Methylation of CpG Islands in Promoter of Type 2 5-Alpha Reductase and Implications of Finasteride Resistance for BPH Therapy

The study aimed to investigate why some patients with benign prostatic hyperplasia (BPH) are resistant to finasteride treatment. The researchers hypothesized that reduced expression of 5-AR2 protein, which is important for proper development of prostate tissue, due to methylation of CpG islands in the 5-AR2 promoter region, may account for the resistance. The study found that methylation of CpG islands in the promoter leads to silencing of the 5-AR2 gene, resulting in reduced or absent expression of 5-AR2 protein. This may partly account for resistance to finasteride in some BPH patients. The study identified the sequence of the 5-AR2 promoter region and found that increased DNMT1 may up-regulate methylation of CpG islands in the 5-AR2 promoter region.