Being Small and Intronic: miRNAs That Count!

Abstract

The roles of intronic miRNAs and their functional interaction with host coding genes represent a topic that is poorly explored. The study by Kwok and colleagues in this issue of <i>Cancer Research</i> presents solid evidence that the FTX locus at chromosome Xq13.2 contains multiple noncoding RNAs (ncRNA) with coordinated expression and concordant functional effects in colorectal cancer cells. The long ncRNA, FTX, and its intronic miRNAs, miR-374a, -374b, -421, and -545, are all interconnected in a functional network, including the downstream protein coding targets <i>DHX9, DICER, PTEN</i>, and <i>RIG-I</i> These data prove that multigenic loci in the human genome have a complex functional landscape that modulates key signaling pathways for cancer progression and that much knowledge with potential clinical utility remains to be revealed from the largest, noncoding portion of the genome.<i>See related article by Kwok et al., p. 1308</i>.