Podoplanin, E-cadherin, β-catenin, and CD44v6 in recurrent ameloblastoma: their distribution patterns and relevance

Podoplanin immunoexpression in odontogenic lesions: a systematic review, meta-analysis, and integrated bioinformatic analysis

BACKGROUND

Podoplanin (PDPN) is a transmembrane glycoprotein implicated in the pathogenesis of odontogenic lesions (OL). It is localized at the membrane and cytoplasmic level, and its interaction with other proteins could trigger cell proliferation, invasion and migration. The main objective of this systematic review is to explore the immunoexpression pattern of podoplanin in OL. In addition, as secondary objectives, we aimed to compare the immunostaining intensity of PDPN in OL, to analyze its interaction networks by bioinformatic analysis and to highlight its importance as a potential diagnostic marker useful in the pathogenesis of OL.

METHODS

The protocol was developed following PRISMA and Cochrane guidelines. The digital search was performed in the databases: PubMed/MEDLINE, ScienceDirect, Scopus, Web of Science and Google Schoolar from August 15, 2010 to June 15, 2023. We included cross-sectional and cohort studies that will analyze the pattern of PDPN immunoexpression in OL. Two investigators independently searched for eligible articles, selected titles and abstracts, analyzed full text, conducted data collection, and performed assessment of study quality and risk of bias. In addition, part of the results were summarized through a random-effects meta-analysis. STRING database was used for protein-protein interaction analysis.

RESULTS

Twenty-nine relevant studies were included. The ages of the subjects ranged from 2 to 89 years, with a mean age of 33.41 years. Twenty-two point two percent were female, 21.4% were male, and in 56.4% the gender of the participants was not specified. A total of 1,337 OL samples were analyzed for PDPN immunoexpression pattern. Ninety-four (7.03%) were dental follicles and germs, 715 (53.47%) were odontogenic cysts, and 528 (39.49%) were odontogenic tumors. Meta-analysis indicated that the immunostaining intensity was significantly stronger in odontogenic keratocysts compared to dentigerous cysts (SMD=3.3(CI=1.85-4.82, p=0.000*). Furthermore, bioinformatic analysis revealed that PECAM-1, TNFRF10B, MSN, EZR and RDX interact directly with PDPN and their expression in OL was demonstrated.

CONCLUSIONS

The results of the present systematic review support the unique immunoexpression of PDPN as a potential useful diagnostic marker in the pathogenesis of OL.

Factors Associated with Recurrence of Ameloblastoma: A Scoping Review

PURPOSE

This scoping review aimed to identify factors associated with the recurrence of ameloblastoma.

METHODS

Systematic searches were conducted in PubMed, Scopus, and EMBASE, based on the board research question: "What factors are related to the recurrence of ameloblastoma?". English-language observational studies addressing the risk and preventive factors associated with recurrent ameloblastoma were included and data were extracted.

RESULTS

Eighty-three retrospective observational studies met the inclusion criteria. The identified prognostic factors for recurrence included: (1) Tumor size/diameter/volume, (2) cortical bone perforation/ soft tissue invasion, (3) multilocular radiolucency, (4) impacted tooth-involving lesions, (5) root resorption, (6) WHO classification - conventional (solid/multicystic) ameloblastoma, (7) histological subtype - mural invasion of unicystic ameloblastoma, (8) conservative treatment modalities - simple enucleation, curettage, and marsupialization, and (9) non-extraction/preservation of involved teeth. No strong evidence linked immunohistochemical expression to recurrence. Interestingly, BRAF p.V600E remained controversial in terms of recurrence, despite being a frequent finding in ameloblastoma.

CONCLUSION

Certain clinical characteristics, radiographic findings, histological subtypes, and treatment choices of ameloblastoma can help identify patients at high risk of recurrence. Further prospective studies to evaluate the prognostic factor model and research on immunohistochemistry are required.

Identification of Molecular Mechanisms of Ameloblastoma and Drug Repositioning by Integration of Bioinformatics Analysis and Molecular Docking Simulation

Background

Ameloblastoma (AM) is a benign tumor locally originated from odontogenic epithelium that is commonly found in the jaw. This tumor makes aggressive invasions and has a high recurrence rate. This study aimed to investigate the differentially expressed genes (DEGs), biological function alterations, disease targets, and existing drugs for AM using bioinformatics analysis.

Methods

The data set of AM was retrieved from the GEO database (GSE132474) and identified the DEGs using bioinformatics analysis. The biological alteration analysis was applied to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Protein-protein interaction (PPI) network analysis and hub gene identification were screened through NetworkAnalyst. The transcription factor-protein network was constructed via OmicsNet. We also identified candidate compounds from L1000CDS2 database. The target of AM and candidate compounds were verified using docking simulation.

Results

Totally, 611 DEGs were identified. The biological function enrichment analysis revealed glycosaminoglycan and GABA (γ-aminobutyric acid) signaling were most significantly up-regulated and down-regulated in AM, respectively. Subsequently, hub genes and transcription factors were screened via the network and showed FOS protein was found in both networks. Furthermore, we evaluated FOS protein to be a therapeutic target in AMs. Candidate compounds were screened and verified using docking simulation. Tanespimycin showed the greatest affinity binding value to bind FOS protein.

Conclusions

This study presented the underlying molecular mechanisms of disease pathogenesis, biological alteration, and important pathways of AMs and provided a candidate compound, Tanespimycin, targeting FOS protein for the treatment of AMs.

Localization of beta catenin across the domain of odontogenic lesions: A systematic review

BACKGROUND

CTNNB1 gene encodes beta catenin, a transcriptional activator of Wnt pathway involved in the pathogenesis of odontogenic lesions. Though located intramembranously, its translocation into cytoplasm and nucleus could trigger cell proliferation, inhibition of apoptosis, invasion and migration of the tumour cell.

MATERIALS AND METHODS

Five electronic databases including MEDLINE by PubMed, Google scholar, Scopus, Trip, Cochrane library and EMBASE until 1 January 2023 without period restriction were thoroughly searched. Those articles that identified CTNNB1 mutation and beta catenin in odontogenic lesions were included for review. Risk of bias was analysed for each study using QUADAS 2 tool and Review Manager 5.3 was used to output its result.

RESULTS

Thirty four published articles were included for data synthesis. A total of 1092 cases of odontogenic lesions were assessed for both CTNNB1 mutation and beta catenin expression. CTNNB1 mutation was observed in ameloblastoma, calcifying odontogenic cyst, calcifying cystic odontogenic tumour and all malignant odontogenic tumours. The beta catenin expression (nuclear and cytoplasmic) was maximum in odontogenic keratocyst and calcifying odontogenic cyst. The expression was variable in ameloblastomas, membranous in odontomas, calcifying cystic odontogenic tumour and nuclear in all malignant tumours.

DISCUSSION AND CONCLUSION

High recurrence of odontogenic keratocyst and aggressiveness of solid ameloblastoma and malignant odontogenic tumours could be associated with the nuclear translocation of beta catenin. Disparity between CTNNB1 mutation and beta catenin expression within odontogenic lesions suggests alternate routes of beta catenin activation. The review results support the unique localisation of beta catenin as a helpful diagnostic factor in the pathogenesis of odontogenic lesions.

A Comparative Evaluation of Collagen in Ameloblastoma and Oral Squamous Cell Carcinoma using Picrosirius Red Staining with Polarizing Microscopy and CD44v6 Immunoreactivity

Background

Solid multicystic ameloblastoma (SMA) is a locally aggressive, benign odontogenic tumor of odontogenic origin with greater rate of recurrence. Epithelial-mesenchymal interaction plays an important role in tooth morphogenesis that shows complete differentiation of epithelial and ectomesenchymal components to the level of tooth formation. Tumor stroma in ameloblastoma is normal mature collagen that prevents differentiation to the level of tooth formation. Current study evaluates the role of stromal elements in aggressive behavior of SMA using picrosirius red staining with polarizing microscopy and CD44v6 immunohistochemistry (IHC).

Objectives

To compare nature of collagen using picrosirius red staining under polarized microscope and IHC expression of CD44v6 marker in SMA and oral squamous cell carcinoma (OSCC).

Methods

Thirty blocks were retrieved from departmental archives and subjected to picrosirius red staining and CD44v6 IHC staining. Slides stained with picrosirius red were observed under polarized microscope to report the birefringence pattern. IHC slides were annotated for intensity of staining of tumor cells.

Results

In contrast to OSCC's 40% red, 40% yellowish-red, and 20% greenish-yellow birefringence, SMA displayed 87% red, 13% yellowish-red, and 0% greenish-yellow. Compared to OSCC, which had tumor cells stained 9% strongly, 64% moderately, 27% mildly, and 0% negatively, SMA revealed 0% strong, 10% moderate, 60% weak, and 30% negative staining.

Conclusion

As opposed to OSCC, which exhibited a greater quantity of greenish-yellow birefringence of immature collagen, SMA showed predominantly red birefringence, which is suggestive of mature collagen with a lack of metastasis. Comparing SMA to OSCC, the lack of significant CD44v6 positivity suggests that there has not been perineural invasion or regional metastases in SMA.

Thymol Isolated from Thymus vulgaris L. Inhibits Colorectal Cancer Cell Growth and Metastasis by Suppressing the Wnt/β-Catenin Pathway

Purpose

Colorectal cancer (CRC) is one of the most commonly occurring cancers and is associated with high morbidity and mortality. Nevertheless, there is currently no safe and effective treatment for this condition. Thymol is a phenolic compound that is recognized as safe for use in food as well as medical and cosmetic fields. Increasing evidence has indicated that thymol exerts prominent antitumor effects in a variety of cancers, including CRC. However, how thymol elicits these effects on CRC and the associated underlying mechanisms remains unclear.

Methods

HCT116 and Lovo cells were treated with different concentrations of thymol. Cell Counting Kit-8 (CCK-8) and transwell migration and invasion assays were used to evaluate cell proliferation, migration, and invasion, respectively. Cell apoptosis and cell cycle distribution were measured by flow cytometry. RT-qPCR, Western blot, and immunohistochemistry were used to detect the expression of related genes and their protein products.

Results

In this study, we tested the antitumor activity of thymol extracted from a Chinese medicinal herb, Thymus vulgaris L. We show that thymol treatment in vitro inhibited cell proliferation and induced apoptosis and cell cycle arrest in CRC. Furthermore, in vivo treatment with 75 and 150 mg/kg thymol led to a significant decrease in tumor volume. Thymol administration induced CRC cell apoptosis through activation of the BAX/Bcl-2 signaling pathway. In addition, thymol suppressed CRC cell epithelial–mesenchymal transition (EMT), invasion, and metastasis via inhibiting the activation of the Wnt/β-catenin pathway, both in vitro and in vivo.

Conclusion

Thymol may prevent CRC progression through inhibition of the Wnt/β-catenin signaling pathway, highlighting its potential as a novel therapeutic option for the treatment of CRC.

Expression of CD34, VEGFR3 and eosinophil density in selected odontogenic tumors- a pilot study

Background

Limited statistically and clinically significant studies have been down on connective tissue factors in the odontogenic tumors. Therefore, the aim of this study was to determine the biological behavior of two selected epithelial odontogenic tumors (Ameloblastoma and Adenomatoid odontogenic tumor) by detecting CD34, VEGFR3 and eosinophil densities.

Methods

In this cross-sectional study, paraffin blocks including 20 cases of ameloblastoma and 20 (AOT), were selected. Totally, 4 sections were prepared for hematoxylin-eosin, Congo red staining, immunohistochemistry with CD34 and VEGFR3. Expression of VEGFR3, CD34 and lymphatic, blood vessels and eosinophil densities was examined.

Results

The mean of blood, lymphatic vessels and eosinophils densities in ameloblastoma were 14.9 ± 6.4, 4.4 ± 2 and 3.2 ± 2.7, respectively; and in AOT, they were 8.9 ± 3.4, 3.6 ± 1.3 and 1.2 ± 07, respectively. There was a significant difference in eosinophils and blood vessels densities between the two lesions (p = 0.005; p = 0.003). By increasing the density of eosinophils, the density of the blood vessels increased in both lesions (r = 0.539, P = 0.001) There was no positive relationship between eosinophils and lymphatic vessels densities in the two above mentioned odontogenic lesions (p = 0.288, R = 0.191).

Conclusion

It can be suggested that tumor angiogenesis and eosinophil densities may play a more effective role than lymphangiogenesis in local invasive behavior of ameloblastoma rather than AOT.

LDLRAD2 overexpression predicts poor prognosis and promotes metastasis by activating Wnt/β-catenin/EMT signaling cascade in gastric cancer

The therapeutic strategies for advanced gastric cancer (GC) remain unsatisfying and limited. Therefore, it is still imperative to fully elucidate the mechanisms underlying GC aggressive progression. The prognostic value and biological functions of low density lipoprotein receptor class A domain containing protein 2 (LDLRAD2) in GC have never been studied yet. We found that LDLRAD2 expression was significantly upregulated in GC and closely correlated with poor prognosis in GC patients. Functionally, LDLRAD2 promoted epithelial-mesenchymal transition, migration and invasion, and metastasis of GC cells. Mechanistically, LDLRAD2 interacted with and inhibited Axin1 from binding to cytoplasmic β-catenin, which facilitated the nuclear translocation of β-catenin, thereby activating Wnt/β-catenin pathway. Inhibition of β-catenin activity markedly abolished LDLRAD2-induced migration, invasion and metastasis. Together, these results suggested that LDLRAD2 contributed to invasion and metastasis of GC through activating Wnt/β-catenin pathway. LDLRAD2/ Wnt/β-catenin axis may be a potential therapeutic target for GC treatment.

The stem cell markers expression CD44v6 and podoplanin in lip cancer: clinical significance

This study aimed to analyze the immunoexpression of cancer stem cell markers, CD44v6, and podoplanin in 91 patients with lip squamous cell carcinomas (LSCC). The immunostaining of podoplanin and CD44v6 was evaluated in ten high-power fields (× 400 magnification) at the invasive front of LSCC, using a semi-quantitative score method. Chi-square test or Fisher's exact test was used to verify the association of podoplanin and CD44v6 expressions with clinicopathologic variables. Spearman's correlation test was used to analyze the correlation between the two antibodies in lip cancer. Disease-free survival probabilities in 5 and 10 years were estimated according to the Kaplan-Meier method and compared using the log-rank test. The independent effects of the significant variables were analyzed by Cox proportional hazards regression model. A strong podoplanin expression was observed in the membrane and cytoplasm of most lip tumor cells, and this was inversely associated with locoregional recurrence (p = 0.028) and with histopathological grade of malignancy (p = 0.026). Additionally, CD44v6 immunostaining was strongly expressed in the membrane of tumor cells in 95.4% of the LSCC. Patients with strong membranous (p = 0.016) or strong cytoplasmic (p = 0.030) podoplanin-positive tumors resulted in significantly better disease-free survival than those who had podoplanin weak/negative tumors, confirming podoplanin expression as a favorable independent prognostic factor. Podoplanin and CD44v6 were strongly expressed by tumor cells and podoplanin immunoexpression can help to determine lip cancer patients with lower risk for disease recurrence.

Regulation of Wnt/β-catenin pathway may be related to Regγ in benign epithelial odontogenic lesions

OBJECTIVES

The aim of this study was to analyze and compare the immunoexpressions of Regγ, Wnt-1, and β-catenin in ameloblastomas, adenomatoid odontogenic tumors (AOTs), and odontogenic keratocysts (OKCs).

STUDY DESIGN

Thirty solid ameloblastomas, 20 AOTs, and 30 OKCs were selected for analysis of the immunoexpression of Regγ, Wnt-1, and β-catenin. Each case was semiquantitatively evaluated in the epithelial component and in their different cellular compartments (membrane, cytoplasm, and nucleus).

RESULTS

Ameloblastomas displayed higher cytoplasmic and nuclear Regγ expression compared with AOTs and OKCs, as well as higher membrane and cytoplasmic Wnt-1 expression (P < .05). β-catenin membrane expression was higher in OKCs compared with ameloblastomas and AOTs (P < .05). Nuclear β-catenin expression was higher in ameloblastomas and AOTs than in OKCs (P < .05). Cytoplasmic and nuclear Regγ expression in AOTs were positively correlated with nuclear β-catenin expression (P < .05).

CONCLUSIONS

The marked expressions of Regγ, Wnt-1, and β-catenin suggest the participation of these proteins in the pathogenesis of the studied lesions. The greater expressions of Regγ, Wnt-1, and nuclear β-catenin in ameloblastomas may be related to their more aggressive behavior. Pro-tumor effects of nuclear β-catenin may be counterbalanced by inhibitory pathways in AOTs, justifying their low aggressiveness.

Is podoplanin expression associated with transforming growth factor-β signaling in odontogenic cysts and tumors?

BACKGROUND

Induction of podoplanin by transforming growth factor-β (TGF-β) has been shown in a number of lesions but not in odontogenic tumors (OTs). We evaluated the association between these markers in OTs for the first time and compared their expression among the different neoplasms.

METHODS

Immunohistochemistry using monoclonal antibody against podoplanin and TGF-β was performed on 76 odontogenic cysts and tumors. Spearman's correlation coefficient, Kruskal-Wallis, and Mann-Whitney U tests followed by adjustment with Bonferroni were used for statistical analysis (P < .05).

RESULTS

A significant difference in podoplanin expression was found among the lesions consisting of solid ameloblastomas, adenomatoid odontogenic tumors, ameloblastic fibromas, odontogenic myxomas (OMs), odontogenic keratocysts, and calcifying odontogenic cysts. Significant differences were observed only between OMs and each of the other neoplasms. Podoplanin immunostaining in the connective tissue was absent in most lesions. TGF-β was significantly different among the study sample but not between the lesions in paired comparisons. None of the studied OTs showed significant correlations between podoplanin-TGF-β, in either the epithelium or the stroma. These markers were also descriptively reported in calcifying epithelial odontogenic tumors.

CONCLUSIONS

The inductive effect of TGF-β on podoplanin seems to be limited, if any, in odontogenic lesions. Podoplanin appears to play a role in some aspects of OTs with epithelial or mixed origins. Despite the possible participation of podoplanin in tumorigenesis, it may not necessarily be involved in the aggressive behavior of OTs.

Proteoglycans as potential biomarkers in odontogenic tumors

Proteoglycans (PGs) are essential for normal cellular development; however, alterations of their concentrations can promote tumor growth. To date, a limited number of studies report the presence of PGs in odontogenic tumors (OTs); therefore, the main purpose of this work is to gather the information published on the study of PGs. The search reported 26 articles referring to the presence of different PGs in distinct OTs from 1999 to May 2017. PGs seem to play an important role during OTs' development as they are involved in several tumor processes; however, the number of reports on the study of these molecules is low. Thus, more studies are necessary in order to gain a better understanding of the underlying pathophysiology of OTs.

Ameloblastoma: current etiopathological concepts and management

Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen-activated protein kinase, sonic hedgehog, and WNT/β-catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for locoregional invasion; but this is often associated with significant patient morbidity. The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiological factors, the management approach, and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.

Maxillary calcifying epithelial odontogenic tumor with sinus and buccal vestibule extension: a case report and immunohistochemical study

Background

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign neoplasia, locally aggressive, that tends to invade bone and adjacent soft tissues. This case report describes the thirteenth known case of CEOT with maxillary sinus extension and the second one that also involves the buccal vestibule mucosa with peculiar histopathological and immunohistochemical data.

Case presentation

Here we report the case of a 45-year-old female with a CEOT diagnosed and treated at the Oral & Maxillofacial Surgery Department, County Clinical Emergency Hospital of Craiova, Romania. The clinical and imaging investigation revealed an intraosseous tumor developed from the left posterior maxilla with maxillary sinus and buccal vestibule mucosa extension. Histopathology found an epithelium-rich CEOT variant, but with scattered S100 positive clear cells, focal small rounded cementum-like deposits and areas with some degree of nuclear pleomorphism. The immunohistochemical investigations emphasised its local aggressiveness behavior with involvement of multiple molecular mechanisms that underlie tumor invasiveness. A subtotal maxillectomy was performed followed by defect reconstruction.

Conclusions

We discuss the relevant clinicopathological features of an aggressive rare case of CEOT with maxillary sinus extension and buccal vestibule mucosa involvement. The immunohistochemical study suggests its utility in attempting to assess the degree of local tumor aggressiveness and thus in adopting the most efficient therapeutic attitude.

Molecular Signaling in Benign Odontogenic Neoplasia Pathogenesis

Several molecular pathways have been shown to play critical roles in the pathogenesis of odontogenic tumors. These neoplasms arise from the epithelial or mesenchymal cells of the dental apparatus in the jaw or oral mucosa. Next generation genomic sequencing has identified gene mutations or single nucleotide polymorphisms associated with many of these tumors. In this review, we focus on two of the most common odontogenic tumor subtypes: ameloblastoma and keratocystic odontogenic tumors. We highlight gene expression and protein immunohistological findings and known genetic alterations in the hedgehog, BRAF/Ras/MAPK, epidermal growth factor receptor, Wnt and Akt signaling pathways relevant to these tumors. These various pathways are explored to potentially target odontogenic tumors cells and prevent growth and recurrence of disease. Through an understanding of these signaling pathways and their crosstalk, molecular diagnostics may emerge as well as the ability to exploit identified molecular differences to develop novel molecular therapeutics for the treatment of odontogenic tumors.

Are podoplanin and ezrin involved in the invasion process of the ameloblastomas?

The association between podoplanin and ezrin in the process of odontogenic tumors invasion has been suggested, but was not studied yet. Our purpose was to investigate the relationship between podoplanin and ezrin expressions in the odontogenic epithelium of ameloblastomas. Forty-seven ameloblastomas were analyzed by immunohistochemistry using anti-podoplanin and anti-ezrin antibodies. The expressions of both proteins were evaluated using a score method and the comparison and association between these proteins were verified, respectively, by Wilcoxon Signed-Rank test and by Spearman’s rank correlation coefficient, using a statistical significance level of 0.05. The majority of tumors (87.2%) exhibited strong membranous expression of podoplanin in the peripheral cells. Cytoplasmic expression of ezrin in the peripheral cells of ameloblastomas was stronger than its membranous expression. No statistically significant correlation was observed between podoplanin and ezrin. However, there was statistically significant difference between membranous podoplanin and membranous ezrin expressions, between cytoplasmic podoplanin and membranous ezrin expressions, and between cytoplasmic podoplanin and cytoplasmic ezrin expressions. There was no statistical difference between membranous podoplanin and cytoplasmic ezrin expressions. These results suggest a synergistic role of both proteins in the process of invasion of ameloblastomas.