Chitinase 3-Like-1 Expression Is Upregulated Under Inflammatory Conditions in Human Oral Epithelial Cells.

OBJECTIVE: Chitinase 3-like-1 (CHI3L1), also known as YKL-40, is a partially secreted glycoprotein and is involved in inflammatory disorders, including inflammatory bowel diseases. CHI3L1 is known to play a role in biological responses such as cell proliferation, tissue remodeling, and inflammation. CHI3L1 forms an immune complex (known as a Chitosome complex) with IL-13 receptor alpha 2 (IL-13 Rα2) and transmembrane protein 219 (TMEM219) to activate the MAPK/ERK and PKB/AKT signaling pathways. The objective of this study is to investigate how the expressions of CHI3L1 and a Chitosome complex in human oral cavity epithelial cells are linked with intraoral inflammatory diseases. METHOD: CHI3L1 and Chitosome complex mRNA expressions were analyzed using human oral squamous cancer cell lines, HSC3 and HSC4 cells. Signaling activation in HSC4 cells was analyzed by using the western blot technique. Immunohistological analysis was performed using surgical samples obtained from patients with benign oral cavity tumors and cysts. RESULTS: Increased expression of CHI3L1 was observed in both HSC3 and HSC4 cells after TNFα stimulation. The expression of Chitosome complex factors increased as CHI3L1 levels increased, resulting in the activation of a downstream signaling pathway. Among the intraoral tissues, the epithelial cells from inflammatory lesions, but not benign tumors, were found to be intensively stained with the anti-CHI3L1 antibody. CONCLUSION: It was indicated that the formation of a Chitosome complex is induced during inflammation, leading to the activation of signaling pathways.

Gingival Squamous Cell Carcinoma Predicted to Originate From the Gingival Sulcular Epithelium in a Young Female: A Report of a Rare Case.

Oral cancer is a disease primarily in older adults and extremely rare in young adults. Risk factors for oral cancer are irritants such as tobacco smoke and alcohol and chronic mechanical irritants but mechanisms involved in carcinogenesis in young adults are unclear because of less exposure to their risk factors. Herein, we report a rare case of gingival squamous cell carcinoma in a 19-year-old female patient, in whom the tumor predictably originated in the gingival sulcular epithelium. Histopathological examination of the resected tissue showed a cancer cell nest invading from the gingival sulcular epithelium without a breakdown of the basement membrane of the marginal gingival epithelium. Six years after the surgery, no recurrence or metastasis has been detected.

Solitary Neurofibroma of the Hard Palate: A Case Report and Literature Review.

BACKGROUND Neurofibromas are benign tumors of neurological origin caused by the proliferation of Schwann cells and fibroblasts; they often occur in the skin and nerves as a symptom of von Recklinghausen disease. Solitary neurofibromas are also known to occur on their own, but solitary development in the hard palate is extremely rare and difficult to distinguish from schwannomas. The neural origin of solitary neurofibromas is also difficult to determine intraoperatively, and there have been no reports that clearly identify the neural origin of neurofibromas in the hard palate. CASE REPORT We report a case of a solitary neurofibroma originating in the hard palate in a 24-year-old woman. She presented to our department with a 1.2×0.8-cm dome-shaped left palate mass. After identification of the nerve at the source, the tumor was resected under general anesthesia. Histopathology was positive for S-100 and CD34 immunostaining, as well as for Alcian blue. Eventually, the mass was diagnosed as a neurofibroma. CONCLUSIONS Solitary neurofibromas originating in the hard palate are difficult to differentiate from other neoplastic lesions, especially schwannomas, based on clinical findings alone. Therefore, it is important to perform a biopsy and immunostaining of the biopsied specimens for S-100 and CD34. In neurofibromas, tumor cells are loose and delicate, often with wavy or serpentine nuclei, and S-100 protein-positive cells are sparser than in schwannomas. An overall pathological diagnosis should be made with regard to CD34, taking into account that schwannomas are CD34-negative and neurofibromas are CD34-positive.