Luciano Marques-Silva

Analysis of p16(CDKN2A) methylation and HPV-16 infection in oral mucosal dysplasia.

Objective: The purpose of this study was to investigate the relationship between p16CDKN2A methylation and epithelial dysplasia (ED). We also evaluated the expressions of proteins related to methylation (DNMT3B and DNMT1). Finally, we tested whether HPV-16/18 or the dmt3b (C46359T) polymorphism is associated with p16CDKN2A methylation status. Methods: To test the hypothesis, a case-control study with 72 (control, n = 24; ED, n = 48) tissue samples from subjects was performed. Methylation-specific PCR, RFLP, and immunohistochemical analyses were performed to evaluate p16CDKN2A methylation status, dmt3b (C46359T) genotyping, and protein levels, respectively. Results: The methylation of p16CDKN2A and HPV-16 was associated with ED gradation (p = 0.001 and 0.002, respectively). In addition, most HPV-16-positive samples (77.8%) exhibited p16CDKN2A methylation; however, changes in DNMT3B and DNMT1 protein levels were not observed in HPV-positive samples. Neither HPV-18 nor the dmt3b polymorphism was associated with p16CDKN2A methylation. Conclusions: There is an association between the presence of HPV-16 in ED and the occurrence of p16CDKN2A methylation. Both variables are also associated with ED development, but further studies are necessary to clarify if they operate independently and if they have any impact on OD malignization.

High HIF-1α expression genotypes in oral lichen planus.

ObjectiveThe aim of this study is to assess whether C1772T and G1790A hypoxia-inducible factor-1 (HIF-1)α polymorphisms are associated with risk of oral lichen planus (OLP).Material and methodsRestriction fragment length polymorphism analysis was used to investigate HIF-1α C1779T and G1790A polymorphisms in 32 OLP and 88 individuals without OLP.ResultsThe frequency of the CC, TT, GA, and AA genotypes was higher in patients with OLP. Notably, individuals carrying the C and A, and T and A haplotypes showed a significant association OLP risk.ConclusionsOur study demonstrated that the C1772T and G1790A polymorphisms of HIF-1α gene increased the risk of OLP. C1772T and G1790A polymorphisms of HIF-1α gene had differing patterns of allelic imbalance in the normal samples and subsequent chronic lesions. Further studies are necessary to elucidate the HIF-1α pathway in OLP, which would facilitate the development of novel therapeutic strategies for the prevention and treatment of OLP.Clinical relevanceThese results, in conjunction with previous studies, suggest that HIF-1α may play important roles in the chronicity of oral mucosa lesions of OLP patients. Taken together, we suggest that HIF-1α polymorphisms enhance its target genes, thereby altering the microenvironment and supporting sequential release of inflammatory mediators or cellular events in OLP. It appears unlikely that inhibition of a single proinflammatory mediator will prove useful in clinical practice, but several ways to reprogram mediators engaged in a wide array of roles simultaneously are encouraging.

IL-17 Genetic and Immunophenotypic Evaluation in Chronic Graft-versus-Host Disease

Although interleukin-17 (IL-17) is a recently discovered cytokine associated with several autoimmune diseases, its role in the pathogenesis of chronic graft-versus-host disease (cGVHD) was not established yet. The objective of this study was to investigate the association of IL17A and IL17F genes polymorphisms and IL-17A and IL-17F levels with cGVHD. IL-17A expression was also investigated in CD4+ T cells of patients with systemic cGVHD. For Part I of the study, fifty-eight allo-HSCT recipients and donors were prospectively studied. Blood samples were obtained to determine IL17A and IL17F genes polymorphisms. Cytokines levels in blood and saliva were assessed by ELISA at days +35 and +100 after HSCT. In Part II, for the immunophenotypic evaluation, eight patients with systemic cGVHD were selected and the expression of IL-17A was evaluated. We found association between recipient AA genotype with systemic cGVHD. No association was observed between IL-17A levels and cGVHD. Lower IL-17A levels in the blood were associated with AA genotype. In flow cytometry analysis, decreased expression of IL-17A was observed in patients with cGVHD after stimulation. In conclusion, IL-17A may have an important role in the development of systemic cGVHD.

Prevalence of oral mucosal lesions in a brazilian military police population.

Background Data obtained from oral health surveys are very important for identifying disease-susceptible groups and for developing dental care and prevention programs. So, the purpose of the current article was to investigate the prevalence of oral mucosa lesions (OMLs) in a population of Brazilian police. Material and Methods Interviews and oral cavity examinations were performed on a sample of 395 police officers who were randomly selected by the calibrated researcher. The number of individuals was obtained by a sample calculation using the finite population correction. The diagnostic criteria were based on the WHO (1997) criteria and adapted to Brazilian surveys. Results In total, 8.61% of the population presented some OML. Traumatic injuries and benign migratory glossitis (BMG) were the most prevalent lesions. Conclusions The prevalence of potentially malignant disorders was lower than among the Brazilian population.The most prevalent lesion among the police officers was related to trauma. Patients dissatisfied with oral health had a higher risk of presenting OMLs. Key words:Mouth disease, mouth mucosa, military personnel, public health, oral pathology, oral leukoplakia.