Areca-treated fibroblasts enhance tumorigenesis of oral epithelial cells.

Several hundred million Asians chew areca nut, which is strongly associated with oral carcinogenesis in people of this region. The impacts of areca nut extract on oral target cells are largely unclear. This study hypothesized an inductive role for areca-nut-exposed stromal cells in the progression of oral carcinomas in an at-risk population. Oral fibroblasts with chronic subtoxic areca nut extract treatment exhibited growth arrest and MMP-2 activation. The supernatant of arrested oral fibroblasts activated the AKT signaling pathway in oral carcinoma cells. The enhancement of proliferation, migration, and anchorage-independent growth of oral carcinoma cells elicited by such supernatant could be abrogated by blockers against MMP-2 or AKT. Subcutaneous co-injection of arrested oral fibroblasts into nude mice significantly enhanced the tumorigenicity of xenographic oral carcinoma cells. This study concludes that areca nut extract may impair oral fibroblasts and then modulate the progression of oral epithelial oncogenesis via their secreted molecules.

Aspergillosis of the temporomandibular joint following irradiation of the parotid region: a case report.

We report a case of aspergillosis in the right temporomandibular joint (TMJ) with a history of parotid carcinoma and post-irradiation otitis. Previous treatment attempts with surgery and antibiotics were unsuccessful. Radical debridement of the glenoid fossae, supplemented with amphotericin B and adjunct hyperbaric oxygen (HBO) therapy, was provided to resolve the symptoms. This case report highlights the need to be aware of the possibility of invasive mycosis in immunocompromised patients.

Primary ectopic thyroid papillary carcinoma in the floor of the mouth and tongue: a case report.

We report a rare case of papillary carcinoma in the tongue and floor of the mouth with metastasis in cervical lymph nodes. Treatment was by total thyroidectomy with right radical lymph node dissection of the neck, followed by 60 Gy of radiotherapy and 100 mCi (131)I. Pathological examination of the thyroid gland showed no primary cancer. We review publications about ectopic thyroid and the value of antithyroglobulin immunostaining for diagnosis and treatment of the tumour.

Accumulation of mitochondrial DNA deletions in human oral tissues -- effects of betel quid chewing and oral cancer.

Accumulation of mitochondrial DNA (mtDNA) mutations in human tissues has been associated with intrinsic aging and environmental insult. Recently, mtDNA mutations have been detected in various tumors, including head and neck tumors. However, the factors affecting the occurrence and accumulation of mtDNA deletions in tumor tissues are poorly understood. In Taiwan, betel quid chewing is a major risk factor for oral cancer. Using polymerase chain reaction (PCR) techniques, we examined large-scale deletions of mtDNA in 53 pairs of tumor and non-tumor oral tissues from the patients with or without betel quid chewing history. The results revealed that irrespective of the history of betel quid chewing, the incidences of the 4977bp deletion and other deletions of mtDNA were lower in the tumor portion as compared with the non-tumor portion. The average proportions of the 4977bp deleted mtDNA in the tumor tissues of the betel quid chewers and non-betel quid chewers were 13- and 5-fold, respectively, lower than those in the corresponding non-tumor tissues. Moreover, the average proportion of 4977bp deleted mtDNA was significantly higher (P<0.05) in the non-tumor oral tissues of the patients with betel quid chewing history than that of the patients without the history of betel quid chewing. These results suggest that betel quid chewing may increase mtDNA mutation in human oral tissues and that accumulation of mtDNA deletions and subsequent cytoplasmic segregation of these mutations during cell division could be an important contributor to the early phase of oral carcinogenesis.