MicroRNAs as targets for engineering of CHO cell factories

MicroRNAs (miRNAs) are strongly implicated in the global regulation of gene expression, and, in this regard, they consequently affect metabolic pathways on every regulatory level in different species. This characteristic makes miRNAs a promising target for cell engineering, and they could have multiple applications in medicine and biotechnology. However, a more profound, mechanistic understanding of miRNA action is needed for their potential to be translated into the development of industrially relevant cell factories with novel features. Here, we highlight the potential of miRNAs for the engineering of Chinese hamster ovary (CHO) cells, these being the most prevalent cell factory system for biophar-maceutical production. A key advantage of miRNAs, in contrast to most cell-engineering approaches that rely on overexpression of regulatory proteins, is that they do not compete for the translational machinery that is required to express the recombinant product. However, we also summarize the limitations and challenges that will have to be overcome to exploit fully miRNA technology.