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Background: We identified an autophagy-inducing areca nut (AN) ingredient (AIAI) in the 30-100 kDa fraction of AN extract (ANE 30-100K). This study was to analyze the role of endocytosis in ANE 30-100K-induced autophagy.Methods: We used benzyl alcohol, dynasore, and shRNA of clathrin and dynamin to assess whether ANE 30-100K-induced cytotoxicity and accumulation of microtubule-associated protein 1 light chain 3 (LC3)-II were affected in oral (OECM-1) and esophageal (CE81T/VGH) carcinoma cells.Results: Both benzyl alcohol and dynasore effectively reduced ANE 30-100K-induced cytotoxicity and LC3-II accumulation in OECM-1 and CE81T/VGH cells. Downregulated protein expression of both clathrin and dynamin by their shRNA also significantly attenuated ANE 30-100K-induced elevation of LC3-II levels in CE81T/VGH cells.Conclusions: These results indicate that AIAI may be engulfed by cells through clathrin-mediated endocytosis, which promotes the execution of the following autophagy program. [ABSTRACT FROM AUTHOR]

Backgrounds: Oral cancer is the 4th leading cause of cancer death for males and the top cancer in young adult males in Taiwan. Tongue squamous cell carcinoma (TSCC) is a common oral cancer and generally associated with poor prognosis. Global DNA hypomethylation at the 5 position of cytosine (5mC) is a well-known epigenetic feature of cancer. Therefore, the purpose of this study was to investigate the relationship of the global 5mC content with the tumorigenesis and prognosis of patients with TSCC.Methods: The levels of global 5mC were evaluated by immunohistochemistry using tissue microarray slides of 248 surgically resected TSCC and 202 corresponding tumor adjacent normal (TAN) tissues.Results: We found that the level of 5mC in TSCC (P < 0.001) was significantly decreased as compared to TAN. Among TSCC tissues, decreased levels of 5mC were associated with female gender (P = 0.036). In addition, the global hypomethylation was associated with the poor disease-specific survival in TSCC patients (adjusted hazard ratio: 1.55, P = 0.043), especially for patients in older age group (> 50 years, P = 0.013), with moderate or poor cell differentiation (P = 0.044), early stage of disease (I-II, P = 0.046), small tumor size (T1-T2, P = 0.005), without lymph node involvement (P = 0.041), and ever received postoperative radiotherapy (P = 0.009).Conclusions: Global hypomethylation was an independent biomarker for the development and poor prognosis of TSCC. [ABSTRACT FROM AUTHOR]