Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family of growth factors that was first known as responsible for sustain the growth, function, and plasticity of neural cells. BDNF exerts its effects by binding to the tyrosine kinase receptor B (TrkB). The BDNF/TrkB axis has been reported to be overexpressed in several neurogenic and non-neurogenic tumors. Its higher expression was associated with a poor prognosis to patients affected by different human malignancies, tumor growth, invasion, and metastasis; epithelial-mesenchymal transition and resistance to chemotherapy. BDNF/TrkB represent promising targets to the development of novel anticancer therapies. Some clinical trials are currently evaluating the efficacy of Trk protein-target drugs in different types of solid tumors. To date, few groups have evaluated the DNF/TrkB pathway in head and neck malignancies. The aims of this study were to review the literature concerning the role of BDNF/TrkB activation in head and neck squamous cell carcinoma and malignant salivary gland tumors and to discuss future perspectives of BDNF/TrkB-target therapy.

ObjectivesTo evaluate the expression of brain‐derived neurotrophic factor (BDNF), its tyrosine kinase receptor B (TrkB), and two downstream targets of this pathway, Akt and ribosomal protein S6 (RPS6), in normal oral mucosa (NOM), oral leukoplakia (OL), and oral squamous cell carcinoma (OSCC) and correlate this expression with OSCC patients’ outcomes, cell senescence, and “stemness” profile.Materials and MethodsTen cases of NOM, 32 OL, and 72 primary OSCC were included. Immunohistochemical analysis for BDNF, TrkB, p‐TrkB, p‐Akt, and p‐RPS6 was performed. Cell senescence and stemness profile of OSCC were evaluated through p16 and BMI‐1 immunohistochemical expression, respectively. The slides were scanned into high‐resolution images and quantified through digital analysis.ResultsOral squamous cell carcinoma presented increased expression of BDNF/TrkB/Akt pathway compared to NOM and OL. OSCC diagnosed in advanced clinical stages presented an upregulation of BDNF and p‐TrkB. BDNF and p‐Akt were identified as predictors of poor disease‐specific survival. The increase in stemness profile was correlated with a decrease in p‐TrkB and p‐Akt expression.ConclusionsBDNF/TrkB/Akt pathway is significantly increased in malignant cells from OSCC. Moreover, BDNF and Akt represent biomarkers capable to predict a poor prognosis of OSCC patients.

Objetivo Avaliar se os indicadores clínicos de saúde bucal e sociodemográficos de crianças em idade escolar (8 a 12 anos), em fase de dentição mista, estão associados com a respiração oral. Métodos Foram avaliadas 55 crianças, selecionadas em uma escola estadual do município de Cachoeira do Sul (RS). Após a autorização dos responsáveis, foram realizados exames por uma fonoaudióloga treinada, para a identificação de crianças com sinais clínicos orofaciais, indicativos de respiração oral. Para a realização dos exames de saúde bucal, os estudantes de odontologia foram treinados e calibrados, de acordo com os critérios para levantamentos epidemiológicos da Organização Mundial de Saúde. Além dos exames intrabucais, foram coletadas informações socioeconômicas e demográficas com os responsáveis pelas crianças, por meio de um questionário. Resultados A prevalência de crianças com sinais de respiração oral foi relevante, porém, menor do que descreve a literatura. Não houve diferença entre os grupos (respiradores orais e respiradores nasais), tanto em relação às variáveis socioeconômicas, como em relação aos aspectos odontológicos testados. Conclusão Não houve associação da respiração oral com nenhum indicador clínico de saúde bucal (cárie, placa visível e sangramento gengival). Também não foi encontrada associação entre as variáveis sociodemográficas e a respiração oral.

No abstract

No abstract