Molecular markers of cell adhesion in ameloblastomas. An update

Ameloblastoma is the most common odontogenic tumor of epithelial origin, and though it is of a benign nature, it frequently infiltrates the bone, has a high rate of recurrence and could potentially become malignant. Cellular adhesion potentially plays an important role in the manifestation of these characteristics and in the tumor biology of ameloblastomas. Losses of cell-cell and extracellular matrix adhesion and cohesion are among the first events that occur in the invasion and growth of tumors of epithelial origin. The present review includes a description of the molecules that are involved in cell adhesion as reported for various types of ameloblastomas and discusses the possible roles of these molecules in the biological behaviors of this odontogenic tumor. Knowledge of the complex mechanisms in which these molecules play a role is critical for the research and discovery of future therapeutic targets

Expression of Interleukin-1ß and Interleukin-8 in Oral Potentially Malignant Disorders and Carcinomas

Objective: To evaluate interleukin-1ß (IL-1ß) and interleukin-8 (IL-8) epithelial expressions in potentially malignant disorders of the oral mucosa as malignant predictive markers.Study design: About 55 tissues embedded in paraffin, comprising 15 oral lichen planus (OLP) lesions, 15 leukoplakias, 15 oral squamous cell carcinomas (OSCC), and 10 samples of normal oral mucosa were included in the study. IL-1ß and 8 expressions were assessed by immunohistochemistry using antibodies antihuman IL-1ß human (sc-7884, Santa Cruz® H-153) and antihuman IL-8 (ab7747, abcam®). The number of positive cells was compared using Student's t-test. Any p-value < 0.05 was considered statistically significant.Results: Nuclear and cytoplasmatic keratinocyte staining were positive for both cytokines in all study groups. However, a statistically significant decrease was observed within all cases compared to normal mucosa, both staining for IL-1β and 8. Moreover, IL-8 showed significant differences between OLP and leukoplakia, and when compared to OSCC.Conclusions: Oral epithelial expression of IL-1β and 8 seems to decrease when the malignant transformation of the oral mucosa increases

Mixed odontogenic tumors: A review of the clinicopathological and molecular features and changes in the WHO classification

Ameloblastic fibromas and ameloblastic fibrosarcomas are rare odontogenic tumors, and controversy exists in the classification of cases presenting hard-tissue production: Ameloblastic fibrodentinoma (AFD) and ameloblastic fibro-odontoma (AFO). These cases are currently considered “developing odontomas” (hamartomatous lesions). To analyze the clinicopathologic features of these lesions and discuss the changes in the 2017 World Health Organization classification

The Tissue Architecture of Oral Squamous Cell Carcinoma Visualized by Staining Patterns of Wheat Germ Agglutinin and Structural Proteins Using Confocal Microscopy

Abstract: Objectives: Tissue architecture and cell morphology suffer profound alterations during oral cancer and are important markers for its progression and outcome. For precise visualization of tissue architecture in oral cancer, we used confocal microscopy to examine the staining pattern of wheat germ agglutinin, a lectin that binds membrane glycoproteins, and the staining patterns of structural proteins. Materials and Methods: Paraffin sections of oral squamous cell carcinoma were stained with fluorescently labeled wheat germ agglutinin and with antibodies against structural proteins, which were revealed by immunohistochemistry with tyramide signal amplification. Results: Membrane localization of wheat germ agglutinin was markedly decreased in the basal layers and in regions of tumor invasion, accompanied by cytoplasmic redistribution of E-cadherin, -actin and syndecan-1. Wheat germ agglutinin staining clearly identified tumor clusters within the surrounding stroma, and tumor cells with elongated morphology. Conclusions: Our results suggest that the wheat germ agglutinin staining pattern is indicative of the degree of cell cohesion in oral squamous cell carcinoma, which decreases in basal layers and invasive tumor clusters with more migratory morphologies. Wheat germ agglutinin staining in combination with confocal microscopy could constitute, therefore, a valuable tool for the study of tissue architecture in oral cancer

Intraoral Sialadenoma Papilliferum: A Comprehensive Review of the Literature with Emphasis on Clinical and Histopathological Diagnostic Features

Sialadenoma papilliferum (SP) is a rare benign epithelial tumor of salivary gland origin, its diagnosis being potentially challenging. It was first described by Abrams and Finck in 1969 as an analog of the cutaneous syringocystadenoma papilliferum. The aim of this comprehensive review is to highlight the clinical and histopathological diagnostic aspects of intraoral SP, analyzing cases previously described and reporting new cases. Methods. Medline, Scopus, and Web of Science were searched up to February 2022, using as entry term “sialadenoma papilliferum”. No time limits were applied and only studies in English were taken into account. Only cases involving the mouth were included. Conference proceedings, personal communications, and letters to the editor were excluded. Results. In total, 42 out of 234 articles fulfilled the inclusion criteria, with 64 cases reported. Mean age of patients with SP was 57.2 years, with a higher prevalence among males. The most affected site was the palate, particularly the hard palate. Four cases with uncertain malignant features have been reported. While clinical manifestations of SP are rather unspecific (e.g., submucosal swelling with ulceration), histopathological and immunohistochemical features are quite peculiar, SP have a limited growth potential, leading to conservative excision as treatment of choice. Conclusions. SP, though rare, should be taken into consideration in the differential diagnosis of intraoral swellings, particularly those located on the palate

The value of Phosphohistone H3 as a cell proliferation marker in oral squamous cell carcinoma. A comparative study with Ki-67 and the mitotic activity index

The Phosphohistone H3 (PHH3) antibody is recognized as a biomarker of cell proliferation, specific for cells in mitosis, of prognostic value in different malignant neoplasms, however it has been poorly studied in oral squamous cell carcinoma (OSCC). The main objective of this study was to evaluate the immunoexpression of the PHH3 in the OSCC, through the correlation with the immunoexpression of Ki-67, the mitotic activity index (MAI), histological grading, clinical-morphological parameters and the rate of survival. The study sample consisted of 62 cases of OSCC diagnosed in the Pathological Anatomy Laboratory of the Faculty of Dentistry, University of the Republic (Uruguay). In each of them, an immunohistochemical technique was performed for Ki-67 and PHH3 (serine 10) antibodies. Image J software was used for the MAI and biomarker quantification, defining the percentage of positivity and mitotic Figures per 1000 tumor cells. a significant association was obtained between the expression of PHH3 (p 0.016) and MAI (p 0.031) with survival time. However, no similar relationship was found with Ki-67 (p 0.295). Although it was confirmed a statistical association between histological grade and Ki-67 immunoexpression (p 0.004), PHH3 did not show a similar relationship (p 0.564). It was confirmed the role of the PHH3 antibody as a biomarker of mitotic Figures in OSCC and as a potential marker of cell proliferation. It is noteworthy that this is one of the first works that evaluates a possible relationship between the expression of this antibody and survival in OSCC

Immunoexpression of Ki-67, MCM2, and MCM3 in ameloblastoma and ameloblastic carcinoma and their correlations with clinical and histopathological patterns

Cell proliferation assays are performed using antibodies against nuclear proteins associated with DNA replication. These nuclear proteins have gained special interest to predict the biological and clinical behaviors of various tumors. The aim of this study was to analyze the presence of Ki-67 protein and the minichromosome maintenance-2 (MCM2) and maintenance-3 (MCM3) proteins in ameloblastoma. Materials and Methods. Cell proliferation marker expression levels were assessed via immunohistochemistry in 111 ameloblastoma cases (72 unicystic ameloblastoma samples, 38 solid/multicystic ameloblastoma samples, and 1 ameloblastic carcinoma). The label index was performed as described previously. Results. MCM2 and MCM3 showed higher proliferation indexes in all variants of ameloblastoma compared to the classic marker Ki-67. No correlation between the proliferation index and the clinical and protein expression data was observed. Conclusion. The results suggest that clinical features do not directly affect tumor cell proliferation. Moreover, the high levels of cellular proliferation of MCM2 and MCM3 compared with Ki-67 may indicate that MCM2 and MCM3 are more sensitive markers for predicting the growth rate and eventually might be helpful as a tool for predicting aggressive and recurrent behaviors in these tumor

Uso de entornos virtuales de aprendizaje en educación superior. Su impacto en el rendimiento académico exitoso en Histología

Artículo original.En el marco de las políticas definidas por la Universidad de la República de respaldo al aprendizaje, la Facultad de Odontología presenta su primera experiencia curricular de integración estudiantil. En la carrera de Odontología, se verifica un importante retreaso académico en los dos primeros años. El proceso de afiliación a la vida universitaria puede generar desajustes en lso rendimientos y riesgo de desvinculación. Entendiendo la importancia del vínculo interpersonal entre estudiantes pares para la continuidad en los estudios, se propone generar estrategias articuladas que contribuyan a neuralizar la fragilidad al ingreso. La Unidad de Apoyo a la Enseñanza expone la experiencia del Curso Turoría entre Pares, curricular, optativo y teórico-práctico destacando que : estudiantes avanzados realizan el acompañamiento socio-afectivo, personal y académico de los ingresantes; afecta a toda la cohorte inicial; es de carácter semivolunatio; contempla un respaldo multidisciplinar; moviliza acciones de apoyo institucional complementarias y en red con otras estructuras de apoyo. (AU