MicroRNAs and androgen receptor 3′ untranslated region: A missing link in castration-resistant prostate cancer?

The ligand-activated transcription factor, androgen receptor (AR) plays a central role in the development and progression of prostate cancer. Prostate cancer initiates as an androgen-dependent disease and further accumulation of multiple sequential genetic and epigenetic alterations transform it into an aggressive, castration-resistant prostate cancer (CRPC). The molecular basis of the transition from androgen-dependent prostate cancer to CRPC remains unclear. However, it is apparent that AR plays a pivotal role in this alteration. The recent discovery that microRNAs (miRNAs) can target the function of AR suggests a functional role of these non-coding RNAs in the pathogenesis of prostate cancer. miRNAs usually function by targeting the 3′ untranslated region (UTR) of a mRNA by base-pairing interactions and modulate translation either by destabilizing the message or by repression of protein synthesis in actively translating ribosomes. Here, we discuss the potential molecular pathways through which AR targeting miRNAs may promote CRPC. Modulation of AR expression by miRNAs presents a novel therapeutic option for prostate cancer, albeit it will likely be used in combination with the existing therapies.