Effects of Ionizing Radiation on Self Renewal and Pluripotency of Human Embryonic Stem Cells

Human embryonic stem cells (hESCs) present a novel platform for in vitro investigation of the early embryonic cellular response to ionizing radiation. Thus far, no study has analyzed the genome-wide transcriptional response to ionizing radiation in hESCs. In this study, we use Agilent microarrays to analyze the global gene expression changes in H9 hESCs after low (0.4 Gy), medium (2 Gy), and high (4 Gy) dose irradiation. Undifferentiated H9 hESCs were cultured on Matrigel in feeder-free conditions, and exposed to ionizing radiation at the indicated dosage (or control) from a Cesium-137 irradiator. Total RNA was isolated 24 hours after irradiation in the same feeder-free culture conditions. Experiment was repeated three times for each group, yielding a total of 12 distinct samples.