Avaliação in vitro e in silico da atividade do S-(-)-Álcool Perílico sobre linhagens celulares do Carcinoma Epidermóide de Língua / In vitro and in silico evaluation of the activity of S-(-)-Peryllic Alcohol on Tongue Squamous Carcinoma cell lines

O carcinoma epidermóide oral (CEO) é a neoplasia maligna mais frequente da cavidade oral e constitui um problema de saúde pública devido a sua alta taxa de incidência e mortalidade devido em muitos casos ao fracasso terapêutico e a resistência tumoral. Assim sendo, destaca-se a busca por novas moléculas biologicamente ativas, como as encontradas nos produtos de origem natural. Este trabalho tem como objetivo avaliar a atividade antineoplásica do S-(-)-álcool perílico (POH) em culturas de células de CEO de língua e predizer sua afinidade através de modelo computacional sobre proteínas que regulam o ciclo celular. Para isso, foram utilizadas duas linhagens celulares de CEO de língua, HSC-3 e SCC-25. Os seguintes grupos foram analisados: G0 (controle; células cultivadas na ausência de POH), G1 (células tratadas com cisplatina a 40 µM), G2 (células tratadas com POH a 0,5 mM), G3 (células tratadas com POH a 1,0 mM), G4 (células tratadas com POH a 1,5 mM) e G5 (células tratadas com POH a 3,0 mM). Diferenças entre estes grupos foram investigadas através dos seguintes ensaios: viabilidade celular (Alamar Blue e Live/Dead assay) e atividade migratória (Wound healing). Foi também realizada a predição de afinidade entre o POH e as moléculas de controle do ciclo celular utilizando a docagem molecular com emprego do software Molegro Virtual Docker, v. 6.0.1. Os dados foram tratados estatisticamente pelo GraphPad Prism 6.0 (GraphPad Software, EUA), análises paramétricas utilizando teste Anova, pós-teste de Tukey e teste estatístico não-paramétricos de Kruskal-Wallis, seguido pelo teste t de estudent foram adotados para determinação de diferenças entre os grupos experimentais. O índice de significância considerado neste trabalho foi de 5%. Para ambas as técnicas de avaliação da viabilidade celular (Alamar Blue e Live/dead assay) analisadas neste trabalho, o POH foi capaz de reduzir a viabilidade celular de linhagens do CEO de língua de maneira dosedependente e tempo-dependente (p<0,05). As concentrações de 1,5 mM e 3 mM do POH obtiveram resultados melhores ou semelhantes aos encontrados na cisplatina 40 µM, para as duas linhagens, na avaliação da viabilidade celular (p<0,05). Os valores de IC50 do POH foram de 1,5 mM para a célula SCC-25 em todos os intervalos de tempo (24 h, 48 h e 72 h), uma vez que, para a linhagem HSC-3, foram de 3 mM para os tempos de 24 h e 48 h e de 1,5 mM para o intervalo de 72 h. O POH foi capaz de inibir a migração das duas linhagens celulares de CEO de maneira dependente da concentração (p≤0,05), comparados ao grupo controle. A habilidade da molécula POH se ligar a proteínas responsáveis pela ativação do ciclo celular foi avaliada usando docking models. Dentre elas, a proteína GTPase Kras mostrou a melhor energia de ligação (-86.70 kcal/mol), apresentando ligações de hidrogênio com os resíduos THR58 (A) e ASP57 (A) e ligações estéricas com os resíduos TRY32 (A) e ALA18 (A). As evidências deste estudo corroboram a ideia de que o POH possui atividade sobre o CEO, sugerindo que essa molécula possa ser uma forte candidata para o desenvolvimento de medicamentos direcionados ao tratamento desta patologia (AU).

Oral squamous cell carcinoma (OSCC) is the most frequent malignant neoplasm of the oral cavity and constitutes a public health problem due to its high incidence and mortality rate caused in many cases by therapeutic failure and tumor resistance. Therefore, the search for new biologically active molecules stands out, such as those found in products of natural origin. This work aims to evaluate the antineoplastic activity of S-(-)-perillyl alcohol (POH) in cell cultures of tongue CEO and to predict its affinity through a computer model on proteins that regulate the cell cycle. For this purpose, two cell lines of tongue CEO were used, HSC-3 and SCC-25. The following groups were analyzed: G0 (control; cells cultured in the absence of POH), G1 (cells treated with 40 µM cisplatin), G2 (cells treated with 0.5 mM POH), G3 (cells treated with 1 .0 mM), G4 (cells treated with 1.5 mM POH) and G5 (cells treated with 3.0 mM POH). Differences between these groups were investigated through the following assays: cell viability (Alamar Blue and Live/Dead assay) and migratory activity (Wound healing). Affinity prediction between POH and cell cycle control molecules were also performed using molecular docking using Molegro Virtual Docker, v. 6.0.1. The data was statistically treated by GraphPad Prism 6.0 (GraphPad Software, USA), parametric analysis using Anova test, Tukey post-test and Kruskal-Wallis non-parametric statistical test, followed by t student test were adopted for determination of differences between the experimental groups. The significance index considered in this work was 5%. For both cell viability assessment techniques (Alamar Blue and Live/dead assay) analyzed in this work, POH was able to reduce the cell viability of tongue CEO lines in a dose-dependent and time-dependent manner (p<0 .05). The concentrations of 1.5 mM and 3 mM of POH obtained better or similar results to those found in 40 µM cisplatin, for the two strains, in the evaluation of cell viability (p<0.05). The IC50 values of POH were 1.5 mM for the SCC-25 cell at all time intervals (24 h, 48 h and 72 h), since for the HSC-3 line they were 3 mM for 24 h and 48 h times and 1.5 mM for the 72 h interval. POH was able to inhibit the migration of the two DSC cell lines in a concentration-dependent manner (p≤0.05), compared to the control group. The ability of the POH molecule to bind to proteins responsible for cell cycle activation was evaluated using docking models. Among them, the protein GTPase Kras showed the best binding energy (-86.70 kcal/mol), featuring hydrogen bonds with residues THR58 (A) and ASP57 (A) and steric bonds with residues TRY32 (A) and ALA18 ( THE). The evidence from this study supports the idea that POH has antineoplastic activity on the CEO, suggesting that this molecule may be a strong candidate for the development of drugs aimed at the treatment of this pathology (AU).

Pindborg tumor associated with a supernumerary tooth: a case report

The calcifying epithelial odontogenic tumor is a rare benign neoplasm that accounts for approximately 1% of all odontogenic tumors. Most of the cases occur in the posterior mandible, and a few involve the maxilla. Despite their relatively indolent biological behavior, tumors in the maxilla tend to grow fast. We report the case of a 33-year-old female patient exhibiting swelling in the right maxilla. An isodense area associated with an impacted supernumerary tooth was found on imaging examination. The histopathologic diagnosis was a calcifying epithelial odontogenic tumor. The treatment of choice was surgical removal of the lesion and associated dental elements. The patient has been followed up for 11 months and shows no signs of recurrence. Besides describing this case, we reviewed the literature on the association of calcifying epithelial odontogenic tumors with supernumerary teeth and found two case reports addressing this subject.

Shear bond strength of metallic brackets: an in vitro study

To evaluate in vitro the shear bond strength of metallic brackets.Material and Methods:Forty premolars were divided into four groups (n = 10) according to the type of brackets used (G1: Morelli® Light; G2: Morelli® Standard; G3: Morelli® Max; G4: Abzil® Agile). For bonding, Transbond XT® (3M Unitek) resin was used in all groups. Teeth were embedded in ¾ inch PVC tubes with special plaster stone, perpendicular to the ground. Brackets were fixed on the geometric centers of the exposed crowns. After bonding, teeth were stored in distilled water, incubated at 37ºC for 24 hours and submitted to 500 thermal cycles for 30 seconds in each bath (5°C and 55°C), respectively. The bond strength test was performed on the Instron® mechanical testing machine with 3kg load cell at speed of 0.5mm/min. Data were submitted to statistical analysis through the Statistica® software, version 5.0, by Kruscal Wallis test, ANOVA and Tukey (p< 0.05).Results:There was no statistically significant difference in the ARI scores; whereas for shear resistance, this difference was significant (Averages: G1 -Light: 17.53MPa; G2 -Standard: 18.11MPa; G3 -Max: 29.33MPa; G4 -Agile: 11.37MPa) and G3 showed better performance, compared to the others. All other groups showed similar behavior among themselves. Conclusion:Max bracket had the highest shear strength. Further studies should be conducted to investigate the meshes of brackets tested in this study...