The studies describing culture of human embryonic stem cells under hypoxic condition mainly focus on the maintenance of pluripotency and differenciation. There are few studies regarding the effects of hypoxia on gene expression in human embryonic stem cells.OBJECTIVE:
To investigate the effects of different oxygen tensions on gene expression profiling of human embryonic stem cells.METHODS:
Gene expression profiling determined by Human Gene Expression Microarrays and differentially expressed genes were analyzed by gene ontology and pathway analysis in one human embryonic stem cell line (FY-hES-7) following prolonged passage under hypoxia (5%O2) and normoxia (21%O2), respectively.RESULTS AND COCLUSION:
1 840 upregulated genes (more than two folds) and 1676 downregulated genes (more than two folds) were identified in the hypoxic group as compared to the nomorxic group. Gene ontology analysis and pathway analysis showed that gene upregulation in the hypoxic group was associated with cell surface receptor linked signal transduction, immune response, ion transport, metabolic process, cell activation and some pathways such as cytokine-cytokine interaction, immune response, but gene downregulation in the hypoxic group was related to transcription regulation, transcription DNA-dependent regulation, neuronal differentiation, cell morphogenesis, embryonic morphogenesis, embryonic organ and system development and the pathways of embryo development and cancer. The gene expression profiling of human embryonic stem cells in different O2 tensions is variable and the functional analyses of differentially expressed genes in hypoxia are beneficial for human embryonic stem cell culture by keeping stable self-renewal capacity, preventing human embryonic stem cell differentiation and reducing the risk of tumor formation.