Christian U. Huebbers

Genetic Signatures of HPV-related and Unrelated Oropharyngeal Carcinoma and Their Prognostic Implications

Purpose: Patients with human papillomavirus (HPV)-containing oropharyngeal squamous cell carcinomas (OSCC) have a better prognosis than patients with HPV-negative OSCC. This may be attributed to different genetic pathways promoting cancer. Experimental Design: We used comparative genomic hybridization to identify critical genetic changes in 60 selected OSCC, 28 of which were associated with HPV-16 as determined by HPV-specific PCR and fluorescence in situ hybridization analysis and positive p16INK4A immunostaining. The results were correlated with HPV status and clinical data from patients. Results: Two thirds of OSCC harbored gain at 3q26.3-qter irrespective of HPV status. In HPV-negative tumors this alteration was associated with advanced tumor stage (P = 0.013). In comparison with HPV-related OSCC, the HPV-negative tumors harbored: (a) a higher number of chromosomal alterations and amplifications (P = 0.03 and 0.039, respectively); (b) significantly more losses at 3p, 5q, 9p, 15q, and 18q, and gains/amplifications at 11q13 (P = 0.002, 0.03; <0.001, 0.02, 0.004, and 0.001, respectively); and (c) less often 16q losses and Xp gains (P = 0.02 and 0.03). Survival analysis revealed a significantly better disease-free survival for HPV-related OSCC (P = 0.02), whereas chromosome amplification was an unfavorable prognostic indicator for disease-free and overall survival (P = 0.01 and 0.05, respectively). Interestingly, 16q loss, predominantly identified in HPV-related OSCC, was a strong indicator of favorable outcome (overall survival, P = 0.008; disease-free survival, P = 0.01) and none of these patients had a tumor recurrence. Conclusions: Genetic signatures of HPV-related and HPV-unrelated OSCC are different and most likely underlie differences in tumor development and progression. In addition, distinct chromosomal alterations have prognostic significance.

Comprehensive Analysis of HPV16 Integration in OSCC Reveals No Significant Impact of Physical Status on Viral Oncogene and Virally Disrupted Human Gene Expression

Infection with high-risk human papillomavirus (HPV) type 16 is an independent risk factor for the development of oropharyngeal squamous cell carcinomas (OSCC). However, it is unclear whether viral integration is an essential hallmark in the carcinogenic process of OSCC and whether HPV integration correlates with the level of viral gene transcription and influences the expression of disrupted host genes. We analyzed 75 patients with OSCC. HPV16-positivity was proven by p16INK4A immunohistochemistry, PCR and FISH. Viral integration was examined using DIPS- as well as APOT-PCR. Viral E2, E6 and E7 gene expression levels were quantified by quantitative reverse transcriptase (RT-q)PCR. Expression levels of 7 human genes disrupted by the virus were extracted from mRNA expression profiling data of 32 OSCCs. Viral copy numbers were assessed by qPCR in 73 tumors. We identified 37 HPV16-human fusion products indicating viral integration in 29 (39%) OSCC. In the remaining tumors (61%) only episome-derived PCR products were detected. When comparing OSCC with or without an integration-derived fusion product, we did not find significant differences in the mean RNA expression of viral genes E2, E6 and E7 or the viral copy numbers per cell, nor did the RNA expression of the HPV-disrupted genes differ from either group of OSCC. In conclusion, our data do not support the hypothesis that integration affects the levels of viral and/or HPV-disrupted human gene transcripts. Thus constitutive, rather than a high level, of expression of oncogene transcripts appears to be required in HPV-related OSCC.

Viral load, gene expression and mapping of viral integration sites in HPV16-associated HNSCC cell lines.

HPV‐related HNSCC generally have a better prognosis than HPV‐negative HNSCC. However, a subgroup of HPV‐positive tumors with poor prognosis has been recognized, particularly related to smoking, EGFR overexpression and chromosomal instability. Viral integration into the host genome might contribute to carcinogenesis, as is shown for cervical carcinomas. Therefore, all HPV16‐positive HNSCC cell lines currently available have been carefully analyzed for viral and host genome parameters. The viral integration status, viral load, viral gene expression and the presence of aneusomies was evaluated in the cell lines UD‐SCC‐2, UM‐SCC‐047, UM‐SCC‐104, UPCI:SCC090, UPCI:SCC152, UPCI:SCC154 and 93VU147T. HPV integration was examined using FISH, APOT‐PCR and DIPS‐PCR. Viral load and the expression of the viral genes E2, E6 and E7 were determined via quantitative PCR. All cell lines showed integration‐specific staining patterns and signals indicating transcriptional activity using FISH. APOT‐ and DIPS‐PCR identified integration‐derived fusion products in six cell lines and only episomal products for UM‐SCC‐104. Despite the observed differences in viral load and the number of viral integration sites, this did not relate to the identified viral oncogene expression. Furthermore, cell lines exhibited EGFR expression and aneusomy (except UPCI:SCC154). In conclusion, all HPV16‐positive HNSCC cell lines showed integrated and/or episomal viral DNA that is transcriptionally active, although viral oncogene expression was independent of viral copy number and the number of viral integration sites. Because these cell lines also contain EGFR expression and aneusomy, which are parameters of poor prognosis, they should be considered suitable model systems for the development of new antiviral therapies.

p16 Expression in carcinoma of unknown primary: Diagnostic indicator and prognostic marker

Carcinoma of unknown primary (CUP) of the neck are heterogeneous tumors in their clinical and biological characteristics, and a preoperative prognostic marker is desirable to optimize staging and therapy and to improve outcome and survival. For CUP syndrome, no optimized diagnostic and treatment strategy or biomarker have yet been determined.

P16(INK4A) immunostaining is a strong indicator for high-risk-HPV-associated oropharyngeal carcinomas and dysplasias, but is unreliable to predict low-risk-HPV-infection in head and neck papillomas and laryngeal dysplasias

Human papillomavirus (HPV) is a risk factor for the development of benign and malignant mucosal head and neck lesions. P16INK4A is often used as a surrogate marker for HPV‐infection, although there is still controversy with respect its reliability. Our aim was to determine if p16INK4A overexpression can accurately predict both high‐risk and low‐risk‐HPV‐presence in (pre)malignant and benign head and neck lesions. P16INK4A immunohistochemistry was performed on paraffin‐embedded tissue sections of 162 oropharyngeal squamous cell carcinomas (OPSCC), 14 tonsillar and 23 laryngeal dysplasias, and 20 tonsillar and 27 laryngeal papillomas. PCR, enzyme‐immunoassay and FISH analysis were used to assess HPV‐presence and type. Of the 162 OPSCC and 14 tonsillar dysplasias, 51 (31%) and 10 (71%) were HPV16‐positive, respectively. All tonsillar papillomas were HPV‐negative and four laryngeal dysplasias and 26 laryngeal papillomas were positive for HPV6 or −11. P16INK4A immunohistochemistry revealed a strong nuclear and cytoplasmic staining in 50 out of 51 HPV16‐positive and 5 out of 111 HPV‐negative OPSCC (p < 0.0001) and in all HPV16‐positive tonsillar dysplasias, whereas highly variable staining patterns were detected in the papillomas and laryngeal dysplasias, irrespective of the HPV‐status. In addition, the latter lesions generally showed a higher nuclear than cytoplasmic p16INK4A immunostaining intensity. In conclusion, our data show that strong nuclear and cytoplasmic p16INK4A overexpression is a reliable surrogate indicator for HPV16 in OPSCC and (adjacent) dysplasias. For HPV6 or −11‐positive and HPV‐negative benign and premalignant lesions of the tonsil and larynx, however, p16INK4A immunostaining is highly variable and cannot be recommended to predict HPV‐presence.

Nuclear translocation of β-catenin and decreased expression of epithelial cadherin in human papillomavirus-positive tonsillar cancer: an early event in human papillomavirus-related tumour progression?

Stenner M, Yosef B, Huebbers C U, Preuss S F, Dienes H‐P, Speel E‐J M, Odenthal M & Klussmann J P

Chromosome stability in tonsillar squamous cell carcinoma is associated with HPV16 integration and indicates a favorable prognosis

Tonsillar squamous cell carcinoma (TSCC) is frequently associated with human papillomavirus (HPV) and chromosome instability. Data from cellular model systems are, however, controversial concerning a relation between HPV and chromosome instability development. Here we studied this association in 77 primary TSCC with known clinical outcome and cell cycle protein expression profiles. Thirty‐two tumors (42%) showed HPV16‐integration. All 77 cases were analyzed by fluorescence in situ hybridization using chromosome 1‐ and 7‐specific centromere DNA probes to detect chromosome instability, indicated by the presence of chromosome imbalances and/or polyploidization for these chromosomes. In addition, eight HPV‐positive dysplasias, seven of which were adjacent to a carcinoma, were analyzed. Disomy for chromosome 1 and 7 was present in 29 out of 77 TSCC (38%), of which 19 were HPV16‐positive (p = 0.002). Aneusomy was observed in the remaining 48 TSCC, of which 13 were HPV‐positive. Aneusomies correlated significantly with tobacco‐ and alcohol consumption (p = 0.001 and p = 0.016, respectively) and a higher T‐stage (p = 0.018). Both HPV‐positivity and chromosome disomy were significantly associated with a favorable disease‐free survival (p = 0.001 and p = 0.025, respectively). Particularly in the HPV16‐positive group chromosome instability is a very strong indicator for an unfavorable prognosis (p = 0.032). In the dysplasias an identical HPV and chromosome copy number status was identified as in the adjacent tumors. We conclude that HPV‐positive TSCC and their precursor lesions are more often genetically stable than HPV‐negative lesions and that these tumors are associated with a favorable prognosis. Chromosome instability is an indicator for unfavorable prognosis, particularly in the HPV‐positive patient group.

Integration of HPV6 and downregulation of AKR1C3 expression mark malignant transformation in a patient with juvenile-onset laryngeal papillomatosis.

Juvenile-onset recurrent respiratory papillomatosis (RRP) is associated with low risk human papillomavirus (HPV) types 6 and 11. Malignant transformation has been reported solely for HPV11-associated RRP in 2–4% of all RRP-cases, but not for HPV6. The molecular mechanisms in the carcinogenesis of low risk HPV-associated cancers are to date unknown. We report of a female patient, who presented with a laryngeal carcinoma at the age of 24 years. She had a history of juvenile-onset RRP with an onset at the age of three and subsequently several hundred surgical interventions due to multiple recurrences of RRP. Polymerase chain reaction (PCR) or bead-based hybridization followed by direct sequencing identified HPV6 in tissue sections of previous papilloma and the carcinoma. P16INK4A, p53 and pRb immunostainings were negative in all lesions. HPV6 specific fluorescence in situ hybridization (FISH) revealed nuclear staining suggesting episomal virus in the papilloma and a single integration site in the carcinoma. Integration-specific amplification of papillomavirus oncogene transcripts PCR (APOT-PCR) showed integration in the aldo-keto reductase 1C3 gene (AKR1C3) on chromosome 10p15.1. ArrayCGH detected loss of the other gene copy as part of a deletion at 10p14-p15.2. Western blot analysis and immunohistochemistry of the protein AKR1C3 showed a marked reduction of its expression in the carcinoma. In conclusion, we identified a novel molecular mechanism underlying a first case of HPV6-associated laryngeal carcinoma in juvenile-onset RRP, i.e. that HPV6 integration in the AKR1C3 gene resulted in loss of its expression. Alterations of AKR1C gene expression have previously been implicated in the tumorigenesis of other (HPV-related) malignancies.

Nuclear translocation of ?-catenin and decreased expression of E-cadherin in HPV-positive tonsillar cancer: An early event in HPV-related tumor progression?

Stenner M, Yosef B, Huebbers C U, Preuss S F, Dienes H‐P, Speel E‐J M, Odenthal M & Klussmann J P

Prevalence and risk factors for oral human papillomavirus infection in 129 women screened for cervical HPV infection

BACKGROUND Oncogenic human papillomaviruses (HPV) are known to be associated with carcinomas of the uterine cervix. Furthermore, current studies have shown that HPV-infection is also associated with a subtype of oropharyngeal cancers. In general, a sexual transmission of the viruses has been shown by numerous studies in the genital lesions. However, there are unknown factors regarding the prevalence and transmission of HPV in the oropharynx. The aim of this study was to evaluate HPV prevalence in the oropharynx in female participants with and without genital HPV infection. In addition, we analyzed risk factors for an oropharyngeal colonization with HPV in their sexual partners, too. METHODS 129 Female participants were tested for presence of HPV-DNA by oral lavage, brush cytology of the tonsils and of the cervix. In addition, 15 male partners of these patients were included in the study. HPV-DNA was detected by PCR (polymerase chain reaction) amplification. For HPV-genotyping, PCR products were hybridized with type-specific digoxigenin-labeled oligonucleotide probes and discriminated into 14 high risk (HR) and 6 low risk (LR)-HPV types. The 129 female and 15 male participants were interviewed by a standardized questionnaire for socioeconomic details, drinking, smoking and sexual behaviours. RESULTS 59 (45.7%) Female participants were negative for a genital HPV-infection. Of these women, 3 (5.1%) showed a positive HPV-PCR result (HR and LR) in the oropharynx. 70 (54.3%) Female participants were positive for a genital HPV infection. In this group, 4 (5.7%) had a positive HPV-detection (HR and LR) in the oral cavity and oropharynx. Female participants with cervical HPV-infection had no higher risk for HPV-detection in the oropharynx (not significant). The analysis of sexual risk factors revealed no specific risk factor for an oral HPV-infection. CONCLUSION A correlation between cervical and oral colonization by HPV could not be demonstrated in our small cohort. Our limited data suggest that sexual transmission of HPV from the cervix uteri to the oropharynx is a rare and unlikely event.