Oral squamous cell carcinoma (OSCC) is the most common type of head and             neck malignant tumor. however, its pathological mechanisms have not yet been elucidated.             In the present study, we screened for candidate tumor-suppressor genes (TSGs)             related to OSCC among 10 candidate genes located in 3p21.3, a region abundant             with TSGs based on previous studies, using semi-quantitative reverse transcription             PCR (RT-PCR). Three genes, GNAT1, SEMA3B and AXUD1, with low or no expression             in OSCC tissues and the cell line TCA8113 were selected, and the promoter methylation             status was further analyzed by methylation-specific PCR (MS-PCR). Hypermethylation             in the promoter regions of SEMA3B was found in OSCC tissues, and a significant             difference in the frequency of methylation of SEMA3B was observed between OSCC             and non-cancerous tissues. Furthermore, TCA8113 cells treated with 5-Aza-Cdc started             to re-express SEMA3B at a concentration of 5 µM or higher. Our study confirmed             that three candidate TSGs with low expression may be involved in OSCC and that             hypermethylation in promoter regions may contribute to the low expression of SEMA3B.             These findings offer novel insights for clarifying the molecular mechanisms of             tumorigenesis of OSCC as well as for aiding in its clinical diagnosis and therapeutic             strategy.
Adolescent Adult