Table 2.

DRUGS THAT RESTORE MIRNA

Agent	What are these agents?	Mechanism of action	Examples
miRNA mimetics	Synthetic small RNAs that contain the exact sequence of endogenous miRNA. They can be modified to have enhanced efficiency by increasing the affinity for a specific target and reducing other unwanted miRNA effects.	They are delivered as perfect complementary duplexes and they act by improving the RISC loading of miRNA.	miR-26a: In a hepatocellular carcinoma mouse model this mimetic inhibited cell growth and apoptosis [34].
Epigenetic modifiers	Molecules that reverse DNA methylation and posttranslational histone modifications	They either inhibit methylation, or interact with enzymes that remove acetyl groups.	5-aza-2′-deoxycytidine and 4-phenylbutyric acid: Restored tumor suppressive miR-127 levels and subsequently inactivated BCL6 proto-oncogene [36].
Enhancers of miRNA processing machinery	Small molecule/drug that enhances RNAi and promotes miRNA processing.	Increase the production of tumor suppressive miRNA y interacting with the binding products of the proteins that regulate miRNA maturation.	Enoxacin: A fluoroquinolone that has been proven to increase the production of tumor suppressive miRNA by binding to the transactivation-responsive RNA-binding protein 2 (TRBP) [38].