Conditional Knockdown of Endogenous MicroRNAs in CHO Cells Using TET-ON-SanDI Sponge Vectors.

MicroRNAs (miRNAs) are small, noncoding RNAs of about 22 nucleotides in length and have proven to be useful targets for genetic modifications for desirable phenotypes in the biotech industry. The use of constitutively expressed "miRNA sponge" vectors in which multiple, tandem miRNA-binding sites containing transcripts are transcriptionally regulated by a constitutive promoter for downregulating the levels of endogenous microRNAs in Chinese hamster ovary (CHO) cells has shown to be more advantageous than using synthetic antisense oligonucleotides. The application of miRNA sponges in biotechnological processes, however, could be more effective, if the expression of miRNA sponges could be tuned.

Multiplex genome editing eliminates the Warburg Effect without impacting growth rate in mammalian cells.

The Warburg effect is ubiquitous in proliferative mammalian cells, including cancer cells, but poses challenges for biopharmaceutical production, as lactate accumulation inhibits cell growth and protein production. Previous efforts to eliminate lactate production via knockout have failed in mammalian bioprocessing since lactate dehydrogenase has proven essential. However, here we eliminated the Warburg effect in Chinese hamster ovary (CHO) and HEK293 cells by simultaneously knocking out lactate dehydrogenase and regulators involved in a negative feedback loop that typically inhibits pyruvate conversion to acetyl-CoA.

Phylogenetic Analyses of Rotavirus A, B and C Detected on a Porcine Farm in South Africa.

Rotaviruses (RVs) are known to infect various avian and mammalian hosts, including swine. The most common RVs associated with infection in pigs are A, B, C and H (RVA-C; RVH). In this study we analysed rotavirus strains circulating on a porcine farm in the Western Cape province of South Africa over a two-year period.

CRISPR Deletion of miR-27 Impacts Recombinant Protein Production in CHO Cells.

MicroRNAs represent an interesting group of regulatory molecules with the unique ability of a single miRNA able to regulate the expression of potentially hundreds of target genes. In that regard, their utility has been demonstrated as a strategy to improve the cellular phenotypes important in the biomanufacturing of recombinant proteins. Common approaches to stably deplete miRNAs are the use of sponge decoy transcripts or shRNA inhibitors, both of which require the introduction and expression of extra genetic material in the cell.