Carlos Alberto de Carvalho Fraga

Analysis of 724 cases of primary head and neck squamous cell carcinoma (HNSCC) with a focus on young patients and p53 immunolocalization

This study evaluated 724 primary head and neck squamous cell carcinoma (HNSCC) in young and old patients, with regard to clinical profile and immunohistochemical expression of p53 protein. Associations among age, epidemiological and clinicopathological parameters, and survival analysis were evaluated. HNSCC in young people occurred in 14.5% (median age 40.7years; male-to-female ratio 5.9:1). A statistical association was demonstrated between age and family history of cancer, and between age and anatomical site. Among older patients, a higher presence of disease was noted in posterior sites. Expression of p53 was found in 71.7% of the samples and a higher expression was noted in lesions of young patients. Survival analysis showed that the age parameter is not a reliable prognostic factor for HNSCC. Among young patients, cervical metastasis was associated with worse survival. The presence of a family history of cancer in young patients could indicate genetic susceptibility and molecular disturbances in the p53 pathway in HNSCC of young and older patients seem to be distinct.

A high HIF-1α expression genotype is associated with poor prognosis of upper aerodigestive tract carcinoma patients

The aim of the present study was to evaluate the role of HIF-1α genetic polymorphisms and protein expression in the development of metastasis in upper aerodigestive tract cancer (UADTC) patients. The expression of pro-angiogenic markers was also evaluated. Protein expression was analysed using immunohistochemistry, and RFLP analysis was used to investigate HIF-1α C1779T and G1790A polymorphisms in 52 patients with UADTC. Primary lesions were divided into 2 groups according to the absence or presence of metastasis. Lymph node samples were divided into 3 groups: metastatic lymph nodes, non-metastatic lymph nodes (both derived from patients with metastatic disease), and control lymph nodes, which were obtained from patients without any metastasis. The allele T was more frequently found in patients with metastatic disease. HIF-1α protein expression in the lymph nodes was increased in the presence of the T allele. Metastatic lymph nodes showed lower levels of HIF-1α, VEGFR1, and MMP-9 proteins compared to lymph nodes without metastasis, while VEGFR2 protein levels were increased. In agreement, HIF-1α expression was correlated with MMP-9. Cox regression analysis demonstrated that higher HIF-1α and MMP-9 protein expression levels and GA and GG genotypes were associated with poor survival. Our findings show that the C1772T and G1790A polymorphisms of the HIF-1α gene are associated with increased expression of the HIF-1α protein in UADTC. The present data indicate that non-metastatic tissues express higher levels of HIF-1α, VEGFR1, and MMP-9, while in metastatic lymph nodes, VEGFR2 protein expression is elevated. The present study also shows that the HIF-1α G1790A polymorphism and its protein expression have an impact on the prognosis of UADTC patients.

Immunohistochemical analysis of TIMP-3 and MMP-9 in actinic keratosis, squamous cell carcinoma of the skin, and basal cell carcinoma

The expression of metalloproteinases and their inhibitors has been related to different invasive and metastatic potentials in cancer. This study aims to investigate the immunohistochemical expression of TIMP-3 and MMP-9 in samples of basal cell carcinoma (BCC), squamous cell carcinoma of the skin (SCC), and actinic keratosis (AK). Immunohistochemistry was performed to evaluate the expression of TIMP-3 and MMP-9 in samples of BCC (n=22), SCC (n=10), and AK (n=15). Ten fields of both tumor parenchyma and tumor stroma were photographed and counted in image software. The ratio of positive cells to total cells was used to quantify the staining. A higher expression of MMP-9 was found in tumor stroma of SCC compared to BCC and AK. No significant differences in TIMP-3 expression were observed among the groups. Considering the well-described differences between these neoplasms, these results provide additional evidence of the role of MMP-9 in tumor invasiveness of keratinocyte-derived tumors.

Metformin increases PDH and suppresses HIF-1α under hypoxic conditions and induces cell death in oral squamous cell carcinoma

Background Metformin is a biguanide, belonging to the oral hypoglycemic agents and is a widely used in the treatment of type 2 diabetes. Evidence indicate that Metformin inhibits cell proliferation in several human cancers and inhibits the Warburg phenomenon in tumor cells. Results Low PDH levels were observed in OSCC, and Metformin promotes an increase in PDH levels in hypoxic conditions. Metformin also reduced HIF-1α mRNA and protein levels. Metformin demonstrated antiproliferative effects, inhibited migration, increased the number of apoptotic cells and increased the transcription of caspase 3. Objective The present study aims to explore the effects of Metformin in hypoxic conditions. Specifically, we focused on pyruvate dehydrogenase (PDH), (hypoxia-inducible factor 1α) HIF-1α levels and the oral squamous cell carcinoma (OSCC) cell phenotype. Additionally, we also investigated a theoretical consequence of Metformin treatment. Methods PDH levels in patients with OSCC and oral dysplasia were evaluated. Metformin was administered in vitro to test the effect of Metformin under hypoxic conditions. The results were complemented by Bioinformatics analyses. Conclusions In conclusion, our current findings show that Metformin reduces HIF-1α gene expression and increases PDH expression. Metformin inhibits cell proliferation and migration in the OSCC cell line model. Additionally, Metformin enhances the number of apoptotic cells and caspase 3 levels. Interestingly enough, Metformin did not increase the mutant p53 levels under hypoxic conditions.

Bioinformatics, Interaction Network Analysis, and Neural Networks to Characterize Gene Expression of Radicular Cyst and Periapical Granuloma

INTRODUCTION Bioinformatics has emerged as an important tool to analyze the large amount of data generated by research in different diseases. In this study, gene expression for radicular cysts (RCs) and periapical granulomas (PGs) was characterized based on a leader gene approach. METHODS A validated bioinformatics algorithm was applied to identify leader genes for RCs and PGs. Genes related to RCs and PGs were first identified in PubMed, GenBank, GeneAtlas, and GeneCards databases. The Web-available STRING software (The European Molecular Biology Laboratory [EMBL], Heidelberg, Baden-Württemberg, Germany) was used in order to build the interaction map among the identified genes by a significance score named weighted number of links. Based on the weighted number of links, genes were clustered using k-means. The genes in the highest cluster were considered leader genes. Multilayer perceptron neural network analysis was used as a complementary supplement for gene classification. RESULTS For RCs, the suggested leader genes were TP53 and EP300, whereas PGs were associated with IL2RG, CCL2, CCL4, CCL5, CCR1, CCR3, and CCR5 genes. CONCLUSIONS Our data revealed different gene expression for RCs and PGs, suggesting that not only the inflammatory nature but also other biological processes might differentiate RCs and PGs.

Th1 and Th2-like Protein Balance in Human Inflammatory Radicular Cysts and Periapical Granulomas

INTRODUCTION Chronic dental periapical lesions result from chronic inflammation of periapical tissues caused by continuous antigenic stimulation from infected root canals. Recent findings have suggested that T helper (Th) 1 and Th2-like cytokines are important in the pathogenesis of chronic periapical inflammatory diseases. However, the mechanisms regulating these immunoinflammatory pathways have not been fully elucidated. Thus, the aim of this study was to evaluate interleukin (IL)-4, IL-12, and interferon γ (IFN-γ) protein levels in human radicular cysts and periapical granulomas. METHODS Archived samples of cysts (n = 52) and granulomas (n = 27) were sectioned and submitted to immunohistochemistry to evaluate the tissue expression of IL-4, IL-12, and IFN-γ. The data were analyzed using the Mann-Whitney U test (P < .05). RESULTS An increased expression of IFN-γ was observed in radicular cysts. IL-4 expression was stronger in periapical granulomas than in radicular cysts. IL-12 was not detected in any of the samples. CONCLUSIONS Our study showed that IFN-γ protein levels are increased in radicular cysts, whereas IL-4 expression is stronger in samples of periapical granulomas. Further studies are necessary to elucidate the signaling pathways mediated by these cytokines and to facilitate the development of more effective periapical disease management strategies.

Impact of the epithelial dysplasia grading and Ki67 proliferation index in the adjacent non-malignant mucosa on recurrence and survival in head and neck squamous cell carcinoma.

This study aimed to evaluate the association between several different aspects of disease in head and neck squamous cell carcinoma (HNSCC): morphological grading, Ki67 proliferation index (PI), invasive front, adjacent non-malignant mucosa (ANMM), recurrence and overall survival of the patients. Sixty-four fully reviewed and followed-up patients with primary HNSCC were matched according to recurrence of the lesion and placed in one of two groups of 32 cases. Chi-square and Fishers exact tests were used to analyze the clinicopathological parameters between both groups of patients. Association between Ki67 PI and clinicopathological parameters was also analyzed through chi-square and Fishers exact tests with the binary logistic regression model used as a multivariate analysis. In addition, survival analysis was also performed. Our results showed that high-risk dysplasia in ANMM and high Ki67 PI in ANMM of HNSCC exhibited a higher risk of tumor recurrence. Survival analysis showed that T3/T4 tumor sizes and high Ki67 PI were significantly associated with an increase in the risk of death in multivariate analysis. Our results revealed that high-risk dysplasia and high Ki67 PI of the ANMM are parameters which are indicative of tumor recurrence. Furthermore, T3/T4 tumor sizes and high Ki67 PI in the invasive front appear to be important prognostic tools for HNSCC.

Infiltrating CD57+ inflammatory cells in head and neck squamous cell carcinoma: clinicopathological analysis and prognostic significance.

This study investigated the immunodetection of CD57+ inflammatory cells in patients with head and neck squamous cell carcinoma (HNSCC) and its association with clinicopathological parameters and overall survival. Data collected from the morphological analysis and immunohistochemical reaction testing of archived HNSCC specimens (n=70) were statistically analyzed by bivariate and multivariate statistical testing at a significance level of P<0.05. The results indicate that CD57+ inflammatory cells predominate within the peritumoral stroma of HNSCC lesions and the existence of two significant relationships: between high CD57+ cell density and the development of a tumor of a large size [odds ratio (OR)=5.610, 95% confidence interval (CI)=1.516–20.763) and between high CD57+ cell density and the development of locoregional metastatic disease (OR=3.401, 95% CI=1.162–9.951). A significant difference in the rate of survival was detected only in HNSCC patients that presented large size tumors (OR=4.747, 95% CI=1.281–17.594). Together, these results suggest that although high CD57+ inflammatory cell density is associated with HNSCC lesions of greater clinical severity, the variable of cell density is not an independent predictor of HNSCC patient survival. Our findings also suggest that the relatively aggressive infiltration of CD57+ inflammatory cells in the peritumoral stroma of head and neck carcinomas may contribute to an ineffective locoregional antitumoral response.

Obesity-Related Genes and Oral Cancer: A Bioinformatics Approach and SystematicReview

Obesity-Related Genes and Oral Cancer: A Bioinformatics Approach and Systematic Review It is important to understand the biological processes linking obesity and cancer to identify new molecular targets for development of better therapeutic strategies. This study aims to synthesize knowledge regarding possible associations between obesity-related genes and oral cancer. We performed literature review about “oral cancer” and “obesity”. Gene databases and bioinformatics algorithms were used to in silico investigation of interactions networks between proteincoding genes, leader genes and molecular pathways that can possibly to link both pathological mechanisms. To this, GeneCards database, softwares STRING, Metaboanalyst and Cytoscape were employed. Genes were found to interact directly or indirectly with both obesity and oral cancer. Analyses of clustering revealed the TP53 gene as leader gene. Leptin was presented in group with the highest scores of relevance. Protein-protein interaction network linking obesity and oral cancer exhibits a power law behavior (correlation: 0.907; R2:0.851). Analysis of linear regression shows that genes related to obesity and oral cancer have higher diseaserelated connectivity than a global connectivity. Onthological analysis demonstrated different mechanisms associated to obesity and oral cancer, such as regulation of apoptosis and positive regulation of cellular process. We hypothesized that leptin is a molecule key in the link between obesity and oral cancer, by interactions with the p53 protein through CREBBP and EP300 proteins and HIF-1α, promoting angiogenesis. This study sought to organize relevant informations to further illuminate the role of genes that may be related to obesity and oral cancer. Angiogenesis genes can to be suggested as important factors to link both pathological processes..

Leptin receptor polymorphism Gln223Arg (rs1137101) in oral squamous cell carcinoma and potentially malignant oral lesions.

The purpose of this study was to assess the LEPR gene Gln223Arg polymorphism (rs1137101) in oral squamous cell carcinoma (OSCC) and in potentially malignant oral lesions (PMOL) in comparison to normal oral mucosa in a Brazilian population. Smokers (n = 89) were selected from a representative sample of 471 individuals from the general population of Montes Claros, Brazil. Participants were age and gender matched to patients with OSCC (n = 25) and oral epithelial dysplasia (n = 25). We investigated the LEPR Gln223Arg polymorphism (A>G; rs1137101) in these groups. Genotype variants were assessed by RFLP-PCR, using MspI (HPAII) restriction endonuclease. The institutional review board of the Universidade Estadual de Montes Claros approved the study (process number 2667/2011). Written informed consent for this study was obtained from all participants. The GG genotype (Arg223Arg) appears to be the more relevant polymorphic variant in OSCC. It occurred, approximately, twice as frequently in OSCC patients than in the general population. In contrast, the A allele in its homozygosis form (Gln223Gln) is significantly associated with the development of PMOL; 80% of the samples from the PMOL group exhibit AA genotype. Our findings suggest new insights regarding LEPR gene variations in the development of OSCC and PMOL.