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Background: Although immunohistochemistry (IHC) along with molecular tests has been investigated in ameloblastoma for BRAF V600E detection, VE1 IHC has not been studied in odontogenic carcinomas (OCs) and benign mixed epithelial and mesenchymal odontogenic tumours (BMOTs). Here, we performed BRAF V600E mutation analysis, examined the expression pattern of VE1 IHC, and comparatively evaluated the performance of two VE1 antibodies in ameloblastomas, OCs and BMOTs., Methods: BRAF V600E detection was performed using Sanger sequencing in a total of 47 odontogenic tumours: 28 ameloblastomas, 6 OCs and 13 BMOTs. VE1 IHC was conducted using two different antibodies (IHC-A and IHC-V), and their performance was analysed by calculating the sensitivity and specificity compared with sequencing., Results: BRAF V600E mutations were identified in 24/28 (85.7%) ameloblastomas, 2/5 (40.0%) ameloblastic carcinomas (ACs), 3/7 (42.9%) ameloblastic fibromas and 1/2 (50.0%) ameloblastic fibro-odontomas. In the presence of the mutation, VE1 showed diffuse cytoplasmic staining in ameloblastomas and ACs, whereas all BMOTs were negative for VE1. IHC-A and IHC-V yielded a sensitivity of 76.7% and 60.0%, respectively, although both antibodies showed 100% specificity., Conclusion: OCs and BMOTs have BRAF V600E mutations in common at lower frequencies than ameloblastoma. Diffuse VE1 cytoplasmic staining in AC suggests the utility of MAPK-targeted therapy as selectively applied in ameloblastoma, and consistent VE1 false-negative expression in BMOTs requires further investigation. Considering the high specificity but low sensitivity of VE1 IHC, molecular tests should be performed to determine the presence of BRAF V600E mutations in odontogenic tumours., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: SOX7, a member of the SOX family of transcription factors, acts as a tumor suppressor in multiple cancers. Downregulation of SOX7 has been reported in advanced tumors and correlates with poor prognosis. The aims of this study were to investigate the effects of SOX7 on cell proliferation, invasion, and colony formation in oral squamous cell carcinoma (OSCC) cells and to evaluate the effectiveness of SOX7 protein as a prognostic indicator for OSCC patients.Methods: oral squamous cell carcinoma (OSCC) cell lines were treated with SOX7 small interfering RNA or SOX7 peptide, and their effects on cell proliferation, invasiveness, and colony formation were investigated by proliferation, in vitro invasion, and clonogenic assays. SOX7 protein expression in OSCC and normal oral mucosal tissues was examined by immunohistochemistry. Associations between SOX7 protein expression and clinicopathological parameters of OSCC patients were statistically analyzed.Results: SOX7 silencing-induced cell proliferation and invasion in SCC-4 cells. SOX7 peptide treatment inhibited cell proliferation, colony formation, and invasion in SCC-9 and SCC-25 cells. Expression of SOX7 protein was decreased in OSCC tissues compared with normal oral mucosal tissues (P<.001). Negative SOX7 expression in patients with OSCC was significantly associated with positive lymph node metastasis (P=.041), advanced TNM stage (P=.024), and poor prognosis (P=.017).Conclusions: These results suggest that SOX7 inhibits cell proliferation, colony formation, and invasion in OSCC as a tumor suppressor and that negative SOX7 expression could be a poor prognostic indicator for patients with OSCC. [ABSTRACT FROM AUTHOR]

Background: The aims of this study were to evaluate expression of Twist and Snail in tumor and stromal cells of epithelial odontogenic tumors and to analyze relationships between Twist and Snail expression and between tumor and stromal expression.Methods: Immunohistochemistry was performed using Twist and Snail antibodies in 60 ameloblastomas (AMs; 20 solid/multicystic, 20 unicystic, and 20 recurrent), six ameloblastic carcinomas (ACs), 10 adenomatoid odontogenic tumors (AOTs), and six calcifying epithelial odontogenic tumors (CEOTs).Results: A higher rate of tumor cells strongly positive for Twist was observed in AC compared to the other tumors (P = 0.019). The rate of tumor cells strongly positive for Snail tended to be higher in AC than in AM (P = 0.060). AM and AC showed a higher rate of Twist-positive stromal cells than AOT and CEOT (P < 0.001). Tumor cells of recurrent AM showed stronger expression of Twist (P < 0.001) and Snail (P = 0.001) compared to AM without recurrence. A moderate positive correlation was observed between tumor expression of Twist and Snail (r = 0.376, P = 0.001) and between tumor and stromal expression of Snail (r = 0.334, P = 0.002).Conclusions: Twist and Snail may affect the epithelial-mesenchymal transition in AC and be involved in recurrence of AM. Stromal Twist expression may be associated with aggressive clinical behavior of epithelial odontogenic tumors. A Twist-Snail pathway may participate in the development and progression of odontogenic tumors, and tumor-stroma interaction in odontogenic tumors may be mediated by Snail. [ABSTRACT FROM AUTHOR]

Background Granular cell tumor (GCT) is a benign soft tissue tumor of neural origin and is characterized by eosinophilic granular cells showing positivity for neuronal markers. Herein, we report the first case of primary intraosseous GCT arising in the maxilla of an adolescent girl. Methods and Results A 16-year-old female patient presented with palatal swelling. Radiographic findings revealed a well-defined radiolucent lesion centrally located in the right maxilla. Mass excision was performed, and histopathologic examination showed sheets and cords of eosinophilic granular cells with cellular pleomorphism. Tumor cells were strongly positive for vimentin, S-100 protein, and CD56, and negative for cytokeratin, desmin, smooth muscle actin, and c-kit. High expression of p53 and Ki-67 was found. The final diagnosis was atypical GCT. Conclusion When evaluating an intraosseous radiolucent lesion with histopathologic features of granular cells, clinicians and pathologists should include GCT in the differential diagnosis. © 2016 Wiley Periodicals, Inc. Head Neck 38:E2467-E2470, 2016 [ABSTRACT FROM AUTHOR]

Objective: Chondrosarcoma is the second most common sarcoma arising in the bone, but it rarely involves the temporomandibular joint (TMJ). To date, 30 cases of TMJ chondrosarcoma have been reported in the English literature, and the authors report an additional case arising from a cystic lesion in a 60-year-old female patient.Clinical Presentation: The clinical and radiological diagnosis of the lesion was initially synovial cyst, and periodic check-ups were done after aspiration of the lesion. After three years, the patient perceived swelling of the lesion, and surgical excision was performed. The final diagnosis was grade I chondrosarcoma.Conclusion: When clinicians detect a cystic lesion in the radiographic imaging of the TMJ, chondrosarcoma should be included in the differential diagnosis. In addition, computed tomography (CT) as well as magnetic resonance imaging (MRI) is recommended for the accurate diagnosis and proper preoperative planning in TMJ chondrosarcoma. [ABSTRACT FROM AUTHOR]

Background: Ameloblastoma is a benign, but locally invasive tumor known for its high rate of recurrence. However, few comprehensive genetic studies have been conducted about its tumorigenesis. Our aim was to identify possible genes involved in the development and progression of ameloblastoma, using microarray analysis with dentigerous cyst as a control. Methods: Total RNA was extracted from two fresh dentigerous cysts and ameloblastoma specimens. Following microarray analysis, semiquantitative reverse transcription–polymerase chain reaction (RT–PCR) and immunohistochemistry were performed on selected genes. Results: Seventy-three genes were overexpressed and 49 were underexpressed. These genes were divided into categories according to function. The microarray results for 13 selected genes were verified with semiquantitative RT–PCR. Conclusions: We identified important genes related to the development and progression of ameloblastoma through a large-scale gene expression analysis. This study will stimulate further investigations on genes significant for early diagnosis and prognosis of ameloblastoma. [ABSTRACT FROM AUTHOR]

Summary: Tumor-infiltrating lymphocytes (TILs) are considered to represent immune reactions of the host to a malignant tumor. Programmed death receptor ligand-1 (PD-L1) is a surface protein that blocks the function of T lymphocytes and is expressed on cancer cells. Tumor-associated fibroblasts (TAFs), which influence tumor growth have also been reported to express PD-L1 and thus inhibit TILs. In the present study, we investigated the densities of CD4+/CD8+ TILs, PD-L1 expression of tumor cells and TAFs in oral squamous cell carcinoma (OSCC). Forty-five cases of OSCC were selected. We evaluated PD-L1 expression and the infiltration degree of each lymphocyte by immunohistochemical examination. These data were analyzed in connection with clinicopathological factors. Peritumoral CD8+ TILs were observed in every patient with OSCC, and their densities were correlated with lymph node metastasis (P <0.001), tumor size (P =0.003), and clinical stage (P <0.001). PD-L1 expression on OSCC cells was observed in 39 cases and was associated with the lower density of intratumoral CD8+ TILs (P =0.047). PD-L1 expression of tumors <4cm in size was correlated with the histological grade of the tumor (P =0.022). TAFs were positive for PD-L1 in 18 cases. Peritumoral TILs were significantly associated with tumor size, lymph node metastasis and clinical stage. Though PD-L1 expressed by OSCC cells did not affect patients’ survival, its correlation with decreased number of intratumoral TILs suggests that the development of a strategy to block the interactions of PD-L1 with TIL would be a useful tool for inhibiting tumor growth. [Copyright &y& Elsevier]

Summary: Oral squamous cell carcinoma (OSCC), the most common malignancy of the oral cavity, remains a lethal disease in over 50% of cases diagnosed annually, due mostly to late detection of this cancer in its advanced stages despite the easy accessibility of the oral cavity for regular examinations. Cripto-1 is a member of the epidermal growth factor (EGF)–CFC protein family and is involved in the activation of several different signaling pathways during embryonic development and cellular transformation. Although the Cripto-1 protein is overexpressed in several human cancers including breast, colon, cervix, gastric, and pancreatic cancer, no prior study has evaluated Cripto-1 expression in OSCC. Therefore, our aims in this study were to examine Cripto-1 expression in clinical samples of OSCC patients using immunohistochemistry, to analyze the correlation between Cripto-1 expression and clinicopathologic parameters, and to identify the oncogenic roles of Cripto-1 in OSCC cell lines. Both epithelial dysplasia (73.3%) and OSCC (55.5%) tissue samples showed significantly higher expression of Cripto-1 than normal mucosa (20%) (p =0.031). In the OSCC samples, there was a significant correlation between Cripto-1 expression and the histological differentiation of OSCC (p =0.015) and a high PCNA index (p =0.011). The in vitro cell proliferation assays demonstrated that recombinant human Cripto-1 (rhCripto-1) induced both SCC-4 and SCC-25 cells to proliferate as compared with control cells (p <0.05 and p <0.01, respectively). In in vitro migration assays, treatment of SCC-4 and SCC-25 cells with rhCripto-1 protein induced a 2.4-fold and 1.7-fold-increase in cell migration, respectively (p =0.000 and p =0.008, respectively). Taken together, our data suggest that Cripto-1 plays a role in the malignant transformation of the oral mucosa and is involved in the tumorigenesis and progression of OSCC by promoting the growth and migration of malignant cells. [Copyright &y& Elsevier]