Arsenic trioxide induces different gene expression profiles of genes related to growth and apoptosis in glioma cells dependent on the p53 status

We have previously reported that As2O3 affected cell cycle progression and cyclins D1 and B1 expression in two glioma cell lines differing in p53 status (U87MG-wt; T98G-mutated). In the present study, we further demonstrated that As2O3 affected proliferation, viability and apoptosis of the two cell lines in a dose- and time-dependent manner, and T98G cells were more sensitive than U87MG cells to As2O3 -induced apoptosis and inhibition of proliferation and viability. We further investigated the expression profiles of genes related with apoptosis and cell cycle in the two cell lines with a human cDNA-microarray (SuperArray) spotted with 267 genes of apoptosis and cell cycle. Thirty five genes were upregulated and 15 genes downregulated at least 2-fold by As2O3 in U87-MG cells; whereas, 38 genes were upregulated and 21 genes downregulated at least 2-fold in T98G cells by As2O3. After As2O3 treatment, p53 expression was upregulated 56.5-fold in T98G cells, but only 6.0-fold in U87MG cells. The results indicate that As2O3 suppresses the growth of U87MG cells mainly by regulating expression of genes of cell cycle arrest, stress and toxicity; whereas As2O3 affects T98G cells mainly by regulating expression of genes belonging to Bcl-2, tumor necrotic factor receptor and ligand families. The data may be helpful for optimizing As2O3 as an anti-cancer drug in the treatment of gliomas.