Methylation status of insulin-like growth factor-binding protein-3 promoter in prostate cancer tissues

Background: It has been postulated that insulin-like growth factor-binding protein-3 (IGFBP-3) is a mediator of growth suppression signals. Recently, a correlation between the promoter hypermethylation of IGFBP-3 and cancer risk was reported in hepatocellular cancer and in non-small-cell lung cancer (NSCLC). We investigated whether the methylation status of IGFBP-3 promoter in prostate tissues influences the progression and prognosis of prostate cancer. Methods: We conducted a case-control study consisting of 38 prostate cancer patients and 57 control subjects, and assessed the relationship of promoter hypermethylation at IGFBP-3 with the clinical and pathological tumor characteristics of these patients. The methylation status was analyzed by two methylation-specific PCR techniques. Results: Hypermethylation of the IGFBP-3 promoter was found in 13 (34.2%) of the 38 cases, and 11 (19.3%) of the 57 controls with one method using a hepatocellular primer as described by Hanafusa et al. With other methods using a NSCLC-primer, as described by Chang et al., hypermethylation was found in four (10.5%) of the cases and two (3.5%) of the controls. No significant differences were observed in the methylation frequencies between the controls and the cases. When the cases were stratified based on their clinical stage (localized or metastatic) and pathological grade (Gleason score of