CLIC4 Function in the Epithelial-Mesenchymal Transition of Epithelial Odontogenic Lesions

BACKGROUND

Odontogenic lesions constitute a heterogeneous group of lesions. CLIC4 protein regulates different cellular processes, including epithelial-mesenchymal transition and fibroblast-myofibroblast transdifferentiation. This study analyzed CLIC4, E-cadherin, Vimentin, and α-SMA immunoexpression in epithelial odontogenic lesions that exhibit different biological behavior.

METHODS

It analyzed the immunoexpression of CLIC4, E-cadherin, and Vimentin in the epithelial cells, as well as CLIC4 and α-SMA in the mesenchymal cells, of ameloblastoma (AM) (n = 16), odontogenic keratocyst (OKC) (n = 20), and adenomatoid odontogenic tumor (AOT) (n = 8). Immunoexpressions were categorized as score 0 (0% positive cells), 1 (< 25%), 2 (≥ 25% - < 50%), 3 (≥ 50% - < 75%), or 4 (≥ 75%).

RESULTS

Cytoplasmic CLIC4 immunoexpression was higher in AM and AOT (p < 0.001) epithelial cells. Nuclear-cytoplasmic CLIC4 was higher in OKC's epithelial lining (p < 0.001). Membrane (p = 0.012) and membrane-cytoplasmic (p < 0.001) E-cadherin immunoexpression were higher in OKC, while cytoplasmic E-cadherin expression was higher in AM and AOT (p < 0.001). Vimentin immunoexpression was higher in AM and AOT (p < 0.001). Stromal CLIC4 was higher in AM and OKC (p = 0.008). Similarly, α-SMA immunoexpression was higher in AM and OKC (p = 0.037). Correlations in these proteins' immunoexpression were observed in AM and OKC (p < 0.05).

CONCLUSIONS

CLIC4 seems to regulate the epithelial-mesenchymal transition, modifying E-cadherin and Vimentin expression. In mesenchymal cells, CLIC4 may play a role in fibroblast-myofibroblast transdifferentiation. CLIC4 may be associated with epithelial odontogenic lesions with aggressive biological behavior.

Does YAP influence cell proliferation and apoptosis in benign epithelial odontogenic lesions?

OBJECTIVE

To analyze the immunohistochemical expression of YAP and its correlation with markers involved in cell proliferation and apoptosis in benign epithelial odontogenic lesions.

STUDY DESIGN

The sample consisted of 95 cases of odontogenic lesions (25 dentigerous cysts, 30 non-syndromic odontogenic keratocysts, 30 conventional ameloblastomas, and 10 unicystic ameloblastomas) and 10 dental follicles used as normal odontogenic tissue. The histological sections were submitted to immunohistochemistry with YAP, cyclin D1, Ki-67, and Bcl-2 antibodies. Immunoexpression was analyzed qualitatively and quantitatively using an adapted method. The collected data were analyzed descriptively and statistically (p ≤ 0.05).

RESULTS

The highest YAP expression was observed in odontogenic keratocysts, followed by unicystic ameloblastomas and conventional ameloblastomas, which exhibited moderate immunoreactivity predominantly in peripheral cells. Furthermore, significant differences in YAP immunoexpression were observed between the groups analyzed, with significant positive correlations between YAP and cyclin D1 in dentigerous cysts and unicystic ameloblastomas and between YAP and Ki-67 in unicystic ameloblastomas (p < 0.05). However, there were no statistically significant correlations between YAP and Bcl-2 immunoexpression in the groups studied.

CONCLUSION

YAP may influence epithelial cell proliferation in odontogenic cysts and tumors, suggesting its possible participation in the progression of the odontogenic lesions studied.

A Systematic Review of Adenoid Ameloblastoma: A Newly Recognized Entity

BACKGROUND

Recently, a new odontogenic tumor has been described, the so-called adenoid ameloblastoma (AdAM). The aim of this review was to determine the clinical and imaging features of AdAM and to describe its main histopathological findings.

METHODS

The systematic review included published cases with a diagnosis of AdAM in the gnathic bones, which had sufficient clinical, imaging, and histopathological data to confirm its diagnosis. The following histopathological diagnostic criteria were adopted: presence of ameloblastoma-like components, duct-like structures, spiral cellular condensations, and a cribriform architecture.

RESULTS

Fifteen articles, corresponding to 30 cases of AdAM, were selected. Most cases affected men (63.3%), with a slight preference for the mandible (16:14) and the posterior region of gnathic bones was the most commonly affected site. The mean age at diagnosis was 40.8 years. Clinically, the lesions usually presented as a swelling (53.3%) and, radiographically, as a well-defined radiolucency (33.4%). Surgical resection (40%) was the most frequently adopted treatment and recurrence occurred in 30% of cases. Microscopic examination showed cribriform areas in most AdAM cases (93.3%); duct-like structures and spiral cellular condensations were seen in 100% of the cases.

CONCLUSION

The small number of reported cases, the existence of erroneous diagnoses, and the adoption of initial conservative management make it difficult to determine whether AdAM has a higher risk of recurrence or more aggressive biological behavior than conventional ameloblastomas.

Immunohistochemical comparative analysis of tumor stem cell biomarkers in pleomorphic adenoma, adenoid cystic carcinoma and mucoepidermoid carcinoma of salivary glands

OBJECTIVE

This study aimed to compare the immunoexpression profile of tumor stem cell (TSC) biomarkers CD44, aldehyde dehydrogenase 1 (ALDH1), OCT4, and SOX2 in salivary gland tumors (SGTs).

STUDY DESIGN

Sixty tissue specimens of SGTs, including 20 pleomorphic adenomas, 20 adenoid cystic carcinomas (ACCs), and 20 mucoepidermoid carcinomas, in addition to 4 samples of normal glandular tissue, were subjected to immunohistochemistry. The expression of the biomarkers in the parenchyma and stroma was evaluated. Data were analyzed statistically by nonparametric tests (P < .05).

RESULTS

Higher parenchymal expression of ALDH1, OCT4, and SOX2 was observed in pleomorphic adenomas, ACCs, and mucoepidermoid carcinomas, respectively. Most ACCs did not express ALDH1. Higher immunoexpression of ALDH1 in major SGTs (P = .021) and of OCT4 in minor SGTs (P = .011) was found. Immunoexpression of SOX2 was related to lesions without myoepithelial differentiation (P < .001) and malignant behavior (P = .002). Furthermore, OCT4 was related to myoepithelial differentiation (P = .009). CD44 expression was related to a better prognosis. Stromal immunoexpressions of CD44, ALDH1, and OCT4 were higher in malignant SGTs.

CONCLUSIONS

Our findings suggest the participation of TSCs in the pathogenesis of SGTs. We emphasize the need for further investigations into the presence and role of TSCs in the stroma of these lesions.

Actinic cheilitis in rural workers: prevalence and associated factors

Objective

To evaluate the prevalence of actinic cheilitis in rural workers and factors associated with the development of this condition.

Methods

A cross-sectional study was conducted in a city in Northeastern Brazil. Data were collected by clinical examination and use of a questionnaire validated with 300 rural workers. The χ² test was employed to identify possible associations between the presence of actinic cheilitis and clinical and demographic variables. Multiple logistic regression analysis was performed using forward stepwise selection. A p value of 0.05 was considered significant.

Results

The prevalence of actinic cheilitis was 12.0% in the sample. The highest prevalence of actinic cheilitis was observed in white males, with low educational level, and an approximately 40-year history of sun exposure. Chronic lesions were commonly found in the lower lip and were characterized by scaling, dryness, and mild edema. Skin color, sex, educational level of patients, and cumulative sun exposure (in years), were identified as predictors of development of actinic cheilitis.

Conclusion

Our results suggest the need to implement educational health strategies aimed to orient the population about risk factors and preventive measures of the disease. Appropriate clinical management of patients with actinic cheilitis is important for prevention of lip cancer.

Immunohistochemical study of the plasminogen activator system in benign epithelial odontogenic lesions

The aim of this study was to analyze and compare the immunohistochemical expression of plasminogen activator system (PAS) proteins (uPA, uPAR, and PAI-1) in ameloblastomas (AMBs), odontogenic keratocysts (OKCs), and dental follicles (DFs) representing normal odontogenic tissue, as well as to investigate possible correlations between these proteins. Twenty AMBs, 20 OKCs, and 10 DFs were selected for immunohistochemical analysis. In each case, the immunoexpression of uPA, uPAR, and PAI-1 was evaluated semiquantitatively based on the percentage of positivity in odontogenic epithelial and connective tissue cells. The epithelial immunoexpression of uPA was significantly lower in AMBs when compared to OKCs (p = 0.001) and DFs (p = 0.029). Significantly higher epithelial immunostaining for uPAR was observed in AMBs when compared to OKCs (p < 0.001). There were no significant differences in the epithelial immunoexpression of PAI-1 between AMBs and OKCs (p = 1.000). The correlations found for the expression of the studied proteins were not statistically significant (p > 0.05). However, the epithelial and connective tissue expressions of uPAR have a strong positive and statistically significant correlation in AMBs. The present results suggest that uPA is involved in the pathogenesis of OKCs and that uPAR may participate in tumorigenesis in AMBs. The high percentage of PAI-1-positive cells suggests a possible role for this protein in the development of AMBs and OKCs. Furthermore, the studied proteins do not seem to act synergistically in AMBs, OKCs, and DFs.

Role of plasminogen activator inhibitor-1 in oral tongue squamous cell carcinoma: An immunohistochemical and in vitro analysis

OBJECTIVE

To evaluate the influence of plasminogen activator inhibitor-1 (PAI-1) on the biological behavior and prognosis of oral tongue squamous cell carcinoma (OTSCC).

METHODS

Immunoexpression of PAI-1 was analyzed in 60 OTSCC specimens and classified as low-expression (≤50% of positive cells) or high-expression (>50%). In vitro effects of recombinant human PAI-1 (rhPAI-1) were assessed through functional assays on the OTSCC-derived cell line SCC-25. Three cell groups were evaluated: G0 (control), G10 (10 nM rhPAI-1), and G20 (20 nM rhPAI-1).

RESULTS

High membrane expression of PAI-1 was associated with tumor budding (p = 0.046) and high-risk cases (p = 0.043). Cytoplasmic and membrane expression of PAI-1 was not associated with patient survival. Cell viability (p = 0.020) and progression to the S-phase of the cell cycle (p = 0.024) were higher in G10 and G20 at 24 h. The percentages of apoptotic/necrotic cells were not affected by rhPAI-1. The presence of rhPAI-1 increased cell migration (p = 0.039) and invasion (p = 0.039) after 24 and 72 h, respectively.

CONCLUSION

Our findings indicate the involvement of PAI-1 in the biological behavior of OTSCC, although its expression may not predict patient survival. The in vitro results suggest that PAI-1 stimulates cell proliferation, migration and invasion and may contribute to the aggressive phenotype of OTSCC.

Role of Twist and Podoplanin in Partial Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma

The aim of this study was to perform a comparative analysis of podoplanin (PDPN) and Twist immunoexpressions in lower lip and oral tongue squamous cell carcinomas (LLSCC and OTSCC, respectively). PDPN and Twist immunoexpressions were semi-quantitatively evaluated by analyzing the invasion front, the compressive areas, the large islands and nests and dissociated cells of the chosen carcinomas. Their statistical associations and correlations with clinical-pathological characteristics were verified by the Mann-Whitney and Spearman's test. Twist expression was low in both carcinomas, with <25% labeling on the invasive front. Significant differences were observed for LLSCC (p=0.032) and OTSCC (p=0.025) regarding PDPN immunoexpression in relation to the worst invasion patterns determined by a histological malignancy gradation system. Statistically significant negative correlations between PDPN membrane expression and general (r=-0.356, p=0.024) and cytoplasmic Twist expressions (r=-0.336; p=0.034) in LLSCC were also observed. Twist and PDPN are suggested to be associated to a more aggressive invasion pattern in both LLSCC and OTSCC cases but not related to the different biological behaviors on these anatomical sites. Also, it was seen that PDPN membrane expression is inversely related to general and cytoplasmic Twist expression in LLSCC cases.

Prognostic Factors and Survival in Adenoid Cystic Carcinoma of the Head and Neck: A Retrospective Clinical and Histopathological Analysis of Patients Seen at a Cancer Center

Adenoid cystic carcinoma (AdCC) is a rare malignancy that accounts for approximately 1% of all head and neck cancers. This neoplasm is characterized by slow but often relentless growth and dissemination. Our aim was to retrospectively evaluate the clinical-pathological features of patients diagnosed with head and neck AdCC and to identify possible prognostic factors. This retrospective observational study analyzed 87 cases of AdCC of the head and neck. Clinical parameters (tumor size, lymph node and distant metastasis, clinical stage, and survival) were obtained from the records. Survival curves were constructed using the Kaplan-Meier method. A p value ≤ 0.05 was considered significant. There was a slight predominance of cases diagnosed in female patients (54%). The mean age at diagnosis was 51.5 years. Analysis using Cox's proportional hazards model considering 10-year disease-specific survival identified histologic pattern and presence of perineural invasion as independent prognostic variables. Primary tumor size and distant metastasis were prognostic predictors of 5- and 10-year disease-free survival. Detailed analysis of the association between clinical-pathological parameters and prognosis can assist professionals with cancer treatment planning and adequate patient management. Considering the long-term aggressive behavior of AdCC, rigorous patient follow-up is important to identify possible locoregional or distant recurrences.

Recurrence-free survival and prognostic factors of odontogenic keratocyst: a single-center retrospective cohort

PURPOSE

The aim of the present study was to evaluate the 5-year recurrence-free survival and prognostic factors of odontogenic keratocyst (OKC) from a single-center retrospective cohort in the northeastern region of Brazil.

METHODS

Forty cases of OKC comprised the study population. In the cohort analyzed, 18 (45%) cases were recurrent OKCs and 22 (55%) were non-recurrent OKCs. Recurrence-free survival was defined as the period from the release of the histopathological report to the occurrence of relapse or last visit to the service.

RESULTS

Comparison of the clinicopathological variables between primary and recurrent OKC lesions revealed no differences in the frequency of epithelial thickness, presence of satellite cysts and cystic spaces, presence of an inflammatory infiltrate, locularity, and lesion borders. The frequency of symptoms was practically the same even after recurrence. Satellite cysts were more frequent in the group of recurrent lesions (n = 9, p = 0.002) and the presence of an inflammatory infiltrate was also significantly associated with recurrent lesions (n = 15, p = 0.006). Previous decompression or marsupialization was associated with recurrence of the lesion (p = 0.010).

CONCLUSIONS

In conclusion, the most significant prognostic factors were previous decompression or marsupialization, as well as, morphological parameters associated with the recurrence cases were the presence of an inflammatory infiltrate and satellites cysts. The risk of recurrence is low but continues due to the particularities of epithelial proliferation in OKC.

Caliber Persistent Artery in the Upper Lip: A Case Report with Unusual Histopathological Findings

Caliber persistent labial artery (CPLA) consists in a dilated portion of the main branch of the labial artery without loss of size. The aim of this study is to report a case of a patient diagnosed with CPLA in the upper lip, emphasizing unusual histopathological and immunohistochemical findings. A 67-year-old female patient with complaint of a pulsating upper lip lesion without painful symptomatology. Under a clinical diagnosis of CPLA, and considering that the patient was edentulous and used a total prosthesis, an excisional biopsy of the lesion was performed to avoid future traumas in the region and consequently possible exuberant local bleeding. At anatomopathological examination structures suggestive of lymphoid follicles and germinal centers were visualized. Immunohistochemistry showed positivity for CD20, CD68, desmin and CD34 and negativity for CD4. The patient did not have a history of allergies, cardiovascular, rheumatic or systemic diseases that could justified the findings. The case presents unusual histopathological structures, evidencing the necessity of more studies about this pathology so scarce in the literature.

Actinic cheilitis: Morphometric parameters and its relationship with the degree of epithelial dysplasia

Actinic cheilitis (AC) is a potentially malignant lesion caused by chronic sun exposure. This study aimed to evaluate the relationship between the degree of epithelial dysplasia and morphometric findings in AC. Sixty-eight slides of AC cases were selected and classified according to the grade of epithelial dysplasia, following morphologic criteria of World Health Organization. For morphometric analysis, the slides were scanned and images were analyzed using Pannoramic Viewer software. We obtained vertical measurements of the parameters: thicknesses of the keratin layer, lamina propria and zone of solar elastosis in three selected fields. Thirty-seven (54.4%) of the analyzed cases were classified as none/mild dysplasia and 31 (45.6%) as moderate/severe epithelial dysplasia. Cases with a moderate/severe dysplasia exhibited a thicker layer of keratin (median = 0.055 mm) than none/mild dysplasia (median = 0.045 mm) (p = 0.033). No significant differences in the thicknesses of lamina propria and zone of solar elastosis were observed according to the grade of epithelial dysplasia. A positive significant correlation between keratin layer and lamina propria thicknesses was found (p = 0.019). Based on our findings, rigorous clinical follow-up should be recommended for patients whose histopathological examination shows a greater thickness of the keratin layer.

Immunohistochemical analysis of lymphatic vessel density and mast cells in oral tongue squamous cell carcinoma

The aim of this study was to analyze lymphangiogenesis and the presence of mast cells in oral tongue squamous cell carcinoma (OTSCC), correlating the findings with clinicopathological parameters (clinical stage, tumor size, nodal metastasis, histological grade of malignancy, local recurrence, and clinical outcome). Fifty-six cases of primary OTSCC were selected. Lymphatic vessels and mast cells were identified by immunostaining with anti-podoplanin (D2-40) and anti-tryptase antibody, respectively. Lymphatic vessel density (LVD) and mast cell density (MCD) were determined in the intratumoral and peritumoral areas. Intratumoral LVD was higher in advanced clinical stages (III/IV) when compared to early-stage (p = 0.017) and in metastatic cases compared to non-metastatic tumors (p = 0.013). Peritumoral LVD and intratumoral or peritumoral MCD did not differ significantly according to the clinicopathological parameters of OTSCCs (p > 0.05). No significant correlations between LVD and MCD were observed at the intratumoral (r = -0.014; p = 0.918) or peritumoral level (r = 0.156; p = 0.251). Our findings suggest that intratumoral lymphatic vessels, compared to peritumoral lymphatic vessels, appear to be more related to the progression of OTSCC. MCD alone does not seem to be determinant for lymphangiogenesis or for the biological behavior of OTSCC, indicating multiple pro- and antitumor effects of these inflammatory cells.

Participation of hypoxia-inducible factor-1α and lymphangiogenesis in metastatic and non-metastatic lower lip squamous cell carcinoma

This study evaluated the lymphatic density and HIF-1α immunoexpression in lower lip squamous cell carcinoma (LLSCC) and their correlation with clinicopathological (nodal metastasis, clinical stage, histological grade, recurrence and disease outcome) and survival parameters in 20 metastatic and 20 non-metastatic LLSCCs. Lymphatic density was established by counting microvessels (D2-40⁺) at the tumor core (intratumoral lymphatic density, ILD) and at the invasive front (peritumoral lymphatic density, PLD) and percentages of immunopositive cells for HIF-1α were established. No statistically significant differences in lymphatic densities in relation to clinicopathological parameters were observed (P > 0.05). All cases exhibited nuclear and cytoplasmic HIF-1α immunoexpression, with relatively high percentages of positivity, but this expression was not statistically different in relation to clinicopathological variables (P > 0.05). Positive correlations were observed between ILD and PLD (P = 0.002), and between nuclear HIF-1α immunoexpression at the tumor core and ILD (P = 0.001). The results suggest ILD and PLD are not directly related to the development of lymph node metastasis in LLSCC. The striking expression of HIF-1α suggests the involvement of this protein in the etiopathogenesis of LLSCCs, possibly stimulating lymphangiogenesis at the tumor core. However, this protein does not seem to exert a determining influence on the biological aggressiveness of these tumors.

Stafne bone defect: a report of two cases and diagnostic considerations

Stafne bone defects are asymptomatic lingual bone depressions of the lower jaw, frequently caused by soft tissue inclusion. The common variant of this entity affects the third molar region, below mandibular canal, and is mostly diagnosed incidentally during routine radiographic examination. The uncommon anterior variant is relatively rare and located in the premolar region of the mandible. Sublingual salivary glands are thought to be responsible for the development of this variant. The aim of this report was to describe a case of Stafne bone defect in the anterior region of mandible and a case in posterior mandible, with emphasis on clinical and radiographic findings. Dental clinicians should be aware of this entity, aiming to avoid unnecessary biopsies. In most cases, clinical and radiographic follow-up is the recommended conduct.

Expressão imunoistoquímica da endoglina (CD105) e do fator de von Willebrand em carcinoma epidermoide oral e sua relação com parâmetros clinicopatológicos

Resumo Contexto A angiogênese tem sido associada à progressão de neoplasias malignas e, embora haja estudos acerca de marcadores angiogênicos no carcinoma epidermoide oral (CEO), existem resultados conflitantes na literatura. Objetivos Avaliar a expressão imunoistoquímica do CD105 e do fator de von Willebrand (FvW) em CEO e sua relação com parâmetros clínicos do tumor. Métodos A imunoexpressão dos referidos biomarcadores foi analisada em 30 casos de CEO e correlacionada a parâmetros clínicos do tumor (idade e sexo dos pacientes, localização anatômica e estadiamento clínico Tumor, Nodo e Metástase, TNM). Resultados A imunomarcação com o anticorpo anti-FvW foi mais efetiva que a do CD105 no CEO. No que concerne à localização anatômica, o assoalho bucal e a região retromolar apresentaram diferenças estatisticamente significativas quanto aos índices angiogênicos (p = 0,004), determinados pela técnica de contagem microvascular (MVC). Não houve relação estatisticamente significativa entre o estadiamento clínico TNM e os índices angiogênicos, com os dois biomarcadores. Conclusões Com base nos achados deste estudo, sugere-se um envolvimento da neoformação vascular na carcinogênese oral, embora não tenha sido evidenciada associação significativa com o estágio clínico da lesão.