Hypermethylation of the PTEN gene in ovarian cancer cell lines.

This study was performed to investigate the hypermethylation status of the PTEN gene in ovarian cancer. To this end, we incubated eight ovarian cancer cell lines with the demethylating agent 5-aza-2' deoxycytidine in three different concentrations for 5 days. Subsequently, the PTEN expression was quantified by both real time RT-PCR and quantitative western analyses. PTEN mRNA varied considerably in response to demethylation whereas PTEN protein concentrations remained constant in all cell lines except OAW42 cells (12.5%). The data suggest that PTEN is highly regulated at translational level. However, methylation of the PTEN gene plays a subordinate role in ovarian cancer.