Identification of prostate cancer-expressed microRNAs associated with clinical recurrence (cR) and prostate cancer-specific survival (PCSS) following radical prostatectomy (RP).

21 Background: We previously identified messenger RNAs (mRNAs) whose expression can distinguish aggressive from indolent prostate cancer. Representing multiple key genomic pathways, these mRNAs are significantly associated with cR and PCSS after RP, providing prognostic information beyond PSA, cT stage and Gleason Score. We evaluated microRNA expression in the same specimens for association with cR and PCSS. Methods: All cT1/cT2 prostate cancer pts treated with RP at Cleveland Clinic from 1987-2004 were identified (n~2,600), of which 127 pts w/ cR and 374 pts w/o cR after RP were randomly selected using cohort sampling. RNA was purified from 2 macrodissected FPE tumor specimens per pt. Expression of 76 test and 5 reference microRNAs was quantified by RT-PCR. Cox regression and control of the false discovery rate (FDR) was used to assess reference-normalized microRNA and mRNA expression for association with cR and PCSS. Results: 106 pts with cR and 310 without cR had sufficient RNA and successful microRNA ...