The Relationships Between TES Protein Level And Its Promotor Region Hypermethylation And Loss Of Heterozygosity In Ovarian Cancer

BACKGROUND AND OBJECTOvarian cancer is the third most frequent female cancer type and the first cause of death by cancer among women. More than 70% of patients were already in late stage once diagnosed, and lost the chance to have an operation. TES is a candidate tumor suppressor gene locating at the human chromosome 7q31, but the function of TES in ovarian cancer is still unknown, our research focuses on two relationships:the TES protein levels and promoter region hypermethylation; the TES protein levels and loss of heterozygosity of TES. We also want to further prove its anti-tumor functions.METHODImmunohistochemistry was used to detect the expression of TES ovarian cancer tissues; Methylation-specific PCR was used to check the methylation status of TES promoter for the analysis between TES expression and its promoter hypermethylation; Microsatellite based PCR was used to detect the loss of heterozygosity of TES in ovarian cancer tissues for the analysis between TES expression and loss of heterozygosity.RESULTBy immunohistochemistry, positive expression of TES was identified in 43.9%(23/41) of ovarian cancer tissues. Promoter hypermethylation of TES was detected in 36.5%(15/41) of ovarian cancer tissues, there is a significant correlation between hypermethylation and TES protein level (p=0.001).We detected TES locus loss in 34.6%(9/26) of ovarian cancers the relationship between TES expression and the frequency of loss of heterozygosity is very obvious(p=0.037).CONCLUSION1. Downregulation of TES expression occurred frequently in ovarian cancer;2. Promoter methylation and loss of heterozygosity of TES are two reasons for the loss of TES expression;...