The Significance Of Methylation Of HIC1 And HOXA9 In Early Diagnosis Of Ovarian Cancer

Background and Objective:Ovarian cancer is one of frequent malignant tumors among the female, which is often referred to as the'silent killer', and it is no evident symptoms in early stage. Early detection can help prolong or save lives. In recent years, with thorough research of tumor genes and tumor suppressor genes such as BRCA1, MINT25 and p73 enable early diagn-osis of ovarian cancer to achieve molecular level. We exam the methylation of HIC 1 and HOXA9 promoter in ovarian cancers via MSP.The purpose is to detect the methylation of HIC 1 and HOXA9 promoter in the tumors and its significance in ovarian cancers early diagnosis.Methods:Samples of surgically resected ovarian tissue were collected from 2006 to 2009, among them 33 cases of ovarian cancer,10 cases of benign tumor tissue,10 cases of normal. The routine H&E-stained sections were reviewed to verify the morphologic diagnosis. Methylation status of the HIC1 and HOXA9 promoter region was analyzed by methylation specific polymerase chain reaction (MSP). Statistical analysis was performed using the SPSS 13.0 software.Results:1. The methylation of HIC1 gene was absent in normal ovarian tissues. With the degree of atypia increase, the trend of the methylation frequency has been gradually strengthened. Compared with benign ovarian tumors and normal ovarian tissues, the methylation frequency of HIC1 in Ovarian cancer was significant differences(P<0.05).2. The frequency of methylation of HIC 1 gene was significantly higher in ovarian cancers of stageâ… andâ…¡than that in stageâ…¢andâ…£. The difference was significant(P<0.05). The methylation frequency of HIC 1 gene in poorly differentiated ovarian cancer tissues was higher than well-differentiated and moderately differentiated tissues, the difference was significant (P <0.05). There was not significant differences between various ovarian cancer tissues (P>0.05).3. The methylation frequency of HOXA9 gene is 10% in normal ovarian tissues.Ovarian cancer compared with benign ovarian tumors and normal ovarian tissues had significant differences(P<0.05).4. The frequency of methylation of HOXA9 gene was significantly higher in ovarian cancers of stageâ… andâ…¡than that in stageâ…¢andâ…£, the difference was significant(P<0.05). The methylation frequency of HOXA9 gene in poorly differentiated ovarian cancer tissues was higher than well-differentiated and moderately differentiated tissues, the difference was significant (P<0.05). There were not significant differences between various ovarian cancer tissues (P>0.05).5. The overall risk of ovarian cancer was increased 5.7-fold by high HIC1 and/or HOXA9 methylation, and 5.0-fold for early stage ovarian cancers by high HIC1 and/or HOXA9 methylation.Conclusions:HIC1 and HOXA9 gene may be involved in the the occurrence and development of ovarian cancer.It can contribute to the early diagnosis of ovarian cancer via detection of HIC1 and HOXA9 aberrant methylation.