Pyrosequencing Analysis of APC Methylation Level in Human Prostate Tissues: A Molecular Marker for Prostate Cancer

Purpose: Epigenetic alterations such as abnormal DNA methylation are associated with many human cancers. Differences in methylation patterns between neoplastic and normal cells can be used to detect cancer. The aim of the present study was to evaluate the effectiveness of detecting Adenomatous polyposis coli (APC) hypermethylation by quantitative pyrosequencing for discriminating between normal and prostate cancer (PCa) cells and for predicting tumor behaviors. Materials and Methods: A total of 218 human prostate tissues obtained from our institute were assessed: 106 specimens of benign prostatic hyperplasia (BPH) and 112 specimens of PCa. The methylation status of APC was analyzed by quantitative pyrosequencing. The association between the APC methylation level and clinicopathological parameters was explored. Results: The level of APC methylation was significantly higher in PCa specimens than in BPH specimens (33.3%±20.7% vs. 1.3%±1.8%, p＜0.001). The sensitivity and specificity of APC methylation status in discriminating between PCa and BPH reached 89.3% and 98.1%, respectively. Similar results were obtained after stratification by stage, Gleason score, and prostate-specific antigen level. The APC methylation level correlated positively with Gleason score (p trend=0.016). There was no association between the APC methylation level and the PSA level or staging. Conclusions: Our results demonstrate that APC methylation is associated with PCa and its aggressive tumor features.