Molecular and Immunohistochemical Cognizance of HPV16 in Oral Leukoplakia, Oral Squamous Cell Carcinoma and Oropharyngeal Squamous Cell Carcinoma

Prior studies have established the carcinogenic role of HPV16 and also demonstrated its unique biological behavior in cervical and oropharyngeal squamous cell carcinoma (OPSCC) but its role in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) is not well explored. Therefore, in the present study, we assessed HPV16 prevalence using PCR and Anti-HPV16 antibodies for the first time and correlated its biological behavior using p16^INK4a and Ki67 proliferation index (PI) in OL, OSCC, and OPSCC. This study included 63 subjects comprising of 25 OL, 26 OSCC, and 12 OPSCC cases. Exfoliated cells were collected and processed for PCR followed by immunohistochemistry with primary antibodies p16^INK4a, Anti-HPV16, and Ki67. The expressions were evaluated and statistical analysis included Chi-square and Spearman's test. Cumulatively 37% (OL-7%, OSCC-14% & OPSCC-16%) of cases showed positive PCR expression. PCR positivity was observed to be significantly higher (p 0.00) in OPSCC (9/12) than OSCC (9/26) and OL (5/25) cases. Overall immunohistochemical expression of p16^INK4a, Anti-HPV16, and Ki67 were significantly (p 0.02) higher in HPV16 (PCR) positive cases. HPV16 + OSCC cases showed higher grades of p16^INK4a and Ki67 expression. We have demonstrated a prevalence of HPV16 in OL, OSCC, and OPSCC through PCR, which may be concluded as a gold standard for the detection of HPV16 DNA.

Differential Wnt-β- catenin pathway activation in HPV positive and negative oral epithelium is transmitted during head and neck tumorigenesis: clinical implications

The aim of this study is to understand the association of HPV infection and wnt-β-catenin self-renewal pathway in development of head and neck squamous cell carcinoma (HNSCC). For this reason, the molecular profiles (methylation/deletion/expression) of antagonists (SFRP1/2 and DKK1), agonists (FZD7 and LRP6) and effector protein β-catenin of the pathway were analyzed in HPV positive/negative oral epithelium at first, followed by its changes during development of the tumor along with correlations with different clinico-pathological parameters. HPV infection alone or in combination with tobacco habit could activate p- β-catenin expression in basal/parabasal layers of oral epithelium through high expression of FZD7 and significant down regulation of SFRP1/2 through promoter hypermethylation due to over expression of DNMT1 with ubiquitous down regulation of DKK1 and up-regulation of LRP6. This phenomenon has been seen in respective HPV positive and negative HNSCC tumors with additional deletion/microsatellite size alterations in the antagonists. Overall alterations (methylation/deletion) of SFRP1/2, DKK1 gradually increased from Group I (HPV-/Tobacco-) to Group IV(HPV+/Tobacco+) tumors, leading to the worst prognosis of the patients. Thus, the transmission of differentially activated wnt-β-catenin pathway from HPV positive/negative basal/parabasal layers of oral epithelium to HNSCC tumors determines differences in molecular pathogenesis of the disease.

Co-presence of human papillomaviruses and Epstein-Barr virus is linked with advanced tumor stage: a tissue microarray study in head and neck cancer patients

Background

Human papillomaviruses (HPVs) and Epstein–Barr virus (EBV), known oncoviruses, can be co-present and cooperate in the initiation and/or progression of human carcinomas, including head and neck. Based on this fact, we recently reported the prevalence of both HPVs and EBV in cervical and breast cancers.

Methods

We herein explore for the first time the co-prevalence of high-risk HPVs and EBV in 98 head and neck (HN) squamous cell carcinoma (SCC) tissues from Bosnian patients using polymerase chain reaction (PCR) and immunohistochemistry (IHC) analysis, as well as tissue microarray methodology.

Results

The majority of these cancer tissue cases were from the oral cavity (68%). We found that high-risk HPVs and EBV are co-present in 34.7% of the SCC samples; with a significant correlation between the various HPV types and EBV co-incidence (p = 0.03). Our data showed that 30.8% of oral SCCs are positive for E6 oncoprotein of high-risk HPVs and 44.6% are positive for LMP1 of EBV. The most commonly expressed HPVs in our HNSCC samples include HPV types 16, 18, 45 and 58. Additionally, 37.5% of oral SCCs are positive for both HPVs and EBV, with statistically significant association between high-risk HPV types and EBV (p < 0.05). More importantly, our data revealed that the co-presence of HPV and EBV is strongly correlated with advanced tumor stage (p = 0.035).

Conclusion

In this study we show that HPV and EBV oncoviruses are co-present in HNSCC, particularly in oral cancer, where they can cooperate in the initiation and/or progression of this cancer. Thus, further studies are necessary to elucidate the mechanism of this cooperation.

Microbial Signatures Associated with Oropharyngeal and Oral Squamous Cell Carcinomas

The microbiome is fundamentally one of the most unique organs in the human body. Dysbiosis can result in critical inflammatory responses and result in pathogenesis contributing to neoplastic events. We used a pan-pathogen array technology (PathoChip) coupled with next-generation sequencing to establish microbial signatures unique to human oral and oropharyngeal squamous cell carcinomas (OCSCC/OPSCC). Signatures for DNA and RNA viruses including oncogenic viruses, gram positive and negative bacteria, fungi and parasites were detected. Cluster and topological analyses identified 2 distinct groups of microbial signatures related to OCSCCs/OPSCCs. Results were validated by probe capture next generation sequencing; the data from which also provided a comprehensive map of integration sites and chromosomal hotspots for micro-organism genomic insertions. Identification of these microbial signatures and their integration sites may provide biomarkers for OCSCC/OPSCC diagnosis and prognosis as well as novel avenues for study of their potential role in OCSCCs/OPSCCs.

Human papilloma virus (HPV) infection leads to the development of head and neck lesions but offers better prognosis in malignant Indian patients

Head and neck cancers constitute a multifactorial global disease burden and are associated with human papilloma virus (HPV) as a possible risk factor. The aim of the study is to understand the relationship between HPV and the development of head and neck lesions in Indian patients. To this end, frequency of HPV was assessed in relation to different demographic and etiological features and correlated with patient survival. The prevalence of HPV significantly increased from mild dysplastic lesions (43.6%) to head and neck squamous cell carcinoma (HNSCC) stage IV (68.5%) with HPV 16 being pre-dominant in both dysplasia (43.8%) and HNSCC (61.5%). Similar trend was observed in increasing grades of the tumour. In invasive lesions, patients aged below the median age of onset showed significantly higher occurrence of HPV than those above it. Patients harbouring HPV showed a significantly better survival irrespective of age of onset. Likewise, better survival was observed in tobacco habit negative/HPV-positive patients, and as reflected in both univariate and multivariate analysis. Majority of the HPV 16-positive samples showed moderate/high nuclear expression of HPV E6 and E7 proteins in tumours and respective basal layer of adjacent normal tissues. Thus, our data indicate that frequent HPV infection, along with tobacco habit, is a pre-requisite factor for the development of HNSCC of Indian patients but offers a better survival even during tobacco usage, implicating its diagnostic and prognostic importance.

Association of Epstein-Barr virus infection with oral squamous cell carcinoma in a case-control study

BACKGROUND

Besides the well-known risk factors, Epstein-Barr virus (EBV) might play a significant role in oral squamous cell carcinoma (OSCC). To explore the role of EBV in OSCC, the prevalence of EBV infection in oral exfoliated cells of OSCC cases and controls in northeastern Thailand was investigated, and the association of EBV in tumor lesion cells was further confirmed.

METHODS

Oral exfoliated cells were collected from OSCC cases and non-cancer controls. Cells from tumor lesions were taken from OSCC patients for further strong confirmation of the association of EBV with OSCC. EBV DNA was detected by polymerase chain reaction (PCR) using primers specific for EBV DNA polymerase. The EBV DNA positive samples were confirmed further by nested PCR.

RESULTS

Epstein-Barr virus was detected in the oral exfoliated cells of 45.05% of OSCC patients and 18.08% of the non-cancer control (P < 0.001). Similarly, EBV was detected in 32.5% of the tumor lesions. Betel quid chewing was statistically significantly associated with EBV prevalence (OR = 2.08), whereas no association with tobacco smoking and alcohol consumption. Alcohol consumption and betel quid chewing were significantly associated with OSCC (OR = 3.05 and OR = 5.05, respectively), but tobacco smoking was not associated. Interestingly, EBV was significantly associated with OSCC (OR = 3.76).

CONCLUSIONS

Epstein-Barr virus prevalence is associated with OSCC and seems to be enhanced by betel quid chewing, suggesting that EBV may, together with betel quid chewing, act as an important etiological risk factor of OSCC.