oa Editorial [Mini Hot Topic: RNA Silencing (Guest Editor: Francisco E. Nicolas)]

RNA silencing has become the most productive field for understanding and exploiting the fundamental system of gene regulation during the last decade. It has been revealed as a new layer of gene regulation that is conserved across all the eukaryotic kingdoms, making the understanding of the molecular mechanism of any biological process incomplete without considering how it is regulated by small RNAs. Despite still being incomplete, the story of RNA silencing has accumulated enough knowledge to be translated into applied developments, and it is now time for the promise to become reality. This thematic issue entitled “Recent Developments on RNA Silencing” reviews, in three extensive manuscripts, most of the current patents and applications related to animals and plants that are based on RNA silencing. In addition, the issue is complemented with a fourth review covering the bioinformatics aspects of RNA silencing, which has become an essential discipline for developments in the field. The first review, a contribution by Francisco E. Nicolas and Alfonso F. Lopez-Martinez, focused on the miRNA silencing pathway of humans and summarizes all the recent developments related to pathological processes. This manuscript entitled “MiRNAs in Human Diseases” reviews a wide range of patents and applications concerning different aspect of human disease, such as diagnosis, prognosis and treatments associated with many pathologies based on gene misregulation. Among the treatments, the authors specifically focused on miRNA modulators, a new generation of compounds designed to replace and/or inhibit miRNA activity in several human diseases, including cancer and viral infections. The review also includes a section dedicated to the delivery of these new compounds. As regards the plant kingdom, this thematic issue presents two perfectly complemented manuscripts that were necessary to cover the high number of inventions published in this field. The first of these reviews is entitled “Recent Patents in RNA Silencing in Plants: Constructs, Methods and Applications in Plant Biotechnology” and has been written by Sara Lopez- Gomollon and Tamas Dalmay. These authors reviewed several general strategies recently used to exploit RNA silencing as a tool to produce plants with improved properties. The second review related to plants is entitled “Patented Specific Applications of Gene Silencing in Plants” and has been written by Ruben Alvarez-Fernandez. In this review, the author focused on patents that are based on engineered gene silencing and designed to solve specific problems, such as the alteration of lignin, biofactories, alkaloids biosynthesis, flowering time fall and many others. The last review, written by Irina Mohorianu, is entitled “Revealing Biological Information Using Data Structuring and Automated Learning”. This is a bioinformatics review that summarizes patents designed to study gene sequence databases, highlighting the applicability of these methods to the RNA silencing field. The diversity of small RNAs and the complexity of the different pathways identified in the general mechanism of RNA silencing make the use of bioinformatics tools essential in most of the new developments related to the field. In fact, many of the patents described in the other three reviews contain bioinformatics analysis of different databases, which makes this review an indispensable contribution to this special issue. In all, this special issue reviews more than two hundred patents related to small RNAs and their applications, which reveals both the importance of this field and the great effort of the authors to thoroughly review all the new advances made in RNA silencing. Finally, I would like to thank all the authors who have taken part for their invaluable contributions to this special issue.