MicroRNAs in Cancer Gene Therapy: Another Look

Abnormalities in microRNA expression in tumor cells are widely used as a basis to develop novel therapeutic and diagnostic approaches in oncology. The former mostly aims to target oncogenic microRNAs or to restore expression of microRNAs with tumor suppressor properties in cancer cells. However recently another way of using specific microRNA loss in tumor cells has been suggested. The strategy relies on frequently lost in cancer cells but abundant in cell of normal tissues specific microRNAs, and aims to control unwanted expression of a gene essential for therapeutic action, either therapeutic transgene or essential for viral replication gene in oncolytic viruses, thus minimizing damage to normal tissues and improving safety of cancer gene therapy. Here, history of development and basic principles of the approach as well as current progress in the field are overviewed, with emphasis on benefits brought by the microRNA-based control of specificity for cancer gene therapy and emerging possibility of personification of treatment.