Proceedings of the 21st Annual Meeting of the European Society for Animal Cell Technology (ESACT), Dublin, Ireland, June 7-10, 2009

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. They have been implicated in diverse cellular functions and are currently the subject of considerable interest in all aspects of cell biology. They are highly conserved evolutionarily – the first published hamster sequence (cgr-miR-21) was found to be identical to human, mouse and rat. In this study, we discuss the identification of several differentially expressed miRNAs after shifting CHO cells from exponential growth at 37◦C to growth arrest at 31◦C (temperature shift). Our data suggest that these miRNAs represent attractive targets for engineering a culture process from growth phase to production phase, thereby potentially replacing or enhancing the use of temperature-shift.