Bioengineered chimeric tRNA/pre‐miRNAs as prodrugs in cancer therapy

Today, biologic prodrugs have led to targeting specific tumor markers and have increased specificity and selectivity in cancer therapy. Various studies have shown the role of ncRNAs in cancer pathology and tumorigenesis and have suggested that ncRNAs, especially miRNAs, are valuable molecules in understanding cancer biology and therapeutic processes. Most miRNAs-based research and treatment are limited to chemically synthesized miRNAs. Synthetic alterations in these miRNA mimics may affect their folding, safety profile, and even biological activity. However, despite synthetic miRNA mimics produced by automated systems, various carriers could be used to achieve efficient production of bioengineered miRNAs through economical microbial fermentation. These bioengineered miRNAs as biological prodrugs could provide a new approach for safe therapeutic methods and drug production. In this regard, bioengineered chimeric miRNAs could be selectively processed to mature miRNAs in different types of cancer cells by targeting the desired gene and regulating cancer progression. In this article, we aim to review bioengineered miRNAs and their use in cancer therapy, as well as offering advances in this area, including the use of chimeric tRNA/pre-miRNAs.