Detection of circulating hypermethylated tumor-specific RASSF1A DNA in ovarian cancer patients / 中华病理学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To detect hypermethylated tumor-specific RASSF1A DNA in the circulation and its significance in ovarian cancers patients.</p><p><b>METHODS</b>Methylation-specific polymerase chain reaction (MSP) was used to study the hypermethylation of RASSF1A in preoperative serum samples from 51 ovarian cancer patients.</p><p><b>RESULTS</b>The RASSF1A gene was not methylated in peripheral blood samples from 51 normal patients and 51 patients with benign ovarian tumors. Hypermethylation of RASSF1A gene was found in circulating tumor-specific DNA in 43.1% of patients (22 out of 51 cases) with ovarian cancers (P < 0.05). There was no difference in hypermethylation of RASSF1A gene amongst various ovarian cancer subtypes (P < 0.05). On the other hand, hypermethylation of RASSF1A gene was more frequently encountered in stage III and IV than stage I and II tumors (P < 0.05). It was rarely seen in well and moderately differentiated groups, as compared with poorly differentiated group (P < 0.05).</p><p><b>CONCLUSIONS</b>There is a higher frequency of RASSF1A hypermethylation in circulating tumor-specific DNA of ovarian cancer patients. RASSF1A has been postulated to play an important role as tumor suppressor gene and can be silenced by promoter hypermethylation. This methylation correlates with clinical stage and histopathologic grade. Such observation may carry diagnostic and prognostic implications when assessing ovarian tumors.</p>