Analysis of microRNA transcription and post-transcriptional processing by Dicer in the context of CHO cell proliferation.
CHO cells are the mammalian cell line of choice for recombinant production of therapeutic proteins. However, their low rate of proliferation limits obtainable space-time yields due to inefficient biomass accumulation. We set out to correlate microRNA transcription to cell-specific growth-rate by microarray analysis of 5 CHO suspension cell lines with low to high specific growth rates. Global microRNA expression analysis and Pearson correlation studies showed that mature microRNA transcript levels are predominately up-regulated in a state of fast proliferation (46 positively correlated, 17 negatively correlated). To further validate this observation, the expression of three genes that are central to microRNA biogenesis (Dicer, Drosha and Dgcr8) was analyzed. The expression of Dicer, which mediates the final step in microRNA maturation, was found to be strongly correlated to growth rate. Accordingly, knockdown of Dicer impaired cell growth by reducing growth-correlating microRNA transcripts. Moderate ectopic overexpression of Dicer positively affected cell growth, while strong overexpression impaired growth, presumably due to the concomitant increase of microRNAs that inhibit cell growth. Our data therefore suggest that Dicer dependent microRNAs regulate CHO cell proliferation and that Dicer could serve as a potential surrogate marker for cellular proliferation.
Department of Biotechnology, BOKU - University of Natural Resources and Life Sciences, Vienna, Austria.
Matthias
M
Hackl
Department of Biotechnology, BOKU - University of Natural Resources and Life Sciences, Vienna, Austria.
Vaibhav
V
Jadhav
ACIB GmbH, Austrian Centre of Industrial Biotechnology, Graz, Austria.
Gerald
G
Klanert
RNA Biology Group, Institute for Genomics and Bioinformatics, Graz University of Technology, 8010 Graz, Austria.
Michael
M
Karbiener
RNA Biology Group, Institute for Genomics and Bioinformatics, Graz University of Technology, 8010 Graz, Austria.
Marcel
M
Scheideler
Department of Biotechnology, BOKU - University of Natural Resources and Life Sciences, Vienna, Austria.
Johannes
J
Grillari
Department of Biotechnology, BOKU - University of Natural Resources and Life Sciences, Vienna, Austria; ACIB GmbH, Austrian Centre of Industrial Biotechnology, Graz, Austria. Electronic address: nicole.borth@boku.ac.at.
Nicole
N
Borth
D000818:Animals; D016466:CHO Cells / Q000166:cytology*; D049109:Cell Proliferation / Q000235:genetics*; D006224:Cricetinae; D003412:Cricetulus; D035683:MicroRNAs / Q000235:genetics* / Q000502:physiology; D046228:Microarray Analysis; D012323:RNA Processing, Post-Transcriptional; D043244:Ribonuclease III / Q000378:metabolism*
D035683:MicroRNAs; D043244:Ribonuclease III
Cell engineering; Chinese hamster ovary cells; Dicer; MicroRNA; Microarray