Importance of miRNAs in Cancer Therapy and Therapeutic Delivery Approaches

Uncontrolled cell division and proliferation due to environmental and genetic factors are characteristics of cancer. Despite traditional treatments such as surgery, chemotherapy and radiation therapy, the incidence and mortality rate of cancer increases every year. Therefore, it is necessary to improve new treatment strategies such as microRNA (miRNA). miRNAs are non-coding endogenous RNA molecules with 18-22 nt in length. They regulate important pathways in different cancer types and play active roles in mechanisms such as proliferation, migration, apoptosis and invasion. Due to their functions in the pathogenesis of cancer as oncogenic or tumor suppressors, miRNAs have been currently used as therapeutic agents. However, the limited biological stability, inability to diffuse into the target tissue and their degradability by nucleases of miRNAs are disadvantages of miRNAs. Viral and non-viral miRNA delivery systems provide high transfection to target tissue and avoid nuclease-induced degradation. This study highlights the importance of miRNAs’ regulatory involvement in cancer processes and therapeutic delivery approaches.