Promoter methylation of sFRP5 in patients with ovarian clear cell adenocarcinoma
Version of Record online: 17 MAR 2010
© 2010 The Authors. Journal Compilation © 2010 Stichting European Society for Clinical Investigation Journal Foundation
European Journal of Clinical Investigation
Volume 40, Issue 4, pages 310–318, April 2010
How to Cite
Ho, C.-M., Lai, H.-C., Huang, S.-H., Chien, T.-Y., Lin, M.-C. and Chang, S.-F. (2010), Promoter methylation of sFRP5 in patients with ovarian clear cell adenocarcinoma. European Journal of Clinical Investigation, 40: 310–318. doi: 10.1111/j.1365-2362.2010.02266.x
- Issue online: 17 MAR 2010
- Version of Record online: 17 MAR 2010
- Received 2 November 2009; accepted 21 January 2010
- ovarian clear cell adenocarcinoma;
- promoter methylation
Eur J Clin Invest 2010; 40 (4): 310–318
Background Specific tumour suppressor genes with promoter methylation in ovarian clear cell adenocarcinoma (OCCA) can be one important epigenetic mark distinguishing OCCA from ovarian serous adenocarcinoma (OSA), benign endometriotic cysts and normal ovarian epitheliums.
Materials and methods Five OCCA cell lines, 63 cancer tissues (48 OCCA and 15 OSA), 10 benign endometriotic cysts and five normal ovarian epitheliums were analysed by methylation-specific PCR using pooled DNAs to determine the methylation status of the promoter of the target genes, including genes for secreted frizzled-related proteins (sFRP1 to 5), adenomatous polyposis coli (APC), retinoblastoma protein 1 (Rb1), breast cancer 1 gene (BRCA1), p14ARF, p15INK4b, p16INK4a and survivin. Methylation frequencies of identified targets were further analysed with individual DNA samples.
Results The sFRP5 promoter was significantly methylated in all OCCA cell lines, with 64·6% in OCCA tissues compared with 13·3% in OSA, and 0% in benign endometriotic cysts and normal ovarian epitheliums (P < 0·0001). With a median follow-up of 44 months, the expected 5-year overall survival (OS) for patients with methylated sFRP5 promoter were significantly worse than for those with unmethylated sFRP5 (52% vs. 88%, P = 0·03). After adjusting for age, stage, and residual disease after primary surgery, patients with unmethylated sFRP5 promoter had an independent good prognostic factor in OS (P = 0·017).
Conclusion The high percentage of promoter methylation in the sFRP5 gene in OCCA indicates its importance in the development of OCCA and is a potential useful marker for prognoses and target for treatment of OCCA.