Frequent SLIT2 Promoter Methylation in the Serum of Patients with Ovarian Cancer

OBJECTIVE: The slit homologue 2 (SLIT2) gene is a tumour suppressor gene. This study investigated the methylation status of the SLIT2 promoter in women with ovarian cancer in terms of identifying whether this might aid the early diagnosis of ovarian cancer. METHODS: Using methylation-specific polymerase chain reaction analysis, the methylation status of the SLIT2 promoter was measured in tumour tissue and serum samples from 36 patients with ovarian cancer and in matched serum samples from 25 controls without cancer. RESULTS: Aberrant methylation of the SLIT2 promoter was present in ovarian tissue from 29/36 (80.6%) ovarian cancer patients, but not in the 25 healthy controls. Among the cases with hypermethylation in their ovarian tissue, 27/29 (93.1%) of the case-matched serum DNA samples, including all four cases of early-stage ovarian cancer, showed hypermethylation of the SLIT2 promoter. CONCLUSIONS: Hypermethylation of the SLIT2 promoter may be a relatively early event in ovarian cancer; thus, its detection may be an effective approach to improve early diagnosis.