The functional role of miRNAs and colorectal cancer: insights from a large population-based study

Identification of causal microRNAs (miRNAs) in colorectal cancer (CRC) is elusive, due to our lack of understanding of howspecific miRNAs affect biological pathways and outcomes. A miRNA can regulate many mRNAs and a mRNA can be associatedwith many miRNAs; appreciation of these complex networks in which miRNAs operate is necessary to transition from identifyingdysregulated miRNAs to identifying individual miRNAs or groups of miRNAs that are suitable for therapeutic purposes. The goalof the paper is to compile results from a population-based study (n = 1,954 cases with matched carcinoma/normal tissue) ofmiRNAs in CRC. The information gained allows for cohesive and comprehensive insight into miRNAs and CRC in terms offunction and impact. Comparison of miRNA expression with mRNA expression from nine signaling pathways in carcinogenicprocesses allowed us to identify miRNA targets within a biological context. MiRNAs that directly influence mRNA expression maybe effective biomarkers or therapeutic targets.