MicroRNAs for Enhancement of CHO Cell Proliferation and Stability: Insights from Neuroblastoma Studies - MicroRNAs as Tools in Biopharmaceutical Production - page 94

3 UTRs. It is also of interest that some miRNAs can directly up-regulate gene
transcription by direct interaction with regions of shared homology within the gene
promoter region (Place et al. 2008 ).
All of the above discussion demonstrates that our understanding of the basic bi-
ology of miRNAs is far from complete. The elucidation of further unconventional
modes of action of miRNAs is likely to have consequences for the use of miR-
NAs as therapeutics in cancer, as well as consequences for the use of CHO and
other established cell lines as “protein factories” for biotechnology and industrial
applications.

6.9 Concluding Remarks

Many of the miRNA/mRNA interaction sites that have been identified in cancer
related studies are highly conserved between vertebrate genomes, indicating that the
same miRNAs are also likely to be involved with the control of CHO cell viability.
Artificial manipulation of miRNA levels in CHO cells holds considerable promise
for increasing the bioprocessing potential of this cell line. The analysis of miRNAs in
CHO cells, however, has been limited do to the lack of a complete DNA sequence map
of either the normal Chinese hamster or CHO genomes. The recent completion of a
DNA sequence map for the CHO genome should allow for the direct identification
of miRNAs in CHO, opening up numerous additional avenues for biotechnology
oriented research (Xu et al. 2011 ).

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