Expression of the cell cycle regulation proteins p53 and p21WAF1 in different types of non-dysplastic leukoplakias

OBJECTIVES: The aim of this study was to analyze the immunolabeling of two cell cycle protein regulators, p53 and p21WAF1, in non-dysplastic leukoplakias with different epithelial alterations: acanthosis, hyperkeratosis and acanthosis combined with hyperkeratosis, and compare them with dysplastic leukoplakias. MATERIAL AND METHODS: This was a prospective cohort study involving 36 patients with oral homogeneous leukoplakias. excisional biopsies were performed and the patients remain under clinical follow-up. The leukoplakias were divided into four groups: 6 acanthosis, 9 hyperkeratosis, 10 acanthosis combined with hyperkeratosis, and 11 epithelial dysplasias. Paraffin-embebeded sections were immunostained for p53 and p21WAF1. Five hundred cells from the basal layer and 500 from the parabasal layer were counted to determine the percentage of positive cells. A qualitative analysis was also carried out to determine the presence or absence of immunohistochemical staining in the intermediate and superficial layers. Groups were compared with ANOVA (

Chemoprevention in oral leukoplakia: challenges and current landscape

Oral potentially malignant disorders have the potential to transform into oral cancer. Oral leukoplakia is a prevalent OPMD with a 9.8% malignant transformation rate. The standard management for OL involves surgical excision, but its efficacy in preventing clinical recurrence and malignant transformation is limited. Therefore, alternative strategies such as chemoprevention modalities have emerged as a promising approach to inhibit the carcinogenesis process. The aim of this review was to identify human studies that investigated the effectiveness of chemopreventive agents in preventing the progression of oral leukoplakia and to provide guidance for future research. Several systemic and topical agents have been evaluated for their potential chemopreventive effects in oral leukoplakia. Systemic agents that have been investigated include vitamin A, lycopene, celecoxib, green tea extract, ZengShengPing, Bowman Birk inhibitor, beta-carotene, curcumin, erlotinib, and metformin. In addition, topical agents tested include bleomycin, isotretinoin, ONYX-015 mouthwash, ketorolac, and dried black raspberry. Despite numerous agents that have already been tested, evidence supporting their effectiveness is limited. To improve the search for an ideal chemopreventive agent for oral leukoplakia, we propose several strategies that can be implemented. Oral leukoplakia chemoprevention presents a promising opportunity for decreasing the incidence of oral cancer. Identifying new chemopreventive agents and biomarkers for predicting treatment response should be a focus of future research

The paradox of autophagy in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of hamartoma development, an effect that seems to be associated with the paradoxical role of autophagy in tumor establishment. Under normal conditions, autophagy is directly inhibited by mTORC1. In situations of bioenergetics stress, mTORC1 releases the Ulk1 complex and initiates the autophagy process. In this way, autophagy promotes the survival of established tumors by supplying metabolic precursors during nutrient deprivation; paradoxically, excessive autophagy has been associated with cell death in some situations. In spite of its paradoxical role, autophagy is an alternative therapeutic strategy that could be explored in TSC. This review compiles the findings related to autophagy and the new therapeutic strategies targeting this pathway in TSC

Tumor-neutrophil crosstalk promotes in vitro and in vivo glioblastoma progression

Introduction: The tumor microenvironment (TME) of glioblastoma (GB) is characterized by an increased infiltration of immunosuppressive cells that attenuate the antitumor immune response. The participation of neutrophils in tumor progression is still controversial and a dual role in the TME has been proposed. In this study, we show that neutrophils are reprogrammed by the tumor to ultimately promote GB progression. Methods: Using in vitro and in vivo assays, we demonstrate the existence of bidirectional GB and neutrophil communication, directly promoting an immunosuppressive TME. Results and discussion: Neutrophils have shown to play an important role in tumor malignancy especially in advanced 3D tumor model and Balb/c nude mice experiments, implying a time- and neutrophil concentration-dependent modulation. Studying the tumor energetic metabolism indicated a mitochondria mismatch shaping the TME secretome. The given data suggests a cytokine milieu in patients with GB that favors the recruitment of neutrophils, sustaining an anti inflammatory profile which is associated with poor prognosis. Besides, glioma neutrophil crosstalk has sustained a tumor prolonged activation via NETs formation, indicating the role of NFkB signaling in tumor progression. Moreover, clinical samples have indicated that neutrophil-lymphocyte ratio (NLR), IL-1b, and IL-10 are associated with poor outcomes in patients with GB. Conclusion: These results are relevant for understanding how tumor progression occurs and how immune cells can help in this process

Transmission electron microscopy in oral cytopathology : a pilot study

Introduction: Cytopathology is a collection method that allows cell analysis through the different techniques. The oral mucosa exfoliated cells observation demonstrates morphological, biochemical and/or molecular aspects depending on the type of processing of the sample. Aim:This study tested the use of oral cytopathology associated with transmission electron microscopy (TEM) to observe the morphology of cells, mainly in relation to the cell nucleus, the cytoplasmic membrane, and cell junctions. Materials and Methods: Exfoliated epithelial cells from the oral mucosa were analyzed by TEM from individuals exposed to tobacco and alcohol, with leukoplakia or with a histopathological diagnosis of squamous cell carci-noma. Results: The cytoplasmic cell-cell junctions in the malignant samples lost the characteristic irregular pattern formed by the numerous interdigitations and the junctional process of normal cells and started to present a straight cytoplasmic surface. The nuclei of cells from leukoplakia and squamous cell carcinoma samples showed heterogeneous staining, while non-lesional cells were homogeneous. Discussion: The analysis of oral cytopathological smears by TEM contributes to the un-derstanding of the changes that occur during the process of malignancy of the oral mucosa, especially with regard to the cytoplasmic membrane and intercellular junctions. Conclusion: TEM may be a good analytical method to investigate morphological changes in exfoliated cells of the oral epitheliumIntrodução: A citopatologia é um método de coleta que permite a análise celular por meio de diferentes técnicas. A observação das células esfoliadas da mucosa bucal demonstra aspectos morfológicos, bioquímicos e/ou moleculares dependendo do tipo do processamento empregado. Objetivo: Este estudo testou o emprego da técnica de citopatologia bucal associada à microscopia eletrônica de transmissão (MET) para observar a morfolo-gia das células, principalmente com relação à membrana citoplasmática, as junções celulares e ao núcleo da célula. Materiais eMétodos: Células epiteliais esfoliadas da mucosa bucal foram analisadas por MET de indivíduos expostos a tabaco e álcool, apresentando leucoplasia ou com diagnóstico de carcinoma espinocelular. Resultados:As junções citoplasmáticas célula-célula nas amostras malignas perderam o padrão irregular característico formado pelas inúmeras interdigitações e o processo juncional das células normais e passaram a apresentar uma superfície citoplasmática reta. O núcleo das células das amostras de leucoplasia e do carcinoma espinocelular apresentou coloração heterogênea, enquanto as células não lesionais foram homogêneas. Discussão: A análise de esfregaços citopatológicos bucais por MET contribui para o entendimento das alterações que ocorrem durante o processo de malignidade da mucosa bucal, principal-mente no que diz respeito à membrana citoplasmática e as junções intercelulares. Conclusão: A MET pode ser um bom método analítico para investigar alterações morfológicas em células esfoliadas do epitélio buca

Efeito da obesidade e/ou periodontite induzida por ligadura na espessura da parede da aorta em ratos wistar

The purpose of this study was to evaluate aortic wall thickness after periodontal disease and/or obesity induction in a Wistar rat model. Sixty male Wistar rats were randomly divided into four groups: control (CT), periodontal disease (PD), obesity (OB), and obesity plus periodontal disease (OB+PD). Groups OB and OB+PD received cafeteria diet for 17 weeks. After they had acquired obesity (week 12), periodontal disease was induced by placing a silk ligature on the maxillary right second molar of groups PD and OB+PD. During the experimental period, body weight and Lee index were assessed. Mean alveolar bone loss (ABL) was evaluated, and aortas were prepared for histometric analysis of the aortic wall by ImageJ software. Body weight and Lee index increased in rats exposed to cafeteria diet. Mean ABL was higher in Groups PD and OB+PD than in control and OB (p<0.05). ABL was 18% higher in Group OB+PD than in Group PD, with statistically significant difference (p<0.001). Aortas were thicker in Groups OB and OB+PD than in control and PD groups, respectively (2.31mm ± 0.28 and 2.33 ± 0.29 vs. 2.18 ± 0.26 and 2.14 ± 0.27). Group OB differed significantly from the control group (p=0.036), and OB+PD and OB differed significantly from PD (p=0.004 and p= 0.001, respectively). Obesity alters aortic wall thickness in Wistar rats. However, the presence of periodontal disease did not affect the aortic wall thickness under the conditions of the present study.O objetivo deste estudo foi avaliar a espessura da parede da aorta após modelos de indução de doença periodontal e/ou obesidade em ratos Wistar. Sessenta ratos Wistar machos foram aleatoria ­ mente divididos em quatro grupos: controle (CT), doença periodontal (DP), obesidade (OB), obesidade mais doença periodontal (OB+DP). Os grupos OB e OB+DP rece beram dieta de cafeteria por 17 semanas. Após de adquirirem obesidade, (semana 12), doença periodontal foi induzido pela colocação de ligaduras de seda no segundo molar superior direito dos grupos DP e OB+DP. Durante o período experi mental, o peso corporal e índice de Lee foram obtidos. Média de perda óssea alveolar (POA) foi avaliada e as aortas preparadas para análise histométrica da parede aórtica (em mm) pelo software ImageJ. Ratos expostos a dieta de cafeteria demonstraram um aumento do peso corporal e do índice de Lee. Uma POA media maior foi observada nos grupos DP e OB+DP comparado aos grupos controle e OB (p<0.05). O grupo OB+DP, quando comparado ao grupo DP, apresentou POA 18% maior e essa diferença foi estatisticamente significativa (p<0.001). Os grupos OB e OB+DP exibiram uma espessura de aorta maior comparado aos grupos DP e controle, respectivamente (2.31 ± 0.28 e 2.33 ± 0.29 vs. 2.18 ± 0.26 e 2.14 ± 0.27). Diferenças significativas foram observadas nas comparações dos grupos OB e controle (p=0,036), e OB+DP e OB comparado ao grupo DP (p=0.004 e p= 0.001, respectivamente). A obesidade parece afetar a espessura da parede da aorta em ratos Wistar. Entretanto, a presença de doença periodontal não afetou a espessura da parede da aorta sob as condições do presente estudo