MicroRNA Detection Methods for Mammalian Cell Lines and Their Applications in Therapeutic Protein Production - MicroRNAs as Tools in Biopharmaceutical Production - page 99

Chapter 7
MicroRNA Detection Methods for Mammalian
Cell Lines and Their Applications in Therapeutic
Protein Production

Nan Lin and Carol Kreader

Abstract Three major categories of detection methods that are applicable to study
miRNA expression in Chinese Hamster Ovary (CHO) cells are reviewed in this
chapter.

Keywords Chinese Hamster Ovary cells · Biotherapeutics · Cell engineering ·

microRNA · qRT-PCR · Microarrays · Next-generation sequencing

7.1 Overview of MicroRNA Detection in Mammalian Cells

MicroRNAs (miRNAs) are 21-25 nt single-stranded non-coding RNAs that play
important roles in gene expression regulation (Bartel 2004 ). Research in miRNA is
among one of the fastest growing fields in life sciences. In applied research, miR-
NAs are proposed to be valuable biomarkers and cell engineering tools in therapeutic
protein production (Muller et al. 2008 ). Sensitive and accurate detection methods
for miRNAs are the foundation for basic and applied research alike. In the past
decade, researchers use quantitative reverse-transcription PCR (qRT-PCR), microar-
rays and other direct detection methods to profile and quantify miRNA expression in
mammalian cells. In the past five years, direct and indirect miRNA detection tech-
nologies have developed even more rapidly with increased sensitivity and throughput
in response to the growing research needs.
To this day, miRNA expression remains understudied in the biopharmaceutical
context, particularly in Chinese Hamster Ovary (CHO) cells, despite the fact that
CHO being the most commonly used host cell system for therapeutic protein pro-
duction. The majority of known mature miRNAs are highly conserved in evolution
(Ambros et al. 2003 ; Lagos-Quintana et al. 2001 ; Berezikov et al. 2005 ), which
provides the rationale for application of existing miRNA detection methods in CHO

N. Lin ( )
Cell Sciences and Development, SAFC/Sigma-Aldrich, 2909 Laclede Avenue,
MO 63103, Saint Louis, USA
e-mail: [e-mail]
C. Kreader
Research Biotechnology, Sigma-Aldrich, 2909 Laclede Avenue, MO 63103,
Saint Louis, USA
e-mail: [e-mail]