Depth of invasion of oral squamous cell carcinoma in Nos2-knockout mice correlated to alterations in systemic inflammatory markers following 4NQO treatment.

BACKGROUND: Peripheral blood analysis is a non-invasive and low-cost technique of prognostic value for several diseases, including oral cancer. Considering the role of inducible nitric oxide synthase in tumor-associated inflammation, this study purposed to evaluate the influence of this enzyme on peripheral blood parameters and systemic inflammatory biomarkers during murine oral carcinogenesis. METHODS: A 50 µg/mL solution of 4-nitroquinoleine-N-oxide was provided to 15 C57BL/6J (Nos2+/+ ) and 16 B6.129P2-Nos2tm1Lau /J (Nos2-/- ) for 16 weeks. Animals were followed for 8 weeks after treatment. Blood samples and tongues were collected for hematological and histopathological analyses. Red blood cells, white blood cells, and platelet cell parameters were analyzed. The neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and the systemic immune-inflammation index were also calculated. The depth of invasion of all carcinomas was measured. RESULTS: Differences were found in several blood parameters. The depth of invasion in Nos2-/- was lower than in Nos2+/+ (p = 0.009), and strong correlations were found between depth of invasion and neutrophil count (ρ = -0.68, p = 0.017), lymphocyte count (ρ = 0.72, p = 0.011), neutrophil-to-lymphocyte ratio (ρ = -0.65, p = 0.025), platelet-to-lymphocyte ratio (ρ = -0.73, p = 0.013), and systemic immune-inflammation index (ρ = -0.67, p = 0.037) in Nos2-/- mice. CONCLUSION: Inducible nitric oxide synthase seems to have an important role in OSCC invasion and progression, which might be associated to alterations in immune-inflammatory cell dynamics evidenced by peripheral blood and systemic inflammatory biomarkers.

In vitro evaluation of the antibacterial and cytotoxic activities of the Euclea natalensis crude extract and fractions against oral infection agents.

OBJECTIVE: This study aimed (i) to evaluate the antibacterial and cytotoxic activities of the crude extract and fractions obtained from Euclea natalensis A.D.C. roots against bacteria that cause periodontal disease and caries and (ii) to identify the isolated compounds. DESIGN: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the extract and fractions were determined by the microplate dilution assay. The cytotoxicity of the extract and fractions was evaluated by using the XTT colorimetric assay and normal human fibroblast cells (GM07492A, lung fibroblasts). The compounds present in the most promising fraction were determined by qualitative analysis through liquid chromatography coupled to mass spectrometry (HPLC-MS-ESI). RESULTS: The MIC results ranged from 25 to > 400 µg/mL for the extract and from 1.56 to > 400 µg/mL for the fractions. To evaluate cytotoxicity, the tested concentrations of the extract and fractions ranged from 19.5 to 2500 µg/mL; IC50 values between 625 and 1250 µg/mL were obtained. Analysis of the main bioactive fraction by HPLC-MS-ESI identified phenolic acids, coumarins, naphthoquinones, lignans, and fatty acids. CONCLUSIONS: The E. natalensis root extract and fractions displayed good antibacterial activity against periodontal pathogenic and cariogenic bacteria. The antibacterial activity may be due to compounds present in the extract and fractions, which also showed low cytotoxicity to normal human cells. These data are relevant and encourage further research into this plant species, which may contribute to the discovery of new herbal medicines that will help to mitigate the problems caused by oral pathogenic bacteria.

The role of the histones H3K9ac, H3K9me3, HP1γ, and H3K36me3 in oral squamous cell carcinoma loco-regional metastasis and relapse.

Molecular markers with unequivocal significance in predicting cervical lymph node metastasis of oral squamous cell carcinoma (OSCC) has not yet been identified. Histones are DNA-binding proteins that can regulate gene expression, and some studies have shown that such proteins are implicated with tumor development and progression. This study aimed to investigate the expression of some histone modifications in OSCC and their roles in cervical lymph node metastasis. To address this goal, H3K9ac, H3K9me3, HP1γ, and H3K36me3 expression levels were investigated immunohistochemically in a retrospective metastatic and non-metastatic OSCC samples. We analyzed the association between these markers with clinical-pathological data and survival rates. Hyperacetylation of H3K9ac was associated with cervical lymph node metastasis and local relapse. High expression levels of H3K9m3 were related to age and symptomatology. Furthermore, it was also found a statistically significant association between high HP1γ-expressing tumors and tumor size. However, no markers were associated with reduced overall survival rate. Our results suggest that covalent histone modifications contribute to OSCC behavior, and H3K9ac may play a critical role in OSCC-derived cervical lymph node metastasis.