The participation of tumor residing pericytes in oral squamous cell carcinoma.

Pericytes are perivascular cells related to vessel structure and angiogenesis that can interact with neoplastic cells, interfering with cancer progression and outcomes. This study focused on the characterization of pericytes in oral squamous cell carcinoma (OSCC) using clinical samples and a transgenic mouse model of oral carcinogenesis. Nestin-/NG2+ (type-1) and nestin+/NG2+ (type-2) pericytes were analyzed by direct fluorescence after induction of oral carcinogenesis (4-nitroquinoline-1-oxide). Gene expression of neuron glial antigen-2 (NG2), platelet-derived growth factor receptor beta (PDGFR-ß), and cluster of differentiation 31 (CD31) was examined in human OSCC tissues. The protein expression of von Willebrand factor and NG2 was assessed in oral leukoplakia (i.e., oral potentially malignant disorders) and OSCC samples. Additionally, clinicopathological aspects and survival data were correlated and validated by bioinformatics using The Cancer Genome Atlas (TCGA). Induction of carcinogenesis in mice produced an increase in both NG2+ pericyte subsets. In human OSCC, advanced-stage tumors showed a significant reduction in CD31 mRNA and von Willebrand factor-positive vessels. Low PDGFR-ß expression was related to a shorter disease-free survival time, while NG2 mRNA overexpression was associated with a reduction in overall survival, consistent with the TCGA data. Herein, oral carcinogenesis resulted in an increase in NG2+ pericytes, which negatively affected survival outcomes.

Nestin and Neuron-glial antigen 2 transgenes unveil progenitor units in murine salivary glands.

OBJECTIVE: Undifferentiated cells play pivotal roles in sustaining tissue homeostasis during physiological turnovers and after tissue impairment. Nestin and Neuron-glial antigen 2 (NG2) are markers frequently deployed to distinguish progenitor populations. In the salivary gland scenario, these markers remain largely unknown. Particularly for a double-labeled group of progenitor cells (NG2+Nestin+), their phenotype and distribution have never been explored in freshly isolated tissues. Herein, we analyzed a subset of plastic cells that express Nestin and NG2 near the ducts and in the periacinar region of the major salivary glands of murine samples. DESIGN: The major salivary glands tissues of Nestin-GFP/NG2-DsRed mice were analyzed under a fluorescence microscope. The cells marked by GFP and DsRed were counted in the merged image component of random representative images obtained for each gland sample at × 20 magnification. RESULTS: In the parotid, submandibular, and sublingual glands, the population of cells exclusively expressing Nestin was more abundant. There was a predominance of Nestin, NG2, and double-labeled cells in the submandibular gland compared to the parotid gland, mainly near the ductal system. Of note, the sublingual and parotid glands had similar populations of Nestin+ and NG2+, especially in acini, and some positive cells were observed surrounding ducts. CONCLUSIONS: Collectively, our study revealed differential expression patterns of Nestin and NG2, alone or in combination, in the salivary gland subset during homeostasis.

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.

Oral myiasis: Analysis of cases reported in the English literature from 1990 to 2020.

Myiasis is an infection caused by the deposition of fly larvae in tissues, and its involvement in the human oral cavity is uncommon. Herein, we have performed a data analysis of published cases of oral myiasis. A search was performed in PubMed, Ovid, Web of Science, Scopus, and LILACS. Geographic distribution, demographic data, associated factors, clinical features, fly types, treatment, and presence of sequelae were analyzed. A total of 122 articles reported the cases of 157 infected individuals. The most affected countries were India (41%) and Brazil (29.5%). Male predominance (67.5%) and a mean of 41.9 years of age were observed. The gingiva (29%) was the most affected site, followed by palate (25%) and lip (21%). There were different forms and combinations of treatments: manual removal of larvae and surgical debridement, application of asphyxiating substances, antibiotic therapy, and use of ivermectin. The condition predominantly affects individuals with neurological and/or locomotor disabilities, of low socioeconomic status, with poor oral hygiene and chemical dependence and individuals with previous injuries or with the absence of lip sealing. The establishment of a standard treatment protocol, enabling comparison in future studies and providing uniformity in treatment strategies offered by health services is strongly recommended.

Photobiomodulation drives pericyte mobilization towards skin regeneration.

Photobiomodulation is being widely applied for improving dermal or mucosal wound healing. However, the underlying cellular and molecular processes that directly contribute to its effects remain poorly understood. Pericytes are relevant cells involved in the wound microenvironment and could be one of the main targets of photobiomodulation due to their plasticity and perivascular localization. Herein, we investigate tissue repair under the photobiomodulation stimulus using a pericyte labeled (or reporter) transgenic mice. Using a model of two contralateral back wounds, one the control and the other photoactivated daily (660 nm, 20 mW, 0.71 W/cm2, 5 J/cm2, 7 s, 0.14 J), we showed an overall influx of immune and undifferentiated cells and higher mobilization of a potent pericyte subpopulation (Type-2 pericytes) in the photoactivated wounds in comparison to the controls. Doppler analysis showed a significant increase in the blood flow in the photoactivated wounds, while marked vascular supply was observed histologically. Histochemical analysis has indicated more advanced stages of tissue repair after photoactivation. These data suggest that photobiomodulation significantly accelerates tissue repair through its vascular effects with direct recruitment of pericytes to the injury site.

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.

Pericyte in Oral Squamous Cell Carcinoma: A Systematic Review.

The microenvironment of oral cancer is highly dynamic and has been proved to affect tumor progression. Pericytes are blood vessels surrounding cells that have recently gained attention for their roles in vascular and cancer biology. The objective of the present study was to survey the scientific literature for conclusive evidence about whether pericytes are part of blood vessels in oral squamous cell carcinoma (OSCC) and their roles in the tumor microenvironment and clinical outcomes. A systematic electronic search was undertaken in Medline Ovid, PubMed, Web of Science, and Scopus. Eligibility criteria were: publications adopting in vivo models of OSCC that included pericyte detection and assessment by pericyte markers (e.g., α-smooth muscle actin, neuron-glial antigen 2 and platelet-derived growth factor receptor-ß). The search yielded seven eligible studies (from 2008 to 2018). The markers most commonly used for pericyte detection were α-smooth muscle actin and neuron-glial antigen 2. The studies reviewed showed the presence of immature vessels exhibiting a reduction of pericyte coverage in OSCC and indicated that anti-cancer therapies could contribute to vessel normalization and pericyte regain. The pericyte population is significantly affected during OSCC development and cancer therapy. While these findings might suggest a role for pericytes in OSCC progression, the limited data available do not allow us to conclude whether they modify the tumor microenvironment and clinical outcome.

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.