MicroRNAs differentially expressed in prostate cancer of African-American and European-American men

African-American (AA) men have higher rates of prostate cancer incidence and mortality compared with European-American (EA) men. Although several socioeconomic and environmental factors may contribute to the disparity, recent studies suggest a biological component, including differential microRNA (miRNA) expression, to the disparity. miRNAs comprise a large family of about 22-nucleotide-long nonprotein coding RNAs that regulate gene expression posttranscriptionally and participate in the regulation of almost every known cellular process investigated to date. miRNAs have been associated with prostate cancer progression, and recent studies indicate that they are differentially expressed between AA and EA. They could therefore contribute, at least in part, to the disparity in prostate cancer between the two groups. In this review, existing evidence on differential miRNA expression between AA and EA prostate cancer patients or cell lines is summarized.