title: Unique gene expression signature by human embryonic stem cells cultured under serum-free conditions correlates with their enhanced and prolonged growth in an undifferentiated stage.
abstract: Understanding the interaction between human embryonic stem cells (hESCs) and their microenvironment is crucial for the propagation and the differentiation of hESCs for therapeutic applications. hESCs maintain their characteristics both in serum-containing and serum-replacement (SR) media. In this study, the effects of the serum-containing and SR culture media on the gene expression profiles of hESCs were examined. Although the expression of many known embryonic stem cell markers was similar in cells cultured in either media, surprisingly, 1,417 genes were found to be differentially expressed when hESCs cultured in serum-containing medium were compared with those cultured in SR medium. Several genes upregulated in cells cultured in SR medium suggested increased metabolism and proliferation rates in this medium, providing a possible explanation for the increased growth rate of nondifferentiated cells observed in SR culture conditions compared with that in serum medium. Several genes characteristic for cells with differentiated phenotype were expressed in cells cultured in serum-containing medium. Our data clearly indicate that the manipulation of hESC culture conditions causes phenotypic changes of the cells that were reflected also at the level of gene expression. Such changes may have fundamental importance for hESCs, and gene expression changes should be monitored as a part of cell culture optimization aiming at a clinical use of hESCs for cell transplantation.
authors.affiliation: Turku Centre for Biotechnology, University of Turku, and REGEA Institute for Regenerative Medicine, Tampere University Hospital, 33520 Tampere, Finland. Heli.Skottman@regea.fi
authors.forename: Heli
authors.initials: H
authors.lastname: Skottman
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Strömberg
authors.forename: Eija
authors.initials: E
authors.lastname: Matilainen
authors.forename: Jose
authors.initials: J
authors.lastname: Inzunza
authors.forename: Outi
authors.initials: O
authors.lastname: Hovatta
authors.forename: Riitta
authors.initials: R
authors.lastname: Lahesmaa
mesh_terms: D015415:Biomarkers; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D016000:Cluster Analysis; D016895:Culture Media, Serum-Free / Q000737:chemistry / Q000494:pharmacology*; D004622:Embryo, Mammalian / Q000166:cytology*; D015870:Gene Expression; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D013234:Stem Cells; D046509:Tissue Culture Techniques / Q000379:methods*
chemical_list: D015415:Biomarkers; D016895:Culture Media, Serum-Free