemical markers. These oropharyngeal TMAs were utilized in several previous publications. Samples were scored for basaloid differentiation by a pathologist blinded to the p16 result. A multivariate survival analysis with Cox-regression and Kaplan-Meier survival analysis was performed.

Results

In the 208 samples, basaloid differentiation correlated with p16 positivity (Spearman’s rho 0.435). Basaloid differentiation and p16 positivity were both independent predictors of improved survival. The 5 year disease specific survival (DSS) was 73% for p16 positive tumors and 35% for p16 negative tumors (p < 0.001). Similarly, the 5 year DSS of basaloid differentiated tumors was 74% compared to 41% for non-basaloid tumors (p = 0.001). Patients with p16 positive and basaloid differentiated tumors had the best survival outcomes with a 5 year DSS of 80%.

Conclusions

Basaloid differentiation is a feature on H&E which correlates with p16 positivity and is a simple, inexpensive, independent, positive prognostic indicator of comparable magnitude to p16 status. Due to the added prognostic value of basaloid differentiation, this feature should be routinely reported by qualified pathologists.

Human papillomavirus and head and neck squamous cell carcinomas in the South-East of France: prevalence, viral expression, and prognostic implications

CONCLUSION

Human papillomavirus (HPV) infection, especially by HPV 16, is frequently detected in oropharyngeal squamous cell carcinoma (OSCC). The expression of viral oncoproteins in tumoral tissues of OSCCs suggests the implication of HPV in tumorogenesis. It should now be systematically detected and considered in each patient's treatment and outcome.

OBJECTIVES

To investigate the prevalence of HPV infection, the oncogenic role of HPV in patients from the South-East of France with head and neck squamous cell carcinoma (HNSCC), and the resulting clinical implications.

METHODS

Biopsy samples from 200 patients with HNSCC were analyzed. For each patient, one or two biopsies of tumoral tissue were analyzed simultaneously with a biopsy of healthy tissue. Fresh frozen tissues were tested by molecular techniques for HPV DNA detection and genotyping as well as mRNA expression of oncoproteins E6 and E7. Expression of p16 was also analyzed by immunohistochemical staining.

RESULTS

HPV DNA tested positive in 11.5% of biopsy samples. The HPV prevalence was higher in OSCCs (91.3 vs 27.3, p < 0.0001) and in patients not consuming tobacco (65.2% vs 95.4%, p < 0.0001). The estimated 3-year overall survival rates were 67.0% for HPV-infected patients versus 39.9% for non-infected patients. The high-risk HPV 16 was the most common type detected (65.2%). In 12 of 18 patients exhibiting DNA of high-risk HPV in their tumor tissue, the same viral genome was also present in normal tissue. E6 and E7 expression was found in 9 of 14 tumoral biopsies tested for these markers.

Detection and genotyping of human papillomavirus by real-time PCR assay

BACKGROUND

Diagnosis of human papillomavirus (HPV) disease remains a challenge due to several factors related to the cost, the workload of available commercial assays to detect and genotype HPV, and to the low prevalence of infected patients.

OBJECTIVE

Our study aimed to develop a real-time PCR, based on SPF10 primers, in order to combine HPV-DNA detection and genotype identification avoiding the negative samples.

STUDY DESIGN

Validation of SYBR-green based SPF10 real-time PCR on HPV-DNA plasmids followed by the investigation of the viral status in 92 samples from oropharyngeal (94%) cutaneous biopsies (3%) and anal smears (3%) which had previously been HPV-genotyped by LiPA hybridization. In-house HPV viral loads were performed to evaluate the SPF10 real-time PCR sensitivity.

RESULTS

Data showed that 100% of HPV plasmids, assessable by LiPA hybridization, were detected and genotyped appropriately after SPF10 real-time PCR assays. These results defined a range of melting temperature peaks for HPV positivity by real-time PCR. The efficient determination of the presence of HPV-DNA by SPF10 real-time PCR was validated for 98% of clinical samples compared to commercial method. Discordant results were due to a low HPV-DNA amount and to a supplementary HPV genotype identified. The SPF10 real-time PCR sensitivity was evaluated between 1 and 10 copies/10(3)cells using in-house HPV (6, 11 and 16) viral load assays.

CONCLUSION

The real-time PCR method was efficient in combining screening and genotyping of HPV-DNA. Cost and workload reduction by SPF10 real-time PCR approach may facilitate earlier diagnosis and clinical management of HPV infected patients.

Identification and characterization of small molecule antagonists of pRb inactivation by viral oncoproteins

The retinoblastoma protein pRb is essential for regulating many cellular activities through its binding and inhibition of E2F transcription activators, and pRb inactivation leads to many cancers. pRb activity can be perturbed by viral oncoproteins including human papillomavirus (HPV) that share an LxCxE motif. Because there are no treatments for existing HPV infection leading to nearly all cervical cancers and other cancers to a lesser extent, we screened for compounds that inhibit the ability of HPV-E7 to disrupt pRb/E2F complexes. This lead to the identification of thiadiazolidinedione compounds that bind to pRb with mid-high nanomolar dissociation constants, are competitive with the binding of viral oncoproteins containing an LxCxE motif, and are selectively cytotoxic in HPV-positive cells alone and in mice. These inhibitors provide a promising scaffold for the development of therapies to treat HPV-mediated pathologies.