Change in prostate tissue gene expression following finasteride or doxazosin administration in the medical therapy for prostatic symptoms (MTOPS) study.

Benign prostatic hyperplasia (BPH) may decrease patient quality of life and often leads to acute urinary retention and surgical intervention. While effective treatments are available, many BPH patients do not respond or develop resistance to treatment. To understand molecular determinants of clinical symptom persistence after initiating BPH treatment, we investigated gene expression profiles before and after treatments in the prostate transitional zone of 108 participants in the Medical Therapy of Prostatic Symptoms (MTOPS) Trial. Unsupervised clustering revealed molecular subgroups characterized by expression changes in a large set of genes associated with resistance to finasteride, a 5α-reductase inhibitor. Pathway analyses within this gene cluster found finasteride administration induced changes in fatty acid metabolism, amino acid metabolism, immune response, steroid hormone metabolism, and kinase activity within the transitional zone. We found that patients without this transcriptional response were highly likely to develop clinical progression, which is expected in 13.2% of finasteride-treated patients. Importantly, a patient's transcriptional response to finasteride was associated with their pre-treatment kinase expression. Further, we identified novel expression signatures of finasteride resistance among the transcriptionally responded patients. These patients showed different gene expression profiles at baseline and increased prostate transitional zone volume compared to the patients who responded to the treatment. Our work suggests molecular mechanisms of clinical resistance to finasteride treatment that could be potentially helpful for personalized BPH treatment as well as new drug development to increase patient drug response.