OBJECTIVE To identify progression-related genes that lead to astrocytoma progression from a low to a high grade by analyzing the gene expression profiles from different tumor grades, and all-trans retinoic acid-treated astrocytoma cell lines．METHODS In this study, all-trans retinoic acid(ATRA) was used to induce differentiation of SHG-44 cells．Then，by using a cDNA microarray, we compared gene expression profiling in different grades of astrocytoma cell lines(CHG-5，WHo Grade II and SHG-44，WHO Grade IV)and in ATRA-induced differentiation in SHG-44 cells．A panel of overlapped genes that might be related to tumor progression was identified，and the cell line individual variation was avoided as well． RESUIJTS In the 31 overlapped genes，the stable over-expression of MDM2 and UGB as well as the repression of SOD2，G3BP, and CSTB in parental SHG-44 ceils was observed and their possible roles in tumor progression were discussed．Moreover, validation of some differentially expressed genes was confirmed by Northern blots．CONCLUSl0N The overlapped genes reported in this study might relate to progression of astrocytoma．Further study of progression-related genes may be helpful to explore the genetic pathways that are involved in astrocytoma progress from a low to a high grade．