摘要To the Editor:Benign prostatic hyperplasia (BPH) is a prevalent chronic disease that predominately affects males aged over 40 years,characterized by benign unregulated hyperplasia that arises from stromal and epithelial prostate cells.[1,2]Although the association between altered microRNA (miRNA) expressions and the incidence of prostate cancer has been widely investigated,there still remains a poor understanding of the mechanism underlying miRNA expressions in BPH of the prostatic stroma.[3] More recently,emerging evidence has highlighted the role of antitumor miRNA-340 (miR-340) in the event of prostate cancer progression and metastasis.[4] However,there remains an inadequate understanding regarding the role of miR-340 in BPH.In this study,we collected prostatic tissues from 75 BPH patients and normal prostatic tissues from 67 non-BPH patients who were admitted into Beijing Friendship Hospital,between June 2012 and December 2013.In an attempt to examine the expression patterns ofmiR-340 in BPH in vivo,we quantified a decreased expression level of miR-340 among obtained prostatic tissues from patients with BPH in contrast to normal prostatic tissues [Figure la],which suggested that downregulated miR-340 was associated with the occurrence of BPH.The study was conducted with the approval of the Institutional Ethics Committee of Beijing Friendship Hospital,Capital Medical University,with all participating patients giving informed consent in accordance with the requirements of the Declaration of Helsinki.