Identification and expression analysis of miRNAs during batch culture of HEK-293 cells.

MicroRNAs (miRNAs) are small non-coding RNAs of about 20-24 nucleotides in length. They regulate gene expression negatively and have been implicated in a wide variety of biological processes. To identify potential miRNAs that may influence the growth and proliferation of mammalian cells cultured in bioreactors, we applied miRNA microarray expression profiling technology to batch cultures of HEK293 cells in protein free media. In our study, we identified miRNAs that were differentially expressed during the exponential and stationary phases, 13 of these showed distinct up regulation trends while 1 exhibited down regulation. These miRNAs have been implicated in cellular differentiation, growth arrest and apoptosis. Specifically, miR-16 and let-7b are potentially useful in the enhancement of bioreactor cell cultures.