Change of heart on miR-21

A team led by researchers at The University of Texas Southwestern Medical Center at Dallas andmiRagen Therapeutics Inc. has reported that blocking microRNA-21 has no effect on stress-induced cardiac dysfunction. The findings prompted miRagen to drop its miR-21 program and pursue other miRNA targets for the indication. But Regulus Therapeutics Inc. is sticking by its miR-21 program in cardiac fibrosis based on its own positive preclinical data and maintaining that its program requires no course correction.

miRagen's interest in miR-21 dates to 2006, when Eric Olson and colleagues identified 21 miRNAs that were upregulated and 7 miRNAs that were downregulated inmouse models of cardiac stress compared with healthy controls. Of the upregulated miRNAs, miR-21 had the largest change in expression.¹...