Comparison of gene expression in human embyronic stem cells grown in MEF-CM or defined media conditions

A fully defined media for human embryonic stem cells (hESCs) was designed after examining the phosphorylation status of 42 receptor tyrosine kinases (RTKs) on hESCs exposed to mouse embryonic fibroblast conditioned medium (CM). Activation of the insulin and insulin-like growth factor-1 receptors (IR, IGF1R) as well as EGFR family members including ERBB2 and ERBB3 led to the design of a simple defined media which supported robust long-term growth of multiple hESC lines and allowed massive expansion of undifferentiated cells. Illumina bead arrays were used to demonstrate the maintenance of gene expression profiles characteristic of pluripotent cells in cultures grown in CM or defined media. Keywords: Comparison of cells in different culture conditions Human embyronic stem cells were maintained in standard MEF-CM conditions, or in a defined medium: DC-HAIF. The samples analyzed were: BG02 cells grown in MEF-CM for 64 passages, BG02 cells grown in defined media for 10 passages, BG02 cells grown in defined media for 32 passages, BG03 cells grown in MEF-CM for 35 passages. Single analyses of the samples were performed using the Illumina bead array system. Comparable labeling, hybridization, detection and data analysis was used with previous analyses of these cell lines (Liu et al 2006 BMC Dev Biol 6:20).