MDV1-miR-M3 suppressed cisplatin-induced apoptosis by directly downregulating expression at the protein but not the mRNA level of Smad2, a critical component in the transforming growth factor beta signal pathway.
Indeed, SMAD2 was confirmed as a target that is directly repressed miR-M3, and rescue of SMAD2 expression using a construct lacking the target sites also antagonized the anti-apoptotic effects of the miRNA.