Leukoplakia and erythroplakia in youngers versus older individuals: a clinicopathological retrospective study.

BACKGROUND: The incidence of oral cancer has exhibited a rise within the young population. Considering that oral potentially malignant disorders (OPMDs) can precede the development of oral cancer, it is imperative to conduct studies in this particular younger population. This study aimed to evaluate the frequency and conduct a comparative analysis of the clinical-demographic characteristics of OPMDs in two distinct age groups. MATERIAL AND METHODS: A retrospective analysis was conducted with patients diagnosed with leukoplakia, erythroplakia, and leukoerythroplakia between 1965 and 2020. The individuals were categorized into two groups: those aged up to 40 years (Group Younger) and those aged 41 years and above (Group Older). RESULTS: A total of 640 lesions were subjected to analysis. Among these, patients aged up to 40 years constituted 10.63% of the sample, however, this proportion decreased significantly to 6.9% between 2010 and 2020. A predominant male representation was observed in both groups, with white lesions being the most common in both as well. However, the frequency of red or mixed lesions was significantly higher (p=0.034) in the older group, along with a higher prevalence of dysplastic lesions (26.9% versus 11.8%, p=0.01). Moreover, the older group exhibited a relatively higher percentage of smokers/ex-smokers (78.6%), compared to the younger group (61.5%, p=0.085) and alcohol consumers/ex-consumers (54.9% versus 22.7%, p=0.028). Elderly individuals exhibited an unfavorable progression (p=0.028). However, a logistic regression analysis identified as significant variables associated with malignant transformation, the presence of epithelial dysplasia, and red lesions diagnosed as erythroplakia. CONCLUSIONS: A declining frequency of OPMDs in young adults was observed over the years, whereas in older adults, these disorders exhibited an unfavorable progression.

TLR4 expression and functionality are downregulated in glioblastoma cells and in tumor-associated macrophages: A new mechanism of immune evasion?

Glioblastoma (GB) is the most common and aggressive form of primary brain tumor, in which the presence of an inflammatory environment, composed mainly by tumor-associated macrophages (TAMs), is related to its progression and development of chemoresistance. Toll-Like Receptors (TLRs) are key components of the innate immune system and their expression in both tumor and immune-associated cells may impact the cell communication in the tumor microenvironment (TME), further modeling cancer growth and response to therapy. Here, we investigated the participation of TLR4-mediated signaling as a mechanism of induced-immune escape in GB. Initially, bioinformatics analysis of public datasets revealed that TLR4 expression is lower in GB tumors when compared to astrocytomas (AST), and in a subset of TAMs. Further, we confirmed that TLR4 expression is downregulated in chemoresistant GB, as well as in macrophages co-cultured with GB cells. Additionally, TLR4 function is impaired in those cells even following stimulation with LPS, an agonist of TLR4. Finally, experiments performed in a cohort of clinical primary and metastatic brain tumors indicated that the immunostaining of TLR4 and CD45 are inversely proportional, and confirmed the low TLR4 expression in GBs. Interestingly, the cytoplasmic/nuclear pattern of TLR4 staining in cancer tissues suggests additional roles of this receptor in carcinogenesis. Overall, our data suggest the downregulation of TLR4 expression and activity as a strategy for GB-associated immune escape. Additional studies are necessary to better understand TLR4 signaling in TME in order to improve the benefits of immunotherapy based on TLR signaling.

Role of inflammation, oxidative stress, and autonomic nervous system activation during the development of right and left cardiac remodeling in experimental pulmonary arterial hypertension.

This study investigated the impact of experimental pulmonary arterial hypertension (PAH) progression by evaluating morphometric and functional parameters, oxidative stress, autonomic nervous system (ANS) activation, and inflammation in the right (RV) and left (LV) ventricles. Male rats were first divided into two groups: monocrotaline (MCT) and control. The MCT group received a single MCT injection (60 mg/kg, intraperitoneal), while control received saline. The MCT and control groups were further divided into four cohorts based on how long they were observed: 1, 2, 3, and 4 weeks. Animals were submitted to echocardiographic and hemodynamic analysis. RV and LV were used for morphometric, biochemical, and histological measurements. Autonomic modulation was evaluated by cardiac spectral analysis, considering two components: low frequency (LF) and high frequency (HF). Lung and liver weight was used for morphometric analysis. MCT induced 100% mortality at 4 weeks. In the RV, disease progression led to mild inflammation and enhanced reactive oxygen species (ROS) in week 1, followed by moderate inflammation, ROS production, and hypertrophy in week 2. By week 3, there was moderate inflammation, oxidative stress, and ANS imbalance, with development of right heart dysfunction. LV biochemical changes and inflammation were observed at week 3. The initial changes appeared to be related to inflammation and ROS, and the later ones to inflammation, oxidative stress, and ANS imbalance in MCT animals. This study reinforces the severity of the disease in the RV, the late effects in the LV, and the role of ANS imbalance in the development of heart dysfunction.

Development of an in vitro model to study tooth cystogenesis.

AIM: To describe an in vitro experimental model of cystic structure formation to conduct research on radicular cyst development. METHODOLOGY: To form spheroid structures, various numbers (1 × 104 , 5 × 104 or 1 × 105 ) of epithelial cells (HaCaT and Cal27) were seeded in 96-well plates previously coated with 1.5% low-melting agarose. After 24 h, the spheroids were collected, embedded in 3D collagen matrix and transferred to 24-well plates previously coated with polymerized collagen and kept for up to 21 days. Images of spheroids were captured at each time-point (1, 5, 9, 15 and 21 days), and samples underwent histological and confocal microscopy analyses. Spheroid area, perimeter and cell dispersion were measured. One-way Anova was used for statistical analysis. RESULTS: Both epithelial cell lines were able to generate regular and circular spheroids after 24 h of incubation regardless of cell density. Spheroid structures in the collagen matrix were uniform in most samples until day 15, when several spots that appeared to be new cultures were seen. Spheroids from HaCaT were significantly more stable than those from Cal27 (P < 0.05). Starting on the third day, the examination of histological sections revealed a cavity with epithelial lining morphology, similar to a pathological radicular cyst. CONCLUSIONS: This study describes an experimental model of cystogenesis in vitro that may be used to test theories and investigates the effects of different growth factors during cyst development and maintenance.

Epithelial oral mucosal cells: Do they behave differently when exposed to oral carcinogens?

OBJECTIVE: To assess the level of maturation and proliferation of epithelial cells and the correlation with immunocytochemical expression of adhesion (E-cadherin) and cell differentiation (involucrin) markers. METHODS: Cytopathological samples were obtained from four groups of patients: control (CG, n=30); alcohol/tobacco (ATG, n=31), leucoplakia (LG, n=31), and squamous cell carcinoma (SCCG, n=22). Cytopathological smears were collected from all groups for AgNOR, Papanicolaou and immunocytochemical staining. RESULTS: There was an increase in anucleated cells in ATG compared to CG and in LG compared to lesion-free groups (P<.05). In addition, there was a higher rate of intermediate cells in lesion-free groups than in LG (P=.001). When these findings were correlated with positive E-cadherin expression, there was a smaller number of anucleated and intermediate cells (P<.05). The proliferation rate was higher in the SCCG than in the CG (P<.05) and in the ATG compared to LG (P<.05). Moreover, cell proliferation increased in the presence of positive E-cadherin expression in the ATG and LG. No statistically significant results were obtained for involucrin analysis. CONCLUSION: Cytopathology combined with quantitative techniques such as Papanicolaou, AgNOR, and immunocytochemical expression of E-cadherin detects changes associated with oral carcinogenesis. The innovative approach used in this study allows assessing the expression of cell adhesion (E-cadherin) and differentiation (involucrin) markers by means of oral mucosal cytopathology. The E-cadherin imunocytochemical expression indicated changes associated with the oral carcinogenesis process. An increase in cell proliferation rate in oral squamous cell carcinoma group was associated with the lower immunoexpression of E-cadherin. Cytopathology combined with quantitative techniques and immunocytochemical expression of E-cadherin may detect early alterations associated with oral carcinogenesis.

Autophagy analysis in oral carcinogenesis.

OBJECTIVE: The aim of this study was to evaluate the levels of autophagy in oral leukoplakia and squamous cell carcinoma and to correlate with clinical pathological features, as well as, the evolution of these lesions. METHODOLOGY: 7 Normal oral mucosa, 51 oral leukoplakias, and 120 oral squamous cell carcinomas (OSCC) were included in the study. Histological sections of the mucosa and leukoplakias were evaluated throughout their length, while the carcinomas were evaluated using Tissue Microarray. After the immunohistochemical technique, LC3-II positive cells were quantified in the different epithelial layers of the mucosa and leukoplakias and in the microarrays of the squamous cell carcinomas. The correlation between positive cells with the different clinical-pathological variables and with the evolution of the lesions was tested using the t test, ANOVA, and Kaplan-Meier survival analysis. RESULTS: We observed increased levels of autophagy in the oral squamous cell carcinomas (p<0.001) in relation to the other groups, but without any association with poorer evolution or survival of these patients. Among the leukoplakias, we observed a higher percentage of positive cells in the intermediate layer of the dysplastic leukoplakias (p=0.0319) and in the basal layer of lesions with poorer evolution (p=0.0133). CONCLUSION: The levels of autophagy increased during the process of oral carcinogenesis and are correlated with poorer behavior of the leukoplakias.

Exposure to alcohol or tobacco affects the pattern of maturation in oral mucosal cells: a cytohistological study.

OBJECTIVE: To assess the maturation pattern of oral mucosal cells of patients exposed to tobacco and alcohol. METHODS: (i) Group without lesions. Smears obtained from the lower lip, border of the tongue and floor of the mouth of 31 control individuals (group I), 49 tobacco users (group II) and 27 tobacco/alcohol users (group III) were stained using the Papanicolaou method. The first 100 cells counted on each smear determined the maturation pattern and the keratinization index (KI). Analysis of variance (ANOVA) and the Tukey multiple comparison test were used for statistical analysis, at a 5% significance level. (ii) Group with lesions. Cytopathological and histopathological studies were conducted for 15 patients: eight with leucoplakia without epithelial dysplasia, two with epithelial dysplasia and five with squamous cell carcinoma. RESULTS: (i) Group without lesions. Statistical analysis revealed a smaller number of superficial cells with nuclei in all sites of the group of tobacco/alcohol users (group III) when compared to the control group (group I), and this difference was statistically significant (P<0.005). (ii) Group with lesions. The severity of histopathological findings increased with the increase in the number of cells of the deeper epithelial layers, with a statistically significant difference in the number of intermediate (P=0.013) and parabasal cells (P=0.049), which increased with the severity of the epithelial maturation disorder: leucoplakias with dysplasia had a greater number of intermediate and parabasal cells than leucoplakias without dysplasia; and the number in squamous cell carcinomas was greater than in leucoplakias with dysplasia. CONCLUSION: The maturation pattern of cells in the three anatomic sites showed changes that may be associated with the synergistic effect of tobacco and alcohol. Also, the severity of histopathological findings was associated with the increase in the number of cells in the deeper epithelial layers.