MicroRNA-100 expression is independently related to biochemical recurrence of prostate cancer

Purpose: Abnormal miRNA expression has emerged as crucial factors in carcinogenesis and is important in the comprehension of prostate cancer behavior. We determined the correlation of miRNA expression profiles with prostate cancer progression.

Materials and methods: We studied frozen specimens from 49 patients treated for prostate cancer with radical prostatectomy. We intentionally chose 28 men without and 21 with biochemical recurrence, defined as prostate specific antigen greater than 0.2 ng/ml. The expression of 14 miRNAs was determined by quantitative reverse transcriptase-polymerase chain reaction. All radical prostatectomy specimens were studied in toto to determine tumor volume, Gleason score and 2002 TNM pathological stage. Benign prostate tissue from benign prostatic hyperplasia served as a control.

Results: Four miRNAs were related to tumor recurrence. Using the Cox regression test the risk of recurrence was 3.0, 3.3, 2.7 and 3.4 for high levels of miR-100, miR-145, miR-191 and miR-let7c, respectively. When considering statistically significant clinical variables on univariate analysis of biochemical-free survival, prostate specific antigen and tumor volume, results revealed that miR-100 and tumor volume were independently related to tumor recurrence.

Conclusions: A high level of miR-100 is related to biochemical recurrence of localized prostate cancer in patients treated with radical prostatectomy. The role of miR-100 during carcinogenesis must be resolved in future studies to better understand the molecular pathways in which miR-100 is involved. This may open the possibility of using it as a prognostic marker and inspire the development of a target drug.