The demand for industrial genetically modified host cells were
increased with the growth of the biopharmaceutical market. Numerous
studies on improving host cell productivity have shown that altering
host cell growth and viability through genetic engineering can increase
recombinant protein production. During the last decades, it was
demonstrated that overexpression or downregulation of some microRNAs in
Chinese Hamster Ovary (CHO) cells as the host cell in biopharmaceutical
manufacturing, can improve their productivity. The selection of microRNA
targets has been based on their previously identified role in human
cancers. MicroRNA-32 (miR-32), which is conserved between humans and
hamsters (Crisetulus griseus), was shown to play a role in the
regulation of cell proliferation and apoptosis in some human cancers. In
this study, we investigated the effect of miR-32 overexpression on the
productivity of CHO-VEGF-trap cells. Our results indicated that stable
overexpression of miR-32 could dramatically increase the productivity of
CHO cells by 1.8-fold. It also significantly increases cell viability,
batch culture longevity, and cell growth. To achieve these results,
following the construction of a single clone producing an Fc-fusion
protein, we transfected cells with a pLexJRed-miR-32 plasmid to stably
produce the microRNA and evaluate the impact of mir-32 overexpression on
cell productivity, growth and viability in compare with scrambled
control. Our findings highlight the application of miRNAs as engineering
tools and indicated that miR-32 could be a target for engineering CHO
cells to increase cell productivity.