MicroRNAs (miRNAs) constitute an evolutionarily conserved class of small 
non-coding RNAs that are endogenously expressed with crucial functions in 
fundamental cellular processes such as cell cycle, apoptosis and 
differentiation. Disturbance of miRNA expression and function leads to 
deregulation of basic cellular processes leading to tumorigenesis. A growing 
body of experimental evidence suggests that human tumors have deregulated 
expression of microRNAs, which have been proposed as novel oncogenes or tumor 
suppressors. Recent studies have shown that microRNA expression patterns serve 
as phenotypic signatures of different cancers and could be used as diagnostic, 
prognostic and therapeutic tools. A few studies have analyzed global microRNA 
expression profiles or the functional role of microRNAs in prostate cancer. Here 
we have reviewed the role of microRNAs in prostate carcinogenesis by summarizing 
the findings from such studies. In addition, recent evidence indicates that 
dietary factors play an important role in the process of carcinogenesis through 
modulation of miRNA expression, though such studies are lacking in regards to 
prostate cancer. It has been proposed that dietary modulation of miRNA 
expression may contribute to the cancer-protective effects of dietary 
components. In this review, we have summarized findings from studies on the 
effect of dietary agents on miRNA expression and function.