Differential Expression of Potential Biomarkers of Oral Squamous Cell Carcinoma Development.

To evaluate molecular epithelial changes, we investigated whether a profile of survivin, cyclin dependent kinase inhibitor 2A (CDKN2A), epidermal growth factor receptor (EGFR), polo like kinase 1 (PLK1), p63, p40 (Δnp63 isoform), cyclin D1 (CCND1) and BCL2 apoptosis regulator (BCL2) proteins could predict malignant transformation. Different tissue segments (tumor adjacent epithelium; dysplasia and tumor) from a total of 109 patients were analyzed by immunohistochemistry. An increased expression of survivin (p < 0.001), PLK1 (p = 0.001), and p63 (p < 0.001) in parallel to reduced immunostaining of p40 (p < 0.001) and BCL2 (p = 0.029) was observed among the tissue segments analyzed. Our study revealed that survivin, PLK1, p63, p40 and BCL2 play a role in oral tumorigenesis and represent promising biomarkers able to recognize mesenchymal phenotype induction in the transition from nonmalignant cells to tumor cells. These results reveals critical interaction between survivin, PLK1, p63, p40 promising proteins during invasive carcinoma development.

Human Papillomavirus DNA Detection by Droplet Digital PCR in Formalin-Fixed Paraffin-Embedded Tumor Tissue from Oropharyngeal Squamous Cell Carcinoma Patients.

INTRODUCTION: High-risk human papillomavirus infection impacts staging and prognosis of oropharyngeal squamous cell carcinomas (OPSCCs). Determination of HPV status in tumor tissue by p16-immunohistochemistry (p16-IHC) can be challenging; therefore, complementary methodologies could be useful in a clinical setting. OBJECTIVE: To test for accuracy and clinical relevance of HPV-DNA detection in formalin-fixed and paraffin-embedded (FFPE) tumor samples by droplet digital PCR (ddPCR). MATERIALS AND METHODS: Fifty OPSCCs were tested for p16-IHC status followed by HPV-16/18 DNA detection/quantification in FFPE-recovered DNA using ddPCR. Accuracy for HPV status determination and association with patient information were also evaluated. RESULTS: 32.0% (16/50) of the cases were p16-IHC positive (p16 +), 42.0% (21/50) had detectable levels of HPV-16 DNA, and none were positive for HPV-18 DNA. A higher median viral load of HPV-16 DNA was observed in p16 + cases (p < 0.0001). Concordance between p16-IHC and HPV-16 DNA ranged from 78.0 to 86.0% and accuracy rates were between 78.0 and 86.0%. P16-IHC and HPV-16 DNA detection was associated with gender, smoking status, and tumor subsite, while only HPV-16 DNA was associated with cT stage. The combination of HPV positivity by p16-IHC and ddPCR showed higher overall survival rates in comparison with p16 + /HPV-DNA- and p16 - /HPV-DNA- results. CONCLUSIONS: Type-specific HPV-DNA detection by ddPCR is highly specific but moderately sensitive for the determination of HPV status and showed clinical relevance, mainly when associated with p16-IHC status. Results highlight the importance of performing HPV-DNA testing in combination with p16-IHC for proper identification of HPV-associated OPSCC and to improve clinical management of OPSCC patients.

Hypermethylation status of DAPK, MGMT and RUNX3 in HPV negative oral and oropharyngeal squamous cell carcinoma.

Squamous cell carcinoma of the oral cavity and oropharynx is the sixth most common type of cancer in the world. During tumorigenesis, gene promoter hypermethylation is considered an important mechanism of transcription silencing of tumor suppressor genes, such as DAPK, MGMT and RUNX3. These genes participate in signaling pathways related to apoptosis, DNA repair and proliferation whose loss of expression is possibly associated with cancer development and progression. In order to investigate associations between hypermethylation and clinicopathological and prognostic parameters, promoter methylation was evaluated in 72 HPV negative oral and oropharyngeal tumors using methylation-specific PCR. Hypermethylation frequencies found for DAPK, MGMT and RUNX3 were 38.88%, 19.44% and 1.38% respectively. Patients with MGMT hypermethylation had a better 2-year overall survival compared to patients without methylation. Being MGMT a repair gene for alkylating agents, it could be a biomarker of treatment response for patients who are candidates for cisplatin chemotherapy, predicting drug resistance. In view of the considerable levels of hypermethylation in cancer cells and, for MGMT, its prognostic relevance, DAPK and MGMT show potential as epigenetic markers, in a way that additional studies may test its viability and efficacy in clinical management.

Human Papillomavirus E6/E7 mRNA detection by in situ hybridization in oral cavity squamous cell carcinoma.

OBJECTIVE: The aim of this study was to evaluate the application of in situ hybridization using E6/E7 mRNA probes to identify the frequency of high-risk HPV transcriptionally active and the use of HPV status as a prognostic biomarker in oral cavity squamous cell carcinoma (OCSCC). METHODS: Ninety-nine OCSCC samples were evaluated from Hospital Santa Rita de Cassia, Hospital Universitário Cassiano Antônio de Moraes and University Hospitals Coventry and Warwickshire NHS Trust. After tissue microarray construction, the slides were submitted to an in situ hybridization detection method for HPV E6/E7 mRNA. HPV status was designated a binary classification. Multiple logistic regression examined the association of HPV with clinical features and other risk factors, using SPSS® software. For all hypothesis tests, a significance level of p ≤ 0.05 was considered. RESULTS: HPV frequency in oral squamous cell carcinoma was 8%. There was no association between HPV and clinical variables and between the main prognostic features and known risk factors. There was no difference in the prevalence of HPV for oral cavity squamous cell carcinoma by geography (Brazil vs UK). CONCLUSIONS: A low frequency of E6/E7 mRNA by RNA in situ hybridization was found in oral cavity squamous cell carcinoma, which supports the evidence that HPV-driven cancer of the oral cavity is uncommon.

Frequency of HPV in oral cavity squamous cell carcinoma.

BACKGROUND: The prevalence of high-risk human papillomavirus (HPV) DNA in cases of oral cavity squamous cell carcinoma (SCC) varies widely. The aim of this study is to investigate the frequency of high-risk HPV DNA in a large Brazilian cohort of patients with oral cavity SCC. METHODS: Biopsy and resected frozen and formalin-fixed paraffin-embedded specimens of oral cavity SCC were available from 101 patients who were recruited at two Brazilian centres. Stringent measures with respect to case selection and prevention of sample contamination were adopted to ensure reliability of the data. Nested PCR using MY09/MY11 and GP5+/GP6+ as well as PGMY09/11 L1 consensus primers were performed to investigate the presence of HPV DNA in the tumours. HPV-positive cases were subjected to direct sequencing. Shapiro-Wilk and Student t test were used to evaluate data normality and to compare the means, respectively. Qualitative variables were analysed by logistic regression. RESULTS: Our results demonstrate that the frequency of high-risk HPV types in oral cavity SCC is very low and is less than 4%. All HPV-positive cases were HPV16. In addition, our results do not show a significant association between the tumour clinical features and the risk factors (tobacco, alcohol and HPV) for oral cavity SCC. CONCLUSION: In the current study, we observed an overlapping pattern of risk factors that are related to tumour development. This, along with a low frequency of high-risk HPV DNA, supports the findings that HPV is not involved in the genesis of oral cavity SCC in Brazilian population.