RNAi therapeutics and applications of microRNAs in cancer treatment.

RNA interference-based therapies are proving to be powerful tools for combating various diseases, including cancer. Scientists are researching the development of safe and efficient systems for the delivery of small RNA molecules, which are extremely fragile in serum, to target organs and cells in the human body. A dozen pre-clinical and clinical trials have been under way over the past few years involving biodegradable nanoparticles, lipids, chemical modification and conjugation. On the other hand, microRNAs, which control the balance of cellular biological processes, have been studied as attractive therapeutic targets in cancer treatment. In this review, we provide an overview of RNA interference-based therapeutics in clinical trials and discuss the latest technology for the systemic delivery of nucleic acid drugs. Furthermore, we focus on dysregulated microRNAs in human cancer, which have progressed in pre-clinical trials as therapeutic targets, and describe a wide range of strategies to control the expression levels of endogenous microRNAs. Further development of RNA interference technologies and progression of clinical trials will contribute to the achievement of practical applications of nucleic acid drugs.