Update on MicroRNA-based Treatment Strategies

Abstract

The family of RNAs comprises several members, protein coding mRNAs and a larger group of non-coding RNAs, which include small, approximately 21-25 nucleotides long microRNAs (miRNAs). In addition to an evolving diagnostic use of RNAs, RNA-based drugs are emerging very rapidly in medicine, which is not only -but currently very prominently visible- due to the impressive success of the first-in-class Covid-19 vaccines such as Comirnaty and Moderna (marketed by the companies Biontech/Pfizer and Moderna, respectively). Although administration of RNA-based drugs comes along with several technical obstacles including delivery approaches, the technology is experiencing a breakthrough and technical and conceptual hurdles that may still remain are very likely to be overcome within the near future. It is therefore highly likely that RNA-based pharmacotherapies may revolutionize medicine by improving vaccination concepts but also by providing novel drugs to treat many other conditions like cancer, metabolic- and degenerative diseases and beyond. It is fascinating to witness the rise of such milestones in medicine and is tempting to elaborate which additional accomplishments can be made using this technology towards personalized medicine comprising diagnostic and therapeutic aspects as well as individual drug design.Although the most recent success with mRNA-based and therefore protein coding vaccines currently takes center stage in media and people’s life, other types of RNAs that are less prominent to the public, like non-coding miRNAs, also develop very successfully towards diagnostic and therapeutic purposes. While the diagnostic use of miRNAs was reviewed in another article in this issue (see article from Hackl et al., this issue), this brief review will provide an update on the emerging therapeutic implications of miRNAs. Despite the fact that no miRNA-based drug has yet reached clinical approval, several compounds are in pre-clinical and clinical development for the treatment of various diseases and great progress has been made during the recent years, which also facilitated the establishment of several innovative biotech companies.Several obstacles associated with this novel approach including off-target effects, tissue specificity and delivery systems exist. However, important improvements have already been made and will continue to be made. It can therefore be assumed that treatments using this class of RNA will also further progress and stimulate additional stakeholders to enter the field to develop novel drug candidates as first-in-class medicinal products to address highly unmet clinical needs. This technology is still at its infancy given that miRNAs were uncovered just about 20 years ago but the conditions are promising for the development of next generation miRNA-based drugs.