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Cancer Medicine Apr 2020Ameloblastoma is a rare odontogenic benign tumor accounting for less than 1% of head and neck tumors. Advanced next generation sequencing (NGS) analyses identified high...
Ameloblastoma is a rare odontogenic benign tumor accounting for less than 1% of head and neck tumors. Advanced next generation sequencing (NGS) analyses identified high frequency of BRAF V600E and SMO L412F mutations in ameloblastoma. Despite the existence of whole genomic sequence information from patients with ameloblastoma, entire molecular signature of and the characteristics of ameloblastoma cells are still obscure. In this study, we sought to uncover the molecular basis of ameloblastoma and to determine the cellular phenotype of ameloblastoma cells with BRAF mutations. Our comparative cDNA microarray analysis and gene set enrichment analysis (GSEA) showed that ameloblastoma exhibited a distinct gene expression pattern from the normal tissues: KRAS-responsive gene set is significantly activated in ameloblastoma. Importantly, insulin like growth factor 2 (IGF2), a member of KRAS-responsive genes, enhances the proliferation of an ameloblastoma cell line AMU-AM1 with BRAF mutation. In addition, Toll-like receptor 2 (TLR2) knockdown readily inactivated KRAS-responsive gene sets as well as increases caspase activities, suggesting that TLR2 signaling may mediate cell survival signaling in ameloblastoma cells. Collectively, the findings may help to further clarify the pathophysiology of ameloblastoma and lead to the development of precision medicine for patients with ameloblastoma.
Topics: Adult; Aged; Ameloblastoma; Biomarkers, Tumor; Cell Proliferation; Child; Female; Follow-Up Studies; Gene Expression Regulation, Neoplastic; Humans; Jaw Neoplasms; Male; Middle Aged; Mutation; NF-kappa B; Prognosis; Toll-Like Receptor 2; Transcriptome; Tumor Cells, Cultured
PubMed: 32096304
DOI: 10.1002/cam4.2931 -
International Journal of Molecular... Apr 2019Histopathological findings of oral neoplasm cell differentiation and metaplasia suggest that tumor cells induce their own dedifferentiation and re-differentiation and... (Review)
Review
Histopathological findings of oral neoplasm cell differentiation and metaplasia suggest that tumor cells induce their own dedifferentiation and re-differentiation and may lead to the formation of tumor-specific histological features. Notch signaling is involved in the maintenance of tissue stem cell nature and regulation of differentiation and is responsible for the cytological regulation of cell fate, morphogenesis, and/or development. In our previous study, immunohistochemistry was used to examine Notch expression using cases of odontogenic tumors and pleomorphic adenoma as oral neoplasms. According to our results, Notch signaling was specifically associated with tumor cell differentiation and metaplastic cells of developmental tissues. Notch signaling was involved in the differentiation of the ductal epithelial cells of salivary gland tumors and ameloblast-like cells of odontogenic tumors. However, Notch signaling was also involved in squamous metaplasia, irrespective of the type of developmental tissue. In odontogenic tumors, Notch signaling was involved in epithelial-mesenchymal interactions and may be related to tumor development and tumorigenesis. This signaling may also be associated with the malignant transformation of ameloblastomas. Overall, Notch signaling appears to play a major role in the formation of the characteristic cellular composition and histological features of oral neoplasms, and this involvement has been reviewed here.
Topics: Adenoma, Pleomorphic; Ameloblastoma; Animals; Cell Differentiation; Cell Transformation, Neoplastic; Humans; Mouth Neoplasms; Myxoma; Odontogenic Tumors; Receptors, Notch; Signal Transduction
PubMed: 31018488
DOI: 10.3390/ijms20081973 -
Ear, Nose, & Throat Journal Dec 2021Ameloblastoma (AM) is a slow growing and aggressive benign tumor with an odontogenic epithelial origin arising from the mandible or maxilla. The odontogenic neoplasm...
Ameloblastoma (AM) is a slow growing and aggressive benign tumor with an odontogenic epithelial origin arising from the mandible or maxilla. The odontogenic neoplasm invades local tissues asymptomatically and accounts for 1% of oral tumors and over 10% of odontogenic tumors. A 64-year-old man with a history of allergic fungal rhinosinusitis (AFRS) undergoing a revision image-guided endoscopic sinus surgery was found to have a fibrous mass suspicious of malignancy projecting inferolaterally and attached to the floor of the left maxillary sinus. Diagnostic biopsies were taken, and additional surgery was required to successfully resect the tumor via a transnasal endoscopic dissection. Multiple permanent pathology samples concluded the diagnosis of an AM. Endoscopic investigations led to the incidental discovery and ultimate complete endoscopic resection of the AM. The utilization of an endoscopic resection compared to the traditional maxillectomy with reconstruction results in significant less short and long-term morbidity for the patient.
Topics: Ameloblastoma; Humans; Male; Maxillary Sinus; Maxillary Sinus Neoplasms; Medical Illustration; Middle Aged; Natural Orifice Endoscopic Surgery; Nose
PubMed: 32484411
DOI: 10.1177/0145561320930555 -
Canadian Medical Association Journal Dec 1950
Topics: Adamantinoma; Ameloblastoma; Jaw; Neoplasms
PubMed: 14792442
DOI: No ID Found -
CA: a Cancer Journal For Clinicians 1968
Topics: Ameloblastoma; Humans; Mandibular Neoplasms; Radiography
PubMed: 4992869
DOI: 10.3322/canjclin.18.4.205 -
Analytical Cellular Pathology... 2018Ameloblastomas are a group of benign, locally aggressive, recurrent tumors characterized by their slow and infiltrative growth. E-Cadherin and syndecan-1 are cell...
Ameloblastomas are a group of benign, locally aggressive, recurrent tumors characterized by their slow and infiltrative growth. E-Cadherin and syndecan-1 are cell adhesion molecules related to the behavior of various tumors, including ameloblastomas. Ninety-nine ameloblastoma samples were studied; the expression of E-cadherin and syndecan-1 were evaluated by immunohistochemistry. E-Cadherin and epithelial syndecan-1 were more highly expressed in intraluminal/luminal unicystic ameloblastoma than in mural unicystic ameloblastoma and solid/multicystic ameloblastoma, whereas the stromal expression of syndecan-1 was higher in mural unicystic ameloblastoma and solid/multicystic ameloblastoma. Synchronicity was observed between E-cadherin and epithelial syndecan-1; the expression was correlated with intensity in all cases. There was a strong association between expression and tumor size and recurrence. The evaluation of the expression of E-cadherin and syndecan-1 are important for determining the potential aggressiveness of ameloblastoma variants. Future studies are required to understand how the expression of these markers is related to tumor aggressiveness.
Topics: Adult; Ameloblastoma; Cadherins; Female; Humans; Male; Middle Aged; Syndecan-1
PubMed: 29850393
DOI: 10.1155/2018/9392632 -
PloS One 2015Ameloblastoma is the second most common odontogenic tumor, known to be slow-growing, persistent, and locally aggressive. Recent data suggests that ameloblastoma is best... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Ameloblastoma is the second most common odontogenic tumor, known to be slow-growing, persistent, and locally aggressive. Recent data suggests that ameloblastoma is best treated with wide resection and adequate margins. Following primary excision, bony reconstruction is often necessary for a functional and aesthetically satisfactory outcome, making early diagnosis paramount. Despite earlier diagnosis potentially limiting the extent of resection and reconstruction, an understanding of the growth rate and natural history of ameloblastoma has been notably lacking from the literature.
METHOD
A systematic review of the literature was conducted by reviewing relevant articles from PubMed and Web of Science databases. Each article's level of evidence was formally appraised according to the Centre of Evidence Based Medicine (CEBM), with data from each utilized in a meta-analysis of growth rates for ameloblastoma.
RESULTS
Literature regarding the natural history of ameloblastoma is limited since the tumor is immediately acted upon at its initial detection, unless the patient voluntarily refuses a surgical intervention. From the limited data, it is derived that the highest estimated growth rate is associated with solid, multicystic type and the lowest rate with peripheral ameloblastomas. After meta-analysis, the calculated mean specific grow rate is 87.84% per year.
CONCLUSION
The growth rate of ameloblastoma has been demonstrated, offering prognostic and management information, particularly in cases where a delay in management is envisaged.
Topics: Adult; Aged; Ameloblastoma; Female; Humans; Jaw Neoplasms; Male; Middle Aged; Young Adult
PubMed: 25706407
DOI: 10.1371/journal.pone.0117241 -
Head and Neck Pathology Jun 2023The World Health Organization's (WHO) chapter on odontogenic and maxillofacial bone tumors provides a global reference for diagnosis of these tumors. In the fifth... (Review)
Review
Proceedings of the 2023 North American Society of Head and Neck Pathology Companion Meeting, New Orleans, LA, March 12, 2023: Odontogenic Tumors: Have We Achieved an Evidence-Based Classification.
BACKGROUND
The World Health Organization's (WHO) chapter on odontogenic and maxillofacial bone tumors provides a global reference for diagnosis of these tumors. In the fifth edition, the inclusion of consensus definitions and development of essential and desirable diagnostic criteria help improve recognition of distinct entities. These are key enhancements since the diagnosis of odontogenic tumors is largely based on histomorphology which is taken in combination with clinical and radiographic appearances.
METHODS
Review.
RESULTS
Despite delineation of diagnostic criteria for ameloblastoma, adenoid ameloblastoma, and dentinogenic ghost cell tumor, a subset of these tumors continues to show overlapping histological features that can potentially lead to misdiagnosis. Accurate classification may be challenging on small biopsies, but potentially enhanced by refining existing diagnostic criteria and utilization of immunohistochemistry and/or molecular techniques in a specific cases. It has become clear that the clinical and histologic features of the non-calcifying Langerhans cell-rich subtype of calcifying epithelial odontogenic tumor and the amyloid-rich variant of odontogenic fibroma converge into a single tumor description. In addition, this tumor shows remarkable clinical, histological overlap with a subset of sclerosing odontogenic carcinoma located in the maxilla. Benign perineural involvement vs perineural invasion is an underexplored concept in odontogenic neoplasia and warrants clarification to reduce diagnostic confusion with sclerosing odontogenic carcinoma.
CONCLUSION
While controversial issues surrounding classification and discrete tumor entities are addressed in the WHO chapter, ambiguities inevitably remain. This review will examine several groups of odontogenic tumors to highlight persistent knowledge gaps, unmet needs and unresolved controversies.
Topics: Humans; Ameloblastoma; New Orleans; Odontogenic Tumors; Mouth Neoplasms; Carcinoma
PubMed: 37278887
DOI: 10.1007/s12105-023-01561-x -
Journal of Cancer Research and... 2020Altered molecular signaling pathways in ameloblastoma have been identified to play a pivotal role in the mechanism of oncogenesis, differentiation, and tumor...
BACKGROUND
Altered molecular signaling pathways in ameloblastoma have been identified to play a pivotal role in the mechanism of oncogenesis, differentiation, and tumor progression. Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin pathway is one of the signaling pathways that are associated with the pathogenesis of ameloblastoma. Phosphatase and tensin homolog (PTEN) controls cell migration and proliferation. It monitors the level of the Akt and maintains cellular integrity. The present study was aimed to study the immunoexpression of PTEN in ameloblastoma to understand its role in the pathogenesis of ameloblastoma.
MATERIALS AND METHODS
Twenty cases of ameloblastoma and ten cases of normal tooth germ were subjected to immunohistochemical staining against PTEN.
RESULTS
Strong PTEN immunopositivity was seen in the tooth germs, while weak positivity was seen in the ameloblastoma. The immunoscore for PTEN was calculated by adding the percentage score and the intensity score. Seventeen cases showed the reduced PTEN expression in the epithelial component of ameloblastoma. The unpaired t-test showed a statistically significant difference in the mean PTEN immunoscore in tooth germ and ameloblastoma.
CONCLUSION
The study showed reduced PTEN immunoreactivity, which plays a role in the pathogenesis of ameloblastoma, through Akt pathway.
Topics: Adolescent; Adult; Aged; Ameloblastoma; Biomarkers, Tumor; Case-Control Studies; Cell Differentiation; Female; Humans; Immunohistochemistry; Infant; Jaw Neoplasms; Male; Middle Aged; PTEN Phosphohydrolase; Proto-Oncogene Proteins c-akt; Signal Transduction; Young Adult
PubMed: 32719259
DOI: 10.4103/jcrt.JCRT_528_18 -
The British Journal of Oral &... Jan 2021Ameloblastoma is the most common benign, but locally destructive, epithelial odontogenic tumour. Peripheral ameloblastoma may involve soft tissues without invasion or... (Review)
Review
Ameloblastoma is the most common benign, but locally destructive, epithelial odontogenic tumour. Peripheral ameloblastoma may involve soft tissues without invasion or involvement of bone. The aim of this structured review was to evaluate the literature and guide clinical management. Three online databases were searched for relevant studies: Medline, EMBASE, and Ovid Evidence-Based Medicine, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. A total of 520 papers were initially identified, and after exclusions were applied, 45 were included. Conservative surgical excision was the treatment of choice. There was no consensus in relation to the extent of the surgical margins required. The management of peripheral ameloblastoma appears to favour conservative excision with narrow margins of normal tissue. Follow up of at least 10 years is recommended to monitor for recurrence.
Topics: Ameloblastoma; Bone and Bones; Humans; Margins of Excision; Neoplasm Recurrence, Local; Odontogenic Tumors
PubMed: 33162201
DOI: 10.1016/j.bjoms.2020.08.084