Comprehensive analysis of gene expression in PAL-treated glioblastoma cells*

We have previously developed plasma-activated medium (PAM) and plasma-activated Ringer’s lactate solution (PAL). PAM induced more intracellular reactive oxygen species (ROS) than PAL did on glioblastoma cells. Gene expression analysis using microarray revealed that PAM induced oxidative-stress dependent cell death on glioblastoma cells. In this study, we have performed microarray analysis of PAL-treated glioblastoma cells. Many histone cluster genes were upregulated more than 2-fold in PAL-treated glioblastoma cells. Histones play a critical role in epigenetic regulation, and histone genes are usually expressed in the S phase (synthesis phase) of cell cycle. Flow cytometry analysis suggest that PAL induced cell cycle arrest on the G2/M and S phases on glioblastoma cells. These results suggest that PAL upregulated histone genes because it induced cell cycle arrest on the S phase on glioblastoma cells.