Areca nut exposure increases secretion of tumor-promoting cytokines in gingival fibroblasts that trigger DNA damage in oral keratinocytes.

Molecular crosstalk between cancer cells and fibroblasts has been an emerging hot issue in understanding carcinogenesis. As oral submucous fibrosis (OSF) is an inflammatory fibrotic disease that can potentially transform into squamous cell carcinoma, OSF has been considered to be an appropriate model for studying the role of fibroblasts during early stage carcinogenesis. In this sense, this study aims at investigating whether areca nut (AN)-exposed fibroblasts cause DNA damage of epithelial cells. For this study, immortalized hNOF (hTERT-hNOF) was used. We found that the levels of GRO-α, IL-6 and IL-8 increased in AN-exposed fibroblasts. Cytokine secretion was reduced by antioxidants in AN-exposed fibroblasts. Increase in DNA double strand breaks (DSB) and 8-oxoG FITC-conjugate was observed in immortalized human oral keratinocytes (IHOK) after the treatment of cytokines or a conditioned medium derived from AN-exposed fibroblasts. Cytokine expression and DNA damage were also detected in OSF tissues. The DNA damage was reduced by neutralizing cytokines or antioxidant treatment. Generation of reactive oxygen species (ROS) and DNA damage response, triggered by cytokines, were abolished when NADPH oxidase (NOX) 1 and 4 were silenced in IHOK, indicating that cytokine-triggered DNA damage was caused by ROS generation through NOX1 and NOX4. Taken together, this study provided strong evidence that blocking ROS generation might be a rewarding approach for cancer prevention and intervention in OSF.

Bone Formation in Pleomorphic Adenoma: A Case Report.

Pleomorphic adenoma is a benign tumour with variable cytomorphological and architectural elements. It is the most common salivary gland tumour in children and adults. We report a case of a 32-year-old Malay woman who presented with a slow-growing, painless, firm, and mobile nodule of 1 cm x 1 cm in size at the angle of her mandible on the right side which could be palpated bimanually. Intraorally, this nodule could be palpated at the retromolar area. On excisional biopsy, this nodule was reported as a pleomorphic adenoma with predominant chondroid stromal elements and a large area of bone formation in the stroma. We discuss the possible pathogenesis, differential diagnosis, and clinical significance of this exceptionally rare phenomenon of bone formation in pleomorphic adenoma in minor salivary glands with the literature review. The clinical significance and relevance on treatment outcome for pleomorphic adenoma with bone formation is currently uncertain as there are only a few cases reported in the literature. A good follow-up study is recommended to assess the clinical significance of pleomorphic adenoma with extensive bone formation.

Diagnostic Enigma of Adenoid Ameloblastoma: Literature Review Based Evidence to Consider It as a New Sub Type of Ameloblastoma.

Adenoid ameloblastoma is a hybrid odontogenic tumour showing histopathological features of both ameloblastoma and adenomatoid odontogenic tumour (AOT), with approximately 40 cases reported in the literature. The aims of the report are to illustrate the diagnostic challenges of adenoid ameloblastoma using three new cases and to analyze evidence in literature to consider adenoid ameloblastoma as a new sub type of ameloblastoma. A literature review was performed with the key words-adenoid ameloblastoma, hybrid/composite odontogenic tumours, hybrid ameloblastoma and adenomatoid odontogenic tumour, ameloblastoma with inductive changes, dentinoid and dentinoma to select the cases compatible with the diagnosis of adenoid ameloblastoma. Out of the 40 cases reported in literature, 31 cases with sufficient information and 3 new cases were analyzed. Out of the 34 adenoid ameloblastomas majority of tumours (76.5%) occurred in adults with age ranging from 25 to 55 years. Slight female predilection with a male:female ratio of 0.9:1 was observed. Approximately, 64.7% occurred in the mandible. Radiologically, 82.4% of adenoid ameloblastomas presented as radiolucent lesions while 47.1% occurred with ill-defined margins and cortical perforation at diagnosis. Histopathologically, 70.8% of tumours presented as plexiform ameloblastomas, while duct like structures/glandular structures were the commonest feature supportive of adenomatoid odontogenic tumour observed in overwhelming majority of 95.9% of adenoid ameloblastomas. 91.6% of tumours showed inductive change in the form of dentinoid. Further, 45.4% of the tumours developed at least one recurrence following surgical excision. The report presents literature review based evidence to show the existence of adenoid ameloblastoma, which is demographically similar to conventional ameloblastoma but with histopathological differences and presenting with higher rate/multiple recurrences, indicating its biological aggressiveness. Thus, we would like to propose the inclusion of adenoid ameloblastoma as a sub type of ameloblastoma in the next revision of the WHO odontogenic tumour classification.

An altered keratinocyte phenotype in oral submucous fibrosis: correlation of keratin K17 expression with disease severity.

Oral submucous fibrosis (OSF) is characterized by abnormal collagen metabolism in the submucosal connective tissue. Its influence on the overlying epithelium is not known but about 14% of OSF cases undergo malignant transformation to squamous cell carcinoma indicating association with abnormality of the epithelium. Here, we have defined the keratin expression profile, by immunohistochemistry and quantitative image analysis, using a panel of 22 anti-keratin monoclonal antibodies on 28 OSF samples. We observed an increase of K1 and K10 in the suprabasal layers, induction of K6 in the basal layer and complete loss of K19 in the epithelium. Furthermore, there was increased K17 expression in the suprabasal layers, which correlated with disease severity. In a subset of the most severe OSF cases (14%), K17 expression was completely lost in the basal layer which might define them to be at most risk to undergo malignant transformation. There was no detectable expression of K8, K18, K7 and K9 and the expression of K4, K13, K14, K15 and K16 did not change in OSF. We propose that the altered keratin profiles could be useful as histological diagnostic markers and provide important insights into the pathogenesis of the disease and its predisposition to malignancy.

Oral biopsies from patients with orofacial granulomatosis with histology resembling Crohn's disease have a prominent Th1 environment.

BACKGROUND: Orofacial granulomatosis (OFG) is an idiopathic inflammatory disorder of children and young adults whose clinical symptoms include swelling of the lips or face, mucosal nodularity (cobblestoning), mucosal tags, hyperplasia of the gingivae, and aphthous oral ulcers. Whether some OFG patients with clinical and histological characteristics resembling Crohn's disease (CD) are a special group (oral CD) or true CD patients with symptoms reaching all the way to the oral mucosa remains to be determined. METHODS: In this study oral biopsies from 10 patients with OFG were analyzed for the presence of T cells, T-cell subsets, B cells, and macrophages, as well as cytokines (IL-4, IL-10, IFN-gamma, IL-12, and TNF-alpha), chemokines (RANTES and MIP-1alpha), and chemokine receptors (CCR3, CCR5, and CXCR3). For comparison, oral tissues from 7 patients with other granulomatous diseases were included. RESULTS: Compared with the non-OFG group, the OFG group had raised levels of CD4(+) T cells, IFN-gamma, IL-10, and RANTES but reduced levels of CD68(+) macrophages outside the granulomas, whereas within the granulomas the levels of CD3(+) and CD4(+) T cells and of IFN-gamma were raised, but the levels of IL-4 were decreased. These data are indicative of a Th1 environment within the oral OFG tissues, which resembles that already observed in gut CD tissues. CONCLUSIONS: Therefore, it can be concluded that some OFG patients have both histopathological and immunopathological features that resemble those observed in CD patients.

Methanol Extract of Holarrhena antidysenterica Inhibits the Growth of Human Oral Squamous Cell Carcinoma Cells and Osteoclastogenesis of Bone Marrow Macrophages.

Oral squamous cell carcinoma (OSCC) frequently invades mandibular bone, and outcomes for treatment with surgical resection are typically poor, ultimately resulting in death. Holarrhena antidysenterica L. (Apocynaceae), distributed throughout Sri Lanka and India, has been used as a folk remedy to treat various diseases. Treatment with methanol extract of H. antidysenterica bark (HABE) inhibited cell viability and BrdU incorporation and induced apoptotic cell death in Ca9-22 gingival and HSC-3 tongue SCC cells. Flow cytometric analysis indicated that HABE treatment preferentially induces apoptotic cell death via increasing the sub-G1 peak in Ca9-22 cells and cell cycle arrest at the G1 phase in HSC-3 cells. HABE treatment in the presence of zVAD-fmk, a pan-caspase inhibitor, rescued cell viabilities in both OSCC cell lines. The ratio of Bax to Bcl-2 increased with reductions in the Bcl-2 protein expression, and the activation of caspase 3 and subsequent cleavage of PARP was detected in HABE-treated Ca9-22 and HSC-3 cells. Furthermore, HABE treatment at noncytotoxic concentrations inhibited osteoclast formation in RANKL-stimulated bone marrow macrophages. Taken together, HABE possesses the inhibitory activity on the growth of OSCC cells and antiosteoclastogenic activity. Therefore, HABE may be a promising alternative and complementary agent for preventing and treating OSCC.

Intralesional corticosteroids as a treatment for restricted mouth opening in oral submucous fibrosis.

OBJECTIVES: Oral submucous fibrosis (OSF) is a chronic debilitating disease of the oral mucosa, associated with an increased risk of malignancy. The primary objective of this study was to evaluate the effectiveness of intralesional corticosteroid injection as a treatment modality for OSF. We also studied the correlation between the treatment outcome and a number of individual variables. STUDY DESIGN: A total of 230 histologically confirmed patients with OSF were included in the study, of which 116 patients with a 30 mm or less interincisal mouth opening were subjected to intralesional injections of 40 mg methylprednisolone at monthly intervals for 6 consecutive months. The effect of the treatment was assessed by evaluating the degree of improvement in mouth opening. RESULTS: All patients included in the study had a history of chewing areca nut. In paired comparison, statistically significant difference (t = -8.78; df = 115; P < .001) was observed in mouth opening over a period of 12 months in the patients who had corticosteroid injections. CONCLUSIONS: Intralesional corticosteroid injection is one of the most widely implemented interventions for OSF at present, particularly for those patients with palpable fibrous bands. The present study provides justification for the use of corticosteroids in improving mouth opening.

Extracellular matrix remodeling in oral submucous fibrosis: its stage-specific modes revealed by immunohistochemistry and in situ hybridization.

BACKGROUND: Oral submucous fibrosis (OSF) is a chewing habit-related pre-cancerous condition of the oral mucosa affecting predominantly south Asians. It is histopathologically characterized by epithelial atrophy and fibrosis of the subepithelial connective tissue. Fibrosis extends all the way into the muscle layer, leading to difficulty in mouth opening. However, the dynamics of extracellular matrix (ECM) remodeling with OSF progression is largely unknown. METHODS: Forty biopsy specimens of OSF and 10 of normal buccal mucosa were examined for expression/deposition modes of eight ECM molecules by histochemistry, immunohistochemistry, and in situ hybridization. RESULTS: In the early stage of OSF, tenascin, perlecan, fibronectin, collagen type III were characteristically enhanced in the lamina propria and the submucosal layer. In the intermediate stage, the ECM molecules mentioned above and elastin were extensively and irregularly deposited around muscle fibers. In the advanced stage, such ECM depositions decreased and were entirely replaced with collagen type I only. Their gene expression levels varied with progression of fibrosis, but the mRNA signals were confirmed in fibroblasts in the submucosal fibrotic areas. CONCLUSIONS: The results indicate that the ECM remodeling steps in OSF are similar to each phase of usual granulation tissue formation. Restricted mouth opening may be a result of loss of variety of ECM molecules including elastin into the homogeneity of collagen type I replacing muscle fibers.