Fractionated ionizing radiation evokes diverse patterns of long-term changes in gene expression and tumor-propagating capacity in human glioma stem cells.

This study addresses long-term effects of clinically relevant regimens of radiation in human glioma stem cells. Our investigations reveal a strikingly diverse spectrum of changes in cell behavior, gene expression patterns and tumor-propagating capacities evoked by radiation in different types of glioma stem cells. Evidence is provided that degree of cellular plasticity but not the propensity to self-renew is an important factor influencing radiation-induced changes in the tumor-propagating capacity of glioma stem cells. Gene expression analyses indicate that paralell transcriptomic responses to radiation underlie similarity of clinically relevant cellular outcomes such as the ability to promote tumor growth after radiation. Our findings underscore the importance of longitudinal characterizations of molecular and cellular responses evoked by cytotoxic treatrments in glioma stem cells. Affymetrix gene expression profiling of human glioma stem cells treated by radiation in order to detect long-term gene expression changes.